iwsmt13 book of abstracts - ornl neutron sciences ... · the international workshop on spallation...

BOOKOFABSTRACTS

13THINTERNATIONALWORKSHOPONSPALLATION

MATERIALSTECHNOLOGY

IWSMT-13

OCTOBER30TH–NOVEMBER4TH,2016

CHATTANOOGA,TENNESSEEUNITEDSTATESOFAMERCIA

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BOOKOFABSTRACTS

13THINTERNATIONALWORKSHOPONSPALLATIONMATERIALSTECHNOLOGY

IWSMT-13


CHATTANOOGA,TENNESSEEUNITEDSTATESOFAMERCIA

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INTERNATIONALORGANIZINGCOMMITTEELouisK.Mansur,USA–ChairmanBernardW.Riemer,OakRidgeNationalLaboratory,USAYongDai,PaulScherrerInstitut,SwitzerlandKenjiKikuchi,IbarakiUniversity,JapanStuartA.Maloy,LosAlamosNationalLaboratory,USAXuejunJia,ChineseAcademyofSciences,ChinaJohnHaines,EuropeanSpallationSource,SwedenMilanKonstantinovic,SCK-CEN,Belgium

LOCALORGANIZINGCOMMITTEEBernardW.Riemer,ORNL,USADavidMcClintock,ORNL,USASabineC.Curry,ORNL,USAIrinaPopova,ORNL,USAWeiLu,ORNL,USA

ADMINISTRATIVESECRETARYSabineCurryOakRidgeNationalLaboratoryOakRidge,TN37831Tel.001-865-576-2795Email:[email protected]

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RECEPTION,REGISTRATION,ANDBANQUETDATES

13thINTERNATIONALWORKSHOPONSPALLATIONMATERIALSTECHNOLOGYCHATTANOOGA,TN,USA


Sunday,October30th,201616:00–18:00 Registration18:00–20:00 ReceptionattheChattanoogaMarriotHotelMonday,October31st,201607:00 RegistrationWednesday,November2nd,201619:00–22:30BanquetattheTennesseeAquarium(OceanJourneybuilding)

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Scope

The International Workshop on Spallation Materials Technology (IWSMT) is the premierinternational forum topresentanddiscuss the latest researchanddevelopmentofmaterialsutilizedinspallationsourcesandacceleratordrivensystems(ADS).Itisalsoanoutstandingforumforexchanginginformationfromoperationalexperienceandpostirradiationexamination(PIE)ofirradiatedspecimensandcomponents.

ThethirteenthmeetingofIWSMTwillagainfocusontheprogresswithmaterials-relatedstudiesfor accelerator based neutron sources and on issues with operating and future spallationfacilities.Ourintentistopromoteopendiscussionofthelatestmaterialadvancesandchallengesand toencouragenew international collaborations. For thismeetingorganizerswould like toinvite collaboration with colleagues in the High Energy Physics and Radioactive Ion Beamcommunitiesinordertofacilitateandpromotecooperationbetweenthedifferentinternationalcommunitiesthatsharemanycommonmaterials-relatedchallenges.Topics

1. Effectsofradiationdamage,helium,hydrogen,andothertransmutationelementsintargetandstructuralmaterials

2. OperationalexperienceandresultsfromPIEofirradiatedcomponents

3. Researchintheareaofmitigatingpressurewaveeffectsinpulsedtargets,i.e.,cavitationerosionandfatigue

4. Researchanddevelopment(R&D)ofspallationtargetsforneutronandADSapplications

5. Sourcetechnologyandengineering:fatigueanalysis,welding,weldevaluation,andthermo-mechanical/fluidmodeling

6. Productionandhandlingofvolatiletransmutationelementsandactivatedtargetcomponents

7. InnovativematerialstechnologyandtechniquesforR&Dofapplicationswithextremeirradiationenvironments

8. ApplicationofmaterialsdatatothedesignandsafetystudyofcomponentsinspallationsourcesandADSsystems

PresentationsandPublication

High-quality full paperswith sufficientmaterials science and engineering content relevant tojournalthemeswillbeselectedbytheorganizerstobeincludedinaspecialvolumeoftheJournalofNuclearMaterials.

InformationonthescopeoftheJournalofNuclearMaterialsislocatedat:http://ees.elsevier.com/jnm/

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WORKSHOPAGENDA

Monday–October31,2016

07:00–08:15 Registration

Session1:WelcomeandKeynoteAddresses

08:20–08:30 OpeningAddress BernieRiemer

08:30–08:40 WelcomeAddress DonAbercrombie

08:40–09:00 PlenaryAddress1-TheInternationalWorkshopsonSpallationMaterialsTechnology LouMansur

09:00–09:40 PlenaryAddress2-ImpactofHandHetransmutationproductsonradiationeffectsinmaterials SteveZinkle

09:40–10:00 CoffeeBreak

10:00–10:25 StatusoftheEuropeanSpallationNeutronSource EricPitcher

10:25–10:50 PresentstatusofChineseSpallationNeutronSourceproject XuejunJia

10:50–11:15 TheProtonPowerUpgradeprojectanditsImpactontheSNSFirstTargetStation BernieRiemer

11:15–11:40 CurrentstatusoftheChineseADSproject ZhiguangWang

11:40–12:50 Lunch

Session2:ProgressofAcceleratorDrivenSystemwithEmphasisonMaterials

12:50–13:15 SINQ-AStatusReport MichaelWohlmuther

13:15–13:40 PresentstatusofJSNSmercurytarget TakashiNaoe

13:40–14:05 CompatibilityresearchofstructuralmaterialsforChinalead-basedresearchreactor ChunjingLi

14:05–14:30 SpallationmaterialsR&DandapplicationforBeamInterceptingDevices(BID)atCERN

François-XavierNuiry


14:50–15:15 Investigationoftargetmaterialformuonproductionunderhighpowerprotonbeamirradiation

ShunsukeMakimura

15:15–15:40 Pulsedheavy-ionirradiationoftungsten JemilaHabainy

15:40–16:05Re-examinationofionirradiationasacredibletooltosimulatehighenergyneutronandproton-inducedvoidswellingforaccelerator-drivendevices

FrankGarner

16:05–16:30 TheRaDIATECollaboration–exploringhighpowertargetmaterialsresponsetoradiationdamage–goals,status,andfutureplans PatrickHurh

16:30–18:00 PosterSession

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Tuesday–November1,2016

Session3:Radiation-InducedEffectsinStructuralMaterials

08:20–08:45 Developmentofadvancedferriticsteelsforhighdoseapplications StuartMaloy

08:45–09:10 TensiletestingofsteelsfromtheSTIP-Virradiation TarikSaleh

09:10–09:35TensilepropertiescharacterizationofirradiatedAISI316Lfromhigh-usetargetmodulesattheSpallationNeutronSourceusingdigitalimagecorrelation

DavidMcClintock

09:35–10:00Swelling,creep,andembrittlementofD9stainlesssteelcladdingandductintwoFFTFdriverfuelassembliesathighneutronexposures

FrankGarner


10:20–10:45 ThebehaviourofAlMg3afterirradiationathighprotonandneutronfluencesinSINQtargets YongDai

10:45–11:10 PostirradiationexaminationoftheMEGAPIEsamplesatJAEA(2) ShigeruSaito

11:10–11:35 ThetransmissionelectronanalysisofdislocationloopsinT91steelsfromMEGAPIEandTWIN-ASTIRirradiationprograms

MilanKonstantinovic

11:35–12:00 BarrierstrengthofdefectsandheliumbubblesforhardeningofmartensiticsteelsirradiatedinSTIP LeiPeng

12:00–13:10 Lunch

Session4:ResearchandDevelopmentofTargetSystemMaterials

13:10–13:35 MechanicalpropertiesandfracturebehaviorofpuretungstenandtantalumafterirradiationinSINQ YongDai

13:35–14:00 Annealingeffectonthemicrostructureandhardnessofirradiatedtungsten

BarbaraHorvath

14:00–14:25 Formationofoxidelayersontungsteninmildlyoxidizinggas JemilaHabainy

14:25–14:50 Low-ZmaterialR&DandapplicationforBeamInterceptingDevices(BID)atCERN

François-XavierNuiry


15:10–15:35 Fatiguepropertiesoftungstenfromdifferentprocessingroutes JemilaHabainy

15:35–16:00 Luminescentmaterialsdevelopmentforbeam-on-targetimagingattheEuropeanSpallationSource ThomasShea

16:00–16:25 Designandfabricationofapassiveirradiationmoduleutilizingthehighneutronfluxfromthe5MWSpallationSourceatESS YongJoongLee

16:25–17:00 Discussion-1

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Wednesday–November2,2016

Session5:ResearchandDevelopmentofTargetSystemDesigns

08:20–08:45 TheESSheliumcooledrotatingtarget FernandoSordo

08:45–09:10 DesignmodificationofISISTS2targetinordertoimprovelongevityamidspallationreactions ArghyaDey

09:10–09:35 Simulatingperformanceoftantalum-cladtungstentargets DanWilcox

09:35–10:00 ManufacturingofESScoldmoderator–machining,welding,andtestingofAl6061-T6alloy

YannickBessler


10:20–10:45 WeldabilityofdiffusionbondingbetweenInvaralloyandstainlesssteelbyhotisostaticpressing TakashiWakui

10:45–11:10MeasuredSNSmercurytargetvesselstrainresponsestobeampulsesandcomparisontosimulationswithvariationsonmercurymaterialmodelbehavior

DrewWinder

11:10–11:35 FailureanalysisontheweldedpartwithsteepchangeofthicknessemployedinJSNSmercurytargetvessel TakashiWakui

11:35–12:00 ThermomechanicalanalysisofESSspallationmaterial FernandoSordo

12:00–13:00 Lunch

19:00–22:30 BanquetattheTennesseeAquariumintheOceanJourneybuilding

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Thursday–November3,2016

Session6:CompatibilityofLiquidMetalswithStructuralMaterials

08:20–08:45 Cavitationdamageindouble-walledmercurytargetvessel TakashiNaoe

08:45–09:10 EffectofoxygenconcentrationonLMEsusceptibilityofCLAMsteelinliquidleadbismutheutectic LiuJing

09:10–09:35 Numericalmodelingofimpuritiesmasstransferinawirewrappedfuelassemblyunderflowingleadbismutheutectic

AlessandroMarino

09:35–10:00 DevelopmentofSIMPsteelforacceleratordrivensysteminChina ZhiguangWang


10:20–10:45 Lowcyclefatiguebehaviorof15-15Tisteelinstaticlead-bismutheutecticwith10-6wt%oxygenconcentrationat550°C ChunjingLI

10:45–11:10 CorrosionbehaviorofTi3SiC2inflowingleadbismutheutecticat1000°C ZunqiXiao

11:10–11:35 OxidationbehaviorsofCLAMsteelinstagnantliquidlead-bismuthEutecticat500°C ShaojianYan


12:00–13:10 Lunch

Session7:AnalysisofTargetSystemMaterialsandComponents

13:10–13:35 Positronlifetimecalculationofvacancyclustersintantalumcontaininghydrogenandhelium QiuXu

13:35–14:00 InvestigationofsamplesofF/MandODSsteelsirradiatedinthespallationsourceSINQbypositronannihilation VladimirKrsjak

14:00–14:25 RatetheoryanalysisofgrowthprocessofheliumbubbleinF82HIrradiatedatSINQ KoichiSato

14:25–14:50 InvestigationofSINQ-irradiatedsamplesbysingledetectorDoppler-broadeningspectroscopy JozefSnopek


15:10–15:35ExperimentalinvestigationofirradiationeffectsinberylliumbeamwindowafterexposureintheNuMIbeamline:preliminaryresultsandplans

ViacheslavKuksenko

15:35–16:00 PlansfortheRaDIATEhigh-energyprotonmaterialsirradiationexperimentattheBrookhavenLinacIsotopeProducerfacility KavinAmmigan

16:00–16:25 HiRadMatatCERNSPS-Adedicatedtestfacilitywithhighintensitybeampulsestomaterialsamples AdrianFabich


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Friday–November4,2016

Session8:SimulationsofRadiationEffectsonMaterialsinSpallationApplications

08:20–08:45 Applicationofrigoroustwostepmethodologyforneutronandprotontransmutationcalculationstospallationtargets. StevenLilley

08:45–09:10 Displacementdamage,heliumandhydrogenproductionindifferentmaterialsirradiatedinSTIP-VI YongDai

09:10–09:35 Simulationofhydrogenthermaldesorptioncharacteristicsinmetalscontaininglargevoids

HayatoYamashita


9:55–10:20 MaterialselectionofthebeamprofilemonitoringdevicesattheESSTargetStation

YongJoongLee

10:20–10:45 ThepresentstatusandprospectiveofSTIP YongDai


11:15–11:45 SummaryandConcludingRemarks

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IWSMT-13ORALPRESENTATIONABSTRACTSTheInternationalWorkshopsonSpallationMaterialsTechnologyMANSUR,LouisK.(OakRidgeNationalLaboratory–retired)The first InternationalWorkshop on SpallationMaterials Technology was held in 1996 at Oak Ridge,Tennessee. Importantgoalsweretomakepreliminarymaterialsselections fornew liquidmetal targethighpowerspallationneutronsourcesinconceptualdesign,andtoconfrontthegreatchallengeofhowtoobtainneededmaterials performance information in a reasonable timewithin available resources.Participants were asked to review and assess the sparse materials experience at existing spallationdevices,aswellastoevaluatetherelevancyofavailableinformationfromfission,fusion,andlowerenergycharged particle irradiation research. Plans were formulated to develop the experimental data andcalculations on which to base design decisions and target lifetime estimates. Opportunities forcollaborations among the relatively few internationally dispersed spallation materials groups wereexplored;jointworkwasplanned.Inbriefintroductoryremarksontheoccasionofthetwentiethanniversaryofthefirstmeetingwementionthebeginnings.Wevisittheoriginallystatedgoalsandassesstowhatextenttheyhavebeenachieved.The core group of researchers present at the first meeting and their collaborators developed thecontinuingIWSMTseries.Poweredbystronginternationalcollaborations,theinfanthasgrowntoproducethehighlysuccessfulworkthathascreatedthepresentwealthofknowledge.The first InternationalWorkshop on SpallationMaterials Technology was held in 1996 at Oak Ridge,Tennessee. Importantgoalsweretomakepreliminarymaterialsselections fornew liquidmetal targethighpowerspallationneutronsourcesinconceptualdesign,andtoconfrontthegreatchallengeofhowtoobtainneededmaterials performance information in a reasonable timewithin available resources.Participants were asked to review and assess the sparse materials experience at existing spallationdevices,aswellastoevaluatetherelevancyofavailableinformationfromfission,fusion,andlowerenergycharged particle irradiation research. Plans were formulated to develop the experimental data andcalculations on which to base design decisions and target lifetime estimates. Opportunities forcollaborations among the relatively few internationally dispersed spallation materials groups wereexplored;jointworkwasplanned.Inbriefintroductoryremarksontheoccasionofthetwentiethanniversaryofthefirstmeetingwementionthebeginnings.Wevisittheoriginallystatedgoalsandassesstowhatextenttheyhavebeenachieved.The core group of researchers present at the first meeting and their collaborators developed thecontinuingIWSMTseries.Poweredbystronginternationalcollaborations,theinfanthasgrowntoproducethehighlysuccessfulworkthathascreatedthepresentwealthofknowledge.

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ImpactofHandHetransmutationproductsonradiationeffectsinmaterialsZINKLE,Steve(UniversityofTennessee)

YAMAMOTO,Takuya(UniversityofCaliforniaSantaBarbara)Duetothresholdenergiesforfastneutron(n,xp)and(n,xα)reactionsthatarenear1-10MeVformanyisotopes, the typical production rates of H and He transmutation products per unit fast fluence (ordisplacementdamagelevel)inmanymaterialsareatleastoneorderofmagnitudehigherforspallationand D-T fusion neutron spectra compared to fission spectra. This can lead to enhanced radiationhardeningandembrittlementatlowirradiationtemperatures(below~0.35TM,whereTMisthemeltingtemperature), either enhanced (fusion) or suppressed (spallation) void swelling at intermediatetemperatures,andenhancedhightemperatureheliumembrittlementofgrainboundariesabove~0.5TM.Inmanycases,pronouncedheliumeffectsbegintoemergeforHeconcentrationsabove~500appm.Thispresentationwillreviewcurrentunderstandingofthemechanismsandconsequencesoffission-,fusion-,andspallation-neutronrelevantHandHeproductionon irradiationprocesses inmaterials.SynergisticeffectsassociatedwithsimultaneousHeandHproductionwillbediscussed.Theroleofdoserate(e.g.,He/dpa, He/s and dpa/s) effects will be discussed in terms of different temperature-and dose rate-dependentregimesforpointdefectsupersaturation.

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StatusoftheESStargetstationPITCHER,Eric(EuropeanSpallationSourceERIC)TheEuropeanSpallationSource,nowunderconstructioninLund,Sweden,aimstobetheworld’smostpowerful pulsed neutron scattering facility. Driven by a 5-MW proton accelerator, the target stationincorporatesmanyfeaturesdesignedtoaccommodatethehigh-powerprotonbeam.Amongthesearearotatingtungstentargetcooledbyheliumgasandtheoptiontorunwithoutaprotonbeamwindow.Asof August 2016, the target station project is 17% complete, and construction has startedwith somecomponentsalreadymanufacturedandreadytobe installed.Alongwiththecentral team inLund,sixEuropeanpartnerinstitutionsarecooperatingtodeliverthetargetstation.Effortsarenowfocusedon

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PresentstatusofChineseSpallationNeutronSourceprojectJIA,Xuejun(InstituteofPhysics,CAS)TheCSNSprojectisdesignedtoprovidemultidisciplinaryplatformsforscientificresearchandapplicationsby national institutions, universities, and industries. CSNS is an accelerator basedmultidiscipline userfacility. ItconsistsofanH- linearaccelerator,arapidcyclingsynchrotronacceleratingthebeamto1.6GeV, a solid tungsten target station, and5 initial instruments for spallationneutronapplications. Thefacilityoperatesat25Hzrepetitionratewithaninitialdesignbeampowerof100kWandisupgradeableto500kW.Theprimarychallengeistobuildarobustandreliableuser'sfacilitywithupgradepotentialatafractionof"worldstandard"cost.AbriefintroductionoftheCSNSprojectanditscurrentstatuswillbegivenatthetalk.

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TheProtonPowerUpgradeprojectanditsimpactontheSNSFirstTargetStationRIEMER,Bernard(OakRidgeNationalLaboratory)

GALAMBOS,John(OakRidgeNationalLaboratory)

InconjunctionwiththefutureSecondTargetStation(STS)atOakRidgeNationalLaboratory'sSpallationNeutronSource(SNS)site,theProtonPowerUpgrade(PPU)projectwilldoublethepoweroftheexistingacceleratorthatwillsupportbothSTSandtheexistingFirstTargetStation(FTS).ThedesignbasisformostoftheexistingFTSwas2MWwith1.0GeVprotonpulsesdeliveredat60Hzpulserepetitionrate.2MWormorewill be available to FTSwith PPU, but PPU increases proton energy to 1.3GeV. Further, theenvisionedoperationofSTSat10Hzimplies50HztoFTS.HigherprotonenergyandthealteredrepetitionratewhenSTSoperates-alongwiththepotentialtogobeyond2MW-requirere-evaluationofthermal,structuralandshieldingmarginsofFTSsystemsaswellaschangesinradiationdamagerates.Affectedtargetsystemsincludereflectors,moderatorsandtheircryogenicsystems,shielding,utilitiesandclose-ininstrument hardware. The original FTS design basis employed simplified bounding assumptions forsystemsheatingwhichareexpectedtoprovidemarginswhenevaluatedwithmoreaccuratemethodswith1.3GeVprotons,butthismustbeverified.Somesystemupgradesmaybenecessary.ThemercurytargetmodulewasanexceptionintheoriginalFTSasitwasinitiallyratedfor1.0MWandlaterincreasedto1.4MW.Whilerecordshavebeenset,operationofthefirst-of-a-kindmercurytargettechnologyattheMWlevelhashaddifficultieswithhalfofthetargetsexperiencingleaksduringneutronproduction.Designchangeshaveincrementallybeenincorporated,fabricationoversightimproved,andsoongasinjectionwillbeinitiatedatalowflowrate.Thejumpto2MWwillrequiremore.PartofPPUincludesscopeforfurtherdevelopinganddeployinghigh-flowheliumgasinjectionintothemercurytargettoprovidemaximummitigationofbeampulseinducedcavitationerosionandvesselfatiguestress.Thesetwophenomenahavedirectlyorindirectlyledtothetargetleaks.Anewtargetvesseldesignwillbuilduponlessonslearnedfromoperationalexperienceandpostirradiationexaminationoftargets.ThispresentationwilldescribethePPUprojectwithemphasisontheFTSscope.

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CurrentstatusoftheChineseADSprojectWANG,Zhiguang(InstituteofModernPhysics,CAS)

ADSTEAM,(China)

Aimedatthechallengingissuesthatconfrontedbythelong-termsustainabledevelopmentofadvancednuclearenergy,aroadmapoftheChineseADS(AcceleratorDrivenSystem)projectwasplannedandthefirststageofthisproject(scheduledfrom2011to2016)waslaunchedbytheChineseAcademyofSciencesat 2011. During the first stage, great progresses have been achieved on the key technologies onaccelerator,targetandsub-criticalreactor,aswellastherelatedresearches.Thesecondstageproject,CIADS,wasapprovedlastyear.Itconsistsofasuperconductingprotonlinacwithbeamcurrentof10mAandenergyofabout600MeV,agranulartargetwithtungstenpellets,andaLBEsub-criticalreactor.Thetotal thermalpowerofreactorandbeamis10MW. It isademonstrationofhighpowercouplingandtransmutation.Recently,anewconceptofADANES(AcceleratorDrivenAdvancedNuclearEnergySystem)wasproposedandputforwardasthefutureplan.Inthispresentation,thecurrentstatusoftheChineseADSprojectwillbeintroduced.More,someissuesontargetandmaterialarealsogiven.

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SINQ–AStatusReportWOHLMUTHER,Michael(PaulScherrerInstitut)

BLAU,Bertrand(PaulScherrerInstitut)

GEISSMANN,Kurt(PaulScherrerInstitut)

HEINRICH,Frank(PaulScherrerInstitut)

WELTE,Jörg(PaulScherrerInstitut)

ThespallationneutronsourceSINQatthePaulScherrerInstitute(PSI)inSwitzerlandisinoperationsince1996.SincethenSINQhasconstantlybeenimproved,onboththeinstrumentsandthetargetstationside.Theimprovementsofthelatterhavebeenachievedmainlybysuccessivelyoptimizingthespallationtargetdesign.TheMarkItargetswerecomposedofsolidzircaloy-IIrodbundles.In2000theywerereplacedbyrodbundlesmadefromleadfilledstainlesssteeltubes(MarkII).ThesesolidtargetswithcannedleadrodsarecolloquiallycalledCannellonitargets.Untiltheendof2005threestainlesssteelCannellonitargetswereusedforneutronproductioninSINQ;eachtargetwasinoperationfor2years.In2006aleadbismutheutectic (LBE) liquidmetal target (LMT)–MEGAPIE–wasoperatedsuccessfullyandprovidedneutronyieldsupto80%higherthanachievedsofarwiththestainlesssteelCannellonitargets.FollowingMEGAPIEthecladdingmaterialoftheCannellonitargetswaschangedfromstainlesssteeltozircaloy-II(MarkIII),againincreasingtheneutronyieldascomparedtothestainlesssteelcladdedleadtargetbyabout6%.Thehugeperformance increaseexperiencedduring theoperationof theLMT (MEGAPIE) triggered furthertargetdevelopmentresultinginamorecompactCannellonitargetsurroundedbyaleadfilledreflector(blanket)withaninvertedbeamentrancewindowgeometryintegratedinthedoublewalledAlMg3safetyshroud, the Mark IV target. The evaluated performance increase of 38% was achieved and SINQ isoperating with Mark IV targets since 2009. Currently the SINQ upgrade project aims for furtherimprovementsbyreplacingtheneutronguidesystem,plannedfor2018/2019,andaredesignedcoldD2moderatorsetup.InthispaperwewillreportdetailsoftheSINQoperation,providedstatisticsaboutbeamtimeontarget,integratedbeamcurrentsreceived,operatinghoursperyearandneutronperformance.Furthermore,theSINQUpgradeProjectandchallengesaswellasdifficultiesfacedduringoperationwillbediscussed.

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PresentstatusofJSNSmercurytargetNAOE,Takashi(J-PARCCenter,JapanAtomicEnergyAgency)

HAGA,Katsuhiro(JapanAtomicEnergyAgency)

KOGAWA,Hiroyuki(JapanAtomicEnergyAgency)

WAKUI,Takashi(JapanAtomicEnergyAgency)

TAKADA,Hiroshi(JapanAtomicEnergyAgency)

The Japan Spallation Neutron Source (JSNS) has been operated since May, 2008 to provide pulsedneutrons by using a liquid mercury target for materials science innovative researches. The goal ofoperationalconditionsofthemercurytargetis1MWata25Hzrepetitionratewitha1µspulseduration.In2015,theprotonbeampowerwasrampedupfrom300kWto500kW.However,theJSNStargetwasfacedwithtroublestwiceinthewatershroudcausedfromthermalstressat500kW.The JSNSmercury target vesselwasmade from stainless steel 316L. It has the triple-walled structureconsistingofmercuryvessel,innerandouterwatershrouds,wheretheboundarybetweenthemercuryvesselandthewatershroudisfilledwithheliumgas.ForthefirsttroubleoccurredinApril,weconcludedthat thewater leakage from thewelding defect outside of the outerwater shroud,where thewatershroudbolttothemercuryvessel,throughavisualinspectionandanalyticalstudies.ForthesecondtroubleoccurredinNovember,waterleakwasdetectedintheheliumlayer.TheresultsofFEMsimulationsuggestedthattheleakpointwasseemedtobefatiguecrackataroundtheportionofmonolithicstructureconnectingthemercuryvesselwiththewatershroudduetothecyclicthermalstressinduced by beam trips. The problem is thought to be caused by the structure that left an unweldedportion.Theleakpointisyettobeidentifiedbyinspection.The JSNS target vessel design was improved to reduce welding lines approximately 30% and boltconnection asmuch as possible. The fabrication by applying new technique, the wire-EDM, is underprogress.Inthepresentation,presentstatusofJSNSmercurytargetincludingoutlineofthewaterleakincidentsandthenewdesignofthemercurytargetvesselwillbereported.

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CompatibilityresearchofstructuralmaterialsforChinalead-basedresearchreactor

LI,Chunjing(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

JIANG,Zhizhong(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

LUO,Lin(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

GAO,Sheng(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

FDS,Team(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

ChinaLead-basedResearchReactor (CLEAR-I) is the reference reactor for theADS (AcceleratorDrivenSubcriticalsystem)programinChineseAcademyofSciences.Liquidlead-bismutheutectic(LBE)ischosenasthecoolantusedintheprimarycoolingsystem.Threemaincandidatestructuralmaterialsinthereactorare316LandT91forthemainstructuralcomponents(mainvessel,internals,etc.),and15-15Ti(1.4970)for the fuel cladding tubes. For LBE cooled reactor, one of themain problems is the compatibility ofstructuralmaterialswithLBE.ThepaperpresentsthemainprogressinthecompatibilityresearchofthestructuralmaterialsforCLEAR-I,includingthecompatibilityfacilities,representativeresultsofcorrosionandmechanicaltests.Tostudythecorrosionbehaviorsandmechanismsofthestructuralmaterialsundernormal conditions of CLEAR-I, KYLIN series loops and some miniature corrosion devices had beendeveloped. In addition, an ultra-high temperature PbBi loop had been developed for evaluating thecorrosionresistanceofmaterialsunderaccidentconditionsupto1000°C.A10,000hcorrosiontestinLBEisunderwayat500°Cwiththedissolvedoxygenof1~3×10-6wt%andtheflowvelocityof1m/s.Thetesthasbeensuccessfullyoperatedfor5000handthedataanalysishasbeenfinished.ToevaluatemechanicalpropertiesofthestructuralmaterialsinLBE,seriesmechanicalfacilitiesincludingslowstrainratetensile(SSRT),creepandfatiguefacilitieshasbeenalreadyconstructedin2014.UptoNow,theeffectsofpre-exposure,oxygencontentinLBEandsurfacestressconcentrationontensilepropertiesofT91steelinLBEhad been conducted systematically. Then, LME susceptibility of T91 and 316L steels in LBE had beenassessed qualitatively among the temperature between 200°C and 600°C. Also, the low cycle fatiguebehaviorof15-15TisteelhadbeencomparedinLBEandairat550°C.Keywords:CLEAR-I;Lead-BismuthEutectic;StructuralMaterials.

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SpallationmaterialsR&DandapplicationforBeamInterceptingDevices(BID)atCERNCALVIANI,Marco(CERN)

PERILLOMARCONE,Antonio(CERN)

TORREGROSA,Claudio(CERN)

FORNASIERE,Elvis(CERN)

ESPOSITO,Raffaele(CERN)

NUIRY,François-Xavier(CERN)

ABERLE,Oliver(CERN)

LAMASGARCIA,Inigo(CERN)

PERONI,Lorenzo(UniversitàdiTorino)

SCAPIN,Martina(UniversitàdiTorino)

SGOBBA,Stefano(CERN)

PEREZFONTENLA,AnaTeresa(CERN)

GOMEZPEREIRA,Laura(CERN)

LEAUX,Floriane(CERN)InthiscontributionwewillreviewthespallationmaterialsR&Dassociatedwiththedesign,operationandmaintenanceofbeaminterceptingdevicesintheCERNacceleratorcomplex.FocuswillbegiventotheredesignoftheantiprotonproductiontargetandtheresultsoftheHiRadMatexperimentcarriedoutinNovember2015toexplorethebehaviourofhigh-Zmaterialsimpactedbyhighintensitybeams.Triggeredbytheextremeconditionsencounteredbyhighintensitybeamsimpactingonhighdensitymaterials,wewilldiscussthestudiescarriedouttounderstandthebehaviourofWandIrathightemperatureandhighstrainrates.InthecontextoftheLHCtransferlines,ringcollimatorsandgeneralbeaminterceptingdevices,resultswillbepresentedontestsongraphite,carbonfibermaterialsandsiliconwhenexposedtotheextremeconditionsofbrightnessoftheLHCmachinebeams,includingtheresultsofanotherHiRadMatexperimentcarriedoutinearly2016.R&DandinvestigationactivitiesassociatedwithTa-claddingonWandTZMmaterialswillalsobeshownaswellasprogressesonTi6Al4V-containedPbtargetsinthecontextofprojectssuchasthenewn_TOFspallationtarget.ThechallengesandissuesassociatedwiththeproposedhighpowerSPSBeamDumpFacilityatCERNwillbeshownaswell.

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InvestigationoftargetmaterialformuonproductionunderhighpowerprotonbeamirradiationMAKIMURA,Shunsuke(KEK)

MATOBA,Shiro(MuonSection,J-PARCCenter,HighEnergyAcceleratorResearchOrganization)

KAWAMURA,Naritoshi(MuonSection,J-PARCCenter,HighEnergyAcceleratorResearchOrganization)

ISHIDA,Taku(NeutrinoSection,J-PARCCenter,HighEnergyAcceleratorResearchOrganization)

HURH,Patrick(Fermilab)

SATO,Akira(OsakaUniversity)

PARK,Joon-soo(MuroranInstituteofTechnology)

SHIMOMURA,Koichiro(MuonSection,J-PARCCenter,HighEnergyAcceleratorResearchOrganization)Polycrystallinegraphiteisaprincipaltargetmaterialformuonproductionunderhighpowerprotonbeamirradiation.Actually,ithasbeenusedinthemuontargetsatJ-PARCandRutherfordAppletonLaboratory,inthemesontargetatthePaulScherrerInstitute,andinneutrinotargetsatFermilab,J-PARC,CERNandothers.Graphitehasextremelyhighperformance for theseapplicationsdueto its thermalproperties,mechanicalproperties,andchemicalstability.However,graphiteiseasilyoxidizedathightemperature.In thecasewhereair isunexpectedly introduced into theprimarybeam lineduringhighpowerbeamoperation,therapidoxidationofgraphitetarget isdetrimentaltosafeoperations.Therefore,arobustclosedareaisrequiredtoenclosetheconsequentcontamination.Furthermore,thedamagedtargetmustbe replaced with a new one before restarting beam operation. The presence of graphite oxidationcontaminantscomplicatestheserecoveryprocedures.Inaddition,sinceasmallerspatialvolumeofthesourceofthesecondaryparticles isbeneficialtomoreefficienttransporttodownstreamexperiments,the density of the target material should be higher. So, modifying the graphite or developing areplacementmaterialforthegraphitethatisdenserandmoreresistanttooxidationisdesired.Recently,we started to investigate new target materials with higher performance. Silicon carbide (SiC) is anexcellentcandidatebecauseithasagoodheatresistanceandhighmechanicalstrength.ThedensityofSiCis1.8timeshigherthangraphite.TheoxidationresistanceofSiCismuchhigherthanthegraphite.Butamonolithic SiC cannotbeusedasa structuralmaterialunder thepulsedheating cycle,because it isbrittle. To take advantage of the goodmechanical properties of the graphite and the good oxidationresistanceoftheSiC,SiCcoatedgraphiteisinvestigated.UndertheRaDIATEcollaboration,theSiCcoatedgraphitewillbeirradiatedatBNL'sBLIPfacilityandpost-irradiationexaminationwillbeperformed[1].Simultaneously, NITE-SiC composite material, developed at OASIS group, Muroran Institute ofTechnology, is also investigated [2]. Brittleness of SiC is improved in this compositematerial. The SiCcompositematerialwill be irradiated and investigated at Research Center for Nuclear Physics, OsakaUniversity[3].Inthispresentation,theinvestigationofthetargetmaterialformuonproductionwillbedescribed.[1]http://radiate.fnal.gov/index.html[2]http://oasis.muroran-it.ac.jp/english/index.html[3]http://www.rcnp.osaka-u.ac.jp/index.html

12

Pulsedheavy-ionirradiationoftungstenHABAINY,Jemila(EuropeanSpallationSource)

LEE,YongJoong(EuropeanSpallationSourceERIC)

IYENGAR,Srinivasan(EuropeanSpallationSourceERIC)

DAI,Yong(PaulScherrerInstitut)

TOMUT,Marilena(GSIHelmholzzentrumDarmstadt)Irradiation of pure tungsten has been carried out at the M3-beamline of the UNILAC facility at GSIHelmholtzCenterforHeavyIonResearch.Tungstenspecimensoftwothicknesses(26umand3mm)wereexposedto4.8MeV/uuraniumandgoldionbeamsforfluencesupto4.0e13ions/cm2.Therepetitionrateofthepulsedionbeamwas0.5-2Hzwithapulselengthof150us.Theexperimentalsetupallowedforsimultaneousmeasurementoftheintensityoftheincomingbeam,thetemperatureandthemechanicalresponseofthesamplewitheachpulse.Inordertostudythebeampulseeffectontheexcitationandpropagationofthermalstresswaves,aLaserDopplerVibrometer(LDV)wasused.TheLDVrecordedthesurfacevelocityofthetungstenfoilsasafunctionoftime.AdynamicmechanicalanalysiswasdoneusingANSYS,andatheoreticaldiagnosiswasmadefortheexperimentaldata.Inorder tostudythe irradiation inducedhardeningasa functionaccumulateddose,nano-indentationtestsareperformedonthedamagedsurfacesofthesamples.Themeasureddataarecomparedwiththecalculateddamagevalues,andacorrelationbetweentheradiation-induceddamageandtheobservedmechanicalpropertyispresented.ThethermaldiffusivitiesofthedifferentsamplesaremeasuredwithaLaserFlashApparatus.Theresultsareconvertedintothermalconductivityasafunctionofradiationdoseandirradiationtemperature.Inadditiontopuretungsten,oxidizedsampleswereirradiatedforthepurposeofinvestigatingtheoxideadhesionunderapulsedbeam, tounderstand themechanicalbehaviourof slightlyoxidized tungstensurfaceinthepresenceofoxygenimpuritiesintheheliumcoolantofthetarget.TheirradiatedoxidescaleisexaminedusingAugerElectronSpectroscopy(AES)andScanningElectronMicroscopy(SEM).Also,theluminescenceof tungstenoxide is investigated,as it showedglaringbeamspotduringuraniumbeamirradiation.

13

Re-examinationofionirradiationasacredibletooltosimulatehighenergyneutronandproton-inducedvoidswellingforaccelerator-drivendevicesGARNER,Frank(TexasA&MUniversity)

WANG,Jing(TexasA&MUniversity)

SHAO,Lin(TexasA&Muniversity)Unavailabilityofhigh-fluxtestreactorsrequiresthationirradiationserveasasurrogateforinvestigatingfactors that lead to swelling resistance of improved alloys.Most current studies are directed towardlower-swellingferritic-martensiticalloysandtheirODSvariants.Thecredibilityofusingchargedparticlesimulation requires that the impact of all neutron-atypical features of ion irradiation be identified,understood andminimized. Two different approaches at TAMU and KIPT to accomplish this goal arepresentedanddiscussed.Inordertodemonstratethationirradiationisacredibletool,itisrequiredthatself-ionirradiationreproducemajoraspectsofneutron-inducedswellingdependencies(compositional,fabricational, flux-spectral) observed in neutron tests. It should also reproduce the swelling behavior(bilinear, steady-state after incubation), but should especially reproduce the well-established post-transientswellingratesof1%/dpaforfcciron-baseand0.2%/dpaforbcciron-basealloys.WhilestudiesatTAMUandKIPTshowveryclearlythebilinearswellingbehaviorofferritic-martensiticalloyswithapost-transientswellingrateof0.2%/dpa,moststudiesonausteniticalloyswereconductedinthe1970s-1990s,butdidnotshowtheexpected1%/dpaforfcciron-basealloys.Manyearlierstudies,especiallyforsimplemetalsandfcc iron-basealloys,arere-examinedhere in lightofrecentlyattained insightsandcurrentcalculationalpractices.Theresultsofthisre-examinationareveryencouraging,attestingtothecredibleuseofionsimulationforvoidswelling.Itisshownthatdpacalculationalcodes(EDEP,BRICE,IONDOSE,earlyversionsofTRIM)usedinearlierstudiesoverestimatedenergydepositionratesby~20-35%,leadingtoartificiallyhighdpalevelsandanincorrectvisualizationofswellingvs.depth.Whentheseearlierdatasetsarere-evaluatedusingSRIMthe1%/dpasteady-stateswellingrateisroutinelyobserved.Additionally,injected-interstitialsuppressionofvoidnucleation,notclearlyobservedinearlierstudiesonausteniticalloys,isequallystronginbothbccandfcciron-basealloys.

14

TheRaDIATEcollaboration–exploringhighpowertargetmaterialsresponsetoradiationdamage–goals,status,andfutureplansHURH,Patrick(Fermilab)TheRaDIATEcollaboration(RadiationDamageInAcceleratorTargetEnvironments),foundedin2012,hasgrowntoover50participantsand11 institutionsglobally.Theprimaryobjective is toharnessexistingexpertise in nuclearmaterials and accelerator targets to generate new and usefulmaterials data forapplication within the accelerator and fission/fusion communities. Current activities include post-irradiation examination ofmaterials taken from existing beamlines (such as the NuMI primary beamwindowfromFermilab)aswellasnewirradiationsofcandidatetargetmaterialsatlowenergyandhighenergy beam facilities. In addition, the program includes thermal shock experiments utilizing highintensity proton beam pulses available at the HiRadMat facility at CERN. Status of current RaDIATEactivitiesaswellasfutureplanswillbediscussed,includinghighlightsofpreliminaryresultsfromvariousongoingRaDIATEactivitiesandthehighlevelplantoexplorethehigh-poweracceleratortargetrelevantthermalshockandradiationdamageparameterspace.

15

DevelopmentofadvancedferriticsteelsforhighdoseapplicationsMALOY,Stuart(LANL)

HOELZER,Dave(ORNL)

ANDEROGLU,Osman(UniversityofNewMexico)

SALEH,Tarik(LANL)

TOLOCZKO,Mychailo(PNNL)

BYUN,Thak-sang(PNNL)

LAVENDER,Curt(PNNL)

ODETTE,G.r.(UCSB)TheFuelCycleR&Dprogramisinvestigatingoptionstotransmuteminoractinides.Toachievethisgoal,newfuelsandcladdingmaterialsmustbedevelopedandtestedtohighburnuplevels(e.g.>20%)requiringcladdingtowithstandveryhighdoses(greaterthan200dpa)whileincontactwiththecoolantandthefuel.Todevelopandqualifymaterialstoatotalfluencegreaterthan200dparequiresdevelopmentandtestingofadvancedalloysandirradiationsinfastreactors.SpecimensofpreviouslyirradiatedHT9specimensarebeing irradiated ina fast reactor tohighdoses (>200dpa). Inaddition, improvements in theradiationtolerance of HT-9 are being made through minor chpanges in the composition. Advanced radiationtolerantmaterialswithfineoxidedispersionstrengtheningarealsobeingdevelopedtoenablethedesiredextreme fuel burnup levels. Recent progress in high dose irradiated materials testing and materialsdevelopmentwillbepresented.TheFuelCycleR&Dprogramisinvestigatingoptionstotransmuteminoractinides.Toachievethisgoal,newfuelsandcladdingmaterialsmustbedevelopedandtestedtohighburnuplevels(e.g.>20%)requiringcladdingtowithstandveryhighdoses(greaterthan200dpa)whileincontactwiththecoolantandthefuel.Todevelopandqualifymaterialstoatotalfluencegreaterthan200dparequiresdevelopmentandtestingofadvancedalloysandirradiationsinfastreactors.SpecimensofpreviouslyirradiatedHT9specimensarebeing irradiated ina fast reactor tohighdoses (>200dpa). Inaddition, improvements in theradiationtoleranceofHT-9arebeingmadethroughminorchangesinthecomposition.Advancedradiationtolerantmaterialswithfineoxidedispersionstrengtheningarealsobeingdevelopedtoenablethedesiredextremefuelburnuplevels.Recentprogressinhighdoseirradiatedmaterialstestingandmaterialsdevelopmentwillbepresented.

16

TensiletestingofsteelsfromtheSTIP-VirradiationSALEH,Tarik(LosAlamosNationalLaboratory)

MALOY,Stuart(LosAlamosNationalLaboratory)

QUINTANA,Matthew(LosAlamosNationalLaboratory)

ROMERO,Tobias(LosAlamosNationalLaboratory)

DAI,Yong(PaulScherrerInstitute)WewillpresenttheresultsfromtheambientandelevatedtemperaturetensiletestingonsamplesfromtheSTIPV irradiationat thePaulScherrer Institute.SampleswereofvariousF/MandODSsteels,andirradiationconditionsrangefrom6-15dpadoseatirradiationtemperaturesfrom135-465°C.Duetotheirradiationenvironments in the targetof the SINQaccelerator, helium injection ranged from245-950APPM.TensiletestswereperformedattheWing9HotCellsatLosAlamosNationalLaboratory.TensileresultsofMA957,MA956andCROFERAPUalloyswillbepresented,andcomparedtosimilaralloysfromthepreviousSTIP-IVirradiation,andotherneutronirradiationsinreactors.

17

TensilepropertiescharacterizationofirradiatedAISI316Lfromhigh-usetargetmodulesattheSpallationNeutronSourceusingdigitalimagecorrelationMCCLINTOCK,David(OakRidgeNationalLaboratory)

GUSSEV,Maxim(OakRidgeNationalLaboratory)

CAMPBELL,Cody(BWXTechnologiesInc.)

GARNER,Frank(TexasA&MUniversity)APostIrradiationExamination(PIE)programismaintainedattheSpallationNeutronSourcetoinspectandtestmaterialfromSNStargetmodulesafterremovalfromservice.TensilespecimenswererecentlyproducedandtestedfromSNSTargets6,8,and9;themaximumdamagedosereachedwasapproximately8dpa.Tensiletestswereperformedinconjunctionwithdigitalimagecorrelation(DIC)characterization,which permitted detailed analysis of the strain distribution and evolution along the specimen gaugesections.Foreachspecimen,truestress-truestraincurveswerecalculatedusingtheexperimentalDICdata set. Deformation hardening behavior was analyzed in the terms of the plasticity constitutiveequations and deformation hardening parameterswere discussed as a function of damage dose andhelium/hydrogencontent.Localyieldstressconceptwasdiscussedandevaluatedtoaddressthepossibleeffectsofdamagedosegradients.Formanyspecimens,deformationbandswereobservedinthesmallstrainarea;thebandparameterswereanalyzedindetail.ScatteringofthemechanicaltestresultswasanalyzedusingthecalculatedDICstrainmaps.Theresultsshowwhileconsiderablehardening(~700MPaincreaseinyieldstrength)occurredinthe316LSNStargetmaterial,appreciableductility(18-24%totalelongation) remained in the material after irradiation to 7-8 dpa in the mixed neutron/protonenvironmentoftheSNStargetregion.

18

Swelling,creep,andembrittlementofD9stainlesssteelcladdingandductintwoFFTFdriverfuelassembliesathighneutronexposuresGARNER,Frank(TexasA&MUniversity)Most data sets on void swelling and irradiation creep of austenitic structural steels were derived inrelativelysmallamounts,makingitdifficulttoextractfullparametricdependenciesfordevelopmentofpredictivecorrelationsofdimensionalchange.Thispaperpresentsamuchlargerdatabasederivedfromfuel claddingandducts constructed fromD9steel, an improved titanium-modifiedvariantofAISI316stainless steel that has been selected for applications to various candidate reactors, including severalaccelerator-drivenspallationconcepts.Thisreportfocusesontheswelling,creep,lengthchange,ovalityandembrittlementbehaviorof20%cold-workedD9claddingandductusedintwomixed-oxidedriverfuelsubassembliesdesignatedD9-2andD9-4.These217-pinassemblieswereirradiatedintheFFTFfastreactortomaximumexposuresof25.3and21.4x1022n/cm2(E>0.1MeV)or115and96dpa,respectively.TheD9-2subassemblyoperatedatlowertemperaturescomparedtothoseofD9-4,leadingtosomewhatdifferentswellingbehavior.SincetheD9-4ductoperatedat lower temperatures than thecladding, theswellingof theductwas relatively low,peakingat6-7%.Thefuelpincladdingreachedswellingvaluesof21-28%inD9-4and37-38%inD9-2,withmuchofthein-coreportionofthepinshavingattainedtheterminalswellingrateof~1%/dpa.Thewell-known"creepdisappearance"phenomenonwasobservedtodevelopatmoderateswellinglevels.Voidswellingwasfoundtovarywithdparate,irradiationtemperatureandsmallheat-to-heatdifferencesin composition. The latter involved relatively small differences in phosphorus content, but producedsignificantdifferencesinswelling.ComparedtodatasetsderivedfromthesmallerEBR-IIfastreactor,itisshownthatthetemperaturedependenceofvoidswellinginthemuchlargerFFTFisratherinvariantoveralargerangeoftemperatures.Whilenopinfailureswereobservedduringin-reactoroperation,failurearisingfromseverevoid-inducedembrittlementoccurredinseveralD9-2fuelpinsandductduringpost-irradiationhandling.

19

ThebehaviourofAlMg3afterirradiationathighprotonandneutronfluencesinSINQtargetsDAI,Yong(PaulScherrerInstitute)

BLAU,Bertrand(PSI)

BRUN,Roger(PSI)

GEISSMANN,Kurt(PSI)

SCHWEIKERT,Herbert(PSI)

WOHLMUTHER,Michael(PSI)TheAl-alloyAlMg3hasbeenusedasthematerialofmanyimportantcomponentsintheSwissspallationneutronsource(SINQ),suchasthetargetsafetycontainer,themoderatortankcontainer,thecentraltubeinwhichthetargetinserted.Thesecomponentsexposetoeitherhighprotonplusneutronfluxorneutronflux.Radiationdamageandheliumandhydrogenetc.may inducea strongdegradation inmechanicalpropertiesofthematerialandfurtherlimitthelifetimeofthecomponents.UnderstandingthebehavioroftheAlMg3materialinthesecomponentsisessentialtoassessthelifetimeofthem,whichisimportantforthesafeoperationofthetarget.Amongthesecomponentsthetargetsafetycontainerreceivesthehighest proton and neutron fluxes, particularly in the proton beam window area. To evaluate themechanical properties of AlMg3 in the beam window, tensile specimens were extracted from thecontainersofSINQTarget3,4and9,whichreceivedprotonchargeof6.8Ah,10.03Ahand13.16Ah,respectively.ThemaximumprotonfluencereceivedbyTarget9is8.56E+25p/m2whichisthehighestoneeverreceivedbyAl-alloysinspallationtargets.Tensiletestresultsshowthattheembrittlementinducedby irradiation increaseswith irradiationdose.At thehighest irradiationdose, the samplesarebrokenimmediatelyafteryieldinginacleavagefracturemode.Thisimpliesthattheupperlimitofprotonfluencefor thecontainer is reached. In this talk the resultsof tensile test, SEMandTEMobservationswillbepresented.ThelifetimeoftheAlMg3safetycontainerwillbediscussed.

20

PostirradiationexaminationoftheMEGAPIEsamplesatJAEA(2)SAITO,Shigeru(JAEA)

KIKUCHI,Kenji(IbarakiUniversity)

SUZUKI,Kazuhiro(JAEA)

HATAKEYAMA,Yuuichi(JAEA)

ENDO,Shinya(JAEA)

SUZUKI,Miho(JAEA)

OKUBO,Nariaki(JAEA)

KONDO,Keietsu(JAEA)The world's first megawatt-class lead-bismuth target, MEGAPIE (MEGAwatt Pilot Experiment), wasdismantledandpost irradiationexamination (PIE) sampleswerepreparedatPSIhot-lab.The sampleswereshippedtoeachinstitutionsincludingJAEA.Thesampleswerecutfromthebeamwindow(BW,T91)and the flow guide tube (FGT, SS316L). And all samples are prepared without LBE. The irradiationconditions of the specimens irradiated at SINQ targetwere as follows: proton energywas 580MeV,irradiationtemperatureswererangedfrom251to341°C,anddisplacementdamagelevelswererangedfrom0.16to1.57dpa.PIEincludingSP(smallpunch)andthreepointbendingtestswereperformed.SPtestswereexecutedforT91andSS316LspecimensatR.T.inaircondition.SpecimensizeforSPtestwith2.4mmsteel-ballis8mmx8mmx0.5mm.T91specimenswerecutfromthe"Spitze(triangle)"sampleandpolishedtothicknessof0.5mm.TheOM/SPspecimensofSS316Lwerepolishedtothicknessof0.5mm.Three-pointbendingtestswereexecutedforSS316LspecimensatR.T.inaircondition.ThebendbarspecimensofSS316Lwhichsizeis1.7mmx1.7mmx16mmwithoutnotchwereemployed.ResultsoftheSPtestsandthree-pointbendingtestsontheirradiatedspecimenswillbepresentedattheworkshop.Cross sectionalobservationon theSpitze sampleandmicrostructuralobservationbyTEMwillbealsoreported.

21

ThetransmissionelectronanalysisofdislocationloopsinT91steelsfromMEGAPIEandTWIN-ASTIRirradiationprogramsKONSTANTINOVIC,Milan(SCK.CEN,Belgiannuclearinstitute,Boeretang200,2400Mol,Belgium)

VANRENTERGHEM,W(Belgiannuclearinstitute,SCK.CEN,Boeretang200,2400Mol,Belgium)

GAVRILOV,S(Belgiannuclearinstitute,SCK.CEN,Boeretang200,2400Mol,Belgium)

TERENTYEV,D(Belgiannuclearinstitute,SCK.CEN,Boeretang200,2400Mol,Belgium)

ThedefectsformedunderneutronandprotonirradiationinT91steel,extractedfromtheMEGAPIEandTWIN-ASTIR irradiation programswere analyzed by transmission electronmicroscopy. The focus wasgiventotheevolutionofdislocationloopsasafunctionofirradiationdose,temperature,andcombinedneutron/protonversusonlyneutronirradiation.Differentspatialdistributionsofdislocationloopswereobserved as a function of dose in MEGAPIE T91 samples. These results are compared with similarobservationsinneutronirradiatedFeCrCwithintheGETMATproject.Differentmechanismswhichcouldbetheoriginofhomogeneousversusheterogeneousdislocationloopdistributionsarediscussedinthelightofmodelingresults.

22

BarrierstrengthofdefectsandheliumbubblesforhardeningofmartensiticsteelsirradiatedinSTIPPENG,Lei(SchoolofNuclearScienceandTechnology,UniversityofScienceandTechnologyofChina)

GE,Hongen(SchoolofNuclearScienceandTechnology,UniversityofScienceandTechnologyofChina;LaboratoryforNuclearMaterials,PaulScherrerInstitut)

DAI,Yong(LaboratoryforNuclearMaterials,PaulScherrerInstitut)Reducedactivationferritic/martensiticsteelsareconsideredasbaselinestructuralmaterials for fusionDEMOandtestreactorsinfuture.Structuralmaterialsinfusionreactorswillundergohighdisplacementdamage and transmutation helium/hydrogen by intense fluence of high energy neutrons. China lowactivation martensitic (CLAM) steel, F82H and Optimax-A have been irradiated in the SINQ targetirradiationprogram(STIP).Aseriesofstudieshavebeenconductedonthemechanicalpropertiesandmicrostructure of CLAM, F82H and Optimax-A steels irradiated in STIP to investigate the dose,temperatureandheliumeffectsonhardeningandembrittlementafterirradiation.Toinvestigatetheeffectsofheliumonhardeningafterirradiation,annealingexperimentsat600°Cweredone to recover the irradiation-induced changes inmechanical properties andmicrostructure.Micro-hardnesstestsandTEMobservationsbeforeandafterannealingofCLAM,F82HandOptimax-Asamplesirradiatedto5-21dpaat56-471°Cwereinvestigatedtoanalyzetherelationshipbetweenhardeningand quantitative results of defects and bubbles. Defects and heliumbubbleswere observed in CLAMspecimens at all doses. The microstructure and hardness of the same specimens before and afterannealing could demonstrate that the hardening in the as-irradiated specimens is attributed to acombinedeffectofdefectclustersandbubbles,whilethatintheannealedspecimensshouldbeessentiallycontributedbyheliumbubbles. Barrier strength (α) of defects andheliumbubbles for hardeningwasevaluatedfromequationsΔτ=αGb(Nd)1/2andΔτ2=Δτdefect2+Δτbubble2.Withthegoodrelationshipbetweenhardnessandstrength,therelationshipbetweenhardeningandquantitativeresultsofcluster,dislocationloopandbubblewereanalyzed.

23

MechanicalpropertiesandfracturebehaviorofpuretungstenandtantalumafterirradiationinSINQDAI,Yong(PaulScherrerInstitut)

HABAINY,Jemila(EuropeanSpallationSource)

LEE,YongJoong(EuropeanSpallationSource)

Tungstenhasbeenusedastargetmaterialinseveralspallationneutronsourcesintheworld.Duetoitspoorwatercorrosionresistance,tungstenhastobecladwithtantaluminsolidtargetswhicharewithawatercoolingsystem.Althoughpuretungstenandtantalumhavebeenwidelyusedformanyyears inspallationtargets,theunderstandingoftheirmechanicalpropertiesandfracturebehaviorinspallationirradiationenvironmentsisstillverypoor.IntheSINQTargetIrradiationProgram(STIP)somespecimensof pure tungsten and tantalum were irradiated at various dose levels and temperatures. In STIP-V,tungsten specimenswere irradiated to doses up to ~29 dpa at temperaturesup to ~560°C. In STIP-IItantalumspecimenswereirradiatedtoaboutthesamemaximumdose,butattemperaturesbelow320°C.Inthiswork,duetothehighactivityoftheSTIP-Vtungstenspecimens,justthoseoflowdoses,1-3.5dpa,weretested.Inordertodetecttheductile-to-brittletransitiontemperature(DBTT)ofthespecimens,bendtestingwasconductedattemperaturesupto450°C.Theresultsshowedallthespecimensbrokeninabrittle fracture mode, even at such low doses. Tantalum specimens were tensile tested. The resultsindicatedtheDBTToftantalumincreasedslowlywithirradiationdose.Thefracturebehaviorofthetestedsamples was investigated using scanning electron microscopy (SEM), which exhibited intergranularfractureforspecimensofbothmaterialsbrokeninbrittlemanner.

24

AnnealingeffectonthemicrostructureandhardnessofirradiatedtungstenHORVATH,Barbara(PaulScherrerInstitut)



TheEuropeanSpallationSource(ESS)willbetheworld'smostpowerfulneutronsourcefacilitybuilt inLund,Sweden[1]asthedemandiscontinuouslygrowingforneutronscatteringandimagingtechniquesformaterialcharacterizationundercontrolledconditions.Theneutronsareproducedthroughaspallationprocessintungstenwhichhashighneutronproductionrateduetoitshighatomicnumber.Tungstenisenvironmentallyfriendlycomparedtoothertargetmaterials,anditsuseinheliumenvironmentavoidscorrosion issues related towater cooling. Its disadvantages, however, are its lowductility and a highductile-to-brittletransitiontemperature.Tungstenisthemostcriticalnon-structuralmaterialanditmustoperatereliablyandpredictablyfortheplannedlifetimeofthetarget.Inordertoestimatethetargetlife,reliabledataisneededonthemechanicalpropertiesoftungstenafterirradiation.DedicatedexperimentswereestablishedinthePaulScherrerInstitutetoexaminethebehavioroftungstenunderrepresentativeoperationalconditions.Inthisstudy,weevaluatethemicrostructureandhardnessofirradiatedtungstensampleof1.6dpaafterannealing in various elevated temperatures (500°C, 600°C, 700°C, 800°C and 900°C for 1 hour). Wecomparethestructure,defectsanddislocationsinannealedirradiatedandunirradiatedsamples.Focusedionbeam(FIB)wasusedtopreparetransmissionelectronmicroscopy(TEM)lamellaswhichwerethinnedby flash electrochemical polishing. Several low and highmagnification TEM imageswere obtained indifferentareasofthesampletoobtainquantitativeinformationofthedislocationsanddefectclusters.Thehardnessofthetungstenhasincreasedafterirradiation(from436to650HV0.5,respectively).Thereis a significant difference in the tungstenmicrostructure after irradiating, as observedwith TEM. Theaveragedislocationdensityslightlyincreasesby18%from16.4/μm2to19.4/μm2afterirradiation.Thedefectclusterdensityis3.20E+05piece/μm3afterirradiation.Annealingtheunirradiatedandirradiatedsamples in500°Cfor1hourresultedonly inaminorchangeinhardness. Initialresultsofannealing in500°Cshownochangeinthedislocationandclusterdensity,norinclustersizedistribution.

25

FormationofoxidelayersontungsteninmildlyoxidizinggasmixturesHABAINY,Jemila(EuropeanSpallationSource)



SURREDDI,KumarBabu(DalarnaUniversity)

NILSSON,Christopher(LundUniversity)

IYENGAR,Srinivasan(EuropeanSpallationSourceERIC)TungstenhasbeenchosenasthetargetmaterialfortheEuropeanSpallationSource(ESS)inLund.Thetarget is cooledbypureheliumgas at a flow rateof 150m/sand10barpressure.As the target canmomentarily reach temperatures above 500°C due to beampulses, impurities in the helium gas, likeoxygenandmoisture,canleadtotheoxidationoftungsten.Inthepresentwork,theoxidationbehavioroftungstenhasbeenstudiedusingsimultaneousthermalanalysis(W-foils)andthermogravimetry(discspecimens). Theoxidized sampleswere characterizedbyEnvironmental scanningelectronmicroscopy(ESEM),Energy-dispersivespectroscopy (EDS),AugerElectronSpectroscopy (AES)andX-raydiffraction(XRD).UsingahotstageinanESEM,non-isothermalstudiesontheoxidationofatungstenfoilinanatmosphereofwatervaporatlowpressure(100Pa)werecarriedoutinsitu.Theresultsshowthatchangesinsurfacemorphologyaresignificantonlyabove600-700°C.Tungstendiscs(20mmindiameter,3mmthick)wereoxidizedisothermallyat400to900°Cfor2hoursinvariousgasmixtures-He(pO2lessthan5ppmatm),He+Ar+H2O(pH2O0,0078atm),andHe+0.5%O2(pO2lessthan0,005atm).Oxidationoftungstenwasobservedinallthesegasmixtures,evenat400°C.Theresultsshowthattheoxidationfollowsamixedparabolicandlinearratelaw.Atlowtemperatures(400-500°C),theoxidelayerisdark,thinandadhesive,andthegrowthrateislow.Beyond600°C,theoxidelayer was observed to be greenish, thick and porous. The activation energy for the phase boundarycontrolledreactionwas foundtobeapproximately64kJ/mol for theHe+0.5%O2gasmixture,and74kJ/molfortheHe+Ar+H2Ogasmixture.Forthediffusioncontrolledreactionbelow750°C,correspondingactivationenergyvalueswereestimatedtobe95and183kJ/mol.TheoxidesformedonthesurfaceoftungstenwerecharacterizedusingAES,XRDandEDS.TheAESstudyconfirmedthepresenceofathinoxidelayeronspecimensoxidizedat400°C(45nmafter2hours,pH2O0.0078atm.).At500°C,theoxidelayerwas10timesthicker.XRDandEDSmethodswereusedtoidentifytheoxidesformedandtheircompositions.Layerswithvaryingstoichiometrywereobserved,rangingfromWO3atthesurfacetoWO2atthemetal-oxideinterface.

26

Low-ZmaterialR&DandapplicationforBeamInterceptingDevices(BID)atCERNNUIRY,François-Xavier(CERN)

CALVIANI,Marco(CERN)

MACIARIELLO,Fausto(CERN)

ABERLE,Oliver(CERN)

KARAGIANNIS,Konstantinos(UniversityofThessaly)

LECHNER,Anton(CERN)

STEELE,Genevieve(CERN)

BUTCHER,Mark(CERN)

PERILLO,Antonio(CERN)

LAMAS,Inigo(CERN)

FERRIERE,Romain(CERN)

GONZALO,Arnau(CERN)In the framework of the LargeHadronCollider (LHC) injectors upgrade (LIU) and theHigh-LuminosityProjectatCERN(EuropeanOrganizationforNuclearResearch,inGenevaSwitzerland),absorbersinthe(SuperProtonSynchrotron)SPStoLHCtransferlinesaswellasringcollimatorsintheLHCwillundergoimportantmodificationsintheforthcomingyears,mainlyfocusedduringtheLongShutdown2foreseenin2019-2020.Inthiscontributionwewillpresentthelow-ZmaterialsR&Drelatedtothehighintensitybeamtestoncarbon based materials for the upgrade of SPS-to-LHC Transfer Line Collimators and LHC InjectionAbsorbers,carriedoutduring2016aswellasforeseenin2017.FocuswillbegiventotheengineeringstudiesofinterestingcarbonbasedmaterialsforCERNcollimatorsandtheresultsoftheHiRadMatexperimentcarriedoutinApril2016.Triggeredbytheextremeconditionsencountered by high intensity beams impacting on low densitymaterials,wewill discuss the studiescarriedouttounderstandthebehaviourofIsostaticgraphiteand3DCarbonComposite(3DCC)athightemperatureandhighstrainrates.InthecontextoftheLHCtransferlines,ringcollimatorsandgeneralbeaminterceptingdevices,resultswillbepresentedontestsongraphiteand3DCarbonComposite(3DCC),includingperspectivesforfuturestudies.

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FatiguepropertiesoftungstenfromdifferentprocessingroutesHABAINY,Jemila(EuropeanSpallationSource)

LOVBERGTSERPELIS,Andreas(LundUniversity)

IYENGAR,Srinivasan(EuropeanSpallationSource)


DAI,Yong(PaulScherrerInstitut)PuretungstenhasbeenchosenasthetargetmaterialattheEuropeanSpallationSourcepresentlyunderconstructioninLund.Inthisfacility,ahighenergy(2GeV)-highpower(5MW)pulsedprotonbeamwillirradiatethespallationvolumeandthetargetissubjectedtocyclicthermo-mechanicalloadingcausedbybeamtripsandbeampulses.Inordertominimizetheprobabilityoffatiguefailure,agoodunderstandingofthefatiguebehavioroftungstenisimportantindesigningthetargetstation.Inthisstudy, thetensileandfatiguepropertiesofpuretungstenfromtwodifferentprocessingrouteshavebeendeterminedatroomtemperature.Therolledandannealed(RA),aswellassinteredandhotisostatically pressed (SH) tungsten test specimens were supplied by Plansee Metall GmbH, Austria.Microstructural examination showed that the rolled material had very large, elongated grains (max.1000μm×50μm) and the HIPed material had an average grain size of -30μm, with finely distributedmicropores.Tensiletestsshowedthatbothtypesofspecimenswereassociatedwithalowtotalstrain(-0.25%)andnegligibleplasticstrain.However,therolledspecimenshadamuchhigherultimatetensilestrength(-1GPa)ascomparedtotheHIPedspecimens(565MPa).Due to the brittle behavior of tungsten at room temperature, the fatigue strength was determinedprimarilybystress-controlledtesting,usingthestaircasemethodandastressratioapproachingzero.Theresultsshowedfatiguelimitsof350MPaand180MPafortherolledandHIPedmaterials,respectively.Thesevaluescorrespondtoarunoutlimitof2.0E6loadcyclesduringwhichnospecimenfailureoccurred.In addition, results from strain-controlled multiple-step testing (strain ratio = 0) indicated a slightrelaxationinstressfortheHIPedmaterialwhiletherolledspecimensshowedtheoppositebehaviorwithamarginal increase instresswith increasingcyclecount.Theresultsobtained in thisstudyhavebeencompared toprevious fatigue test datawith rolled and forged tungsten specimens, and a correlationbetween the degree of grain deformation and direction dependent tensile/fatigue properties ispresented.Theimplicationofthefatiguetestresultsonthespallationtargetdesignisdiscussed.

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Luminescentmaterialsdevelopmentforbeam-on-targetimagingattheEuropeanSpallationSourceSHEA,Thomas(ESS)


BLOKLAND,Willem(ORNL)

THOMAS,Cyrille(ESS)

HARTL,Monika(ESS)

ADLI,Erik(UniversityofOslo)

GJERSDAL,Havard(UniversityofOslo)

JAEKEL,Martin(UniversityofOslo)

JOSHI,Shrikant(UniversityWest)

BJORKLUND,Stefan(UniversityWest)

SAMPATH,Sanjay(StonyBrookUniversity)Luminescentmaterial deposited onto surfaces of the European Spallation Source (ESS) target wheel,protonbeamwindowandtuningdumpwillprovideimagesofthehighpowerprotonbeam.Todate,nocoatinghasbeenidentifiedthatpossessestherequiredpropertiesforthischallengingapplication.Theseproperties include: tolerance to the radiation environment of the 5 MW spallation target, a shortluminescencelifetimethatallowsimagingwithinthe2.86millisecondpulse,adequateluminescenceyieldat temperatures exceeding 200 degrees C, andmechanical integrity throughout the life of the targetcomponents.Buildingonworkfirstperformedinsupportofasimilar imagingsystemattheOakRidgeNationalLaboratory'sSpallationNeutronSource,aninternationalcollaborationhaslaunchedacampaigntodevelopmaterialsandcoatingprocessesintimeforESStargetconstructionandcommissioning.Wereport here on the first series of experiments for the down-selection of the luminescent coatingtechnology. The studies carried out so far have probed themechanical integrity of the coatings, theluminescenceyield,theluminescencelifetime,theemissionspectrumandthetemperaturedependence.These functional characteristics weremeasured in response to photon and proton bombardment. Inaddition,X-rayandneutronscattering techniqueshaveprovided informationabout thestructuralandchemical characteristics of the samples. To assess changes induced by the anticipated radiationenvironment,severalirradiationexperimentsareplanned,includingbombardmentbylowenergyions,aswellasin-situirradiationintargetstations.

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Designandfabricationofapassiveirradiationmoduleutilizingthehighneutronfluxfromthe5MWSpallationSourceatESSLEE,YongJoong(EuropeanSpallationSourceERIC)

MASI,Federico(EuropeanSpallationSourceERIC)

KICKULIES,Marc(EuropeanSpallationSourceERIC)

BESSLER,Yannick(ForschungszentrumJuelich)

ZANINI,Luca(EuropeanSpallationSourceERIC)Ahigh levelofparticleradiationfieldcreatedbythespallationprocess limitsthe lifetimeofthebeamintersecting andmoderating components near to the 5MW target at ESS, due to radiation inducedmaterialdegradations.ThesecomponentsareexposedtoahighfluxofprotonsandneutronsuptoaGeVlevel of kinetic energy. Understanding material degradation under such a radiation environment isimportantinsettingoptimalservicelifetimesofaffectedcomponentsandtherebyrealizingcostefficientoperationofthefacility.Whilethereareextensivestudiesontheradiationdamageofmaterialsinreactorenvironments,thereisalimitedamountofdataavailableforprotonandfastneutronirradiations.A STIP type passive irradiationmodule is being built in the pre-moderator at ESS,which receives theneutronfluxwithakineticenergyfromsub-meVupto1GeV.Thisirradiationmoduleisdedicatedtothestudyoftheradiationdamageofthematerialsofpotentialtargetstationsystemapplications,foralongerlifetimeandahigherreliabilityofthefacility.Inthispaper,thedesignandthefabricationstatusoftheirradiationmodulearepresented.Theirradiationmoduleoperatesparasiticallytotheoperationofthepre-moderatorandiscooledbythewater flow thatmoderates the neutrons from the target. A typical stainless steel alloy sample in themodulewillreceiveamaximumradiationdamageof7dpaperoperationalyearat5MW.Thecalculatedmaximumheliumproductionrateinsteelis110appmperoperationalyear,makingtheheliumproductiontodparatioof15.6appm/dpa.Thisirradiationconditionisalsosuitableforfusionsteelirradiation.Asthefusionsteelsshowsagoodfastneutronradiationresistanceinviewofheliumembrittlementandswelling,thesecouldalsoserveascandidatematerialsforthetargetvesselatESS,whichreceivesdirectprotonbeam.Forthisreason,thismodulealsocontainssomematerialsamplesofcommoninteresttofusionengineering.A STIP type passive irradiationmodule is being built in the pre-moderator at ESS,which receives theneutronfluxwithakineticenergyfromsub-meVupto1GeV.Thisirradiationmoduleisdedicatedtothestudyoftheradiationdamageofthematerialsofpotentialtargetstationsystemapplications,foralongerlifetimeandahigherreliabilityofthefacility.Inthispaper,thedesignandthefabricationstatusoftheirradiationmodulearepresented.

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TheESSheliumcooledrotatingtargetSORDO,Fernando(ConsorcioESS-Bilbao)TheEuropeanSpallationSourceisanambitiousEuropeanprojecttobuildanewgenerationSpallationNeutronSourceinLund(Sweden).Thetotalbudgetoftheprojectis€1,800,000,000sharedbetween17Europeancountries.Themaincharacteristicofthesourceisits5MWlongpulseprotonbeamwhichwillimpactonatungstenrotatingTargetcooledbyheliumgas.OnNovember2014,ESS-BilbaowaschosenasESSpartnerfortheTargetwheel,shaftanddriveunit.Along2yearsESS-BilbaohasdevelopedtheengineeringdesigntofulfillthetechnicalspecificationsofESSandintroducingsignificantmodificationscomparedwiththeESS-TDRproposal.ThispapersummarizestheTargetworks,includingprotypingactivitiesforthedifferentsubcomponents:Spallationmaterial,internalstructures,vessel,shaftanddriveunit.

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DesignmodificationofISISTS2targetinordertoimprovelongevityamidspallationreactionsDEY,Arghya(MaterialsScientist)

JONES,Leslie(RutherfordAppletonLaboratory)

TheworkingfrontofatargetofISISTargetStation2(TS2)isanassemblyofTantalumcladTungstencoreandaTantalumwatercoolingjacket.Theaimofthetantalumcladdingistopreventthetungstencomingincontactwiththepressurizedandfastcoolingwater.Howeveragammaspectralanalysisonthecoolingwaterafteratargethasfailedshowstheevidenceoftransmutedproductsoftungstenintothewater.TheneutronicanalystsatRALhavefoundthattheactivityofsometransmutedproductssuchasisotopesof175Hfand172Luaresignificantlyhigherthaniftheywereproducedfromthetantalumcladdinglayer.AMonteCarlosimulationsuggeststhattheoriginofthesetransmutedproductsistheTungstencore.Aninvestigationonthedesignandmanufacturingprocessofthetargethashelpedusto identifythattheelectronbeamweldjointsonthetantalumcladdingasoneoftheareasofweakness.Thepenetrationoftheweldusingtheexistingmethodwasfoundtobeinadequateandthegrainsundertheweldlinewerefoundtobesignificantlyenlarged.Afailureofthecladdingthroughtheweldjointwouldcausethetargetlifetobesignificantlyshortened.Inordertoimprovetheweldpenetration,astudyusingdifferentsettingsoftheweldparameterssuchasweldcurrent,beamrotationandbeamfocushasbeencarriedout.Thestudyconcludes thatmaximumweldpenetrationcouldbeachievedusingacombinationofhighweldpower,subsurfacefocusoftheelectronbeamandlowmaterialvolumearoundtheweldline.Asignificantmodificationinthedesignofthefrontofthetargethasalsobeenundertakentoensurefullpenetrationattheweldjoints.ThiswillensureadelayforwatercomingincontactwithTungstenthroughtheweldingjoint. In addition recent EBwelding trials with a revised strategy, usingmultiple pass electron beamweldingatdifferentenergies,hasbeensuccessfulinachieving4500μmweldpenetration.TheresearchersalsoconsideringRotaryFrictionWeldingandTantalumColdSpraytechniquetodevelopthecladdinglayeronthetungstencore.AnearlysuccesshasbeenachievedregardingweldabilitybetweenTungstenandTantalumusingRotaryFrictionWelding.

32

Simulatingperformanceoftantalum-cladtungstentargetsWILCOX,Dan(STFC)Tantalum-clad tungsten targets are important for many accelerator facilities. Significant work onsimulatingtheperformanceofsuchtargetshasbeencarriedoutatthe ISISspallationneutronsource,drivenbyadesire to improvethe lifetimeofexistingTargetStation2 (TS2) targetsandtodevelopanimprovedtargetforTargetStation1(TS1).DetailedFEAsimulationswerecreatedforthecurrentTS1,upgradeTS1andcurrentTS2targets.Possiblecausesof target failurewere investigated. Themain concernwas found tobe failureof the tantalumcladding leading to corrosion of the tungsten core. Factors limiting the cladding lifetime includemanufacturing pre-stress, fatigue due to beam-induced thermal stress, and radiation damage.Manufacturingissuessuchasweldqualitymustalsobeconsidered.SimulationspredictthattheHotIsostaticPressmanufacturingprocesswillintroducealargetensilepre-stressinthecladding,whichmayadverselyaffectfatiguelife.Preliminaryneutrondiffractionexperimentstomeasurethispre-stresshavebeencarriedoutusingtheEngin-XinstrumentatISIS,andtheresultswerecompared to FEA simulations. Fatigue loadingwas calculated for targetswith andwithout pre-stress.Thereisonlylimitedfatiguedataavailablefortantalum;fatiguetestsareplannedusingISIStantalumtoprovide more data in the region of interest. Likely effects of radiation damage were consideredqualitatively,butlackofdatahaspreventedanydetailedsimulation.SimulationresultsforcurrentISIStargetswereusedtosetdesignlimitsfortheTS1upgradetarget.Thenewtargetwillbelesshighlystressedthanthecurrenttargets,despitebeingmorehighlyoptimizedforneutronics.Thepotentialforpushingfuturetantalum-cladtungstentargetstohigherbeampowerswasinvestigated,andthelikelylimitingfactorsfortargetdesignconsidered.

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ManufacturingofESScoldmoderator–machining,weldingandtestingofAl6061-T6alloyBESSLER,Yannick(ForschungszentrumJuelichGmbH,Germany)

KICKULIES,Marc(EuropeanSpallationSourceERIC,Sweden)

BUTZEK,Michael(ForschungszentrumJuelichGmbH,Germany)

TheEuropeanSpallationSource(ESS)willdelivertheworld'shighestfluxofcoldandthermalneutronsforbasicandappliedresearchesinvestigatingthemolecularbuildingblocksofmatter.Innormaloperation,theESSspallationtargetwillbeoperatingat5MWprotonbeampower.Thehighlyenergeticprotonbeamdeliveredbythelinearacceleratorhitsthetungstentargetwherethespallationneutronsareproduced.The fast neutrons aremoderated to cold and thermal neutrons by amoderator and reflector systemlocatedintheclosevicinityofthespallationtarget.Theengineeringchallengeistoachieveanoptimalbalancebetweenmoderation,neutrongainandcooling.Thecurrentdesign ishighly integratedwhichposeschallengesinmanufacturing.InthispaperthemanufacturingandtestingofthefinalESScoldbutterflymoderatorisdescribed.Thecoldmoderatorwith17bardesignpressureandaflowchannelstructuretoenableahighhydrogenflowtobeabletoremovetheneutronicheatdepositionischallenging.Theweldsneedtobeplacedoutsidethehighstress areas. But at the same time the welds must be accessible and testable. Therefore, the coldmoderatorisunwindintoanupperandalowerhalf.ThecoldmoderatorishighspeedmilledfromtwosolidAl6061-T6workpiecestoachievehighprecision.Aftermachining,toachievehighqualityrepeatableweldingtheworkpiecesmustbecarefullycleaned.Fatisremovedwithultrasoniccleaning.Oxidelayersare removed by pickling. New oxide layer build-up is limited by vacuum packing of the work piecesimmediatelyafterdryingafterthepicklingbath.Thecompleteweldingseamiselectron-beamweldedina vacuum chamber. A filler AlSi12 is used to avoid crack formation. After manufacturing and X-rayanalyzingof thewelds,burst testswithwaterandwith liquidnitrogen, toconsider the lowoperationtemperature,hasbeensuccessfullyperformed.Finally,afracturemechanicsanalysishasbeendonetoconfirmtheexperimental.

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WeldabilityofdiffusionbondingbetweenInvaralloyandstainlesssteelbyhotisostaticpressingWAKUI,Takashi(Researcher)

NAOE,Takashi(JapanAtomicEnergyAgency)

SUZUKI,Hiroshi(JapanAtomicEnergyAgency)

STEFANUS,Harjo(JapanAtomicResearchAgency)


HAGA,Katsuhiro(JapanAtomicResearchAgency)

WAKAI,Eiichi(JapanAtomicResearchAgency)

TAKADA,Hiroshi(JapanAtomicResearchAgency)

FUTAKAWA,Masatoshi(JapanAtomicResearchAgency)Themercury target vessel is used at the Japan SpallationNeutron Source (JSNS) in the Japan ProtonAcceleratorResearchComplex(J-PARC).Itwasmadeoftype316Lstainlesssteel(SS)withabigsizeof1.3x1.3x2.5m3.Attheratedoperationalpowerof1MW,itisreplacedeveryyearandallusedtargetvesselisstoredintheJ-PARCsite.Aimingatreducingtheamountofradioactivewastes,wehavebeenstudyinganadvancedtargetstructureonwhichfronthalfofthetargetcouldbeseparatedfromthereusablerearpartwith a flange. Since twomercury flow channels of inlet and outlet and one helium gas line areconnectedintheflange,itisrequiredtohavehighsealperformancewiththeheliumleakrateoflessthan10-6Pa･m3/stopreventradioactivematerialsleakfromthesealpart.Theimportantdesignconditionisthatthelargethermalexpansionoflessthan0.008mmisinducedinhomogeneouslyintheflangeduringtheprotonbeaminjection.Weinvestigatedtheavailabilityof Invaralloy(Fe-36%Ni)withthethermalexpansioncoefficientaboutonetenthsmallerthanthatofSSfortheflange.HoweverthereisnodataaboutthecorrosionresistanceoftheInvaralloyagainstthemercury.Therefore,theInvaralloyblockiscoveredwiththeSSlayerandtheyarebondedbythehotisostaticpressing(HIP).Inthisstudy,bondingtemperaturewereparametricallychanged(973,1173,1373and1473K)undertheconstant treatment time and pressure (2 hr and 100MPa) in order to find out the suitable bondingcondition.ThecontentsofNiandCrandthehardnessinthediffusionlayerchangedgraduallyandthethicknessdiffusionlayerincreasedwithanincreaseofthetreatmenttemperature.Thetensiletestswerecarriedout.Thefracturedatthebondinginterfacebeforetheneckingoccurredforbondedat973K.Theotherbondedinthehigherthan1173KfailedattheInvaralloyside.Thegrainsizebecamelargeandthetensilestrengthdecreasedwithanincreaseofthetreatmenttemperature.Fatiguetestsforbondedat1173Kwerecarriedout.ThefatiguefractureoccurredattheInvarsideandfatiguelifeintheregionofthelowcyclefatigue.ThistendencyissameasthatfortheInvarbulkheat-treatedat1173K.Fromtheseresults,itwasconcludedthattheoptimumtreatmenttemperatureis1173K.

35

MeasuredSNSmercurytargetvesselstrainresponsestobeampulsesandcomparisontosimulationswithvariationsonmercurymaterialmodelbehaviorWINDER,Drew(ORNL)

RIEMER,Bernie(SNS/ORNL)

BLOKLAND,Willem(ORNL)

The dynamic strain response of the SNSmercury target vessel has beenmeasured from beam pulseinducedpressurewavesforthefirsttime.Measurementshavebeenmadeontwotargetssofar.Datawasobtainedusingcommerciallyavailablefiber-opticstrainsensors.Thefirstsetofsensors,installedonthe13thSNStarget,wasmanufacturedofregularmulti-modefiber.Forthe14thSNStarget,thesesensorswere manufactured out of radiation-resistant multi-mode fiber and we also added prototype strainsensors, under development at SNS, made of highly radiation-resistant single-mode fiber. The strainmeasurementsof the13th target captured responses from23 singlepulsesand6burstsof10pulsesdeliveredat60Hz.Sensorsfailedatdifferentintegratedchargedependingontheirlocationonthetarget.Single pulse intensities ranged from10.6 to 25.4micro-C (0.6 and 1.4MWequivalent at 60Hz). Theradiation-resistantmulti-modesensorsonthe14thtargetlastedbetween104and105timeslongerthanthestandardsensors,andthesingle-modefibersensorsapproximately3timeslongerthantheradiation-resistantmulti-modefibers.Theresultsoftheprototypesingle-modestrainsensorsareintheprocessofbeingverified.Theproportionalityofpeakstrainresponsestopulseintensitywereevaluatedandfoundtobequitelineardespitethenon-linearcavitatingbehaviorofthemercury.Measuredresponseswerealsocomparedtosimulationresults.Thematchisverygoodatthelocationclosesttothebeamaxisandentrancepoint.Atmostlocationsawayfromthispointthesimulationmatchesthestructuralresponsecharacterwellbutover-predicts peak strain magnitudes. This simulation deficiency was investigated through trialsimulations varying mercury and steel material behavior parameters including bulk viscosity (affectsvolumetric strain rate response),mercury tensile cutoff pressure (cavitation threshold),mercury bulkmodulus,andsteelRayleighdamping.Thispresentationwillpresent,compareanddiscussthemeasuredandsimulatedstrainresponsedataandthelessonslearnedfromtheinvestigationsonmaterialbehaviorchangestoimprovethematchtothemeasurements.

36

FailureanalysisontheweldedpartwithsteepchangeofthicknessemployedinJSNSmercurytargetvesselWAKUI,Takashi(JapanAtomicEnergyAgency)





FUTAKAWA,Masatoshi(JapanAtomicEnergyAgency)AtahighpowerspallationneutronsourceofJ-PARC(JSNS), in2015therewastroublewiththewater-cooledshroudofaneutronproductionmercurytargetduringtheoperatingperiodswitha500kWprotonbeampower.Thewater-cooledshroudissurroundingamercuryvesselinside.Thesevesselandshroudaremadeoftype316Lstainlesssteelanddesignedtoendurepressuresofmercuryandwater,thermalstressanddynamicstressinducedbythepulseprotonbeaminjection(Power:1MW,repetitionrate:25Hz,pulseduration:1μs).Sincetheoperationalgoalis1MW,redesignofthetargetisneededbasedonthecauseanalysis.However,visualinspectionwasdifficultbecausewaterleakdinsideoftheshroud.Wefocusedontheweldinglinebecauseadefectmayexistinit,especiallyinthepositonwhereitisdifficulttoweld,andthedefectinthewatershroudhaveapotentialtoinitiatewaterleakagepathduetorepeatedstressinoperation.IncaseoftheJSNSwatershroud,therewasaweldinglineonwhichthicknesschangedsteeplyfrom3mmto8mm.Weinvestigatedthisweldinglinebyusingapartialtestmodelsimulatingitsgeometryandweldingprocessalongwithnumerical simulations. Furthermore, crackpropagationanalysis from thedefect inweldingwascarriedoutbasedonthefracturemechanics.Asaresultofamicroscopicinspection,wefoundinsufficientpenetrationofweldingandacrackofca.1mminlengthwithintergranularfracturesurfacenearthepositionwherethethicknesschangedsteeply.A numerical analysis simulating welding process showed that temperature became lower near thispositionbecausetheheatconductionvolumeincreasedwithincreasingthickness,indicatingthecauseoftheinsufficientpenetration.Therepeatedstressrangeduetothe500kWprotonbeampulsereached76MPa.Anditwasestimatedthattheinitialcrackofmorethan0.9mminlengthcouldpropagatethroughthethicknessfromwaterchanneltotheoutersurfaceofwatershroud(8.5mm)bytherepetitionofbeampulseuptooccurrenceofwaterleakage(2.5x107times).TheseresultsindicatetheprobabilitythatwaterleakagepathintheJSNSwatershroudwasformedbythecrackpropagation inbeamoperation fromthe initial crackgenerated in theweldingprocessnearweldingwithsteepchangeofthickness.

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ThermomechanicalanalysisofESSspallationmaterialSORDO,Fernando(ConsorcioESS-Bilbao)

AGUILAR,Adrián(ConsorcioESS-Bilbao&InstitutodeFusiónNuclear)TheEuropeanSpallationSourceisanambitiousEuropeanprojecttobuildanewgenerationSpallationNeutronSourceinLund(Sweden).Thetotalbudgetoftheprojectis€1,800,000,000sharedbetween17Europeancountries.Themaincharacteristicofthesourceisits5MWlongpulseprotonbeamwhichwillimpactonatungstenrotatingTargetcooledbyheliumgas.OnNovember2014,ESS-BilbaowaschosenasESSpartnerfortheTargetwheel,shaftanddriveunit.Along2yearsESS-BilbaohasdevelopedtheengineeringdesigntofulfillthetechnicalspecificationsofESSandintroducingsignificantmodificationscomparedwiththeESS-TDRproposal.TheproposedconfigurationfortheSpallationmaterialisbasedon10x30x80mmWbrickinacrossflowconfiguration cooled by 2mm helium channels. The complex geometry of the helium paths and thetransienteffectsproducedbythecombinationofbeamandwheelspinning,forcetodevelopacomplexCFDstrategy.ThispapersummarizesthemethodologyforCFDandmechanicalanalysisandtheoperationalconditionsforthespallationmaterial(temperatureandstress)onsteadystateandtransients.

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Cavitationdamageindouble-walledmercurytargetvesselNAOE,Takashi(JapanAtomicEnergyAgency)

WAKUI,Takashi(JapanAtomicEnergyAgency)

KINOSHITA,Hidetaka(JapanAtomicEnergyAgency)



HARADA,Masahide(JapanAtomicEnergyAgency)


FUTAKAWA,Masatoshi(JapanAtomicEnergyAgency)TheJapanSpallationNeutronSource(JSNS)isdesignedtobeoperatedwithinjecting3GeV,1MWprotonbeamatrepetitionrateof25HzontoamercurytargetatJapanProtonAcceleratorResearchComplex(J-PARC).Amercurytargetvessel,madeof316Lstainlesssteel,with3mmthickatthebeamwindowfrontisdamagedduetothecavitationcausedbytheprotonbeam-inducedpressurewavesinmercury.Severecavitation damage reduces the structural integrity of the target vessel, and so currently dominant toshortenservicelifeofthetargetvesselfor2,500MWhoperationratherthanradiationdamage(5dpafortentativecriteria).Aimingatmitigatingthecavitationdamageandthepressurewavesbyfastermercuryflow in narrow channel, double-walled structure with the narrow channel was applied to the beamwindowfrontoftargetvesselinadditiontoinjectinggasmicrobubbleintoflowingmercury.Firstdouble-walledmercurytargetvesselwasoperatedfromOctober,2013toMay,2014,resulting inaccumulatedbeampowerofapproximately670MWh for1670hoursoperation.Before replacing thetarget vessel, the beam window front was cut out using an annular cutter in order to examine thecavitationdamageinsidethetargetvessel.Asavisualinspection,band-likedamagewasrecognizedoncut specimen facing narrow channel. For more detailed inspection, we employed replica method tomeasurethedamagedepth.Asaresult, therewasthecavitationdamagewithmaximumpitdepthofapproximately25μmontheband-likedamage.Furthermore,wecarriedoutnumerical simulation forpressurewavepropagationinordertoinvestigatewhytheband-likedamagewasformed.Thecalculatedresult showed that the distribution of negative pressure period was correlated with the damagedistributioninthenarrowchannel,andthepowerdependencyfornegativepressureperiodwasrelativelysmallerthanthatofbulkside.In theworkshop, resultofcavitationdamage inspectionwillbepresented,and thecavitationdamagedistribution innarrowchannelbasedonthenumericallycalculatednegativepressureperiod includingpowerandbeamprofiledependencywillbediscussed.

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EffectofoxygenconcentrationonLMEsusceptibilityofCLAMsteelinliquidleadbismutheutectic JING,Liu(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)




TEAM,Fds(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

Liquid leadbismutheutectic (LBE) isoneof the reference spallation targetsandcoolantmaterials foracceleratordrivensubcriticalsystems(ADS)duetoitsexcellentheattransferperformance,lowermeltingpoint and good neutronics performance, etc. However, the use of LBE gives rise to the performancedegradation of structuralmaterials. And structuralmaterialswould likely suffer a risk of liquidmetalembrittlement(LME)effect.AnunderstandingofliquidLBEembrittlementonthesestructurematerialsisoneofessentialissuesforthedevelopmentofADS.TheChinaLowActivationMartensitic(CLAM)steelpromisestobeselectedastheoneofthepromisingcandidatematerialsforthefuture'sADSduetoitsgoodstrengthandtoughnessatelevatedtemperature,aswellasitslowactivationafterhighfluxneutronirradiation. Previous studies revealed that the occurrence of LME was closely related to oxygenconcentrationatinterfaceofsolid/liquid.SotheinfluencesofdissolvedoxygenonLBEembrittlementofCLAMwere conductedat 400°Cwith a constant strain rateof 10-5 s-1. The fracture surfaceand crackpropagationbehaviorwereexaminedbySEM,EDSandEBSDtechnologiesaftertestedinLBEwiththeoxygen concentrations of 10-6 wt%, 10-7 wt% and 10-8 wt%, respectively. The results showed thatcleavagecracksourcesappearedontheouteredgesof fracturesurface,andthesourcesnumberwaslikelyindependentonoxygenconcentration.Also,theEBSDexaminationindicatedthatcrackinginducedby LME was transgranular and translath, and the plastic deformation around the crack tip reducedseriously when the dissolved oxygen decreased to 10-8 wt%. In brief, low dissolved oxygen in LBEpromotedtheoccurrenceofLMEonCLAMsteel,somoreattentionshouldbepaidontheLMEriskcausedbytheoxygendepletion inLBEat thesolid/liquid interfaceor incracktips.TheeffectsofLMEonthefatigueandcreeppropertiesofCLAMinLBEwillbeconductedinthefuture.Keywords:LeadBismuthEutectic;ChinaLowActivationMartensiticSteel;LiquidMetalEmbrittlement;OxygenConcentration

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NumericalmodelingofimpuritiesmasstransferinawirewrappedfuelassemblyunderflowingleadbismutheutecticMARINO,Alessandro(SCK-CEN)

Dr.LIM,Jun(SCK-CEN)

Mr.KEIJERS,Steven(SCK-CEN)

Dr.AERTS,Alexander(SCK-CEN)It is widely recognized that the coolant chemistry control is one of the key technologies for thedevelopment of lead-bismuth eutectic (LBE) cooled nuclear systems. In particular, oxygen is a criticalchemicalelementforLBEcoolantmanagement,becauseof itsmaininfluenceonthecorrosionrateofstructuralmaterialsandcore internalsand itspotentialcontaminationof thecoolantby formingsolidoxide (PbO). The oxygen concentration in LBE should be therefore continuouslymaintainedwithin atargetedrangebetweenthedissolutionlimitofaprotectiveoxidelayertoavoidfastdissolutionofthestructuralmaterialelementsandthesolubilitylimitofoxygentoavoidformationofPbOduringoperation.The supplied oxygen will be consumed mainly by oxidation of fuel cladding. The amount of oxygennecessary for a continuousoxide scale formationon the fuel claddingdependson temperature, localoxygenconcentration,flowvelocityandtypeofsteel.Thermodynamicrequirementsfortheformationofa protective oxide layer should be evaluated at the interface between structural steels and LBE.Experimentaldataonsteels'corrosionhoweveroftenrefertobulkoxygenconcentration.Thisismainlybecause it is practically impossible tomeasure the local oxygen concentrations near to steel surface,especiallyforcomplexsystems.Therefore,numericalmodelingisimportantandnecessarytobridgethegaponinformationneededtoevaluatelocaloxygenconcentrationlevelsand,consequently,corrosionrates.Anumericalmodelofoxygenmasstransferina19-pinfuelassemblywillbepresented,takingintoaccountthe oxidation of fuel cladding materials. This simulation provides a full mapping of the oxygenconcentration through a fuel bundle enabling the identification of critical areas in terms of oxygendepletion,andconsequentlycorrosion.Furthermore,itisofprimaryimportancetoidentifyrate-limitingfactorsanddeterminerepresentativeexperimentalconditionsfortheR&Dprogramoncorrosion.Anumericalmodelofcorrosionproductsreleasefromafuelassemblywillbealsopresentedassumingthatthedissolutionprocessofsteels is limitedbymasstransfer.Differentboundaryconditionswillbeappliedatthesteels/liquidinterfacedependingonthelocaloxygencontent.Thissimulationwillallowtoquantifytheeffectoftheoxygenconcentrationonmasstransferlimitedcorrosion.

41

DevelopmentofSIMPsteelforacceleratordrivensysteminChinaWANG,Zhiguang(InstituteofModernPhysics,CAS)

WEI,Kongfang(InstituteofModernPhysics,CAS)

YAO,Cunfeng(InstituteofModernPhysics,CAS)

SHEN,Tielong(InstituteofModernPhysics,CAS)

SHAN,Yiyin(InstituteofMetalResearch,CAS)

CHANG,Hailong(InstituteofModernPhysics,CAS)

ZHANG,Hongpeng(InstituteofModernPhysics,CAS)FocusedonthematerialsrequirementforthedevelopmentofADSinChina,anovelmaterialwithawholemartensiticphase,tentativelynamedSIMPsteel,hasbeenfabricatedunderthecollaborationbetweenInstituteofModernPhysicsandInstituteofMetalResearch,CAS.TheSIMPsteelwillbeusedinLead-Bismuth eutectic (LBE) environment and itwill support some innovative design of CIADS. In the pastseveralyears,optimizeddesign,fabrication,processingandevaluationfortheSIMPsteelhavebeendone,andapilotscaleof5,000kgSIMPingothasbeenachieved.Theroutineperformance,hightemperatureproperties aswell as resistances to intense ion irradiation and LBE corrosionof thenewmaterial aresystematicallytested.ItisfoundthatSIMPsteelexhibitsgoodpropertiesunderhightemperature,highstress,liquidmetalcorrosionandionirradiation.Inthepresentreport,thecurrentstatusoftheADSprojectinChinaandtheresearchprogressoftheSIMPsteelwillbeintroduced.

42

Lowcyclefatiguebehaviorof15-15Tisteelinstaticlead-bismutheutecticwith10-6wt%oxygenconcentrationat550°CLUO,Lin(InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

LI,Chunjing(InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

JIANG,Zhizhong(InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

LIU,Jing(InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

HUANG,Qunying(InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)AcceleratorDrivensubcriticalSystem(ADS)hasbeenconsideredasaneffectivetechnologicalsolutionfornuclearwastetransmutation.ChineseAcademyofSciences(CAS)hadlaunchedanADSresearchprojectsince2011.ChinaLEAd-basedReactor(CLEAR)whichwasdesignedbyInstituteofNuclearEnergySafetyTechnology(INEST/FDSTeam),CAS,wasselectedasthereferencereactorforADS.Thefirststageoftheprojectistoconstructa10MWlead-bismuthcooledresearchreactornamedChinaLead-basedResearchReactor(CLEAR-I).ThemechanicalpropertiesofstructuralmaterialsinLead-bismutheutectic(LBE)mayexhibitthetendencyofdegradation,andtheextentofdegradationiscloselyrelatedtodissolvedoxygenconcentration.ThecandidatematerialforfuelcladdingtubesofCLEAR-Iis15-15Tisteelandwillsufferfromcyclicstressesandstrains.Therefore,itisnecessarytostudythefatiguebehaviorof15-15TiinLBEunder theworkcondition toensure thesafetyof the fuel cladding tubes. In thispaper, the lowcyclefatiguebehaviorof15-15TisteelinstaticLBEwasstudiedwithaself-designedfatiguetestsystemat550°Cand10-6wt%dissolvedoxygen.Theexperimentswerecarriedoutwiththesymmetricalcycling(R=-1)andafrequencyof0.5Hzandatotalelongation(Δϵt/2)between0.3%and2%.Afterthefatiguetests,surfaceoxide scales, fatigue cracks, fracture featuresof the sampleswereanalyzed respectively,withscanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and electron backscatterdiffraction(EBSD).The15-15TisteelinstaticLBEdidnotshowsignificantdegradationoffatiguelifeunderthetestconditionsoflowstrainamplitude,slowstrainrateand10-6wt%dissolvedoxygen,comparedtoair.Themicroscopyanalysisindicatedthatthesurfaceoxidefilmblockedthepropagationoffatiguecrack.Thepaper showed that the fatigue lifeof15-15Ti steel in static LBEunderaboveconditions couldbeexpectedwithitsfatiguedatainair.

43

CorrosionbehaviorofTi3SiC2inflowingleadbismutheutecticat1000ºCXIAO,Zunqi(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

YAN,Shaojian(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

TIAN,Shujian(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)


LIU,Jing(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)



Lead Bismuth Eutectic (LBE) has been considered as one of the promising candidate coolants andspallation neutron target materials for the applications in lead alloy cooled fast reactors (LFRs) andacceleratordrivensystems(ADS),duetoitsfavorablethermal-physical,chemical,andneutronproperties.Compatibility of claddingmaterials with the coolant at temperature above 650°C is required for thefeasibility of the high-efficiency LFRs. It is expected that Ti3SiC2 can be the candidate of the claddingmaterialsinsuchreactors.Sothecorrosionbehaviorofthismaterialinleadalloyabove650°C,especiallyabove800°CisimportantinordertoimprovetheefficiencyofLFR.Toevaluatethecorrosionbehaviorofthecandidatestructuralmaterials inLBEatelevatedtemperatures,anultra-hightemperaturethermalconvection loop was designed and built in Institute of Nuclear Energy Safety Technology, ChineseAcademyofSciences.Thedesignedmaximumtemperaturefortheloopis1000°Candtheflowvelocityinthetestsectionisabout0.1m/s.Inthisstudy,corrosionbehaviorofTi3SiC2inflowingLBEwascarriedoutintheultra-hightemperatureloopat1000°Cfor1000h.Theweightandcompositionofthespecimensbeforeandaftercorrosionweretestedandanalyzed.Themicrostructureofthespecimenswasobservedwithscanningelectronmicroscope(SEM).Theresultsshowedthatadouble-layeroxideformedontheTi3SiC2aftercorrosion.TheexternallayeroftheoxidewascomposedofTiO2withinclusionsofTi-Pb-Si-Oand the internal layer was composed of TiO2 with inclusions of SiO2. And no dissolution attack wasobserved after corrosion. Longer time experiments will be carried out further in the near future.Keywords:LeadBismuthEutectic;Ti3SiC2,Corrosion,LeadAlloyCooledFastReactors

44

OxidationbehaviorsofCLAMsteelinstagnantliquidlead-bismutheutecticat500°CYAN,Shaojian(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)


XIAO,Zunqi(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)

TIAN,Shujian(KeyLaboratoryofNeutronicsandRadiationSafety,InstituteofNuclearEnergySafetyTechnology,ChineseAcademyofSciences)



Liquid lead-bismutheutectic (LBE) isunderwide investigationanddevelopment foracceleratordrivensubcriticalsystems(ADS)andhigh-powerspallationneutrontargets,duetoitshighneutroneconomyandgoodthermal-physicalpropertiesetc.However,oneofthekeychallengesofdesignandapplicationofLBEcooled systems in advanced nuclear reactors is the ability of available structural materials to resistcorrosion.Reducedactivationferritic/martensiticsteels(RAFMs),whichreplaceelementsproducinglong-livedisotopesbyreducedactivationelements,areconsideredsuitablefornuclearapplications,astheirsensitivitytoswellingunderirradiationislower.Inthisrespect,someinvestigatorshavecontributedinassessing the corrosion and oxidation behaviors of RAFMs in contractwith LBE. China low activationmartensitic(CLAM)steel,asoneofthemainRAFMs,wasexposedtostaticLBEwitharound10-6,10-7,and10-8wt.%dissolvedoxygenat500°Cupto2,000h,inordertoinvestigatethecorrosionandoxidationbehaviorsofCLAMsteel.Themicrostructure,chemicalcomposition,andthicknessoftheoxidescaleoftheexposedsteelswerecharacterizedbymeansofscanningelectronmicroscopyandenergy-dispersiveX-rayspectrometry.Theexperimentaldatashowedthatamulti-layeredoxidescale,consistingofFe3O4,Fe(FexCr1-x)2O4andinternaloxidationzone(IOZ)wasformed,whichcouldisolatethesteelmatrixfromLBE on the surface of CLAM steel. The thickness of oxide scale was a function of dissolved oxygenconcentrationandexposuretime.TheresultsindicatedthatCLAMsteelhadpotentialintheapplicationof LBE cooled advanced nuclear systems. Keywords: Lead Bismuth Eutectic; Corrosion; OxidationBehaviors;CLAMSteel

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PositronlifetimecalculationofvacancyclustersintantalumcontaininghydrogenandheliumXU,Qiu(ResearchReactorInstitute,KyotoUniversity)

POPOV,E(InstituteforNuclearResearchandNuclearEnergy,BulgarianAcademyofSciences)

TROEV,T(InstituteforNuclearResearchandNuclearEnergy,BulgarianAcademyofSciences)

ZHANG,Jian(ResearchReactorInstitute,KyotoUniversity)

DAI,Yong(PaulScherrerInstitut)Tungsten(W)isusuallyselectedasthematerialforsolidtargetofaspallationneutronsourcebecauseofitshighneutronyields.However,corrosionresistanceofWispoorinthecoolingwater.Tantalum(Ta)claddings can solve the problem of the corrosion, therefore, Ta-cladded W is considered to be theoptimized target for spallation neutron source. Investigation of mechanical property changes andmicrostructuralevolutioninTaunderhigh-energyneutronirradiationisimportanttomaintainthesafetyoftargetofspallationneutronsource.Inthepresentstudy,theeffectsofheliumandhydrogen,whichareproduced by nuclear reaction, on lifetime of vacancy clusters were investigated using quantum-mechanical electronic-structure calculations based on the density-functional theory (DFT). Positronlifetime calculations were carried out using the Kohn-Sham approach based on the DFT. In order toinvestigatetheeffectsofHandHeboundwithvacanciesonthepositronlifetime,DFTcalculationswereperformedasafunctionofthevacancy-clusterssizeinTacontainingHorHeseparatelyandHandHecomplexly.ThelatticeconstantforTais0.33nmwhilethedistancebetweenthebulknearest-neighboursis0.2858nm.Thecubiccellwithperiodicboundarycontains2000atoms.Theequilibrationprocesswas5psandthecalculationofpositronlifetimeswasmadeafteranother40ps.ThecalculationresultsindicatethatthelifetimeofperfectTais117.3ps,anditis216.0pswhensinglevacanciesareexists.Thelifetimeincreaseswithincreaseinnumberofvacancyinvacancycluster.Thelifetimeofsinglevacanciesdecreasesto191.7pswhenthevacancycontainsaHatom,whileitdecreasesto158.6pswhenthevacancycontainsaHeatom.ItisclearthattheeffectofHeonlifetimechangeislargerthanthatofH.

46

InvestigationofsamplesofF/MandODSsteelsirradiatedinthespallationsourceSINQbypositronannihilationKRSJAK,Vladimir(PaulScherrerInstitut)

DAI,Yong(PaulScherrerInstitut)ExtensivepositronannihilationexperimentsonspallationsamplesofF/MsteelswereperformedatthePaulScherrerInstitute.Evolutionofradiationdefectsandformationofheliumbubbleswasinvestigatedin the temperature range of 100 – 500°C and up to themaximum displacement damage of 20 dpa.CombiningTEMinvestigationresultsenabledustoevaluatespecifictrappingrateofpositronsintoHe-Vacancy clusters. The results show that small (~1nm)He-bubbleswith relatively highnumber density(≥1024m-3)are important traps forpositrons.Theyare trappedat thebubblesata rate similar to thetrapping rate at mono-vacancies (1.3×10-14 m3s-1). Helium-to-vacancy ratio has been found to varybetween0.2-1.0anditseemstobeinverselyproportionaltothesizesofthevacancyclusters.Inlow-dpasamples,theheliumispredominantlyconfinedinsmallvacancyclusters(He/V~1),whileinhigh-dpasamplescontainlargeheliumbubblesinwhichvacanciesprevail.Theobtainedresultsarediscussedwithrespect to molecular dynamics simulations published in literature. Comparison of more than 70measurements on various steel samples show saturation of positron trapping for samples irradiatedabove300°C.Itseemsthatthereisonlylittle(ifany)connectionbetweenthissaturationanddisplacementdamage (dpa). The reasonable interpretation of this is an enhanced coalescence of helium bubbles,decreaseoftheirnumberdensityandtherelatedincreaseofpositronmeanfreepath(i.e.decreaseofpositrontrappingrate).Ourmeasurementsalsoshow,thatpresentsofoxidedispersionscansuppressthesaturationofpositronlifetime.Whilethesaturationhasbeenobservedinthenon-ODSEuroferalreadyataround250°C,nosaturationcouldbedistinguishedintheODSEuroferuntil450°C.ThissuggestsabetterresilienceagainstradiationdamageandHeproductionduringirradiationinspallationtargets.

47

RatetheoryanalysisofgrowthprocessofheliumbubbleinF82HirradiatedatSINQSATO,Koichi(KagoshimaUniversity)

ERI,Shotaro(KagoshimaUniversity)

XU,Qiu(ResearchReactorInstitute,KyotoUniversity)

YOSHIIE,Toshimasa(ResearchReactorInstitute,KyotoUniversity)

DAI,Yong(PaulScherrerInstitute)In spallationneutron sources andacceleratordriven systems, irradiationdamage is significantlymoreseriousthanthatinfissionreactors.Thereducedactivationferritic/martensiticsteelisacandidateforthestructuralmaterialsofthefacilities,whichismoreirradiation-resistantthanthetraditionalnuclearreactormaterials.Onefeatureofspallationneutronsourcematerialsistheformationofalargeamountofgasatoms by the nuclear spallation reaction, and the formation of heliumbubble has great influence onmechanicalpropertiesofstructuralmaterials.Weinvestigatedthegrowthprocessofheliumbubblesbypositronannihilationlifetime(PAL)measurements.Thepositronmeanandlonglifetimesdecreaseatlowdoses(<13dpa)andincreaseathighdoses(>13dpa)inF82HduetotheresultsofPALmeasurements.But transmission electron microscopy shows that the bubble size increases and the concentrationdecreaseswithincreasingtheirradiationdoseandtemperature.Thisphenomenonisattributedtotheabsorptionofheliumatomsbyheliumbubbles.Inthisstudy,theeffectofheliumonthegrowthofheliumbubbleswasexaminedbyratetheory.Thegrowthofpointdefectclusterswerecalculatedusingthedynamicratetheoryundertheirradiationconditions for the second SINQ (Swiss SpallationNeutron Source) target irradiation program (STIP-II).Irradiationtemperaturewas360-572K,andirradiationdosewas6.1-20.3dpa.Thefollowingeffectswereignored:(1)Theeffectofhydrogenontheevolutionofdefectstructure,(2)theinteractionofheliumwithinterstitials and interstitial clusters, (3) the effect of the largeprimary knock-onenergies, (4) theonedimensionalmotionofinterstitialclusters.The bubble sizewas almost constant and the concentration of bubbles increasedwith increasing theirradiationdoseat373K.Thebubblesizeandtheconcentrationofbubblesincreasedwithincreasingtheirradiationdoseat473and573K.At10dpa,thebubblesizeincreasedandtheconcentrationofbubblesdecreasedwithincreasingtheirradiationtemperature.Inpreviousstudy,highpressureandlowpressureheliumbubblesweredetectedinonesamplebyPALmeasurements.Thechangeintheratioofheliumtovacancywillalsobediscussed.

48

InvestigationofSINQ-irradiatedsamplesbysingledetectorDoppler-broadeningspectroscopySNOPEK,Jozef(PaulScherrerInstitut)

KRSJAK,Vladimir(PSI)

DAI,Yong(PaulScherrerInstitut)Arecentlydevelopedmethodforpositronannihilationspectroscopyusinginternal44Ti/44ScsourcewasappliedforameasurementofDopplerbroadeningspectroscopy(DBS).ThisapproachenablestoperformfastandeffectivecomparativecharacterizationofsteelsamplesirradiatedinthespallationsourceSINQ.Despiteacommonstandardinusing2-detectorcoincidencesetupofDBS(CDBS),previouslypublishedwork [1, 2] shows that transmutation helium, produced during spallation reaction, provides acharacteristicpeakinhigh-countpartofspectra.Thissuggests,thatcoincidencemode,whicheffectivelysuppresses background and noise in the spectra, is not necessary in such investigation. Firstmeasurementsusingnew1-detectorDBSandcomparisontopreviousdataobtainedfromCDBSconfirmthishypothesis.OurDBSdatacanbeacquiredwithinfewhours,insteadoffewdayswhenusingCDBS.Moreovertheyarefreeofkaptoncomponent(annihilationintheencapsulationofradioisotopesource)sinceonlyinternalpositronswereusedforthemeasurement.

49

ExperimentalinvestigationofirradiationeffectsinberylliumbeamwindowafterexposureintheNuMIbeamline:preliminaryresultsandplansKUKSENKO,Viacheslav(UniversityofOxford)

AMMIGAN,Kavin(FermiNationalAcceleratorLaboratory)

DENSHAM,Chris(RutherfordAppletonLaboratory)

HURH,Patrick(Fermilab)

ROBERTS,Steve(UniversityofOxford)Itisnowrecognizedthatmaterialsdegradationbyradiationdamageistheoneofthemostchallengingfactorsofdesignofthenextgenerationofmulti-megawatthighintensityprotonacceleratorfacilities.Theexistingdatabaseonmaterialsresponsetoradiationeffects,relevanttoprotonacceleratorenvironments,isverylimitedandthiscomplicatesmaterialsselectionandlifetimepredictions.Aninternationalresearchcollaboration,RadiationDamageInAcceleratorTargetEnvironments(RaDIATE),wasrecentlylaunchedinordertoexploreradiationdamageissuesindifferentcandidatematerialsundertherelevantenvironment.Investigation of Be covers a large part of the RaDIATE collaboration, since it has been selected as apromisingcandidateforbeamwindowsandtargetcomponentsinnewgenerationofprotonacceleratorparticlesources.Aberylliumbeamwindow(gradePF60)fromthe"NeutrinosattheMainInjector"(NuMI)beamlinehasbeenirradiatedby120GeVprotonsover7yearsofbeamexposureat70°Cuptoanintegrateddamagelevelof0.5dpaandnowisavailableforanalysis.Upto2000appmofHeand1800appmofHhavebeengeneratedduringtheirradiation.TheevolutionofmicrostructureofthebeamwindowduringirradiationhasbeeninvestigatedatdifferentscalesbymicroscopyandthroughnanoscaleinvestigationoftheevolutionofimpuritydistributionsusingAtom Probe Tomography. Descriptions of the experimental program and the results of the currentactivitieswillbepresented.*Work supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with theUnitedStatesDepartmentofEnergy.

50

PlansfortheRaDIATEhigh-energyprotonmaterialsirradiationexperimentattheBrookhavenLinacIsotopeProducerfacilityAMMIGAN,Kavin(FermiNationalAcceleratorLaboratory)HURH,Patrick(Fermilab)ROBERT,Zwaska(Fermilab)CHRIS,Densham(RAL)STEVE,Roberts(OxfordUniversity)KUKSENKO,Viacheslav(OxfordUniversity)CALVIANI,Marco(CERN)PERILLO-MARCONE,Antonio(CERN)SIMOS,Nick(BNL)MAUSNER,Leonard(BNL)HANSON,Albert(BNL)PELLEMOINE,Frederique(FRIB)AMROUSSIA,Aida(FRIB)BOEHLERT,Carl(MSU)SENOR,David(PNNL)CASELLA,Andrew(PNNL)ISHIDA,Taku(KEK)NAKADAIRA,Takeshi(KEK)MAKUMURA,Shunsuke(KEK)LEE,YongJoong(EuropeanSpallationSourceERIC)SHEA,Thomas(ESS)THOMAS,Cyrille(ESS)TheRaDIATEcollaboration(RadiationDamageInAcceleratorTargetEnvironments)wasfoundedin2012tobringtogetherthehigh-energyacceleratortargetandnuclearmaterialscommunitiestoaddressthechallenging issue of radiation damage effects in beam-interceptingmaterials. Success of current andfuturehighintensityacceleratortargetfacilitiesrequiresafundamentalunderstandingoftheseeffectsincluding measurement of materials property data. Toward this goal, the RaDIATE collaboration hasorganizedamaterialsirradiationrunattheBrookhavenLinacIsotopeProducerfacilityinearly2017.Theexperiment utilizes the 181 MeV proton beam to irradiate several capsules, each containing manymaterialsamples,configuredforspecificpost-irradiationexaminations.Materialsexpectedtobetestedinclude various grades/alloys of beryllium, graphite, silicon, iridium, titanium, TZM, and aluminum.Attainable peak damage from an 8-week irradiation run ranges from 0.03 DPA (beryllium) to 7 DPA(iridium). Helium production is expected to range from 5 appm/DPA (iridium) to 3,000 appm/DPA(beryllium).Themotivation,specimenmaterials,irradiationparameters,experimentalset-upandpost-irradiationexaminationplansofthisexperimentwillbedescribed.

51

HiRadMatatCERNSPS-AdedicatedtestfacilitywithhighintensitybeampulsestomaterialsamplesFABICH,Adrian(CERN)HiRadMat(HighIrradiationtoMaterials) isafacilityatCERNdesignedtoprovidehigh-intensitypulsedbeamstoanirradiationareawherematerialsamplesaswellasacceleratorcomponentassembliescanbetested.Thehighenergybeamparameters(440GeVprotonswithapulseenergyofupto3.4MJandapulselengthof7.2us)canbetunedtomatchthespecificneedsofeachexperiment.HiRadMatisanareadesigned to perform single pulse experiments in order to evaluate the effect of high-intensity pulsedbeamsonmaterialsusedinaccelerated-drivendevicesorhighpowertargetsinadedicatedenvironment.The facility is designed for a1016maximumnumberofprotonsper year tobedistributedamong theexperiments. This paper will demonstrate the possibilities for research using this facility and showexamplesofexperimentsscheduledintheperiod2012-2016.Thefacility,auniqueplaceforperformingstate-of-the art beam-to-material experiments, operates under EuCARD2 transnational access andthereforewelcomesandfinanciallysupports,undercertainconditions,experimentalteamstoperformtheirexperiments.

52

ApplicationofrigoroustwostepmethodologyforneutronandprotontransmutationcalculationstospallationtargetsLILLEY,Steven(STFC)

DAVIS,Andrew(UniversityofWisconsin)

Therigoroustwostep(R2S)methodcanbeusedtocalculatethedecayradiationsourcetermatsometimeaftertheendofirradiation.ThefirstofthetwostepsistocalculatethemultigroupenergyspectrumasafunctionofpositionusingaMonteCarlocodesuchasMCNP,thiscouldbedoneusingcelltallies,anoverlaidmeshoraconformalmesh.Inthesecondstepthemultigroupenergyspectrumforeachcellormesh element is then used in a transmutation inventory solver such as FISPACT-II, ALARA, ACAB tocalculatetheactivityandemittedgammaspectraatagivendecaytimeforagivenirradiationscenario.The inventorycodesusecross section libraries foreach interaction, candealwithcomplex irradiationhistoriesandmultistepreactions.Thedataforeachcellormeshelementcanbecombinedtomakea3dimensionalmapof the inducedactivity ina facility.Anoptionaladditional step is touse thegammaspectra to generatea source term foruse in aMonteCarlo code to calculate shutdowndosearoundirradiateditems.Rigoroustwostepmethodologieshavebeenusedinfusionapplicationsforseveralyearshowever they have not been extensively applied to high energy facilities such as spallation neutronfacilities.Typically,inhighenergyfacilitiesothercodessuchasFlukaandCinderhavebeenusedwhichusephysicsmodelstocalculatethedecay.Oneofthemainreasonsforthis isa lackofavailablecrosssection data compatible with the transmutation solvers and the need to include not only neutronactivationbutalsoprotonactivation.TherecentTENDL2016crosssectionlibraryincludesdataupto1GeVforprotonsandneutrons,whichprovidesthepossibilitytoutilisetherigoroustwostepmethodasanalternativetophysicsmodelbasedcode.ThisworkdescribestheinitialdevelopmentofaprototypeR2ScodeforspallationneutronicswhichusesMCNPforthefirststepandcanuseALARAorFISPACT-IIforthesecondstep.ThenewR2Scodeusesandexpandsupontheroutines inPyne,anopensourcenuclearengineeringtoolkit.TheprototypecodeisthenappliedtotheISIStargetstation1andtargetstation2.TheresultsarecomparedtoresultsfromFluka.Inthefuturewehopetocomparewithpostirradiationmeasurementsoftargetcomponents.

53

Displacementdamage,heliumandhydrogenproductionindifferentmaterialsirradiatedinSTIP-VIAULET,David(PSI)

BERGMANN,Ryan(PSI)

WOHLMUTHER,Michael(PSI)

DAI,Yong(PaulScherrerInstitut)TheSINQTargetIrradiationProgram(STIP)hasbeendevelopedatPaulScherrerInstitut(PSI)duringthelasttwentyyears.Itisaimedtoanalyzetheradiationdamageinducedbyspallationindifferentstructuralmaterialswhichcontributestoamajorunderstandingontheirradiationeffects.Itisalsoprovidingdatafordevelopingfuturespallationsourcesaswellasadvancedspallationtargets.STIPVIwasconductedinSINQTarget9duringtheyears2011(6,366mAh)and2012(6,994mAh)receivingatotalprotonchargeof13.16Ah.Theirradiationparameterssuchasprotonandneutronfluxes,displacementdamage(dpa),heliumandhydrogenproductionhavebeencalculatedbasedonacomputersimulationusingtheMCNPXcode.ThetargetmainlyconsistsonaninvertedAlMg3semi-sphereasthebeamentrancewindowandtherod-container boxwhich consists on 306 rods fitting 36 rows. Two different proton beam (575MeV)profiles have been implemented for comparison. Beam 1 has an experimentally measured profileobtainedfromthegammamappingoftheirradiatedAlMg3beamwindow.Beam2hasatwo-dimensionaltruncatedGaussiandistribution fit fromtheexperimentaldata.Theprotonandneutronfluxes for theexperimentalbeamatthecenterofthecalotteare8.56x1025p/m2and4.36x1025n/m2.Regardingthetarget,themaximumprotonfluxis8.32x1025p/m2atrow0andthemaximumneutronfluxis1.97x1026n/m2atrowsix.Ithasbeenalsocalculatedtheradiationdamageinthecenterofthecalotteobtaining8.76dpaand2410appmHe.ForsteelsirradiatedSTIP-VIthemaximumradiationdamageis32dpawith2,990appmHeand12,600appmH,whichisthehighestvalueseverreachedinspallationtargets.Besidessteels,theirradiationparametersofAl,zircaloy.Ta,WandSiCwerealsocalculated.Itwasfoundthatthemaximumdamageis72dpawhichwasproducedinzircaloy,whilethemaximumheliumconcentrationis3,540appmproducedinTa.ThedetailedneutronicinformationofSTIP-VIwillbepresentedinthistalk.

54

SimulationofhydrogenthermaldesorptioncharacteristicsinmetalscontaininglargevoidsYAMASHITA,Hayato(JapanAtomicEnergyAgency)

SATO,Koichi(KagoshimaUniversity)

KOMAZAKI,Shin-ichi(KagoshimaUniversity)Itiswellknownthatalargenumberofhydrogenandheliumatomsareformedinthestructuralmaterialsofthespallationneutronsources.Hydrogenatomsaretrappedbyavarietyofdefectsinsteelssuchasvacancies, small vacancy clusters, dislocations, grain boundaries, precipitates, voids/bubbles. So, it isimportant to know about the interaction between hydrogen and such defects. Thermal desorptionanalysis (TDA) is often utilized to know trapping sites of hydrogen atoms. In the present study, thesimulationtechniqueforstudyingtheeffectofirradiation-induceddefectsonhydrogendesorptioncurveshasbeendeveloped.SimulationsforpureFewereperformed.ThesimulationmodelofhydrogendesorptionandadsorptioninconsiderationofhydrogencoverageofsamplesurfacewasproposedbyDavenportetal[1].Thismodelwas expanded in this study. The dissolved hydrogen were calculated by a kinetics calculation inconsideration of trapping and dissociation of hydrogen in the irradiation-induced defects. In theinteractionbetweenhydrogenatomsandvoids,theeffectofdissociationandadsorption,recombinationofhydrogenatvoidsurfacewasalsotakenintoaccount.Inaddition,hydrogendiffusioninsideofsampleswasalsocalculatedaccordingtothediffusionequation.Theeffectofvoidsurfaceonthedesorptioncurveswasexamined.Thepeakheightandtemperatureofsimulationalcurvesincreasedwiththeincreaseofthevoidradiusandthenumberdensity.Largevoidsobservedbyscanningelectronmicroscopy(SEM)areformedinthecreeprupturedpureFe(10MPa/973K). Although the void number density obtained by SEM was used, the simulational curve did notcorrespondwith the experimental one. The experimental curvewas influenced by the defectswhichcannotbeobservedbySEM.Theeffectofsuchdefects(includingirradiation-induceddefects)wasalsodiscussed.[1]J.W.DavenportandG.J.Dienes,Phys.Rev.B25(1982)2165.

55

MaterialselectionofthebeamprofilemonitoringdevicesattheESStargetstationLEE,YongJoong(EuropeanSpallationSourceERIC)

HARTL,Monika(EuropeanSpallationSource)

THOMAS,Cyrille(EuropeanSpallationSourceERIC)

SHEA,Thomas(EuropeanSpallationSourceERIC)

HABAINY,Jemila(EuropeanSpallationSource)Inordertomonitorpropertiesofthe5MWprotonbeamdirectedontotheESStarget,anumberofbeamdiagnosticswillbeinsertedinaregionupstreamofthespallationtarget.TheplanneddiagnosticsattheESS target stationare themulti-wireprofilemonitor, thehaloaperturemonitor, andbeam footprint-imagingsystem.Thebeamfootprintimagingsystemconsistsofluminescentcoatingsonthetargetwheelandprotonbeamwindow,andopticalcomponentstotransmitimagestocameraslocatedoutsideofthehighradiationarea.Sincesomeofthesedevicesintersectthehighpowerprotonbeam,thebeaminduceddynamic thermomechanical loads and radiation damage in themonitoringmaterials limit the servicelifetimeofthebeamdiagnostics.Inthispaper,wepresenttheworkingprinciplesandthematerialsselectionofthebeamdiagnosticsatESS. The radiation damage and the thermomechanical stresses in the candidate beam-intersectingmaterialsundertheESSbeamconditionarecalculated.Thesimulatedresultsarecomparedtodedicatedexperimentalresultsandtoknownoperationalrecordsofothermajorhighpoweracceleratorfacilities,inordertoestimatethematerialdependentservicelifetimes.Theimpactofthebeam-intersectingpartontheprotonbeamtransverseemittanceandthemeasurementuncertaintiescausedbythefastrecoilelectronsfromthebeamupstreamregionareanalyzed.Inthispaper,wepresenttheworkingprinciplesandthematerialsselectionofthebeamdiagnosticsatESS. The radiation damage and the thermomechanical stresses in the candidate beam-intersectingmaterialsundertheESSbeamconditionarecalculated.Thesimulatedresultsarecomparedtodedicatedexperimentalresultsandtoknownoperationalrecordsofothermajorhighpoweracceleratorfacilities,inordertoestimatethematerialdependentservicelifetimes.Theimpactofthebeam-intersectingpartontheprotonbeamtransverseemittanceandthemeasurementuncertaintiescausedbythefastrecoilelectronsfromthebeamupstreamregionareanalyzed.

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ThepresentstatusandprospectiveofSTIPDAI,Yong(PaulScherrerInstitut)The SINQ Target Irradiation Program (STIP) has undergone 20 years since itwas initiated at the FirstInternationalWorkshopon SpallationMaterials Technology in 1996 inOakRidge.During this 20-yearperiod,sevenirradiationexperiments,STIP-ItoSTIP-VII,wereconducted.Ineachexperimentmorethanonethousandtestspecimensfromaboutfortykindsofmaterialswereincluded.Themaximumirradiationdoseofeachexperiment,exceptforthatofSTIP-I,is20dpaormoreinsteels.Alargeamountofresultshavebeenobtained frommechanical testingandmicrostructural investigationofSTIP samples,whichhaveshownagreatimpactontheR&Dofhighpowerspallationtargets,andevenonfusioncommunity.However,ontheotherside,thereareseveralunexpectedincidentshappenedinSTIPirradiations,e.g.insomecasestheend-capsofthespecimenrodsfelloffduetovariousreasons.Manyspecimenswerelostbecause of such damages. In this presentation an overview of STIPwill be given. The failures of thedamaged specimen rodswill be shown and discussed. The future plan of the STIP irradiationwill bedescribed.

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IWSMT-13POSTERPRESENTATIONABSTRACTS

Temperaturemeasurementforin-situcrackmonitoringunderhigh-frequencycyclicloadingNAOE,Takashi(JapanAtomicEnergyAgency)

XIONG,Zhihong(SunYat-senUniversity)

TSUTSUI,Kihei(LancemoreCo)

FUTAKAWA,Masatoshi(JapanAtomicEnergyAgency)

At the Japan SpallationNeutron Source (JSNS), amercury targetmade of 316L stainless steel suffersradiation damage under high proton and neutron radiation environment. Along with the radiationdamage,thetargetvesselsufferscyclicimpactstresscausedbytheprotonbeam-inducedpressurewaves.Actually,theJSNStargetvesselsuffershigherthan2×108cyclicloadingwithastrainrateofapproximately50s−1atmaximumduringtheservice lifeof2,500hat1MWprotonbeamoperation. Inthepreviousstudy, we carried out an ultrasonic fatigue test to investigate the gigacycle fatigue strength of thestructuralmaterial of target vessel, and found that specimen surface temperature rose abruptly justbeforeresonancefrequencychangingduetooccurrenceof fatiguecrack.Fornuclear facilitiessuchaspowerplantsandneutronsources,itisnecessarytodevelopanon-destructivein-situmonitoringsystemto detect fatigue crack in early stage. In this study, as a fundamental study, in order to clarify themechanismof temperature riseduetooccurrenceofcrack, specimensurface temperatureduring theultrasonic fatiguetestwasmeasuredusinga2Dthermography.Theexperimental resultsshowedthatsurface temperature rose locally only at the tip of fatigue crack and the position of the maximumtemperature moved with the crack propagation. Therefore, we carried out numerical simulation tounderstandthemechanismoftemperaturerisecausedbycyclicloading.Thesimulationresultssuggestedthattheheatduetoplasticdeformationatthecracktipisdominantforthetemperatureriseratherthantheheatduetothefrictionbetweencracksurface.Themechanismoftemperatureriseduetoplasticdeformation has the potential to detect microcracks at the very early stage. The measurement oftemperaturedistributionisapplicabletechnologyasanin-situmonitoringrelatedtostructuralintegrity.

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CharacterizationofWsuppliersforESStargetSORDO,Fernando(ConsorcioESS-Bilbao)

JAVIER,Gil(CEIT)

TheEuropeanSpallationSourceisanambitiousEuropeanprojecttobuildanewgenerationSpallationNeutronSourceinLund(Sweden).Thetotalbudgetoftheprojectis€1,800,000,000sharedbetween17Europeancountries.Themaincharacteristicofthesourceisits5MWlongpulseprotonbeamwhichwillimpactonatungstenrotatingTargetcooledbyheliumgas.

OnNovember2014,ESS-BilbaowaschosenasESSpartnerfortheTargetwheel,shaftanddriveunit.Along2yearsESS-BilbaohasdevelopedtheengineeringdesigntofulfillthetechnicalspecificationsofESSandintroducingsignificantmodificationscomparedwiththeESS-TDRproposal.

Thenewtargetproposalisbasedoncommercialhotrolledtungstenbricks(10x30x80mm)thatcanbeproducedbyseveralsuppliersallovertheworld.Inordertoselectthebestpartnerfortheproductionofthespallationmaterial,ESS-BilbaohasreceivedsamplesfromsixdifferentsuppliersanditsmechanicalcharacterizationhasbeencompletedatCEIT-IK4facilities.

Thepapersummarizestheresultsfromthecharacterizationprocessandtheselectedtechniques.

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StructuralintegrityinvestigationofJSNSmercurytargetvesselbynondestructiveInspectionWAKUI,Takashi(JapanAtomicResearchAgency)

WAKAI,Eiichi(JapanAtomicResearchAgency)



HAGA,Katsuhiro(JapanAtomicResearchAgency)

TAKADA,Hiroshi(JapanAtomicResearchAgency)

FUTAKAWA,Masatoshi(JapanAtomicResearchAgency)

MercurytargetvesselfortheJapanSpallationNeutronSource(JSNS)havebeenfabricatedandinstalledatMaterials&LifescienceexperimentalFacility(MLF)inJapanProtonAcceleratorResearchComplex(J-PARC).Themercurytargetvessel,whichiscomposedoftype316Lstainlesssteel,isdesignedasmulti-walledstructurecomposedofthemercuryvesselanddouble-walledwatershroudtakingintoaccountofthe safety. The double-walledwater shroudwith cooling flow channels covers themercury vessel toprevent themercury leakage tooutsidewhenoccurringof failureof themercuryvessel.Themercuryvesselandwatershroudareassembledbythetungsteninertgas(TIG)welding.Intheassembleprocess,thewatershroudisfixedonthemercuryvesselbyboltsandtheareaaroundboltareweldedtosecuretheairtightness.Atmomentwhenthepulsedprotonbeamsinjectingthemercurytarget,temperaturesofthevesselandmercuryincreasesrapidlybecauseoftheabruptheatdeposition,andthemercurytargetvessel suffers large thermal and dynamic cyclic stress caused by beam trip and pressure waves,respectively.Thus, it isconcernedabout thecrackpropagationoriginated fromweldingdefect. In thisstudy,thenondestructiveinspectionbythephasedarrayultrasonicsystem(GEKKO,M2M)withthetotalfocusingmethod(TFM)wascarriedoutonthewelded316LsteelsampleandJSNSmercurytargetvesseltoevaluate thestructural integrityof the targetvessel.Furthermore, the radiographictestswerealsocarriedout.Thesizeanddistributionofthewelddefectswereinvestigatedbytwokindsof inspectionmethods. The allowable proton beampowerwas estimated based on the size ofweld defects in themercuryvessel.Inthisworkshop,theseresultswillbepresented.

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ExperimentalworkforgasinjectionsystemsinORNLSNStargetBARBIER,Charlotte(ORNL)

DOMINGUEZ-ONTIVEROS,Elvis(ORNL)Targetreliabilityathighpower(>1.3MW)isacentralissueattheSpallationNeutronSource(SNS)atOakRidgeNationalLaboratory(ORNL).Whenthepowerful,shortpulse,60Hzprotonbeamimpactstheliquidmercurytarget,anintensepressurewavepropagatesintothemercuryandthestainlesssteelvesselwhichleadtolargenumbersofstresscycles(>109)andcavitationdamagetothetargetvessel.Ithasbeenshownthatthepresenceofsmall,non-condensablegasbubblesdistributedintheliquidmetalcouldconsiderablymitigatethepressurewave,andpotentiallythecavitationerosionassociatedwithit.Thus,agasinjectionsystemwillbeimplementedintheSNSmercurytargetatORNLstarting2017.Becauseofthechallengesassociatedwiththepresenceofgasinthemercuryloop,twogasinjectionsystemsarecurrentlypursued.Thefirstgenerationgasinjectionsystemconsistsofaninletorificesbubbler(IOB)andwillbelimitedtolowgas flowrate injection (<1SLPM),whereas thesecondgenerationgas injectionsystem, theswirlbubblers,willallowtoreachupto1%ofvolumefractioninthetarget(~15SLPM).Experimentsinwaterandmercuryforbothgasinjectionsystemswillbepresented.Experimentalmethodsusedtodeterminebubblesizedistributionwillbepresentedindetails.

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StatusofSNSSecondTargetStationconceptualdesignRENNICH,Mark(OakRidgeNationalLaboratory)SelectionofkeyelementsoftheSNSSecondTargetStationduringoverthelast12monthshassolidifiedthebasicconceptforthetargetstation.Mostimportantlyasolidrotatingtargetwasselectedbecauseofoperatingandsafetyadvantages.Thischoiceledtoaseriesofrelateddecisionswithmajorconsequencesintheconfigurationofthemonolithandbuildinglayout.Sincethetargetismountedverticallyratherthanonahorizontalcartalargehotcellisnotrequiredforoperations.Eliminationoftheshieldedcellresultedintheprocesssystemsbeingmovedtotheprotonbeamsideofthemonolith.Therotatingtargetdecisionalsoresultedinamoderator/reflectorplugconfigurationdesignedtoshiftonrailsinordertoberemovedwithout disturbing the target. An Architect-Engineer study of the overall second target station siteincorporatedthesechangesintoabuildingdesignwhichmaintainedearlierconceptsforneutronbeamlinebunkersandmultipleoperatingfloors.

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Performanceofdual-phaseferritic-martensiticsteelEP450ascladding,wirewrapandductofhighburn-upfuelassembliesafterirradiationto108-163dpainBOR-60GARNER,Frank(TexasA&MUniversity)Ferritic-martensiticsteelsareproposedtoserveasstructuralcomponentsofvariouscandidateadvancedreactorconceptsthatwillexperienceveryhighdisplacementdoses.Twoimportantrequirementsarelowvoidswellingandanabilitytoallowveryhighfuelburn-up,withoutleadingtofailurebyembrittlement.Previouslytherehasbeennodemonstrationthatsuchgoalscanbereached,butasuccessfulfuelpinsserieshasnowshownthatsuchpromisecanbeachieved.Fourvibropacked37-pinfuelassemblieswereirradiatedintheBOR-60fastreactorwithcladding,wirewrapandductsconstructedfromtheEP-450dual-phaseferritic-martensiticsteel.Irradiationproceededtohighexposureswithoneassemblyreaching30%burn-upandthestructuralsteelreceivingmorethan160dpa.Nopinfailuresoccurredduringirradiationinanyofthefourassemblies.Theupperlimitofbothburn-upandsteeldpawerethereforenotdeterminedinthisexperiment,eventhoughthelowerhalfoftheassembliesexperiencedareductioninDBTT.TheEP450steeldisplayedaremarkablestability to irradiationunderallconditionsstudied.Themajormicrostructuralcomponents,temperedmartensiteandferritegrainsintheratioof1:1,wereessentiallyunchangedbyirradiation.Secondaryphasesformedwithinthetemperedmartensiteandferritephases,varyingprimarilyasafunctionoftemperature,buttherewasnonegativeconsequenceonpinintegrity.Very low levels of void swellingwere found, not exceeding 1%. At the highest exposure the primarycontribution to cladding deformation arose from mechanical stresses caused by gas pressure andespeciallyfuelswelling.Theseresultsofferassurancethatferritic-martensiticsteelsmayservewellinbothneutronoraccelerator-drivenreactors.

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MicrostructureandmechanicalpropertiesofprototypicelectronbeamweldsusedtofabricateAISI316LtargetvesselsfortheSpallationNeutronSourceGUSSEV,Maxim(OakRidgeNationalLaboratory)

MCCLINTOCK,David(OakRidgeNationalLaboratory)

LEONARD,Donovan(OakRidgeNationalLaboratory)

GARNER,Frank(TexasA&MUniversity)Atotalof14targetmoduleshavebeen installedandoperatedattheSpallationNeutronSource(SNS)sincebecominganoperational facility in2006.The tenthoperational targetmoduledevelopeda leakduringoperationatanelectronbeam(EB)weld,whichwasmadebywelding throughthecarbon-richatmosphereofasurfacehardeningtreatmentcalledKolsterising(R).Thoughtheexactcauseofthefailurewas not established, it was suspected that welding through the Kolsterising(R) treated layer mightintroducecarbonintotheweldanddegradethejointstrength.Therefore,aseriesofweldmentswereproduced to simulate the actual target fabrication procedures, which included EB welding with andwithout Kolsterising(R) layer, double-pass EB welding, and TIG repairing welding. Tensile andmicrostructure samples were produced from the different representative weld conditions andcharacterizedusingelectronprobemicroanalysis(EPMA)microscopy,electronback-scattereddiffraction(EBSD) microscopy, and tensile testing accompanied with digital image correlation. MicrostructurecharacterizationrevealedthatthecarbonatmosphereofthehardenedKolsterising(R)layerappearstodissolveintosolidsolutionafterwelding.Someinsignificantelementalsegregationofalloyelementsandferrite formation were observed in the weldment and heat affect zone but were not considereddetrimentaltotheweldstrength.Thetensiletestsdemonstratedhighductilityoftheweldedmaterial;localstrengthvariationsinthewelds, ingeneral,wereingoodagreementwiththeliterature.Noweldperformancedegradationduetoweldingthroughthecarbon-richKolsterising(R)layerwasobservedfortheweldconfigurationsexamined.

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HardnessofacarburizedsurfacelayeronAISI316Lstainlesssteelfromhigh-useSpallationNeutronSourcetargetvesselsafterirradiationMCCLINTOCK,David(OakRidgeNationalLaboratory)

HYRES,James(BWXTechnologiesInc.)

CAMPBELL,Cody(BWXTechnologiesInc.)Duringoperationthemercury-facingsurfacesofthetargetvesselattheSpallationNeutronSource(SNS)aredamagedbycavitation-inducederosion. Amethod implementedto increasetheresistanceof thetargetsurfacestocavitation-induceddamageisasurface-hardeningtreatmentcalledKolsterisingâ.Thetreatmentincreasesthecarboncontentatthesurfaceto~6wt%,whichgraduallydecreasestothebasemetal carbon concentration of ~0.2wt%C at approximately 50µm. At the timeof deployment, thestabilityofthecarbonatmosphereafterirradiationwasunknown.Specimensweresampledfromhigh-use SNS target vessels after removal from service and characterized to evaluate the stability of thehardenedsurfacelayer,whichwerecharacterizedusingVickersmicrohardnesstesting.Resultsshowthatthe carbon-rich hardened layer was still present on all specimens after irradiation to 6.4 – 7.4displacementsperatom(dpa)andgradualdecreaseinthehardnessprofilewaspreserved.Whilesomeslighthardeningwasobservedfromirradiation,thehardenedKolsterisingâlayerappearstoremainstableafterirradiationinthemixedproton/neutronenvironmentoftheSNStargetregionandwillcontinuetobeimplementedinfuturetargetdesigns.

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NeutronpoisonburnoutandeffectsonSNSmoderatorperformanceGALLMEIER,FranzX.(OakRidgeNationalLaboratory)

LU,Wei(OakRidgeNationalLaboratory)

IVERSON,ErikB.(OakRidgeNationalLaboratory)

REMEC,Igor(OakRidgeNationalLaboratory)

POPOVA,Irina(OakRidgeNationalLaboratory)TwoofthefourSNSmoderatorsprovidingthermalandcoldneutronbeamstothescatteringinstrumentsaredecoupled fromthesurrounding reflectorbycadmium layers,andpoisonedbygadoliniumpoisonplates in the center of the bulkwater and liquid hydrogen vessel to produce narrow neutron pulsesessential for high-resolution time-of-flight techniques in resolving the neutron energies of the beamsincident to and scattered by samples. Due to the high neutron flux levels, the decoupler and poisonmaterials burn out over time such that the moderators need to be replaced. Required poison anddecoupler thicknesseswere established in thedesignphase to guarantee a component life of 30,000MWh.Thedesigncalculationsassumedasthelife-limitingcriterionthatthetransmissionofthepoisonplate not be higher than that of 50 µm fresh gadolinium. Using this criterion, the end-of-life of themoderatorswillbereachedinyear2016.Assimultaneousburnupofpoisonanddecouplerwasnotconsideredinthedesignanalyses,andaclearimpactonthemoderatorperformancewasnotinvestigated,amorerigorouseffortwaslaunchedtore-calculate theburn-out effects. Thepoisonplate anddecouplerwere segmented toevaluate the localvariationofburn-upwithMCNPX-2.7.0calculations.Isotopetransmutationratesweredirectlycalculatedin MCNPX using the continuous energy cross sections and fed into a scripted burnup program thatiterativelycalculatedtheisotopicchangesinthematerialzonesandfedthesebackinsubsequentMCNPXanalysesbyapredictor-correctoralgorithm.Thelocalvariationofburn-upislarge;thepoisonplatesburnoutfasterinthemoderatorcenterwithpeakburnoutinzonesclosertothetarget;thedecouplerisdegradedfastestatthesidesfacingthecoupledmoderatorexhibitingpeakburnupclosetothetarget.Thepoisonanddecouplerburnupmanifestsitselfin two effects: a gradual increase of the peak brightness reaching 10-20% at 40,000 MWh for thedecoupledwaterandhydrogenmoderators,andan increaseof the long-timetailof thepulseshapes,which ismorepronounced forwavelengths>2Å.Massivebroadeningof thepulseshapes is seenonlyabove40,000MWhdeliveredbeamenergy.Becausethemoderatorpulsewidthisonlyonefactoroftheinstruments’energyresolution,themoderatorlifetimecanprobablybeextendedfrom30,000MWhto40,000MWhwithlittleimpactonscience.Instrumentperformancemonitoringisclearlyrecommendedapproachingtheendoflifeofthemoderators.

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ExaminingSNSfirsttargetstationfortheProtonPowerUpgradeprojectLU,Wei(OakRidgeNationalLaboratory)

GALLMEIER,Franz(OakRidgeNationalLaboratory)

IVERSON,Erik(OakRidgeNationalLaboratory)

REMEC,Igor(OakRidgeNationalLaboratory)

MCMANAMY,Thomas(OakRidgeNationalLaboratory)Asaprerequisite for theSNSSecondTargetStation (STS), theProtonPowerUpgrade (PPU)project isaimedtodoublethecurrentacceleratorcapabilityfrom1.4MWto2.8MWwithamoreenergeticprotonbeamof1.3GeV.Amongtheenhancedcapability2.0MWistobedeliveredatthefirsttargetstation,ofwhichmost componentshavedesign limits of 1.4 - 2.0MW.Hence it is imperative to reexamine thephysicalstrainofthefirsttargetstationforengineeringconcernsorredesignpurpose.Inthispresentation,the moderator performance, the energy deposition to the whole target monolith and the radiationdamagetocertain targetstationcomponentsare investigated.Somepreliminary results showthatbyincreasingtheprotonenergyto1.3GeVtheperformanceofthedownstreammoderatorsismoderatelyimprovedby~8%whilethatoftheupstreamoneskeepsthesame.However,themoreenergeticprotonbeam shifts the energy deposition burden to the downstream part of the target station as well. Ifnormalizedtothesamebeampower,theenergydepositionofthe1.3GeVbeamthroughoutthemajorityoftheinnerreflectorplug(IRP)andouterreflectorplug(ORP)isgenerallylessthanthatofthe1.0GeVbeam.Butattheregionaroundthetransitionandbackpartofthetargetvessel,itseesafactorof2-3increaseoftheenergydepositionload.Adetailedstudyisundergoingtoevaluateitsengineeringimpact.Theradiationdamagestudyalso finds thepeakdisplacementproductionrate for theORPoccursatasimilar locationwithmore thana factorof2 increase,which results in~15dpa for thedesignedORPlifetime.

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NeutronicsanalysesfortheSpallationNeutronSourceSecondTargetStationREMEC,Igor(OakRidgeNationalLaboratory)

GALLMEIER,Franz(OakRidgeNationalLaboratory)

RENNICH,Mark(OakRidgeNationalLaboratory)

MCMANAMY,Thomas(OakRidgeNationalLaboratory)

POPOVA,Irina(OakRidgeNationalLaboratory)

LU,Wei(OakRidgeNationalLaboratory)Twooftheword-classneutronscatteringfacilities,theSpallationNeutronSource(SNS)andtheHighFluxIsotopeReactor(HFIR),arelocatedattheOakRidgeNationalLaboratory.TheSNSandHFIRarefundedbytheU.S.DepartmentofEnergy,OfficeofScience,OfficeofBasicEnergyScience,andareoperatedasuser facilities, available to researchers from all over the world. Currently there are thirteen neutronscatteringinstrumentsinoperationattheHFIRandtwentyattheSNSFirstTargetStation.TheSNSwasdesignedfromthebeginningtoallowadditionoftheSecondTargetStation(STS),andanupgrade of the accelerator power. At this time both advances: the accelerator upgrade and theconstructionoftheSTSareinpreparation.CurrentbaselinedesignfortheSTScallsforarotatingcompacttungstentarget.Thetargetstationisdrivenwithshort(<1μs)protonpulsesat10Hzrepetitionrateand466kWprotonbeampower,andisoptimizedfor high intensity and high resolution long wavelength neutron applications. The possibility toaccommodatetheSTSoperationat20Hzand932kWisalsobeingconsidered.Theprotonbeamfootprintassmallasacceptablefromthemechanicalandheatremovalaspectsisplannedtogenerateacompact-volumeneutronproductionzoneinthetarget,whichisessentialfortightcouplingofthetargetandthemoderators and for achievinghigh-intensitypeak thermal and coldneutron fluxes. The STSwill allowoperationofapproximately22beamlinesandwillexpandandcomplementthecurrentnationalneutronscatteringcapabilities.ThispaperwillpresentanupdateofthestatusoftheneutronicsanalysesperformedfortheSTSandwilldiscuss theperformanceof themoderators,heating rates, radiationdamage,activationanalyses, andshieldingcalculationswhichprovideinputintheengineeringdesign.

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PARTICIPANTSLISTFIRSTNAME LASTNAME INSTITUTE EMAILAdrián AGUILAR

VILLAMORConsorcioESS-Bilbao [email protected]

Kavin AMMIGAN FermiNationalAcceleratorLaboratory

[email protected]

Charlotte Barbier ORNL [email protected] Bessler ForschungszentrumJülich [email protected] Blokland ORNL [email protected] Campbell BWXTechnologies,Inc. [email protected] Coates STFC [email protected] Curry ORNL [email protected] Dai PaulScherrerInstitut [email protected] Dey RutherfordAppletonLaboratory [email protected] Fabich CERN [email protected] Gallmeier ORNL [email protected] Garner TexasA&MUniversity [email protected] Gohar ArgonneNationalLaboratory [email protected] Habainy EuropeanSpallationSource,ERIC [email protected] Horvath PaulScherrerInstitut [email protected] Hurh Fermilab [email protected] Iyengar EuropeanSpallationSource,Lund [email protected] Jia InstituteofPhysics,CAS [email protected] Jones ISIS [email protected] Kickulies EuropeanSpallationSource,ERIC [email protected] Kikuchi IbarakiUniversity [email protected] Kogawa JapanAtomicEnergyAgency [email protected] Konstantinovic SCK.CEN [email protected] Krsjak PaulScherrerInstitute [email protected] Kuksenko UniversityofOxford [email protected]

c.ukYongJoong Lee EuropeanSpallationSource,ERIC [email protected] Li ChineseAcademyofSciences [email protected] Lilley STFC [email protected] Liu ChineseAcademyofSciences [email protected] Lu ORNL [email protected] Makimura P-PARC [email protected] Maloy LosAlamosNationalLaboratory [email protected] Mansur ORNL–retired [email protected] Marino SCK-CEN [email protected] McClintock ORNL [email protected] Naoe JapanAtomicEnergyAgency [email protected]çois-Xavier NUIRY [email protected] Peng UniversityofScienceand

[email protected]

Eric Pitcher EuropeanSpallationSourceERIC [email protected]

69

Irina Popova ORNL [email protected] Remec ORNL [email protected] Rennich ORNL [email protected] Riemer ORNL [email protected] Saito JapanAtomicEnergyAgency [email protected] Saleh LosAlamosNationalLaobratory [email protected] Sato KagoshimaUniversity [email protected] Shea EuropeanSpallationSource [email protected] Snopek PaulScherrerInstitute [email protected] Sordo ConsorcioESS-Bilaboa [email protected] Wakui JapanAtomicResearchAgency [email protected] Wang ChineseAcademyofScience [email protected] Wei ChineseAcademyofScience [email protected] Wendel ORNL [email protected] Wilcox STFC [email protected] Winder ORNL [email protected] Wohlmuther PaulScherrerInstitute [email protected] Xiao ChineseAcademyofScience [email protected] Xu KyotoUniversityJapan [email protected] Yamashita JapanAtomicEnergyAgency [email protected] Yan ChineseAcademyofScience [email protected] Zhang ChineseAcademyofScience [email protected] Zinkle UniversityofTennessee [email protected]

iwsmt13 book of abstracts - ornl neutron sciences ... · the international workshop on spallation...

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