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PIE Needs and Relevant Facilities at Cadarache

Coordinated and Presented byAlice Ying

With contributions from J. Furlan, V. Massaut, Y. Poitevin, S. Reyes, A. Tesini, M. Youssef, and WSG members

TBWG-16 Nov. 17 2005

Beijing, China

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Assumptions

• Parties believe that the post-irradiation examination (PIE) of the test blanket module (TBM) is an important part of the testing program.

• It has been recommended that an Annex be included to the ITER Hot Cell for TBM PIE and be located close to the ITER HCB or near ITER. – The TBWG has highlighted that such an enterprise

can be a collaborative effort between the parties and encouraged a prior agreement and official framework concerning the items of intellectual property to be established.

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TBM PIE Scenarios (Revised)

1. TBM shipped back to the country of origin or partner party after testing in ITER

2. Specimen Preparation + PIE3. Specimen Preparation Only (PIE done

at the host country)4. Specimen Preparation + limited PIE at

ITER site (i.e., ceramic breeder pebble bed integrity)

Have not reached a recommended reference scenario to TBWG on TBWG 16

However, most WSG task leaders favor option 4 and/or option 2

Scenario

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Is it practically feasible to transport the entire TBM back to the country of

origin? • Transfer to the country of origin:

transportation provision will have to conform to the international transport regulations. Casks licensed to transport tritium (in bottles) exist for small specimens, at least, so that it seems to be possible either to extend their content to the tritiated spices (in a primary container ?) and to design a proper adapted cask.

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Figure shows the neutronics model for the case of 20 cm of lead shielding within a 2 cm of steel

The dose has been tallied in the first cm of air around the case, we have used the highest dose value in the air zone that is closer to the FW (left side of the figure)

20 cm lead2 cm thick steel case

DCLL TBM structures

ONEDANT Transport Model for Dose Calculations

Due to the time constraint, Gamma ray transport calculations were performed only for the dominating radioactive element of Mn54 found in the ferritic steel (half life time= 1 year)

Goal: to estimate thickness of steel and/or lead needed to reduce the cask surface does rate to 2 micro-Sv/h

PbLi was drained out of the TBM before transportation. The model includes the W armor, the FS structures and the SiC layers.

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Steel shielding

1.00E+001.00E+01

1.00E+021.00E+03

1.00E+041.00E+051.00E+06

1.00E+071.00E+08

1.00E+091.00E+10

0 10 20 30 40 50

Steel thickness (cm)

Do

se (

uS

v/h

r)

Dose t = 1 week

Dose t = 1 month

Dose t = 3 months

Dose t = 6 months

Lead shielding within 2 cm thick steel case

1.00E+001.00E+01

1.00E+021.00E+031.00E+041.00E+05

1.00E+061.00E+071.00E+08

1.00E+091.00E+10

0 5 10 15 20 25

Lead thickness (cm)

Do

se

(u

Sv

/hr)

Dose t = 1 week

Dose t = 1 month

Dose t = 3 months

Dose t = 6 months

•Two shielding concepts investigated, one uses only a steel case of various thicknesses around the TBM

•Another case assumes a 2 cm thick steel container filled with lead shielding at different thicknesses

•In the case of steel, 40 cm are needed to reduce the dose below 2 Sv/hr (mass of container ~ 9 tonnes)

•In the second case Pb thickness of 20 cm would reduce the dose below the allowed limit (total

mass of steel case and Pb shielding ~ 5 tonnes)

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TBM Cooling may not be an issue after 1 day after shutdown (DCLL)

10-14

10-13

10-12

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

10-1 100 101 102 103 104 105 106 107 108 109 1010 1011

F82HLiPbSiCtotal

Time after Shutdown, Sec

1 s 1 m 1 h 1 d 1 mo 1 y 10 y 100 y 1000 y

Total Afterheat generated in the Test Blanket Moduleand contribution from each material

TBM dimension48.4 cm Toroidal166 cm poloidal72 cm radial (including 30 cm back manifold)

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Issues Concerning TBM Transports

Transfer of TBM parts towards other facilities should be submitted to constraints such as:

• use of casks approved to circulate on public road networks (even from ITER to Cadarache centre),

• specific TBM content (including Beryllium) included in the approved content of these casks,

• acceptance of possible tritium outgassing during transportation,

• capability of ITER to dock those casks.

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Outline

• Relevant PIE Facilities at Cadarache • PIE Needs

– Review of Basic Operational Procedure/ Processes Involved in PIE

– Route to Reference Scenario Definition • Schedule• Operational Procedure• PIE Categories• Criteria?

– Burdens

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Relevant Facilities at Cadarache: LECA-STAR

• This facility is dedicated to irradiated fission fuel studies. It offers a large panel of means and long experience related to preparation and examination of experimental devices. That is to say, roughly:– numerous hot cells, including large ones (up to 9 m x

3 m),– heavy loads handling (up to 60 t in the facility and 2 t

in the hot cells),– adapted in-cell tools (fine visual inspection, cutting

(fine & coarse), welding, scientific equipments for structural examination, …)

– a team of experienced experts.

A half-port TBM weighs ~ 2 t

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Relevant Facilities at Cadarache: CHICADE

• This facility deals with chemical and characterization studies of nuclear wastes. It offers tools for destructive and non-destructive survey and for radiochemical analyses.

• Main basic equipments are various shielded containments, a hot cell (so-called ALCESTE: 7 m x 6 m) and usual means to operate (heavy loads handling, up to 15 t in the facility, depending of the zone).

• The facility, whose aim is different, has not well adapted means nor experience to deal with the requirements.

Can this facility be used to accommodate any unscheduled PIE? For example, can it be used as a temporary storage until ITER HC becomes available?

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Facilities at Cadarache Summary

• LECA-STAR has capacity to handle, dismantle and sample large objects prior to performing experimental tasks. Structural examination equipments and know-how are available too but are dedicated to irradiated fission fuel.

• CHICADE offers hot surfaces and volumes but has no experimental means well-adapted to the requirements.

LECA-STAR Facility

Need to know the sample size of the large objects

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Action Items

• TBWG should take actions to finalize a reference scenario (as well as an alternative if necessary)– Further study is scenario dependent, involving the

concerned units’ staffs in Cadarache.• WSG members to define “Coarse” cutting

specifications/requirements: precision, complexity, etc.– So that ITER can, in future, try to take TBM

requirements for a best compromise for a cutting machine.

– Or a cutting technique specific for the TBM.

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What is the most pressing issue?

• It should be noted that ITER site layout, including the nuclear buildings, will be finalized in 2006 so any TBM/PIE/HC relevant issue which may impact the layout (HC and any additional annex and relevant site services, in particular) should be addressed soon by the TBWG.

Per email message of Tesini to Ying dated Oct. 25, 2005

Related immediate issue/action:

1. Establish PIE reference scenario including flow path and associated operations

2. Recommend alternative option

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Scenario APer email message of Tesini to Ying dated Oct. 25, 2005

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If TBM’s transportation outside the ITER boundary can be an issue:

–With regard to PIE, possible component flow path could be:

a) TBM is removed from plug within the ITER HC, packaged in suitable shielded container (safety, Tritium, transport issues to be addressed)

b) TBM is delivered to LECI-PELECI facility unless the on-site LECA-STAR can handle the TBM's (for which Jackie's memo quotes 2 ton max handling capacity). If possible (for size, availability) usage of the LECA-STAR facility appears preferable as it may help relax the TBM's transportation issue (within the same site)

Concerning the heavy loads handling, just one point to avoid confusion:In the hot labs there are generally two families of heavy loads handling means: those used to handle the casks (outside the hot cells) able to lift several tens of tons (60 t in LECA-STAR), and those dedicated to handle things inside the hot cells (2 t in LECA-STAR).(if it is possible to assume that ITER site & Cadarache centre belong to the same site, avoiding transportation on the public roads, constraints should still remain, but they should be lighter on the cask's design and licensing).

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Concern• It should be noted that ITER site layout, including the nuclear

buildings, will be finalized in 2006 so any TBM/PIE/HC relevant issue which may impact the layout (HC and any additional annex and relevant site services, in particular) should be addressed soon by the TBWG.

Minimum Request to ITER HC: Regarding the capability of ITER HC to dock those casks

• Space required for packaging six irradiated half-port modules in suitable shielded containers (safety,Tritium, transport issues to be addressed)

• Space and tools needed to accommodate above operations

• Tools: – Overhead crane and forklift/scissor jack with rail for transferring

TBM from port plug to shielded container– Water cooling systems to remove decay heat (may be

necessary before one month after shutdown)• Space: space for 6 shielded containers

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Scenario B

per Furlan’s memo to Ying dated on Aug. 22, 2005

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If a half-port size TBM’s transportation outside the ITER boundary can be an issue:

• Dismantle TBM previously in ITER hot cells, producing medium size pieces.

• The next step, needing accurate visual inspection (corrosion & cracks identification) and accurate cutting methods, could be performed in a CEA hot lab if not feasible in ITER.

• This precise sampling of medium size specimens could be performed in Cadarache (LECA-STAR or CHICADE). Then the samples could be dispatched from there to hot labs or to the Party if requested, using small size casks.

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Further details on the capabilities of facilities near Cadarache

Handling of materials containing tritium in the facilities: the question is to know the amount of tritium which could be released (in the vent system). Up to now the facilities are allowed to make controlled releases, provided they remain lower than a maximum yearly activity limit.  If needed a demand to increase the limits may be made (probably in the frame of the whole site).

Measure of residual tritium: my knowledge is there are no adequate existing equipments in the Cadarache hot cells up to now (but it seems to be possible to design specific equipments).

Additional 1. Tests in CEA Saclay: in the LECI lab the whole panel of physical,

chemical, mechanical examinations & testing of irradiated samples is available, so it is for the samples preparation (examples: machining of tensile strength samples, EBM samples  ...).

 

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Approximate weights of various TBM (preliminary)

HH DD+ Earlier

DT

Low duty cycle DT

High duty cycle DT

Port 2 Water-cooled ceramic breeder TBM: 1990 kg

Port 16 He-cooled ceramic breeder TBM: 1905 kg

Port 18 DCLL: 1100 kg (after PbLi drained)

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In Tesini’s view, even coarse cutting in ITER HC is nearly impossible

Disassembly Cell(Receive and Cut open

TBM to remove sub-assemblies and

specimen capsules)

TBM From Hot Cell Building (After cooled down)

Specimen Preparation Cell

(x-ray photography)

Low Level Radwaste Building

Specimen Preparation Cell

(grinding, ion milling)

Airtight tritium glove

box

Airtight tritium glove

boxPackaging

I

II (Fine sectioning

)

III (PIEs)

(Coarse sectioning)

ITER HC Facilities at Cadarache with upgrade to handle tritium

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Disassembly and coarse sectioning cell

• Shielded, tritium proof containing cell

• Being able to operate on ½ port test blanket modules

• A remotely operated screw driver, laser beam cutter, precision saw, vise, and manipulator will be utilized for cutting open TBMs to remove sub-assemblies and specimen packets

• Need “collectors” for receiving pebbles

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Concerns of using relevant facilities at Cadarache

• Of course a peer review should be made in order to check the feasibility of the requested operations in the various facilities, in particular concerning safety (activity and shielding, tritium and other species content, Beryllium, …).

• If Tritium measurements were required a specific feasibility should have to be launched, although LECI had to deal with in the framework of a past programme.

• An other point to check is the remaining life time of the facilities (or parts of them) with regard of the TBM programme schedule.

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There are benefits of performing PIE near ITER site

• PIE such as tritium reconstruction, tritium recovery from ceramic breeder and beryllium pebble beds

• PIE on ceramic breeder pebble bed packing state and integrity

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Performing PIE at the party’s site is also desirable

• It is in the interest of the material community to study the irradiation effect even at the low doses

• Most likely, full PIE hot cell facilities are available in the Party

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– 1 - As correctly observed by Yves, it should be demonstrated that even the TBM's initial, coarse cutting operations can be satisfactorily carried out inside the ITER Hot Cell.

– 2 - Even if this is possible, we should carefully consider the relative influence of the TBM's coarse cutting and ITER Hot Cell operations on the overall TBM experimental programme:

• a) the ITER HC is temporarily available but there is no TBM's to cut • b) TBM's are ready for cutting but the ITER HC is busy with higher

priority operations

– 3 - The above TBM/HC requirements/availability situation will worsen if the TBM's are coming into the ITER HC a) frequently and/or b) in high number. This situation is directly linked with the overall TBM's experimental programme and should be carefully considered by the TBWG

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(1)   Is it possible to handle structural and breeder materials which contain tritium (within the facilities in Cadarache)? If not, what kind of facility modification is needed to do that in the hot cell in Cadarache?

(2)   Is it possible to measure the residual tritium in breeder and multiplier pebbles (within the facilities in Cadarache)? 

(3)   Is it possible to transfer breeder and multiplier materials, which contain tritium, to the country of origin? (related to smaller, more manageable specimens) Is there any authorized appropriate cask available? Can we assume no tritium leak during transportation?

(4)   What kind of test piece can be made in CEA Saclay?  What kind of tests can be performed?

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• “Visual inspection and metrology associated with deformation measurement of the whole TBM, as well as TBM dismantling producing medium size pieces is performed in ITER hot cells.The next step, needing accurate visual inspection (corrosion & cracks identification) and accurate cutting methods, could be performed in a CEA hot lab if not feasible in ITER. This precise sampling of medium size specimens could also be performed in Cadarache (LECA-STAR or CHICADE).Then the samples could be dispatched from there to hot labs LECI-PELECI in Saclay for mechanical tests and metallographic examinations or to the Party if requested, using small size casks.”