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TRANSCRIPT
LA-lJR -91-2976
●
DE92 000213
Los Alamos Mllonal Labomloq . omarwd tw Iho Unwwmw ~ C-llfornm for IM UnM SlaIwSDewmwnl of Enow under comfmcl W-7405 -ENG44
!Mived byOSTI.Ocr041991
TITLE: ADDRESSINGI!IXEDI?ASTEIN PLIJTONILWPROCESSING
AUTHOR(SK D. C. Christensen,C. L. Sohn,and R. A. Reid
SUBMITTED TO: Am-lean ~hemlcal society!Atlanta,GAOct. 1-3, 1991
DISCLAMER
l%iammflwweoremrd mewra-nlofwork moneoraf byanuerrcyofthe Unlted!h!uChwernkent, Nklh he Unltd SIda Wvernn&M nor ●ry qsm-y Itkf, nor wry of heircmployoee,m-ha wry wmrsmy, ●ar w Implid, or euurnee mry Iesd Ihbllhy w reqmrrsl.bllhy for Ihe ecwmcy, uwnfdelc~ of umhdrw of mry Informdkn, ●p@rduh prducl, or~ diwM, w repmwnh Ihd ih uw would noi infrin~ privntaly ownuJ righl-. RAr-anw twain to my s~ifk mrmmemini prtdud, p~, or Mmka by Ire$e name, Ire&mark,mmrufeclumr, ,Wdhwrwlm &me nd rramumlly arnslllule or imply 11serdommonl, recamnmnddkm, IX !cvorlng by he [Jnhal Wet- (Jwvwnmenl or eny •~ncy lherwf. The dewsd apinlum d aukm expfaeai hemln do nd newuearily 91ele of re(lect Ihcmsof thtUnkd SIeleo (brarnrnenl or my apcy Ihnrmfo
Ih@ pubhshof rccngnitos Ihal lhn 11S Oovcrnmanl rmlmnma nonwacluslva fnymlly has hcermo 10 publlsl! or !apruduco
lLOSAhlllilOSLosAlamos,NewMexico87545Los Alamos National Laboratory
WNm DISTHIW.JIION or lot!IS DOCUMEPJ I IS LJNLIMITED ~
Dana C. Christ.nmn●nd
C~rOl L. ~OhNualoar Natmials Taobnology Division
Los Aluos htional LaboratoryLos Alamom, MM 07S4S
505-6c7-ass6
Riohard A. RidAndormon Oahool of Naxmgamont
University of Now MoxiooAlbuqumqw, NM .7131
sos-a77-3oaa
ADDRESSING MIXED WASTE IN PLUTONIUM PROCESSING
Dana C. Chri8t9nmn
Carol L. SohnNuclaar Natarials Tmcbaoiogy Division
Los AlamocINational MboratoryLos Ahmm, W 87545
505-667-2556
Riahard A. RaidAndormon Sahool of Xa.aagamnt
University of Maw MxhoAlbuquorqu, MU 87131
505-a77-3oll
ADDRESSING MIXED WASTE IN PLUTONIUM PROCESSING
INTRODUCTION
For the past forty years, multiple facilities throughout the
Department of Energy (DOE) Complex have produced nuclear weapons,
processed recoverable residues, and genoratad a variety of waste
materials. Today, the Complex is comprised of 13 government-
ownod and contractor-operated installations. It in organized
into three functional elements: Sacilitios for ~roducing nuclaar
materials, laboratories and tasting ●ites, and plants for
producing non-nuclaar components. Although these facilities havo
always baan concamed with wamte products and msterials, the
●volution of tougher regulations and stiffer ponaltios along with
●scalating costs of wasto disposal has producod a graater focus
on tho wasto minimization and mnagament problam.
In tha proc~ssing of nuclaar mata%iala, sewral types of
wasta forw ●xist that includo both radioaetiva ●nd non-
radioactive ●lamants. Waatao can ba aonaidara(lhasaxdous if (1)
thqf ●rt spocifiaally listad by tho Environmental Protoctioa
Agancy (EPA) as hazardous, or (2) thay axhibit ● special
characteristic such as correaivity or texicity. If 8 WaStO i8
hasardous, tho EPA has ●txiatar ssquiramantu regarding it-
charaatorisation troatmant, ‘ltoraso,and burial, tharaby
increasing tha disposal uost to Ltu gmarator. A major aoncmn
today is with “mixad waste” whiah hm Km dafined by tha BPA ●s
● radioaotiva wasta with ● Easardou@ oomponant that is subjaat to
tha XPA’S Ramourco Consamation ●nd R@aovory Aat (RCRA)~ ●btitla
C rogulationso
2
Within the DOB Complex, mixad waste im or has been generated
at the production facilities at Pinellas, Mound, Kansas City, Y-
12, Rocky Flat8, Savannah River, and Pantex) the National
Laboratories at Los AlamoB, Bandia, and Livermore~ and the Nevada
Teat Site. Since DOE did not recognize the EPA’8 participation
in the management of mixed waste until 1907, it io con8idexed to
be a relatively new concern.
MBTHODOLOQICAL APPROACH
Although an overall goal is the minimisation of all waste
generated in actinide processing facilities, current emphasis is
directed tmard reducing and managing mixed waste in plutonium
processing facilities. Moro specifically, the focus is on
prioritizing plutonium processing tachnologias for development
that will address major problams in mix-d waste management.
A five ●top methodological ●pproach to identify, analyze,
solve, and initiats corractiva ●ction for mixad waste problems in
plutonium processing facilitim has bean dovolopod. A brief
description of this ●pproach follows:
1. Idantify tho Major Problams in Mixed Wcsta Management atPlutonium Procacsing Faailitiosl
a.
b.
a.
d.
Dwalop ● promss flow ●haat that dosc!ribasourrantproduat fabrication, #@rap roaovery, and wasteminimisation ●nd mana~amant operations.
Identify ●p-oifio mixad wasta management goals forprooassing faailitios.
Comparo uurrant parfomana, with dasirod parfomancamixmd waata managomont.
Probl@ms are indioatod when thara i- a discrepancybatwaen ●ctual ●nd denirad perfomanae.
in
3
2. Prioritize tha Major Pxoblems~
a. Identify criteria to ba u-ad in ●stablishing problampriorities.
b. Use the paimviso comparisons faature in EXPERT CHOICE(EC)* On the criteria to assign importance weights toeach criterion.
c. Use l?cto compute problam priorities through pairwisecomparison of each problem relativo to each criterion.
3. For tho Problem with tho Highest Priority:
a. Identify betwaen 2 and 5 altornativo solutiontechnologies.
b. Specify relevant critarla for @valuating the●ffectiveness of tha alttrnativa solution technologies.
c. Use EC (pairwis@ comparisons) to ●ssign importanceweight- to criteria.
d. usc EC to rank altornativo problam solutions throughpairwiso co~arison.
4. Rapoat 8tap 3 for Bach of tho Major Froblamm
5. D.volop and ●valuat@ a procass flow shoot that incorporatestho most dosirod ●olutiona to all of the major problezwidontifiod in stop 3 abovo.
● . Creata and vali&ata an analytical modal to imltato thobahavior of th- now procom flow shaot.
b. Usa tho modal to tast tho now proooss configuration foroperational feasibility and potontial mataria~ flowbottlanacks by mnning ● variety of ‘what-if” scmarios.
c. Us@ tho roaulta of tha modgling ●xoreiso to modify theproposad flow #ha@t.
d. Implomont tha resultant flow ●heat whioh promotos anintograt-d sat of plutonium fabrication, scrap/r@siduarQcov@ry, ●nd wmta minimisation/managamant Proeasmas.
Sworal advantages ●ra associated with ~hc usa of thim
methodological framwork. Pirst, an opuational definition of a
Wxad wasto problcm is providad in stap 1. That is, ● problam-.-----..-----------● WPERT CHOICE (EC) is ●n USOr-frhXidlycoftwara paakago forimplamanting tho Analytic Hiararchy Proeoss methodology umd insolving eomplox problams involving multiplo parformanoo critaria.
4
exists when current levels of performance● in wamta managamant are
below stated goals for the processing facility. Both the amount
of tho performance discr~pancy and the typa of mixed waate
involved should be used when determining whether or not to label
a problem as “major-. Second, since there is always a Iimitad
amount of managerial time and energy available for problem
solving, a systematic procedure to datarmine problem priorities
i- desirable. Third, a quantitatively-based mathod for
aggregating the ramkinga
alternative solutions to
probability of selecting
of an analytically-based
flowahaet performance of
of different performance criteria on
the major problems will increase the
the bast ●lternative. Finally, the use
integrated modal to ●ssess tho overall
all the bamt solution alternatives
●llows tha linkages or Mxrfacas batwaen proposed facility
processes to be ●valuated before implamantation ocsurs.
Zhe intarrela~ionships between the these flva SC-pm are
diagrammatically illustrated fin~igura 1. It is important to
nota tho i:arative natur~ of this ●pproach, ●s dopictad in t-he
third and fourth stops, for prioritizing tho ●ffoc~ivenass of
mambars of ● set of altarnativs procosc tochnologiss for a
particular problem. This focus on tha selection and/ox
devolopmant technologies for tha molution of mixed wast~ problem
ia ● koy charactoriatia of this problam-drivan methodology.
The use af the ~lytia Hicrarahy Process [AMP) is also
supportive of this probl~m-oriantad aathodolouiaal foaus.
Basiually, AMP is a mathod for stmcturing a aowlex decision
making problam into its oomponant partaf arranging thssa parts
into ● hlararchic ord~rl ●ssigning quantitative #cores that
5
measure the relative importance of each criteria on the decision
goal~ and synthesizing the analytical assessments into an
aggregated performance measure for each of the competing
alternative solutions. EXPERT CHOICE (EC) is an user-friendly
software package for implementing AHP Methodology. Since moat
problems involved multiple (tangible and intangible) criteria, EC
was used to enforce a coheelvo thought pettarn on the part of the
analysts as they geek to identify the best alternative.
The next section illuotrateg the use of the EC computer
software package to develop weights for the various performance
criteria ●ccording to their perceived importance, systematically
●valuate all altamativo procssaes againat each criterion, end
aggragate the individual criteria scores into a composite
perfo~e measure for ●ach of the candidate process
technologies.
AN ILLUS~TION
Assume that newly defined wasto management goals have been
davaloped for the IJNL plutonium processing facility. Current
performance levals indicata that th~ goal for mixad waste
generation is not being met. This problem is to be addressed by
salecting ● metal shaping procoss that will reduce the generation
of mixed waOte. Bach of tho components of step 3 art illustrated
for this scenario.
~eD 3aU Three altornativo metal shaping solution technologies:
1. Wrought Process
2. hloarNot Shape Casting
3. Net Shapa Casting
6
The wrought process involvas taking flat plates of plutonium
and rolling them into sheets. The sheet- are then hydroformed
into the desired hemispherical shape. Both the rolling and the
hydroforming processes involve the use of machine oils as
lubricant with the subsequent requirement to clean off the oils
with organic solvents such as carbon tetrachloride. Finally, the
hemispherically-formed components are processed to final contour
~loying the traditional machining techniques which uoe flood-
cooling of the cowonent w-ithoil-based coolants. The oil flood
cooling approach requires tha use of largo amounts of oolventa to
remove the oil from the final machined components am well as from
tha glovebox enclosures and processing equipment.
An altornativo technology, tha near not shape casting
process, utilizes the diract casting of plutonium into the
required hemispherical shape followed by the machining. This
proce~sing alternative avoids the need to roll and hydroform.
Although there is a significant reduction of mixed waste on an
unit oporation level, the impact on tha mixed waste generation
and disposal problem is fairly modost.
The third fabrication tochniquo, n~t ●hap. casting, involves
casting tho plutonium vaxy closaly to tha final spmcifiod contour
●o that rolling, hydroforming, and moot of tha machining
oparationa are ●liminatad. Again, th~ gan@ration of mixed waste
is further r~duced, although from an ovarall plant pormpectiva,
tha improvamant is modast. Sinco this technology is ralativoly
now ●nd still wolving, th~ro is moro uncertainty surrounding its
rcportod porformanco than that ●ssociated with tha two fomer
altornativos. Thus, ●ven though it ●pp-ars to produca the
7
smallest amount of mixed waste, it may be inappropriate to
conclude it is Lhe best metal shaping process.
Although each of the threo technologies could be used for
foxming the required plutonium c-nents and each has both
desirable and undesirable attributes, it is not obvious which
should be selected. UP provided an organized framework for
syst-tically evaluating tho preferred al’carnative.
step 3b. Tb.reerelevant criteria:
1. ~t of Mixed Waste Generated
Pour Subcriteria each representing one of the four types ofmixed waste generated:
a) Kg of Low Level Solid Mixed Waste per kg of metal produced
b) Kg of TRW Solid Mixed Waste per kg of metal produced
c) Kg of Low Level Liquid Mixed Waste par kg of metal produced
d) Kg of TRW Liquid Mixed Waste per kg of metal produced
2. Difficulty in Disposing of Mixed Waste that is Qenerated
Five SubCriteria ●ach associated with minimizing the impactof mixed waste diapoaal:
a) Technical Maturity - the more technically mature the metalshaping process, the greater tha confidence in the validity oftha waste ●stimates presented.
b) Complexity - th~ greatgr tho number of diff~rent types ofmixed wasto g~narated by a metal shaping procoss, the morecomplox the required mixed wasta disposal infrastmcturo.
c) Flexibility - the groatar tha flexibility of the metal shapingprocas~, the more likely tho procass will be abla to respond tonow mixed waste r~quiraments.
d) Haalth and Safety - tha primary concarn is to minimiso thepotantial radiation and chemical ●xposure of pnrsonnel involvedin tha mixed wasta disposal process.
●) costs - tho processing costs of mixed wast~ disposal areassumed to be directly relatad to th~ amount of mixed wasteganerated.
8
3. public Perception of Mixed Wasto Generation and DisposalProblem
Three Subcriteria each related to an ●spect of mixed wastedisposal:
a) Transportation - the travel route and its usage frequency fortransporting mixed waste from its generating source to its finaldeethation.
b) Ultimate DiSpOSal Destination - the location and container-ization method of the final burial site for generated mixedwamte.
c) Packaging - the ability of the tr~port contair :0 remainintact in case of an accident during tha mvement . .JiXOd wasteto its disposal destination.
Figure 2 displayo the hierarchical ordering of these
criteria as they relate to the overall goal of identifying the
metal shaping process that will produce tha minimal impact on
mixed wanta generation and disposal. w reducing a problem into
its ●lements and grouDing these ●lemants at different levels, a
hierarchy is formed. Weights reflecting the relative importance
of ●ach criteria (and mbcriteria) can then be assigned by
perfo-ng pai-ise comparison at ●ach level in the critaria
hierarchy. As previously mentioned, this NIP modeling stricture
is especially effectivo when a variety of different types of
crit~ria, some quantitative and some qualitative, must be
aggregated into an overall score to rank ●ach solution
alternative.
ste~ ~co Bstabliching Criteria/Subcriceria Weights:
.Aashown in Figure 2, the r~lativa importmca of the three
major criteria was determined. Public perception of the mixed
wasta problam was thouuht to ha four timas am Important as the
difficulty in disposing of the mixed wasta and over twice as
9
important as the actual amount of waste that is generated. Since
quantitative data were a~ailable on the costs associated with
disposing of an unit of each type of mixed waste, they were used
to determine the weights for the four different t~m of mixed
waste generated. In contrast, pairwise comparisons based on
qert judgments were used to determine the priorities
associated with each of the five subcritoria related to mixed
wasto disposal ~ !~iculty. Finally, the rolativo importance of
●ach of the three dimensions thought to h related to the
public’s perception of the mixed wasta problem was subjectively
●valuatmd by the analysts. The results of these evaluations are
shown in Figure 3.
flt@D3d. Ranking Alternative Solution Technologies Against the
Criteria/Subcriteria:
Numerical estimates are made of the amounts of mixed waste
that are ge.narated by aach of the compoting metal shaping
tocbnologies. Since less rather than more mixed waste is
prafarred, the inverso of these amounts was directly used to
ascartain the preference of ●ach technology ralative to each of
the four subcriteria under ‘Amount of Mixed Wast@ Generated”.
Again, expert judgement, though tho pairwisa comparison
tocbnique, was used to rank tho desirability of ●ach alternative
technology relative the five ‘Difficulty in Disposing of the
Mix-d Waste Generatedn subcriteria. It is interesting to note
that tho performance of the throo tochnologias was assoss~d as
●qual for the thrao ‘Public Parcoption” wbcriteria, that is, it
is ●ssumed tho public is indiffcrmt about which metal shaping
10
technology is used to ganerate mixed
synthesizing procedure indicate that
squally preferred:
Near
8inco the alternative
it 1s Lmportant to examine
Th9 pcmformance of each of
Wrought
Ne~:s~~e
Net Shape
wa8te . me results of the
tbe alternatives are about
Casting = .309
Canting = .331
Casting = .360.
technology scores aro relative clese,
EC’S built-in sensitivity analyses.
the altermativo tacbnologies is
graphically displayed in Figure 4. It is noteworthy that Net
8hape Casting achieves its ovarall profarencc through its higher
ranking in the first critsrion, Amount of Mixed Wasto (kneratod,
●ven though this criteria has only ● 0.25 waight.
S~Y AND CONCLUSIONS
If the T Lxad waste generation and disposal rnituationwas Lhe
only major p. ~lam, it would be appropriate to roco-nd that tho
Casting process be incorporated into a now procass flow
tho plutonium processing facility. Mfora implamanting
ramovo tho current mmtal shaping procass and install
Casting, howovar, it is nacossary to imitate fauility
parformauc ● with a modal. A computar-based dymamic simulation
modal will allow a t~st of tha mow procoss configuration under a
numbar of diffcrant operational configurations and material
flw8 . If tha ●mploymant of tha now -tal shaping prousss had
soma undaairablo ●ffocts on other maasuras of faaility
parfomanco, then tha bahavior of tha soaond ranhd prorass, Near
Nat Shapo Casting, would ba modalod
implamantation could ba data~inod.
11
befor, ● final daoision for
LIST O? FIGURE TITLES... . .
FIGURE 1 - A ~THODOLOQICAL APPROACH FOR ADDRESSING MAJOR
PROBLEMS IN A PLUTONIUM PROCESSING FACILI~
FIGURE 2 - CRITERIA/SUBCRITERIA HIERARCHY WITH ASSIGNED WEIGHTS
FIGURE 3 - SUBCRITERIA ORDERJYDWIN~ BY C-UTBD PRIORITIES
PIQURM 4 - RELATIVE AND O~L PBRPOWANCE OF ALTERNATIVE
TBCHNOLOQIEW
12
\ DESIRED FACILITY / I DETERMINE MAJOR MIXED I \ ACTUAL FACILITY /
LFiRFORMANCE WASTE PROBLEMS BYLEVELS FOR COMPARINO ACTUALWITH
MIXED WASTE DESIRED PERFORMANCE
rSET OF POTENTIAL SPECIFY WEIGHTS FORCRITERIA FOR RELEVANT CRITERIA AND
IDENTIFYIN(3 PRIORITIZE MAJOR PROBLEMSMIXED WASTE I USING Expert Chob PAIRWISE
\ PROBLEMS / I COMPARISON FEATURE
\
/
SET OF POTENTIALCRITERIA FOREVALUATING
\ NEW PROCESS~ECHNOLOGIES/
i
SELECT PROBLEMWITH HIOHEST
PRIORITY
m
SPECl~ WEIGHTS FORRELEVANTCRITERIA ANO
RANK THE PROBLEM SOLVINGPOTENTIAL OF TECHNOL~lESUSING ExportCholco PAIRWISE
COMPARISON FEATURE
~–
+!!!No
CREATE SET OF ALTERNATIVEFLOWSHEETS USING
COMBINATIONS OF HIGHLYRANKED TECHNOL~lES
CREATE AND OPERATE A SETOF ALTERNATIVE (LOWSHEETMODEL8 ● ANALYZE RESULTSFOR TECHNOL~Y INSIGHTS
E=iEiElINCORPORATE EFFECTIVE TECHNOLOGIES
SELECT METAL SHAPING PROCESS TO MINIMIZE Il@ACT OF MIXED WASTE
IGOAL1.000 I
I
t I I
nGEN0.250
II
I
I I I 1TDISP IF0.1s0
q
PUBP0.600
mmmm I “p’”mm00450
mm --- MOUNT 0? MIXED WASTE TO ~E 6=-TED / XO 3? METAL PRODUCEDMPLEXY “-- DISPOSAL COmLEXXTY - f (~ER 0? TYPM MIXED WASTE OENERATED)MT8 --- ASSUME DISPOSAL COSTS ARE DIRECTLY RELATED MIXED WASTE MT OENMPDIFF --- DIFFICULTY IN DISPOSINGOF ICIXEDWASTEXXIBLY --- FLEXIBILITY0? CMTINO PROCESS TO MEET lfEUMIXED WASTE UOUMTIONSXH8A?E --- ABILITY 0? MIXED WA8TS DISPO$AL PROCESS TO MIN. UOm EXPOSUREi-LIQ --- LOW UVEL MIXED LIQUID WASTE (LT] ~~mTED / METAL PRODUCED (XO)+SOLXD --- UW XJVEL SOLID MIXED WMTE (KG) a~_TED / ~AL ●RODUCED (X@)ISCMT --- HEAR NET SHAPE CASTZNGICMT =-- Mm $XAPB CASTINGKRMt --- PAa6E OR CONTAINERUSED TO TRMMPORT MIXED UA8TEJBPERCP --- ~LIC ?ERCZPTION0? NIXED WASTE GENERATION AND DI#’O$AL PROBL~~mn ‘“- DEGME 0? COMFID~CE IN ESTIXATES 0? MIXZD WASTE a~mT~D MOUNTlA#IJSPRT--- TRANSPORTATION COMC~S--ROUTS AND TRUCK USAOS FREQUENCYKbLIQ --- TRU NIXED LIQUID WASTE (LT) OmmTm / ~~ p~oDucrD (x~)IU-SOLI--- TM SOLID MIXED WASTE (KC) OENWTED / METAL ?RODUCED (RO),T-DISP--- ULTIMATE DISPOSAL (BURIAL) SITE WCATIONtOUGJIT--- UROUGNT CASTINO
LernAlamo- National Laboratory
SELECT METAL SHAPING PROCESS TO MINIMIZE IHPACT OF MIXED WASTE
Sortod Synthasis of Imml 2 Nodas with raspoct to GOAL
OVERALL INCONSISTENCY INDEX = 0.00
ANSPRT 0.270
CKAGE 0.270
U-SOLI 0.140
U-LIQ 0.065 ~
T-DISP 0.060 ~
STS 0.052 ~
-LIQ O.oas ~
-SOLID 0.017 ~
EXIBLY 0.012 -
KPLEXY 0.008 _
-TY 0.007 =
1 ● 000
HPLEXY --- DISPOSAL CO~LEXITY = f (NUKBER OF TYPES MIXED WASTE GENERATED)6TS --- ASSUMEDISPOS(RLCOSTS ARE DIRE~LY RELATED MIXED WASTE MT GENEXIBLY ‘-- FLEXZBILTYOF CASTING PROCESS TO MEET NEW NIXED WASTE REGULATIONSrNsArE -“- ABILITY OF MIXED WASTE DISPOSAL PROCESS TO MIN. WORKER EXPOSURE-LIQ --- LOW LEVEL MIXED LIQUID WASTE (LT) GENERATED / METAL PRODUCED (KG)-SOLID --- MW LEVEL SOLID MIXED WASTE (KG) GENERATED / METAL PRODUCED (KG)CKAGE --- PACKME OR CONTAINER USED TO TRANSPORTMIXED WASTECWSATY --- DEGREE OF CONFIDENCE IN ESTIMATESOF MIXED WASTE GENERATED AMOUNTMSPRT --- TRANSPORTATIONCONCERNS--ROUTE AND TRUCK USAGE PREQUENCYU-LIQ --- TRU KIXED LIQUID WASTE (LT) GENERATED / METAL PRODUCED (KG)U-SOLI --- TRU SOLID MIXED WASTE (KG) GENERATED / METAL PRODUCED (M)r-DZ8P --- ULTIMATE WASTE DISPOSAL SITE MCATION & CONTAINERIZATIONMETHOD
Rltx50
40
30
20
10
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