»' ProcasdingPr 田・醐ngs s oof f th甘暗e FourtFou 同hh IntarrationaInterr 刷。....Syn l Symposiu唱曲面出前m o。" n ADVANCEADVANCED D NUCLEA制UCLEAR ENERGY R ENERGY RESEARCRESEARCH H ROLESROLE! ヲ ANDA 九・ 'D DIRECTIOND1 RECTIO .v OFOF l l1 MATERIALA TERIAL SCIE1"CE SCIENCE I.¥" INI.¥" NUCLEARSUC ιEAR TECHNOLOGYTECHNOLOGY REACTIOREACTION N OOF F CERIUCERIUM M DIOXIDDIOXIDE E WITWITH H ALKALALKALI I METAMETAL L ALKOXIDESALKOXIDES. NOBUAKNOBU AKl I SATSATO O ANAND D TAKEOTAKEOFUJIN FUJ 刷 O Rcscarch ResearcRcscarch h InstitutIn stitutc e oof f MineraMinetal l DressinDrcssing g anand d Metallurgy,， ToftokTohoku u UniversityUniversily ,， KatahiraKa凶 nra ,， SendaScndai i 9809剖 ,'， JAPAJAPAN N Phone PhonPhone e 022-227-6200,， FAFAX X 022-261-0938022-261-093 8 ABSTRACAHSTRACT T tiotion n oof f Ce0Ce02 2 anand d metarnetal l calciucalcium m formforms s CaoO anand d CeCeO O at at 1273 1271273 3 Kll). K"). ThThc e gas-soligas-solid d reactiorcaction n procespmccss s usinusing g volatilvolatik e alkali alkali hIn 也thiis s paper,， wwe e studstudy y 也巴the reactioreaction n betweebetween n Ce0Ce o22 Jud md rnctal metarnctal l alkoxidealkoxidcs s hahas s manrnany y advantageadvantagcs s iin n producinprodu c.i ng g ththc e MOBuMOBu' 1 (M=Li(M= Li， , KK) ) fofor r ththe e formatioformation n oof f ，comple 'umplex x oxide oxide uranatcs(plutonatcs) uranatcs(plutonatcsuranatcs(plutonatcs) ) whicwhich h ararc e expectecxpectcd d tto o improvirnprovc e thc the undeunder r severasever 司l ∞conditionsnditions ,，∞ comparinmp 宿泊g witwith h 白thosose e obobtaine凶 ned d dissolution dissolutiodissolution n behaviobehavior r oof f ththc e fuefucl into l into nitrinitric c acidacid. IIn n this this bby y aan n aqueouaqueous s memethod出od. work. workwork. , ththc e reactionrcactioss s oof f Ce0CcO? 2, whicwhich h wawas s useused d aas s a non-non­ radioactivc radioactivc stand-in of puO with MOBu' 1 (M= K) radioactive stand-in of Pubz2,， wit h MOBu (M=Li Li， , K) undcr undcr unde r scveral severa l conditions conditions wcrewere examined. examined. In In the the case case ofof 白thCe 2.EXPERI2.EXPERIMENTAL品位NTALS S !"IM>~cvCeトデ1.>.0O 22_.，x synthc~~z~~synthesized byb y anan aqaqueoul! eo .u .s s .metho~method,， t~~the latiicc latiicc lattic e pararnctcr parameter waswa s slightly slightly increased increased with wit h increasing increasing M 2.1 2.1 SampleSampl e preparation preparation conccntration concentration,， y ，, upu p to to 0.20. 0.20. WhenWhe n the the Li LiOBuOBu' ' vaporvapor Li Lithiu thium m andand pot potassiu蹴 ium m t-butoxide t-butoxide werewer e synthesized synthesized byb y rcactcd rcactcd reacted with with CcOηaCcO „ a newne w fluoritc fluoritc phase phase having having a=5a=5.493.4 935 5 the the reaction reaction ofof each each metal metal withwith t-BuOH.t-BuOH. 百Thle e t-BuOHt-BuO H えX. γ=0.044.v=0.044. x=O.30x=0.30 waswa s forrncd formed over over 97397 3 K.K. A similar similar waswa s dehydrated dehydrated using using dried dried molecular molecular sieves sieves before before use use cocompounIn pound d (a=5 (a=5.479.4- 797 7 A， %,y=0.035 y=0.035， x=0.22) , x=0.22 )was wa sobscrved observedby by because because of of the the hygros hygroscopi∞picpropc c propertie凶 cs s ofof 也the metmeta aI l alkox- alkox­ thc thc th e rcaction reaction of of CeO ヲ, with with KOBu'.KOBu'. ides. ides. Special Special commercialcommercial grade grade ofof Ce02Ce0 2 and and t-BuOHt-BuO H KcywordsKeyword s : solid solid solution,， alkoxide ，, ccriurn ceriu m oxide ，, from from WakoWak o PuPur re e Chemicals Chemicals Co. Co. Lt Ltd d. werewere used. used. 醐 gas-solid gas-solid gas-solid rcaction reaction,， MOXMO X fu fuel e/， , volat volatili! e process. process. 百Thle e CeCe0o22 solid soli d solution solution ωcontaininining g the the knownknow n amounl amount of of o f lithium lithium or or popotassiu泊ssium m waswa s obtained obtained byb y drying drying homoge-homoge­ 1. 1. 1. lNTRODUCTlONINTRODUCTIO N nized nized solution solution ofof Ce(NH4h(4)2(N0N0 33)6 )6 andan d 'Li LiOHHOH'H 220- 0 or or K 22Cz C2004 4 合'Ofromm WakoWak o Pure Chemicals Chemicals Co. Co. Lt Ltd.d. ，, followed followe d by by MixcdMixe d oxide oxid e forrnation formation with wit hrnetal alkali alkali metal 加from pluto- pluto- calcination calcination in in air air at at 11731173 K for for 10 10 hours. hours. niurn-uraniurn niurn-uraniurn nium-uranium dioxide dioxide fuel fuel is is expect expecter. d to t o result result in in great great cnhanccrncnt cnhanccrncnt enhancement of of thc th e dissolution dissolutio n rau:: rate of of spent spent into fuel fuel into 2.2 2.2 Reaction Reaction prωedureprocedur e v nitr;~nitr "~id."dd. For For producing producing such such uranatcs(plutonates) uranates(plutonates)，, the th e Ce02Ce0 2 and and MOBu'MOBu ' werewere placed placed 恒in a quartz quartz double doubl e cell cell ga ga ga I' rcactlon reaction proccss process using usin g volatile volatile compoundscompound s of of separately separately after after weighing weighing in in 相an argon argon utmospheric atmospheric glove glove I. aLI. Ictals ictals ，, is is advantageous advantageous comparing comparing with with 出the solid- solid- box. box. TheTh e doubledouble celi cell waswa s set set in in a twotw o stage stage heater heater as as solid solid soli d rcaction reaction in i n reaction reactio n efficiency efficiency andan d hornogencity homogeneity of of shownshow n in in FigureFigure 1 after after ssealin巴aling g underunde r vacuum.vacuum . TheTh e t thc thc the formcd formed mixcdmixe d uranium uranium oxides. oxides. OneOn e of of such suc h volatile volatile MOBu ' Wwa錨s heated heated for fo r vaporizing to to react react with with CeCe0oz2 ぽat compoundscompound s is is metal metal alkoxides(M(OR) alkoxides(M(OR) ，). x). Mhig俳句h temperaturmp ぽ aωre e part. part. AAfte批 r 血there reaction，伺 ction. , 出直the identification identification Gcnerally Gcnerally Generally spcaking speaking ，, alkoxides alkoxide s have hav e increasing increasing volatili- volatili­ o.f f the the product product by by X-rayX-ra y djffracti diffractio∞n andand chemical chemica l analysis analysis ty ty ty with with incrcasing increasing side side chain chain of of alcohol alcohol，, while whil e they they are are wereconducted. were conducted. increasingly increasingly increasingly hygroscopic hygroscopic andan d thermally thermally unstable1l. unstable'). Buthoxides(MOBuButhoxides(MOBu') arc are knownknow n to to have have the th e highest highest vola- vola­ ' 2 tility tility tility amongamon g alkali alkali metal metal alkoxides(MOR alkoxides(MOR) )2 l. ). TtT.C. 監2記長。切断 ate 封切や ヲ CcOCe02 is is uscd used as as a a non-radioactive non-radioactive stand-in stand-in of of PuO?Pu0 2. Sincc Sincc U0 and alkali metals forrn many types of Since U022 and alkali metals form many types of com~com­ 33 3 pounds such as Li U0 >, M U,_ 0+x 3l ', similar reaction pou~ds such as ，u Z2U<?4 4 )，.M yyU)_P2 y 2+x ，_si~ilar ~e~~~~n (JL 二三塁L 〉又 can can can bc be cxpcc!cd expected to to take take plaec place between between CC02Ce0 2 and and LiOR. LiOR. OnO n thc the othcr other hand hand， , the th e nonstoichiornetry nonstoichiometry of of Ce02Ce0 2 has has long long bccn bccn been studied studied in in connection connection with with thermodynamksthermodynamirs44--66)，, Quartz tube 7 8 9 mW$ß.] ~mω臨凶@ structurcstructure7•S' )' and an d elcctrical electrical cconduction唖nduction 9). ). TheTh e subphase subphase 10 digaram digaram waswa s gh'cn given by by BevanB e van et eal t allO )). showing showing manyman y Fi Figur伊 re e 1 1 Experimental Experimental app apparatus祖国.. ox oxyge'y gcn n difficient diffident oxides oxides，, CeOz_ Ce0 2.x5 (O.Ol<x<O (0.01<x<0.1).1).百 . Thle e reac- reac­ 163-163 In In thc casc of Li .Cc O _. ， thc !atticc paramcter was 2.3 2.2.3 3 X-raX-ra¥' y MeasuremenMcasurcmcnt t In the case of LiyCe^.O,-,1 市 2 , the lattice parameter was X-raX -ray y diffractiodiffr3ction n experimentcxpcrirncn~s、 werwcrce carriecarricd d ouout t witwith h a slightlsli giJ tly y increaseincre ぉcd d witwitli h increasinincreasing g lithiulithium m concentration∞nc 四国tion ,， yy Rigak Rigaku u RAD-1RAD-I BB diffractomclediffractornctcr r syste system m usinusing g CuKαCuK a uuω0.19p to 0.19 a凶s showshown n iin n FigurFigu 問e 22. Th ec relatiorclation n betweebetwccn n ththe e radiation. radiationradiation. Th ec slislit t systesystcm m useuscd d wawas s 1.0-0.3mm-1.0l. O-O .3 mm- l. O. Thec valuev1ilues s oofx f x an組 ddy y alsalso o iis s showshown n aas s a straighstraight t linlinc e acrossinaα -o ss 泊g diffraction diffractiodiffraction n anglanglc e wawas s correctecorrccted d usinusing g a silicosilicon n standarstandard d zerzero o poinpO int t aas s seesccn n iin n FigurFi l?ll rc e 22. samplc. samplesamplc. ThThc e latticlatticc e parameterparamctcr ,、 a,， wawas s determinedctcrmined d bby y ththc e ThTIi ec latticlatticc e parametepru 百metcr r anand d x-valuX-¥' ・alue e o of f KyCe^O^K."Ce I_.0 2_,克明町 were NcJson-Rile Nclson-Rilcy v extrapolatiocxtrapohition n methorncthod d fofor r ththc e highigh h anglanglc e increaseincrcased d linearl:lim1r ly y witwith h increasinincreasing g potassiupotassium m 凶concentranccn 回目­ 0 0 pcaks peakpcaks s (60 (60°<28<135°)<26 <135 ).