The TRIO-01 experiment was designed to test in-situ tritium recovery and heat transfer performance of a candidate solid breeder, ..gamma..-LiAlO/sub 2/. The results showed that nearly all the tritium generated was recovered. Only < 0.1 wppM tritium remained in the solid after irradiation testing. The heat transfer performance showed that temperature profiles can be effectively controlled

Bate, L. C.

Billone, M. C.

Clemmer, E. D.

Clemmer, R. G.

Dudley, I. T.

Dyer, F. F.

Finn, P. A.

Fisher, P. W.

Greenwood, L. R.

Misra, B.

The TRIO-01 experiment is a test of in-situ tritium recovery from ..gamma..-LiAlO/sub 2/ with test conditions chosen to simulate those anticipated in fusion power reactors. A status report is presented which describes qualitatively the results observed during the irradiation phase of the experiment. Both the rate of tritium release and the chemical forms of tritium were measured using a helium sweep gas which flowed past the breeder material to a gas analysis system

Arons, R. M.

Poeppel, R. B.

UNT Digital Library

COMF-830 942—24DE84 000610THE TRI0-01 EXPERIMENT: IN-SITU TRITIUM-RECOVERY RESULTS*DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United StatesGovernment. Neither the United States Government nor any agency thereof, nor any of theiremployees, makes any warranty, express or implied, or assumes any legal '-ability or responsi-bility for the accuracy, completeness, or usefulness of any information, ar.•: ratus, product, orprocess disclosed, or represents that its use would not infringe privately owned rights. Refer-ence herein to any specific commercial product, process, or service by trade name, trademark,manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom-mendation, or favoring by the United States Government or any agency thereof. The viewsand opinions of authors expressed herein do not necessarily state or reflect those of theUnited States Government or any agency thereof.byR. 6. Clemmer, p. A. Finn, M. C. Billonet, B. MisraR. M. Aronst, and R. B. PoeppelArgonne National LaboratoryF. F. Dyer, I. T. Dudley, L. C. Bate, E. D. Ciemmer,J. S. Watson, and P. W. FisherOak Ridge National LaboratoryAugust 1983to be presented at the Third Topical Meeting on Fusfon ReactorMaterials, September 19-22, 1S33, Albuquerque, Mew Mexico.Work supported by the Office of Fusion Energy, U.S. Department of Energy.Northwestern University, Evanston, IL.TCelanese Research Corporation, 86 Mars Avenue, Summit, NJ 07901.OfSTRIMinM OF THIS OOCUMHT ISTHE TRIO-01 EXPERIMENT: IN-SITU TRITIUM RECOVERY RESULTS*R. G. CLEMMER, P. A. FIK?J, M. C. BILLOHEt, B. HISRA, R. M. ARONS?, and R. B. POEPPELArgonne National Laboratory, Argonne, Illinois 60439F. F. DYER, I. T. DUDLEY, L. C. BATE, E. D. CLEMMER, J. S. WATSOM, and P. M. FISHEROak Ridge National Laboratory, Oak Ridge, Tennessee 37630ABSTRACTThe TRIO-01 experiment 1s a test of 1n-s1tu tritium recovery from Y-L1A102 with testconditions chosen to simulate those anticipated In fusion power reactors. A status report1s presented which describes qualitatively the results observed during the irradiationphase of the experiment. Both the rate of tritium release and the chemical forms of tritiumwere measured using a helium sweep gas which flowed past the breeder material to a gasanalysis system.1 . INTRODUCTIONThe TRIO-01 experiment 1s a comprehensivetest of In-situ tritium recovery from aminiaturized solid breeder blanket assembly.The design and objectives of the experimentare described in a previous report.'Presented herein are key results and observ-ations during the irradiation as well as astatus report of work 1n progress.2. FABRICATION AND CHARACTERIZATION OFY-LiA102 BREEDER MATERIAL SPECIMENSLIAIO2 powder was prepared by mixingstoichiometric quantities of AI2O3 andIsotopically depleted (M).5% 6L1) LI2CO3In a water slurry. The slurry was spraydried, and then calcined 1n air at 800°Cfor eight hours. The tnicrosti ucture ofthe pellets Is shown in Reference 1.Small grains 0.1 \m, were combined Intoroughly spherical agglomerates "̂ 50 um 1ndiameter. The agglomerates were sinteredtogether, providing a matrix with largepores to facilitate gas phase transportof the tritium released. This type ofnrtcrostructure with a Mmodal pore distri-bution is considered advantageous fortritium release as shown in STARFIRE.2The characteristics of the fabricatedpellets are summarized in Table 1. X-raydiffraction showed that the material wasphase pure Y-LiA102« The fiLi isotopiccontent was determined to be 0.S5 ± .01%.Chemical analyses using emission spectros-ccpy and neutron activation showed thatthe LIAIO2 had cation Impurity levels<100 ppm. The chloride level Initiallywas high, about 2000 ppm. Heat treatmentfor 20 hours at 630°C reduced the chloride*Mork supported by the Office of Fusion Energy, U.S. Department of Energy.*Now at Northwestern University, Evanston, IL.?Now at Celanese Research Corporation, 86 Mars Avenue, Summit, NJ 07901.TABLE 1•H-1A102 breeder pellets - characteristicsMicrostructure: Bimodal pore distribution having grains 0.1 ym diameter and agglomerates^50 urn diameter. Smear density ^65* of theoretical.Material: Phase-pure Y-L1A102.Contaminants: Cations <100 wppmHal ides < 50 wppmĤ O <0.4 wt tCO2 i ° « 4 >rt *Pellet Size: Hollow cylinders, 25.4 ran O.D. x 15.9 mm I.D. x M2.7 rai high. Sevenpellets - total weight 12.9 g.IsotopicContent: Depleted, 0.55 ± .013 6L1.level to 500 ppm. A final baking of thepellet for 17 hours at 1050T. reduced thechloride content to 15 ± 5 wppm.3. EXPERIMENTAL CONDITIONSThe Irradiation phase of the experi-ment was conducted in the A2 core positionof the Oak Ridge Research Reactor (ORR).The assembly, or capsule, containedpellets of TL1A102 in the form ofhollow cylinders. The Y-L1A102 pelletswere so arranged* that the sweep gasnominally He/O.U H2) flowed past theInside surface of the pellets and then outto the gas analysis system3 where anumber of analytical measurements wereperformed. The temperature was controlledby means of varying the He/Ar ratio of theflowing gap gas 1n the Inner and outercapsules. Approximately 50 parameters(Table 2) were continuously monitored«nd recorded during Irradiation. Thisinformation is presently being analyzed.The test matrix (Table 3) consistedof 33 runs at different temperatures andsweep gas flow conditions (composition,flow rate) . The nominal gas compositionwas He/0.12. H2 flowing at 100 cc/min.Gther compositions were 100% helium andHe/0.2S 02* The effect of sweep gasflow rates was examined at 300 cc/minand 30 cc/min. The total Irradiationfluence was approximately 3 x 102* nvtand the lithium burnup was M).2S.4. EXPERIMENTAL RESULTSSignificant results and observationsto date are reported. These resultswil l be completed after post-irradiationexamination 1s done and a final analysts1s performed.4.1 Tritium releasePreliminary experimental results fromthe f i rs t nine runs (Table ?J are shown inFigure 1. The dark line represents theresponse of the tritium monitor whichTRITIUM LEVELS IN SWEEP GAS, Ci/m3600°C 650°C0.1%H 2 R H 2 I H 2STEADY-STATE(REF.)SCINTILLATION TRAPS (2nd SET-HT)iL i L l i i id io _tu>8 10 12DAYS IN ORRFIGURE 1Preliminary tritium release results from the irradiation of Y-L1A102 in the TRIO-01 •xptrinwnt.TABLE 2Parameters monitored In tfia TRIO-O1 experimentTemperature • The outer and inner diameter of the breeder pellets In two orientationsdesignated east and west - ten thermocouples.• Seven reaction beds (oxidation, reduction, and getter In the gxs analysissystem) - seven thermocouples.Neutron Flux • Self-powered neutron detectors on the outside of the assembly for acontinuous measure of thermal flux Incident on the capsule.• Dosimeters located inside and outside the capsule to provide fluence dataon the Y-LiAlOp pellets.• Reactor power - continuous monitor.Tritium • On-line monitors to record tritium in HT form.• Traps to collect HTO and HT forms.• Gas samples for mass spectroscopy.• Collection of tritium permeating Into gap gas.• Tritium levels in secondary containment - monitored continuously.0 Tritium level in laboratory air - monitored continuously.Other Nuclide • Other radionuclides, measured by Ge(Li) detector.Gas Flow • Pressure and flow rate of sweep gas and gap gas monitored.senses the molecular {HT+T2) tritium level.Corrections for meter calibration, pressure,and flow are 1n progress to provide quantit-ative values. The dotted line represents anestimate of the tritium generation rate.Final values will be those obtained fromdosimetry. The small barred circles representIntegral tritium which was measured In scin-tillation traps. The results 1n Figure 1 arerepresentative of those obtained In all33 runs. Individual results are discussedbelow.• Recoil effects: When the breederassembly was exposed to neutron at low power(3-30 kW and up to 12 MW), a measurableresponse was noted In the tritium monitors.Breeder temperatures were 30-200*C respec-tively. It was estimated, therefore, that<v5t of the tritium generated during theselow temperate tests was released by recoil.• Temperature effects: The tritiumrelease rate at a nominal 600°C with a sweepgas composition of He/0.It Hz appeared toreach steady state within a few hours. AnIncrease 1n the nominal breeder temperatureresulted in a small positive spike whichrepresented the difference between the tritiumretained at a nominal 600°C versus thatretained at a nominal 700°C. A decrease 1ntemperature to 550°C resulted first 1n 4negative spike which represented tritiumaccumulation at the lower temperature.Equilibration was slow, requiring nore thanthree days to build a steady state tritiumprofile. A further decrease in temperature to500"C resulted again in « negative spike.Temperature cycling resulted in repro-ducible behavior.• Sweep gas composition: Removal of thehydrogen additive from the sweep gas has •TABLE 3Test matrix for TRIO-01RunNo.123456789101112131415161718192021222324252627282930313233Time(Days)221521326114521131142131237734223Nominal8TemperaturePC)600"700"700"550"500"550"600"650"650"400"500"550"600"700"700"700"700"700"650"650"650"600"550"600"500"550"525"500"480"480"500"550°650"Changes 1nNomi nalSweep GasComposition--He/1.OS H2---100% He100% He100% He100% He100% He100% He300 cc/min30 cc/min-He/0.2% 0 2-------300 cc/min----"Average temperature on west side. Coldesttemperature Is MOO* lower, hottest temper-ature is approximately 50* higher.negative effect upon tritium release (Run 9vs. Run 8). In a later test (Run 20),addition of oxygen to pure helium did notappear to enhance release rates.• Fluence effects: Tritium release ratesdid not appear to have significantly changedfrom the beginning to the end of Irradiation.4.2 Amount and form of tritium collectedThe total amount of tritium collected was^35 C1. Of this total, -v5% representedtritium permeation into the gas annular gap.The majority of the tritium collected waspresent as HT and T£ (99%).4.3 Temperature controlThe temperature of the breeder was moni-tored by thermocouples at ten separate loc-ations as a function of radius (Inside vs.outside); axial position (along the length);and geographic direction (east vs. west).The radial temperature gradients were anaverage of 100", ard longitudinal gradientswere <10°. There was a side-to-side temper-ature difference, the east side being 50"colder than the west side. Thus, for a givennominal temperature, some breeder material wast60°C hotter and some was -OOO'C cooler.The east side was postulated to be colderowing to asymmetry in gap dimensions. RecentPIE results showed that the Inner capsule wasleaning directly to the east side, therebysupporting the postulate.4.4 Thermal conductivity effectsDuring Irradiation, about 0.2% of thelithium in the sample was consumed. Thislowered the heating 1n the capsule from about560 H to 510 W, or about 10%. The radialtemperature gradient systematically decreasedduring irradiation, being 10% lower at the endof irradiation. Since the thermal conductivityIs proportional to the ratio of the heattransport rate divided by the radial temper-ature gradient, 1t appears that the thermalconductivity did not change significantlyduring the experiment.4.5 Radionuclides detectedThe trace levels of contaminants such asNa, K, and U led to production of volatileradionuclides which were detected by Y-rayspectroscopy during the experiment. Theprimary species aetecteo were F, He, 11,Ar, Kr, Rb, Xe, and Cs. It was noted that theactivities were very strongly dependent uponthe breeder material temperature, releaserates were faster at higher temperatures.This topic will be addressed later.4.6 Design of gas analysis safety systemThe gas analysis system, with two levelsof containment to protect workers, worked verywell. The tritium levels in the sweep gaswere of the order of 5 Ci/m3 (six orders ofmagnitude above maximum levels of HTO in air).The levels in the glove box were ^100-1000vCi/m3. Levels in the room were <1 vCi/s?.during the course of the experiment.5. WORK IN PROGRESSQuantitative analysis of the data requiresthe resu l t s from post- irradiat ion examination(PIE) as well as normalization of a l l data.PIE wi l l cons i s t of 1) residual trit iumcontent of the breeder material , 2) 6L1burnup, 3) dosimetry, and 4) characteri-zation of the Irradiated breeder specimens.6. CONCLUSIONSAlthough analysis of the data has notbeen completed, a number of conclusionscan be made. 1) Tritium release andtritium recovery has been demonstrated for* Miniaturized solid breeder blanketassembly. 2) Thermal-hydraulic and heattransfer performance by controlled vari-ation of temperature using a gas gap hasbeen demonstrated. 3) The recovery oftritium from the helium sweep gas streamhas been demonstrated. 4) Radioactivespecies are present in the sweep gas.5) For L1A102. 51 of the tritium recoveredhad permeated through the primary claddingto the gap gas. 6) Addition of hydrogento the purge gas appears to enhancetritium release. 7) Addition of oxygen tothe purge stream does not enhance tritiumrelease. 8} The containment systemsperformed well 1n protecting workers fromhigh levels of tritium.ACKNOWLEGEMENTSThe authors wish to express their appre-ciation for the support and encouragementof S. D. Berk and other members of the staffof the U.S. DOE Office of Fusion Energy.Many people have contributed to the techni-cal success of this project. We wish tothank V. A. Haroni, C. C. Baker, N. J.Steindler, J. L. Scott, and J. R. Conlin.We wish to thank R. T. R1e1 and L. J.Jensen for preparation of this manuscript.REFERENCES1. R. G. Clemmer, et a l . . The TRIO-01experiment, 5th ANS Topical Meeting onthe Technology of Fusion Energy,Knoxville, Tennessee, April 26-29,1983, and references therein.2. C. C. Baker, e t a l . , STARFIRE - Acommercial tckamak fusion power plantstudy, Argonne National Laboratory,ANL-FPP-80-1 (1980).3 . P. A. Finn, e t a l . , The design, fabri-cation and testing of the gas analysissystem for the tritium recoveryexperiment, TRIO-01 (to be published).

TRIO-01 experiment: in-situ tritium-recovery results

f.1 " -93CONF-830942—93DB85 014312STHE TRI0-01 EXPERIMENT: IN-SITU TRITIUM RECOVERY RESULTS*• • g a lbyR. G. Clemer, P. A. Finn, M. C. Bilionet, B. Misra,R. M. .Aronsf, and R. B. PoeppeiArgonne National LaboratoryF. F. Dyer, I. T. Dudley, L. C. Bate, E. D. Clemmer,J. L. Scott, J. S. Watson, and P. V. FisherOak Ridge National LaboratoryOctober 1983Presented at the Third Topical Meeting on Fusion Reactor Materials.- Septerter 19-22, 1983, Albuquerque, New Mexico.*Work supported by the Office of Fusion Energy, U.S. Department of Energy.'Northwestern University, Evanston, IL.kelanese Research Corporation, 86 Mars Avenue, Sumrft, KJ 07901.THE TRIO-01 EXPERIMENT: IN-SITU TRITIUM RECOVERY RESULTS*R. G. CLEHHER, P. A. FINN, M. C. BILLONE*, B. HISRA, R. H. ARONS?, and R. B. POEPPELArgonne National Laboratory, Argonne, I l l i n o i s 60439F. F. DYER, I . T . DUDLEY, L. C. BATE, E. D. CLEHHER, 0 . I . S c o t t , 0 . S. WATSON, andP. V. FISHEROak Ridge National Laboratory, Oak Ridge, Tennessee 37830ABSTRACTThe TRIO-01 experiment Is a test of 1n-s1tu trit ium recovery from Y-L1A1Q2 with testconditions chosen to simulate those anticipated in fusion power reactors.. A status reportI s presented which describes qualitatively the results observed during the irradiationphase of the experiment. Both the rate of tr i t ium release and the chemical forms of tr i t iumwere measured using a helium sweep gas which flowed past the breeder material to a gasanalysis system.1 . INTRODUCTIONThe TRIO-01 experiment is a comprehensivetest of in-situ tr i t ium recovery from aminiaturized solid breeder blanket assentoly.The design and objectives of the experimentare described in a previous report.1Presented herein are key results and observ-ations during the Irradiation as well as aStatus report of work 1n progress.2. FABRICATION AND CHARACTERIZATION OFY-L1A102 BREEDER MATERIAL SPECIMENSLIAIO2 powder was prepared by nixingstoichiometric quantities of M2O3 and1sotop1cally depleted (M).5l 6L1) LI2CO3In h water slurry. The slurry was spraydried, and then calcined In sir at 800*Cfor eight hours. The microstructure ofthe pellets is shown in Reference 1 .Small grains'0.1 tin, .were conttined intoroughly spherical agglomerates-*^urn 1ndiameter. The agglomerates were sinteredtogether, providing a matrix with largepores to faci l i tate gas phase-transportof the trit ium released. This type ofRile restructure with a M modal pore d i s t r i -bution 1s considered advantageous fortr i t ium release as shown in STARFIRE.2The characteristics of the fabricatedpellets are summarized in Table 1 . X-raydiffraction showed that the material wasphase pure Y-L1A102* The ^L1 tsotopiccontent was determined to be 0.55 s .01X.Chemical analyses using emission spectros-copy and neutron activation showed thatthe LIAIO2 had cation Inpurity levels<100 ppm. The chloride level I n i t i a l l ywas high, about 2000 ppm. Heat treatmentfor 20 hours at 830'C reduced the chloride*Work supported by the Office of Fusion Energy, U.S. Department of Energy.*Now at Northwestern University, Evanston, IL .fNow at Celanese Research Corporation, 86 Mars Avenue, Summit, NJ 07901.TABLE 1r-LIAlOg breeder pellets - characteristicsMicrostructure: Bimodal pore distribution having grains O.I jim diameter and agglomeratesMaterial:Contaminants:Pellet Size:IsotopicContent:*50 nm diameter. Ssiear density *>«5X of theoretic*!.Phase-pure Y-L1A102.Cations <100 wppmHaiides < SO wppmH20 <0.4 wt XCO2 £0.4 wt XHollow cylinders, 25.4 mm O.D. x 15.9 mm I.D. x M2.7 mm high.pellets - total weight 42.9 9.Depleted, 0.55 1 .011 6Li.Sevenl eve l to 500 ppm. A final baking of thep e l l e t for 17 hours a t 1050°C reduced thechloride content to 15 * 5 wppn.3 . EXPERIMENTAL CONDITIONSThe Irradiation phase of the experi-ment was conducted in the A2 core pos i t ionof the Oak Ridge Research Reactor (ORR).The assembly, or capsule, containedp e l l e t s of T-L1A102 l n *** f o m o fhollow cyl inders . The Y-L1A10J p e l l e t swere so arranged1 that the sweep gasnominally He/O.IX H2) flowed past theInside surface of. the p e l l e t s and then outt o the gas analysis system3 where anumber of analytical measurements wereperformed. The temperature was controlledby neans of varying the He/Ar rat io of theflowing gip gas in the inner and outercapsules. Approximately 50 parameters(Table 2) were continuously monitoredand recorded during irradiat ion. ThisInformation i s presently being analyzed.The t e s t matrix (Table 3) consistedof 33 runs a t dif ferent temperatures endsweep gas flow conditions {composition,flow r a t e ) . The nominal g$s compositionwas He/0.IX H2 flowing a t 100 cc/min.Other compositions were 1001 helium andHe/0.21 0£- The e f f ec t of sweep gasflow fa te s Was examined a t 300 cc/minand 30 cc/min. The total Irradiationfluence was approximately 3 x 10 2 ' nvtand the lithium burnup was M5.21.4 . EXPERIMENTAL RESULTSSignif icant resu l t s and observationst o data are reported. These r e s u l t swi l l be completed after post-trradiat1onexamination i s done and a final analystsI s performed.4 .1 Tritium releasePreliminary experimental re su l t s fromthe f i r s t nine runs (Table 3) are shown 1nFigure 1. The dark l i n e represents theresponse of the tritium monitor whichTRITIUM LEVELS IN SWEEP GASi Ci/nr8 10 12DAYS IN ORRFIGURE 1Preliminary tritium release results fron the Irradiation of Y-L1A10, 1n the TRIO-01TABLE 2Parameters monitored In the TRIO-O1 experimentTemperature • The outer and Inner diameter of the breeder pellets In two orientationsdesignated east and west - ten thermocouples.• Seven reaction beds {oxidation, reduction, and getter In the gas analysissystem) - seven thermocouples.Neutron Flux • Self-powered neutron detectors on the outside of the assembly for •continuous measure of thernal flux Incident on the capsule,t Dosimeters located inside and outside the capsule to provide fluence dataon the Y-LIAIO2 pellets.• Reactor power - continuous monitor.Tritium • On-line monitors to record tritium 1n HT form.• Traps to collect HTO and HT forms,t Gas samples for nass spectroscopy.• Collection of trit ium permeating into gap gas.• Tritium levels in secondary containment - monitored continuously.• Tritium level in laboratory air - monitored continuously.Other Nucltde • Other radionuclides, measured by Ge(L1) detector.Gas Flow • Pressure and flow rate of sweep gas and gap gas monitored.senses the molecular (HT+T2) trit ium level.Corrections for meter calibration, pressure,and flow are in progress to provide quantit-ative values. The dotted line represents anestimate of the tritium generation rate.Final values w i l l be those obtained fromdosinetry. The small barred circles representIntegral trit ium which was ueasured 1n scin-t i l l a t i o n traps. The results in Figure 1 arerepresentative of those obtained In a l l33 runs. Individual result; are discussedbelow.t Recoil effects: When the breederassembly was exposed to neutron at low power(3-30 kV and up to 12 HW), a measurableresponse was noted in the trit ium monitors.Breeder temperatures were 30-200*C respec-t ively . I t was estimated, therefore, that•Si of the tritium generated during theselow temperate tests was released by recoil .• Temperature effects: The trit iumrelease rate at a nominal 600*C with > sweepgas composition of He/0. I t H2 appeared toreach steedy state within a few hours. AnIncrease In the nominal breeder temperatureresulted 1n a small positive spike whichrepresented the difference between the trit iumretained at a nominal 600*C versus thatretained at a nominal 700*C. A decrease Intemperature to 550*C resulted f i r s t in anegative spike which represented tr i t iumaccumulation at the lower temperature.Equilibration was slow, requiring more thanthree days to build a steady state tr i t iumprof i le . A further decrease 1n temperature tc500*C resulted again in a negative spike.Temperature cycling resulted 1n repro-ducible behavior.• Sweep gas composition: Removal of thehydrogen additive froo the sweep gas has •RunNo.1234567B9101112131415161718192021222324252627282930313233TestTiwe(Days)221521326114521131142131237734223TABLE 3matrix for TR10-01Nominal*TemperatureCO600*700*700*550*500*550*600*650*650*400#500*550*600*700*700*700*700*700*550*650*650*600°550*600*500'550*525*500*480*480*500*550*650*Changes 1nNominalSweep GasComposition-He/1.OS Hz-1001 He100S Heloot He1001 He10« He1001 He-300 cc/min30 cc/min--He/0.21 02---•----300 cc/irtn----•Average temperature on west side. Coldesttemperature Is MOO" lower, hottest temper-ature fs approximately 50* higher.negative effect upon tritium release (Run 9vs. Run 8 ) . In a la ter test (Run 20) ,addition of oxygen to pure helium did notappear to enhance release rates.The addition of H2 seems to significantlyenhance tritium release rates. This effectcould greatly simplify blanket design byIncreasing the size of the temperature"window"2. This significant benefit must beweighed zgainst complications 1n Isotopeseparation and possibly Increased permeationlosses. The subject requires further study.• Fluersce effects: Tritium release rave*did not appear to have significantly changedfrom the beginning to the end of Irradiation.4.2 Amount and form of tritium collectedThe total amount of tritium collected was"-35 C i . Of this t o t a l , *5 t representedtr i t ium permeation Into the gss annular gap.The majority of the tritium collected waspresent as HT and T2 (991).4.3 Temperature control• The temperature of the breeder was moni-tored by thermocouples at ten separate loc-ations as a function of radius (inside v^ioutside); axial position (along the length);and geographic direction (east .vs. west).The radial temperature gradients were anaverage of 100*, and longitudinal gradientswere <10". There was a $1de-to-s1de temper-ature difference, the east side being 50*colder than the west side. Thus, for a givennominal temperature, some breeder material wast50*C hotter and some was M00*C cooler.The east side was postulated to be colderowing to asymetry In gap dimensions. RecentPIE results showed that the inner capsule wasleaning directly to the east side, therebysupporting the postulate.4.4 Thermal conductivity effectsDuring Irradiation, about 0.2X of thelithium In the sample was consumed. Thislowered the heating 1n the capsule from about560 W to 510 V, or about 101. The radialtemperature gradient systematically decreasedduring Irradiation, being lot lower at the endOf Irradiation. Since the thermal conductivityIs proportional to the ratio of the heattransport rate divided by the radial temper*ature gradient, 1t appears that the thermalconductivity did not change significantlyduring the experiment.4.5 Radionuclides detectedThe trace levels of contaminants such asNa, K, and U led to production of volatileradionuclides which were detected by y-rayspectroscopy during the experiment. Theprimary species detected vere F, Ne, Cl,Ar. Kr. Rb, Xe, and Cs. It was noted that theactivities were wry strongly dependent uponthe breeder rater!al temyierature, releaserates were faster at higher temperatures.This topic will be addressed later.4.6 Design of gas analysis safety systemThe gas analysis system, with two levelsOf containment to protect.workers, worked verywell. The tritium levels 1n the sweep gaswere of the order of 5 Ci/m3 (six orders ofmagnitude above nxinum levels of HTO 1n air).The levels In the glove box were i-100-lQOOVCI/B 3 . Levels In the room were <1 uCI/m3.during the course of the experiment.S. WORK IN PROGRESSQuantitative analysis of the data requiresthe results froa post-1 rradiation examination(PIE) as well as normalization of all data.PIE will consist of 1) residual tritiumcontent of the breeder material, 25 6L1bumup, 3) dosinetry, and 4) character!-lation of the Irradiated breeder specimens.6. CONCLUSIONSAlthough analysis of the data has notbeen completed, a number of conclusionscan be made° 1) Tritium release andtritium recovery has been demonstrated fora miniaturized solid breeder blanketassembly. 2) Thermal-hydraulic and heattransfer performance by controlled vari-ation of temperature using a gas gap hasbeen demonstrated. 3) The recovery oftritium from the helium sweep gas streamhas been demonstrated. 4) Radioactivespecies are present In the sweep gas.5) For 1.1 AT02, 2% of the tritium recoveredhad permeated through the primary claddingto the gap gas. 6) Addition of hydrogento the purge gas. appears to enhancetritium release. 7) Addition of oxygen tothe purge stream does not enhance tritiumrelease. 8) The containment systemsperformed well in protecting workers fromhigh levels of tritium.ACKNOWLEGEMENTSThe authors wish to express their appre-ciation for the support and encouragementof S. 0. Berk and other members of the staffof the U.S. DOE Office of Fusion Energy.Many people have contributed to the terhni-cai success of this project. We wish tothank V. A. Maroni. C. C. Baker, H. J.Steindier, J. L. Scott, and J. R. Conlin.He wish to thank R. T. Riel and L. J.Jensen for preparation of this manuscript.REFERENCES1 . R. G. Clenrer, e t a i . , The TRIO-01experiment, 5th ANS Topical Meeting onthe Technology of Fusion Energy,Knoxviile, Tennessee, April 26-29,1983, ind references therein.2. C. C. Baker, et a i . , STARFIRE - Aconmercial tokamak fusion power plantstudy, Argonne National Laboratory,ANL-FPP-8O-1 (1980).3. P. A. Finn, et a i . , The design, fabr i -cation and testing of the gas analysissystem for the tritium recoveryexperiment, TRIO-01 (to be published).

TRIO-01 experiment: in-situ tritium recovery results

THE TRIO-01 EXPERIMENT: IM-SITU TRITIUM RECOVERY RESULTSR. G. Cleaner, P. A. Finn, M. C. Billone, B. Misrs,and h. R. GreenwoodArgonne National Laboratory9700 South Cass AvenueArgonne, Illinois 604391'. F. Dyer, I. T. Dudley, t. C. Bate, E. D. Cleaner,P. W. Fisher, J. L. Scott, and J- S. WatsonOak Ridge National LaboratoryP. 0. Box XOak Ridge, Tennessee 37830AbstractThe TRIO-01 experiment was designed to testin-situ tritiua recovery and heat transfer performanceof a candidate solid breeder, y-LlA102> The resultsshowed that nearly all the tritium generated wasrecovered. Only <0.1 wppm tritiua reaained in thesolid after irradiation testing. The heat transferperformance showed that temperature profiles can beeffectively controlled•IntroductionThe TRIO-01 experiment involves the irradia-tion of 1-LIAIO2 in the Oak Ridge Research Reactor(ORR) under well-defined conditions of teaperature,neutron flux, sweep gas flow, and configuration.Tritium, in its various chemical forms (and othergases evolved from the impurities in L1A1O2 duringIrradiation) is moved by a sweep gas to an analyticaltrain in which measurements on the composition of theeffluent are performed. Previous reports havedescribed the experimental configuration and soaeInitial results.[1-4]The primary purpose of the experiment wasto test in-situ tritium recovery. To this end, thedesign made every attempt to provide conditionsfavorable for tritium release. LIAIO2 was ealectedbecause of Its chemical Inertness, low hygroscopiclty,good thermal stability, high melting point,[5] excel-lent stability under neutron irradiation,[6,7] andfabricability.[Q] The breeder pellets were fabricatedwith an engineered microstructure, having a biaodalpore size distribution [5] with grains of 0.1 pnradius compacted into agglomerates i<S0 yn in diameter.The overall density was 65* of theoretical. Fabrica-tion and characterization of the pellets is describedelsewhere.[1,2] The importance of obtaining quantita-tive values for both Integral and real-time data ontritium production and tritium release was recognized.Wherever possible, a number of independent aethodswere used to determine such quantities.The Irradiation phase of the experlaent wascompleted In June 1983 and post-irradiation examina-tions are underway. Significant results to date, andthe implications thereof to blanket design, arepresented.ExperimentalFull-power operation of the experlaentbegan on March 12, 1983 and ended on June 13, 1983.During this period 33 tests, or runs (Table 1), wereconducted. Observations Bade during testing have beendiscussed.[1] Presented below are recent results.Neutron FluxThe thermal neutron flux incident upon thecapsule was continuously recorded with three self-powered neutron detectors, as illustrated in Fig. 1.CONF-831203--35DE84 004003C S 3 3i.8.8 S3MSHRDISTRIBUTION OF THIS M M T IS MIMJTfDTABLE 1Test Matrix for TKIO-01RunNo.123456789101112131415161718192021222324252627282930313233Tt»e(Days)221521326114521131142131237734223Komlnal*Temperature<*C)600*700*700°550*500°550°600°650*650°400*500°550°600°700°700°700°700°700°650°650°650°600°550°600°560°550°525°500°480°480°500°550°650°Changes InNominal0Sweep GasCosposition-He/1.01 H 2-----100Z He100Z He1002 He100% He100% He1002 He-300 cc/min30 cc/nln--He/0.2T» 0 2--------300 cc/ain----'Average temperature on west side. Coldesttemperature is ^100° lower, hottest temper-ature is approximately 50° higher.^Nominal sweep gas is 0.1Z H2 in He, at aflow rata of 100 cc/ain.The flux levels were about 30Z lover than the levelsin a core mockup test, and showed considerablevariations. These variations in neutron flux wereconsiderably greater than variations in the ORR powerlevel. These flux data are being used to calculatetritium production rates during the experiment.Capsule TeaperaturesTemperatures were monitored continouslywith ten thermocouples, located on the inside andoutside surfaces of the breeder ring. The abilityto achieve temperature control was essential toHISTORY10 20 30 40 50 6U 70 BO SO 100Doijs after 10-MRR-1983Fig. 1. TRIO-01 Flux Historysuccessfully conducting the 33 runs (Table 1).The temperature history is shown in Fig. 2. Fromthese data heat transfer analysis was performed andthe key results were:[4]1) The capsule performed well throughoutthe course of the experiment, and the design nodeIsaccurately predicted temperature profiles.2) One side was about SO°C colder,presumably owing to gap asymmetry. PIE resultsconfirmed this.Fig. 2. TRIO-01 Capsule Temperatures3) Irradiation to a fluence of2 x 1021 nvt - equivalent to about 0.6 MH/y inSTARFIRE [5] had no detectable effect upon eitherhfcat transfer coefficient* or thenaal conductivity.It 1* noted that thermal conductivity change* wereexpected to be significant, po««lbly aa such as a50Z decrease, at these dose level*. The fact thatthe themal conductivity did not change la a signifi-cant and positive result for solid breeder blankets.4) The radial temperature gradientssystematically decreased, as nuclear heating de-creased, owing to burnup of 6L1. The *L1 burnupwas calculated to be 0.181.Tritium RecoveryDuring Irradiation, tritium In Its variouschemical forms was collected. The results aresunaarized In Table 2. The predominant fora, in thesweep gas being about 94Z of the total, was thenoncondensable or BT forn. The condensable (HTO)fora accounted for about 4Z of the total and most ofthe HTO was evolved after Run #20, when 0.21 O2 wasadded to the sweep gas. A total of 0.6 Ci or about2Z of the tritium was collected In the gap gas. Thetotal tritium recovered was about 35 Cl. This wouldcorrespond to a &L1 burnup of 0.1851.TABLE 2Total Tritium CollectedFornMolecular (HT,T2)(noncondenslble)Oxide (HT0.T20)(condensible)Permeation into gapTOTALCuries32.61.50.634.7 RecoveredPercentof Total94Z4Z22Two samples of LIAIO2 breeder specimenswere analysed for tritium. The residual content was0.02 and 0.0S wppm tritium in the two samples. Fromthese preliminary results, the residual content Isless than 0.1 wppm following run number 33, which hada nominal temperature of 6S0°C. This result showsthat nearly all the tritium produced during irradia-tion was released. More specimens of LIAIO2 arebeing analyzed for tritium in order to obtain moreaccurate values.Post-Irradiation ExaminationsSamples of the irradiation pellets ofLIAIO2 are being Investigated by scanning electronalcroscopy. A preliminary survey indicate that theaicrostructure has not significantly changed as aresult of test conditions. Grain size appears to be0.1 (ia In radius in the Irradiated specimens.Integral Results and PoslietryIn addition to tritium, accounting andthermal analysis, two more methods ware used todetermine Integral quantities such as total tritiumproduction and lithium burnup, namely Li-6 assay enddoslmetry. Li-6 assay was determined by mass spec-troaetry. The irradiated material showed a residualLi-6 content of 0.38Z and 0.381 in two staple*.Since the initial content was 0.551 llthlua-6, theburnup as deteralned by M I S spectrooetry Is 0.17Z.The accuracy of that number is approximately 10Z ofthe nominal value.Neutron doxlmetry measurements were con-ducted in the ORR in order to measure the flux andenergy spectrum as veil as *Li burnup reaction rates.Measurement* were also made during the TRIO irradia-tion in order to determine the neutron exposure,6Li burnup, and radiation damage. The spectralmeasurement was performed in the A2 position forabout nine hours on April 26, 1982. Twenty-onedifferent neutron activation rates were measured,Including ''Li monitors, fission detectors, andthermal covers. The STAYSL computer code was thenused to adjust calculated neutron spectra to fit theactivation measurements. Selected reaction rateswere measured over the vertical height of about 60 cmat eight different radial positions, four outside andfour Inside of a dummy TRIO sub-assembly. The *Liburnup rate was measured by ORNL and R1ES and calcu-lated from the doslmetry results. The measurementsand calculations agreed with +4Z. These results arereported in [9].Dosimetry measurements were also performedduring the actual TRIO Irradiation in the A2 positionof ORR from March 10 to June 13, 1983 for an exposureof 2558 HWD. Fe, Ni, and Ti monitor wires werecoirradiated in separate dosimetry tubes on the westside, east side, and center of the TRIO capsule. The10 mil wires were cut into six pieces, each about1.4 cm, and gamma counted by Ge(Li) spectroscopy.The reaction rates were corrected for decay duringthe Irradiation using the flux history measured bythe self-powered neutron detectors.The measured reaction rates are listed inTable 3. As can be seen, the thermal flux (indicatedby the 58Fe(n,g) reaction) is about the same on theeast and west sides, but about 32Z lower in thecenter of the assembly due to self-shielding effectscaused by the stainless steel and Li compounds, asdiscussed in detail below. It is interesting to notethat the activity and flux levels are significantlylower (30-402) than In the previous mockup measure-ments. The measured reaction rates were used toadjust the neutron spectrum measured in the mockuptests with the STAYSL computer code. The resultingfluence values are listed in Table 4. The fast fluxgradients are rather steep (100Z from west to east);however, this has little effect on the tritium rates,only the fast damage rates.TABLE 3Measured Activation Rates Results are Normalized to30 MW. Values are averages of six samples.PositionWestCenterEast58Fe(n,g)1.24E-108.31E-111.22E-1054Fe(n,p)5.34E-123.42E-122.67E-1246Ti(n,p)7.47E-135.26E-133.82B-13Energy,TotalThermal(22000.5 eV -Fast, >.AdjustedMeV(>.5 eV)m/s)0.1 MeV1 MeVTABLE 4Heutron Fluence ValuesNeutron Fluence, E20Center19.16.936.146.016.15West26.710.309.138.989.05n/cmZEast19.79.528.445.135.00The llthlua burnup rates were then computedusing the adjusted neutron spectrum. The outer ratewas found to be 9.7E-08 atoas/atom-s while the innerrate was 6.5E-08 atoms/atom-s. These two values wereused to determine the total burnup using an iterativeprocedure to calculate the time-dependent burnup andresultant decrease in self-shielding. The stainlesssteel sleeve was »bout 0.5 cm thick resulting in acalculated neutron absorption loss factor of about0.69 using an analytical approximation for self-Shielding. This effect was estimated to be about0.74 using our previous flux measurements in themockup experiment. The Initial llthlun self-shieldingis about 0.952 decreasing to about 0.968 by the endof the irradiation. These two factors would predictan average lithium burnup rate of 5.87E-08 atom/atoo-s. Over the 97 days of the run this wouldresult In a net burnup of 37.72 of the Initial 6Liatoms and a net tritium activity of 39.2 Cl. Due tothe uncertainties in the fluence measurements andself-shielding approximations, the calculated tritiumvalues have an estimated accuracy of 10-152. If weuse the measured Li-to-iron activity ratios from themockup experiment, the estimated tritium level wouldbe lowered to about 37.5 Cl.On the basis of lithium burnup, the radia-tion damage is equivalent to 0.6 MW-yr, or about twomonths in STARFIRE.[5] The neutron dose was calcu-lated to be 4.9 x 10 1' Rads. The gamma dose wascalculated to be 3.5 x 10*2 Rads, based on a gammaheating rate of 4.8 W/g. The total dose Is about8.4 x 10i2 Rads - equivalent to about four monthsin STARFIRE.[5]The Integral data, as determined by fourindependent methods, is shown In Table 5. Theagreement between the various methods is quite good -all are within experimental error. The error in themean values Is thus reduced about 5Z. These resultsdemonstrate that the tritium is accounted for.Work In ProgressA number of tasks are in progress orplanned, Including:1) Calculations of tritiun Inventory (orcontent) in the L1A102 for the 33 test runs. Thisdata will then be correlated to test conditions,notably temperature.2) Evaluation of the dynamic data untritium release to provide in formation on transportmechanisms.TABLE 5try of Results - Integral Tritium DataZ ZTritium, Burnup Burnup EstimatedMethod Cl (6Li) (Li) ErrorTritium [35J 33 0.18 5ZCollected6Li Assay 32 31 |0.17 | 10*Thermal 35 [33] 0.18 10ZGradientDosimetry 39 J38| 0.21 10-1SZAverage 35 33 0.16 5ZQ - Quantity directly measured or determined by themethod.3) Evalution of permeation rates asa function of test conditions.4) Thermal analysis to provide moreprecise values of thermal conductivity and heattransfer coefficients.DiscussionThe experiment sought to test the feasibi-lity of in-situ tritium recovery under conditionswhich simulate a fusion reactor blanket. Theresults, although for rather short irradiation timesand burnup levels, are very positive, showing thatinventories could be very low, <0.1 vppm, in a solidbreeder blanket- This would be an inventory of lessthan 100 g In STARF1RE [5]. It is noted that inven-tories were apparently higher at lower temperatures.However, concerns raised during the STARFIRE study,which Indicated that radiation damage could possiblysubstantially increase tritium Inventories, appearnot to be serious. Heat transfer results demonstratethat design codes work well [4] and that thermalconductivity is not significantly changed under thetest conditions. Thus, for conditions of limitedradiation damage, it appears that L1A102 performswell with respect to tritium recovery and heattransfer.The results for L1A102 are believed togive some confidence that chemically similar materialswill also perform well. Such materials are theternary lithium oxides: lithium zlrconates, lithiumsilicates, etc. LijO Is considered to be somewhatdifferent chemically because it is more reactive.Preliminary results from sealed-capsule tests of Li20show tritium retention values of tio vppm at about900°C and M.00 wppm at about 500°C [7] for neutrondoses similar to TRI0-01. In the Tulip experiment[10], sealed-capsule tests of LI2O showed tritiumretention values of about 100 ppm at 600°C. It islikely that tritium release would be better in anopen capsule. A TRIO-type test with Li2O wouldhelp to better quantify tritium inventories for thisbreeder material.ConclusionsAlthough much analysis work remains,some significant conclusions can be made at thistime:1) It was demonstrated that nearly allthe tritlua was releaaed and recovered.2) The realdual content of tritlua in theLiAK>2 waa <0.1 wppm, following a teat run at anoninal temperature of 650° with 0.1Z H2 in thesweep gaa.3) Irradiation to a 6Li burnup of 0.18%(equivalent to 0.6 HW-y/a2) did not appear tochange theraal conductivity or microstructure of theLiA102.AcknowledgmentaThe authora wish to express their appre-ciation for the support of the Office of FusionEnergy, U.S. DOE. Many people have contributed tothe technical success of this project. We vlfh tothank V. A- Maronl, C. C. Baker, H. J. Stelndler, andJ. R. Conlin. We wish to thank L. J. Jensen andR. T. Riel for preparation of this manuscript.References[1] R. G. Clemmer, P. A. Finn, H. C. Blllone,B. MiBra, R. M. Arons, R. B. Feoppel, F. F. Dyer,I. T. Dudley, L. C. Bate, E. D. Cleaner,J. L. Scott, J. S. Watson, and P. W. Fisher,"The TRIO-01 experinent: In-dtu tritium recoveryresults," presented at the Third Topical aeetlngon Fusion Reactor Materials, Albuquerque, NewMexico, September 19-22, 1983. To be publishedin the Journal of Nuclear Materials-[2] R. G. Cleaner, R. F. Malecha, and I. T. Dudley,"The TRIO-01 experiment," Nuclear Technology/Fusion. vol. 4, p. 63, September 1983.[3] P. A- Finn, G. A. Reedy, M. I. Homa,R. G. Clemmer, G. Pappas, M. A. Slaweckl,D. G. Graczyk, D. L. Bowers, and E. D. Cleaner,"The design, fabrication, and testing of thegas analysis system for the tritium recoveryexperiment TRIO-01," to be presented, Phila-delphia, Pennsylvania.[4] B. Mlsra, R. G. Clemmer, and P. A. Finn, "Heattransfer performance of a solid breeder blanketcomparison of TRIO-01 experimental data withmodel," ANS Transactions, 4£, 176 (1933).15] C. C. Baker, et al., " STARFIRE—A commercialtokamak fusion power plant study," ArgonneNational Laboratory Report No. ANL/FPP-80-1,1980.[6] L. Yang, et al., "Irradiation study of lithiumcompound samples for tritium breeding applica-tions," GA Techuologles Report, GA-A16047,July 1981.[7] G. W. Hollenberg, et al., "A fusion solid breederexperiment in a fast neutron fission reactor," inProceeding of the Conference on Fast, Thermal, andFusion Reactor Experiments, April 12-15, 1982,American Nuclear Society, La Grange Park,Illinois.[B] R. B. Poeppel, Argonne National Laboratory,private communication.[9] I. R. Greenwood, "Ooslaetry results for the TRIOtest in ORJt," Daaage Analysis and FundaaentalStudies Quarterly Progress Report, DOE/ER-0046/10,pp. 9-18, August 1982.[10] D. L. Porter, et si., "Irradiation and coapatibl-llty testing of LI2O materials at EBR-II," ArgonneNational Laboratory Report Mo. ANL/FPP/TM-167,December 1982.

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TRIO-01 experiment: in-situ tritium recovery results

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