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Release of Fission Products from UC-ZrC Fuel Inserts; Degagement des produits de fission liberes dans des noyaux combustibles UC-ZrC; Vydelenie produktov deleniya iz topliv UC - ZrC; Liberacion de productos de fision por pastillas de combustible de UC-ZrC

Conference:

Abstract

The release of fission products from pellets of the approximate composition UC + 20 ZrC has been investigated in a loop during irradiation. The purpose was to check the possibility to use these pellets as inserts for the spherical fuel elements of the high temperature reactor presently being built at Juelich by Brown-Boveri/Krupp Reaktorbau G.m.b.H. The tests were carried out on free pellets and on pellets enclosed in graphite capsules. Some pellets had a 1- to 2-mm thick border zone consisting of pure zirconium carbide. The samples were placed in electric resistance furnaces reaching a maximum temperature of 1600{sup o}C. The neutron fluxes during the irradiation were 3 to 4 x 10{sup 10} n/cm{sup 2}s. The loop permitted the measurement of the release of the rare gas isotopes Kr{sup 85m}, Kr{sup 87}, Kr{sup 88}, Xe{sup 133} and Xe{sup 135} during irradiation and the indirect determination of I{sup 133} and I{sup 135} after shut-down of the reactor. The minimum release of I{sup 131}, Sr{sup 89}, Ba{sup 140} and Ce{sup 141} was radiochemically determined after withdrawal of the specimen. It was also possible to measure the recoil fraction {epsilon}{sub R} alone when the fuel insert was suspended within a furnace of larger  More>>
Authors:
Barth, F.; Von der Decken, C. B.; Schifferstein, K.; [1]  Clauss, A.; Reichel, H.; Rygaert, J.; Ruston, W. R. [2] 
  1. Brown Boveri/Krupp Reaktorbau G.M.B.H., Duesseldorf (Germany)
  2. Societe d'Etudes de Recherches et d'Applications pour l'Industrie (S.E.R.A.I.), Brussels (Belgium)
Publication Date:
Nov 15, 1963
Product Type:
Conference
Resource Relation:
Conference: Conference on New Nuclear Materials Technology, Including Non Metallic Fuel Elements, Prague (Czech Republic), 1-5 Jul 1963; Other Information: 9 figs., 5 tabs., 10 refs.; Related Information: In: New Nuclear Materials Including Non Metallic Fuel Elements. Vol. II. Proceedings of the Conference on New Nuclear Materials Technology, Including Non Metallic Fuel Elements| 586 p.
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; BARIUM 140; CERIUM 141; DIFFUSION; FUEL PELLETS; GRAPHITE; IODINE 131; IODINE ISOTOPES; IRRADIATION; KRYPTON ISOTOPES; STRONTIUM 85; STRONTIUM 89; TEMPERATURE RANGE 0400-1000 K; URANIUM CARBIDES; XENON ISOTOPES; ZIRCONIUM CARBIDES
OSTI ID:
22143643
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13R0490098349
Submitting Site:
INIS
Size:
page(s) 535-555
Announcement Date:
Oct 31, 2013

Conference:

Citation Formats

Barth, F., Von der Decken, C. B., Schifferstein, K., Clauss, A., Reichel, H., Rygaert, J., and Ruston, W. R. Release of Fission Products from UC-ZrC Fuel Inserts; Degagement des produits de fission liberes dans des noyaux combustibles UC-ZrC; Vydelenie produktov deleniya iz topliv UC - ZrC; Liberacion de productos de fision por pastillas de combustible de UC-ZrC. IAEA: N. p., 1963. Web.
Barth, F., Von der Decken, C. B., Schifferstein, K., Clauss, A., Reichel, H., Rygaert, J., & Ruston, W. R. Release of Fission Products from UC-ZrC Fuel Inserts; Degagement des produits de fission liberes dans des noyaux combustibles UC-ZrC; Vydelenie produktov deleniya iz topliv UC - ZrC; Liberacion de productos de fision por pastillas de combustible de UC-ZrC. IAEA.
Barth, F., Von der Decken, C. B., Schifferstein, K., Clauss, A., Reichel, H., Rygaert, J., and Ruston, W. R. 1963. "Release of Fission Products from UC-ZrC Fuel Inserts; Degagement des produits de fission liberes dans des noyaux combustibles UC-ZrC; Vydelenie produktov deleniya iz topliv UC - ZrC; Liberacion de productos de fision por pastillas de combustible de UC-ZrC." IAEA.
@misc{etde_22143643,
title = {Release of Fission Products from UC-ZrC Fuel Inserts; Degagement des produits de fission liberes dans des noyaux combustibles UC-ZrC; Vydelenie produktov deleniya iz topliv UC - ZrC; Liberacion de productos de fision por pastillas de combustible de UC-ZrC}
author = {Barth, F., Von der Decken, C. B., Schifferstein, K., Clauss, A., Reichel, H., Rygaert, J., and Ruston, W. R.}
abstractNote = {The release of fission products from pellets of the approximate composition UC + 20 ZrC has been investigated in a loop during irradiation. The purpose was to check the possibility to use these pellets as inserts for the spherical fuel elements of the high temperature reactor presently being built at Juelich by Brown-Boveri/Krupp Reaktorbau G.m.b.H. The tests were carried out on free pellets and on pellets enclosed in graphite capsules. Some pellets had a 1- to 2-mm thick border zone consisting of pure zirconium carbide. The samples were placed in electric resistance furnaces reaching a maximum temperature of 1600{sup o}C. The neutron fluxes during the irradiation were 3 to 4 x 10{sup 10} n/cm{sup 2}s. The loop permitted the measurement of the release of the rare gas isotopes Kr{sup 85m}, Kr{sup 87}, Kr{sup 88}, Xe{sup 133} and Xe{sup 135} during irradiation and the indirect determination of I{sup 133} and I{sup 135} after shut-down of the reactor. The minimum release of I{sup 131}, Sr{sup 89}, Ba{sup 140} and Ce{sup 141} was radiochemically determined after withdrawal of the specimen. It was also possible to measure the recoil fraction {epsilon}{sub R} alone when the fuel insert was suspended within a furnace of larger diameter. The measured values of {epsilon}{sub R} were only slightly higher than the calculated ones. At higher sample temperatures the diffusion fraction {epsilon}{sub D} could be calculated by subtraction of the recoil fraction from the total release. From {epsilon}{sub D} it was possible to calculate D/r{sub 0}{sup 2}s{sup -1} using the approximation equations of Fliigge and Zimens where D = diffusion constant and r{sub 0} = mathematically defined mean particle radius. The logarithmic plot of these values against 1/T yielded the activation energies (T = sample temperature in {sup o}K). The activation energies for the diffusion of krypton and xenon did not show significant differences. There were likewise no big differences in the activation energies obtained from different types of pellets, although the values of D/r{sub 0}{sup 2} sometimes differed by four orders of magnitude at the same sample temperatures. After irradiation, the activities of the isotopes I{sup 131}, Sr{sup 85}, Ba{sup 140} and Ce{sup 141} were determined in the graphite of the capsules. Except for I{sup 131}, the activities were higher than those expected for a release by recoil only. The values for Sr{sup 89}, Ba{sup 140} and Ce{sup 141} are too high to be a result of a diffusion of their corresponding rare gas precursors. It is assumed that the measured isotopes or their non-rare gas precursors were released by diffusion. (author) [French] Les auteurs ont etudie sous irradiation, dans une boucle, le degagement des produits de fission liberes par des pastilles dont la composition approximative etait UC + 20 ZrC. Il s'agissait de verifier la possibilite d'utiliser ces pastilles comme noyaux d'elements combustibles spheriques pour le reacteur a haute temperature actuellement construit a Juliers par la societe Brown-Boveri/Krupp Reaktorbau GmbH. Les essais ont ete faits sur des pastilles encapsulees dans du graphite et sur des pastilles non encapsulees. La surface de certaines pastilles etait constituee par une couche de carbure de zirconium pur d'une epaisseur de 1 a 2 mm. Les echantillons ent ete places dans des fours electriques a resistance pouvant atteindre une temperature de 1600{sup o}C. Pendant l'irradiation, les flux de neutrons etaient de 3 a 4 x 10{sup 10}n/cm{sup 2}s. La boucle permettait de mesurer, pendant l'irradiation, le degagement de {sup 85m}Kr, {sup 87}Kr, {sup 88}Kr, {sup 133}Xe et {sup 135}Xe et de determiner indirectement les quantites de {sup 133}I et {sup 135}I, apres l'arret du reacteur. Le degagement minimum de {sup 131}I, {sup 89}Sr, {sup 140}Ba et {sup 141}Ce a ete determine radiochimiquement apres retrait des echantillons. Il a ete egalement possible de mesurer la fraction de recul {epsilon}{sub R} seule, le noyau combustible etant suspendu a l'interieur d'un four de plus grand diametre que le precedent. Les valeurs obtenues pour cr n'etaient que legerement superieures aux valeurs calculees. Pour des temperatures plus elevees de l'echantillon, on a pu calculer la diffusion {epsilon}{sub D} en retranchant la fraction de recul de la quantite totale. Partant de {epsilon}{sub D} il a possible de calculer D/r{sub 0}{sup 2}(s{sup -1}) , a l'aide des equations d'approximation de S. Fluegge et K.E. Zimens ou D est la constante de diffusion et r{sub 0} le rayon moyen de la particule defini mathematiquement. En portant ces valeurs en ordonnees et les valeurs de 1/T en abscisse sur un graphique logarithmique, on a obtenu les energies d'activation (T = temperature de l'echantillon en {sup o}K). Les energies d'activation pour la diffusion de Kr est de Xe ne presentaient pas de differences significatives. Il n'y avait pas non plus de differences significatives entre les energies d'activation obtenues pour differents types de pastilles bien que les valeurs de D/R{sub 0}{sup 2} aient parfois differe de quatre ordres de grandeur pour une meme temperature de l'echantillon. On a determine, apres irradiation, les activites de {sup 131}I, {sup 85}Sr, {sup 140}Ba et {sup 141}Ce dans le graphite des capsules. A l'exception de {sup 131}I, on a observe des activites superieures a celles auxquelles on s'attendait pour un degagement par recul uniquement. Pour {sup 89}Sr, {sup 140}Ba et {sup 141}Ce, les valeurs etaient trop elevees pour etre dues a une diffusion de leurs precurseurs respectifs qui sont des gaz rares. On suppose que les radioisotopes mesures ou leurs precurseurs qui sont des gaz non rares ont ete liberes par diffusion. (author) [Spanish] Los autores investigaron la liberacion de productos de fision poi pastillas de combustibles cuya composicion aproximada responde a la formula UC + 20 ZrC sometidas a la irradiacion en un circuito de reactor. Su proposito era comprobar si esas pastillas se pueden usar como rellenos en los elementos combustibles esfericos del reactor de temperatura elevada que construye actualmente en Juelich la compania Biown-Boveri/Krupp Reaktorbau GmbH. Se llevaron a cabo dos clases de ensayos: con pastillas libres y con pastillas encerradas en capsulas de grafito. Algunas pastillas tenian una zona limitrofe de carburo de circonio puro de 1 o 2 mm de espesor. Las muestias se colocaron en hornos electricos de resistencia que permiten alcanzar una temperatura maxima de 1600{sup o}C. Los flujos neutronicos durante la irradiacion oscilaron entre 3 y 4 x 10{sup 10}n/cm{sup 2}.s. El circuito permitio medir e l desprendimiento de los isotopos {sup 85m}Kr, {sup 87}Kr, {sup 88}Kr, {sup 133}Xe y {sup 135}Xe en el curso de la irradiacion y determinar indirectamente el {sup 133}I y el {sup 135}I despues de la detencion del reactor. El desprendimiento minimo de {sup I31}I, {sup 89}Sr, {sup 140}Ba y {sup 141}Ce se determino por metodos radioquimicos una vez retirada la muestra. Tambien se podia medir la fraccion de retroceso {epsilon}{sub R} aisladamente, suspendiendo el relleno de com bustible en el interior de un homo de diametro mayor. Los valores medidos de {epsilon}{sub R} fueron ligeramente superiores a los calculados. Para temperaturas mas altas de la muestra, se podia calcular la fraccion de difusion {epsilon}{sub D} restando la fraccion de retroceso de la cantidad total desprendida. A partir del valor de {epsilon}{sub D}, se pudo calcular la relacion D/r{sub 0}{sup 2} (s{sup -1}) con las ecuaciones aproximadas de S. Fluegge u K. E. Zimens, siendo D la constante de difusion y r{sub 0} el valor medio matematicamente definido del radio de las particulas. La representacion logaritmica de estos valores en funcion de -1/T permite encontrar las energias de activacion (T = temperatura de la muestra en {sup o}K). No se observaron diferencias significativas en las energias de activacion para la difusion del cripton y del xenon. Tampoco se hallaron grandes diferencias en las energias de activacion determinadas en distintos tipos de pastillas, aunque algunas veces los valores D/r{sub 0}{sup 2} paragraph diferian en cuatro ordenes de magnitud para una misma temperatura de la muestra. Despues de la irradiacion, se determinaron las actividades de los isotopos {sup 131}I, {sup 85}Sr, {sup 140}Ba y {sup 141}Ce en el grafito de las capsulas. Exceptuando el {sup 131}I, las actividades resultaron superiores a las previstas para un desprendimiento debido solamente a retroceso. Los valores correspondientes al {sup 89}Sr, {sup 140}Ba y {sup 141}Ce son damasiado altos para que puedan atribuirse a una difusion de loe respectivos gases nobles precursores. Se supone que los isotopos medidos, o sus precursores distintos de los gases nobles se desprendieron por difusion. (author) [Russian] Provedeno issledovanie vo vremya oblucheniya v petle vydeleniya produktov deleniya ieh tabletok, imeyushchikh priblizitel'nyj sostav UC + 20 ZrC. Tsel' - proverka vozmozhnosti ispol'zovaniya podobnykh tabletok v kachestve topliva v sfericheskikh teplovydelyayushchikh ehlementakh vysokotemperaturnogo reaktora, postroennogo v Yulikhe ''Obshchestvom stroitel'stva reaktorov Braun Boveri/Krupp''. Ispytaniyu podvergalis' svobodnye tabletki i tabletki, vstavlennye v grafitovye kapsuly. Nekotorye iz tabletok imeli pogranichnuyu zonu ieh chistogo karbida tsirkoniya, tolshchinoj 1 - 2 mm. Obraztsy pomeshchalis' v pechi ehlektricheskogo soprotivleniya, dayushchie maksimal'nuyu temperaturu 1600{sup o}C. Nejtronnyj potok vo vremya oblucheniya sostavlyal 3 - 4 x 10{sup 10} n/cm{sup 2} -sek. Petlya pozvolyala izmerit' vydelenie izotopov inertnykh gazov Kr{sup 85m}, Kr{sup 87}, Kr{sup 88},Xe{sup 133} i Xe{sup 135} vo vremya oblucheniya, i kosvennoe opredelenie I{sup 133} i I{sup 135} posle vyklyucheniya reaktora. Minimum vydeleniya I{sup 131}, Sr{sup 88}, Ba{sup 141} i Ce{sup 141} byl opredelen radiokhimicheskim metodom posle izvlecheniya obraztsa iz reaktora. Krome togo sushchestvovala vozmozhnost' otdel'nogo izmereniya doli otdachi {epsilon}{sub R} , esli toplivnaya serdtsevina byla podveshana v pechi s bol'shim diametrom. Izmerennye velichiny {epsilon}{sub R} lish' neznachitel'no prevyshali vychislennye. Pri bolee vysokikh temperaturakh obraztsa mozhno bylo vychislit' dolyu diffuzii {epsilon}{sub D} vychitaniem doli otdachi iz polnogo vydeleniya. Poluchiv {epsilon}{sub D}, mozhno vychislit' D/r{sub 0}''2 sek, upotreblyaya uravneniya priblizheniya S. Flyugge i K.EH.Tsimensa, gde D - konstanta diffuzii, r{sub 0} rasschitannyj matematicheskim putem srednij radius chastitsy. Grafik zavisimosti logarifma ehtikh velichin ot 1/T daet ehnergiyu aktivatsii (T - temperatura obraztsa, {sup o}K). Raznitsa mezhdu ehnergiyami aktivatsii diffuzii kriptona i ksenona'okaehalas' neznachitel'noj. Malo otlichalis' drug ot druga takzhe i ehnergii aktivatsii, opredelennye dlya razlichnykh tipov tabletok, nesmotrya na to, chto velichiny D/r{sub 0}{sup 2} v nekotorykh sluchayakh pri tekh zhe temperaturakh obraztsa razlichalis' na 4 poryadka. V grafite kapsul posle oblucheniya byli opredeleny aktivnosti izotopov I{sup 131}, Sr{sup 85}, Ba{sup 140} i Ce{sup 141}. 3a isklyucheniem I{sup 131}, aktivnosti byli vyshe ozhidaemykh dlya vydeleniya tol'ko za schet otdachi. Velichiny dlya Sr{sup 85}, Ba{sup 140}, i Ce{sup 141} byli slishkom veliki, chtoby ikh mozhno bylo ob{sup y}asnit' diffuziej sootvetstvuyushchikh im inertnykh gazov-predshestvennikov. Predpolagaetsya, chto izmerennye izotopy ili ikh neinertnye gazy-predshestvenniki vedelyayutsya putem diffuzii. (author)}
place = {IAEA}
year = {1963}
month = {Nov}
}