Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT) (방사성폐기물학회지)

Korean Radioactive Waste Society (한국방사성폐기물학회)
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Determination of 129I in simulated radioactive wastes using distillation technique

증류법을 이용한 모의 방사성폐기물 중 129I 의 정량

  • Received : 2011.06.07
  • Accepted : 2011.09.07
  • Published : 2011.09.30
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Abstract

It is clarified in the radioactive waste transfer regulation that the concentration of radioactive waste for the major radio nuclide has to be examined when radioactive waste is guided to the radioactive waste stores. In case of the low level radioactive waste sample, the analytical results of radioactive waste concentration frequently show a value lower than minimum detectable activity (MDA). Since the MDA value basically depends on the amount of a sample, background value, measurement time, counting efficiency, and etc, it would be necessary to increase a sample amount with a intention of minimizing MDA. In order to measure a concentration of $^{129}I$ in low and medium level radioactive waste, $^{129}I$ was collected by using a distillation technique after leaching the simulated radioactive waste sample with a non-volatile acid. The recovery of $^{129}I$ measured was compared with that measured with column elution technique which is a conventional method using an anion-exchange resin. The recovery of inactive iodide by using the distillation method and column elution were found as $86.5{\pm}0.9%$ and $87.3{\pm}2.7%$, respectively. The recovery and MDA value calculated for distillation technique when 100 g of extracted solution of $^{129}I$ was taken, were found to be $84.6{\pm}1.6%$ and $1.2{\times}10^{-4}Bq/g$, respectively. Consequently, the proposed technique with simplified process lowered the MDA value more than 10 times compared to the column elution technique that has a disadvantage of limited sampling amount.

방사성폐기물이 처분장에 인도 될 때 주요 방사성 핵종의 방사능 농도를 규명 하도록 방사성폐기물 인도 규정에 명시되어 있다. 저준위 방사성폐기물 시료의 경우 측정된 방사능 농도가 최소검출 방사능 농도(MDA: Minimum dectable activity) 이하의 값을 나타낼 경우가 많으며, MDA는 시료의 양, 바탕 값, 계측시간 및 계측효율 등에 따라서 달라지므로 MDA를 낮추기 위하여 가능한 많은 양의 시료를 취할 필요가 있다. 모의 잡고체 시료에 첨가된 요오드의 회수율을 결정하기 위한 방법으로서 모의 시료 중 비 방사성 요오드를 비휘발성 산으로 침출시킨 후 침출액을 직접 증발시키는 방법과 음이온 교환수지를 이용하I-를 흡착하여 분리하는 칼럼용리방법으로 측정하여 회수율을 비교한 결과, 증류법과 칼럼용리방법의 회수율은 각각 $86.5{\pm}0.9%$, $87.3{\pm}2.7%$로 나타났다. 증류법에 의한 모의 방사성 시료 중 $^{129}I$ 요오드의 회수율 및 MDA는 $84.6{\pm}1.6%$, $1.2{\times}10^{-4}Bq/g$로 각각 나타났으며, 분리공정을 단순화하고 많은 양의 시료를 취함으로써, 칼럼용리 방법의 단점을 보완하고 10배 이상 MDA를 낮출 수 있는 결과를 얻을 수 있었다.

Keywords

References

  1. N. Boukis and E. Henrich, "Two-step procedure for the iodine removal nuclear fuel solution", Radio Chimica Acta., 55, pp. 37-42 (1991).
  2. T. Sakurai, A. Takahashi, N. Ishikawa, Y. Komaki, M. Ohnuki, and T. Adachi, "The behaviour of iodine in a simulated spent fuel solution", Nuclear Technology, 85, pp. 206-212 (1989). https://doi.org/10.13182/NT89-A34241
  3. D. Geithoff and V. Schneider, "Prevention of the Volatilization of fission Iodine in the dissolution of $UO_2$ samples", Nuclear Research Center, KARLSRUHE KFK-258 (1964).
  4. N. Lavi, "A fast radiochemical procedure for separating iodine from fission products", Journal of Radioanalytical Chemistry, 20, pp. 41-49 (1974). https://doi.org/10.1007/BF02515899
  5. M. H. Studier, C. Postmus, Jr., "Ageneralized Procedure for the isolation of Iodine without carrier its determination by neutron activation using 129I as an isotopic tracer", ANL-6577 (1992).
  6. J. C. Clayton and J. M. Riddle "Some studies onthe oxidation states of fission-product Iodine($^{129}I$) in irradiated $UO_2$", WAPD-TM-851(1969).
  7. D. M. lvak, L. A.Waldman, "Iodine and Cesium in oxide fuel pellets and Zircaloy-4 cladding of irradiated fuel rods (LWBR Development Program)", WAPD-TM-1394 (1979).
  8. L. C. Bate and J.R. Stokely, "Determination of Iodine-129 in mixed fission products by neutron activation analysis", ORNL/TM-7449 (1980).
  9. H. Kamioki and K. Hoizumi, "Determination of radioactive iodine isotopes in the 99Mo produce by distillation", JAERI-M 8070 (1979).
  10. X. H. Dahlgaard, B. Rietz, U. Jacobasen, S. P. Nielsen and A. Aarkrog, "Determination of chemical species of iodine in seawater by radiochemical neutron activation analysis combined with ionexchange preseparation", Anal. Chem., 71, pp. 2745-2750 (1999). https://doi.org/10.1021/ac9813639
  11. 최계천, 송병철, 박세교, 한선호, 송규석, "음이온수지 흡착 컬럼용리 방법에 의한 요오드 종 분류", 2010 한국방사성폐기물학회 추계학술대회 논문 요약집, PP. 405-406, 2010.10.7-8, 노보텔 앰버서더 부산
  12. W. E. Browning, Jr., C. E. Miller, Jr., R. P. Shields and B. F. Roberts, "Release of fission products during in pile melting of $UO_2$", Nuclear Sci. Eng., 18, pp. 151-162 (1964). https://doi.org/10.13182/NSE64-1
  13. V. J. Filistovich, T. N. Nedveckaite, B. J. STYRA, "Activation analysis of $^{129}I$", Journal of Radioanalytical and Nuclear Chemistry, Articles, 97(1), pp. 123-130 (1986). https://doi.org/10.1007/BF02060418
  14. H. Kleykamp, Nuclear Technology, "The chemical state of fission products in oxide fuels at differents stages of the nuclear fuel cycle", 80, pp. 412-422 (1988).
  15. L. C. Bate and J. R. Stokely, "Iodine-129 separation and determination by neutron activation analysis", Journal of Radioanalytical and Nuclear Chemistry, 72(1-2), pp. 557-570 (1982).
  16. N. Boukis and E. Henrich, "Iodine-129 analysis in nuclear fuel solutions", Radio Chimica Acta, 54, pp. 103-108 (1991).
  17. J. S. Edmonds and M. Morita, "The determination of iodine species in environmental and biological samples", Pure & Appl. Chem., 70(8), pp. 1567-1584 (1998). https://doi.org/10.1351/pac199870081567
  18. R. Ikiseki, E. Kimura, T. Takashi, N. Ikedal, "Distribution and behaviour of long lived radioiodine in soil", Journal of Radioanalytical and Nuclear Chemistry, Articles, 138(1), pp. 17-31 (1990). https://doi.org/10.1007/BF02049344
  19. E.H.P. Cordfunke and R.J.M. Konings, "Chemical interaction in water-cooled nuclear fuel; A thermochemical approach", Journal of Nuclear Materials, 152, pp. 301-309 (1988). https://doi.org/10.1016/0022-3115(88)90341-8
  20. E.H.P. Cordfunke and R.J.M. Konings, "The release of fission products from degraded $UO_2$ fuel; Thermochemical aspects", Journal of Nuclear Materials, 201, pp. 57-69 (1993). https://doi.org/10.1016/0022-3115(93)90159-V
  21. 최계천, 한선호, 지광용, 최기섭, "방사성폐기물 중 $^{129}I$ 측정을 위한 시료의 전처리", 방사성폐기물학회지, 3(1), PP. 49-56 (2005).