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Current Status of Immobilization Techniques for Geological Disposal of Radioactive Iodine in Japan

Published online by Cambridge University Press:  19 March 2015

Kazuya Idemitsu  and
Tomofumi Sakuragi
Kazuya Idemitsu
Affiliation:
Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka, Japan
Tomofumi Sakuragi
Affiliation:
Radioactive Waste Management Funding and Research Center, Tokyo, Japan
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Abstract

Nuclear reprocessing plants in Japan produce radioactive iodine-bearing materials such as spent silver adsorbents. Japanese disposal plans classify radioactive waste containing a given quantity of iodine-129 as Transuranic Waste Group 1 for spent silver adsorbent or as Group 3 for bitumen-solidified waste, and stipulate that such waste must be disposed of by burial deep underground. Given the long half-life of iodine-129 of 15.7 million years, it is difficult to prevent release of iodine-129 from the waste into the surrounding environment in the long term. Moreover, because ionic iodine is soluble and not readily adsorbed, its migration is not significantly retarded by engineered or natural barriers. The release of iodine-129 from nuclear waste therefore must be restricted to permit reliable safety assessment; this technique is called “controlled release”. It is desirable that the release period for iodine be longer than 100,000 years. To this end, several techniques for immobilization of iodine have been developed; three leading techniques are the use of synthetic rock (alumina matrix solidification), BPI (BiPbO2I) glass, and high-performance cement. Iodine is fixed as AgI in the grain boundary of corundum or quartz through hot isostatic pressing in synthetic rock, as BPI in boron/lead-based glass, or as cement minerals such as ettringite in high-performance alumina cement. These techniques are assessed by three models: the corrosion model, the leaching model, and the solubility-equilibrium model. This paper describes the current status of these three techniques.

Keywords

Ihot isostatic pressing (HIP)amorphous
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1744: Symposium EE – Scientific Basis for Nuclear Waste Management XXXVIII , 2015 , pp. 3 - 13
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Federation of Electric Power Companies (FEPC) and Japan Atomic Energy Agency (JAEA), “Second Progress Report on Research and Development for TRU Waste Disposal in Japan,” Repository Design, Safety Assessment Means of Implementation in the Generic Phase. FEPC TRU-TR2-2007-01 or JAEA Review 2007-010.Google Scholar
Kikuchi, M., Kitamura, M., Yusa, H., Horiuchi, S., Removal of radioactive methyl iodide by silver impregnated alumina and zeolite, Nuclear Engineering and Design, 47(2), 283–287 (1978).CrossRefGoogle Scholar
Ramos, V.S., Crispim, V. R., Brandão, L. E. B., New filter for iodine applied in nuclear medicine services, Applied Radiation and Isotopes, 82, 111–118 (2013).CrossRefGoogle ScholarPubMed
Nishimura, T., Sakuragi, T., Nasu, Y., Asano, H., and Tanabe, H., Development of Immobilization Techniques for Radioactive Iodine for Geological Disposal, In: Proceedings of Workshop “Mobile Fission and Activation Products in Nuclear Waste Disposal”, Jan. 16th–19th 2007, La Baule, France, NEA No. 6310, 221–34 (2009).Google Scholar
Fujihara, H., Murae, T., Wada, R., and Nishimura, T., “Fixation of radioactive iodine by hot isostatic pressing”, in ICEM ’99: (the 7th International Conference Proceedings on Radioactive Waste Management and Environmental Remediation, Nagoya, Japan, September 26-30, 1999), pp 1–5.Google Scholar
Wada, R., Nishimura, T., Kurimoto, Y., and Imakita, T., HIP Rock Solidification Technology for Radioactive Iodine-Contaminated Waste: Kobe Seiko Giho 53, 47–55 (2003); in Japanese.Google Scholar
Fujihara, H., Murase, T., Nishi, T., Noshita, K., Yoshida, T., and Matsuda, M., Low Temperature Vitrification of Radioiodine Using AgI–Ag2O–P2O5 Glass System, Mater. Res. Soc. Symp. Proc., 556, 375–82 (1999).CrossRefGoogle Scholar
Kato, H., Kato, O., and Tanabe, H., Review of Immobilization Techniques of Radioactive Iodine for Geological Disposal, In: Proceedings of the International Symposium NUCEF-2001, 31st Oct.–2nd Nov 2001, JAERI, Tokai, Japan; 697–704 (2002).Google Scholar
Advocat, T., Fillet, C., Bart, F. et al. ., New Conditionings for Enhanced Separation Long-lived Radionuclides, In: Proceedings of the International Conference “Back-End of Fuel Cycle: From Research to Solution”, Global’01, Sept. 9th–13th, 2001, Paris, France.Google Scholar
Izumi, J., Yanagisawa, I., Katsurai, K., et al. ., Multi-layered Distributed Waste-Form of Iodine-129: Study on Iodine Fixation of Iodine Adsorbed Zeolite by Silica CVD, In: Proceedings of the Symposium on Waste Management 2000, Feb. 27th–March 2nd, 2000, Tucson, Arizona, USA.Google Scholar
Nakazawa, T., Kato, H., Okada, K., Ueta, S., and Mihara, M., Iodine Immobilization by Sodalite Waste Form, Mater. Res. Soc. Symp. Proc., 663, 51–7 (2001).CrossRefGoogle Scholar
Toyohara, M., Kaneko, M., Ueda, H., Mitsutsuka, N., Fujiwara, H., Murase, T., and Saito, N., Iodine Sorption onto Mixed Solid Alumina Cement and Calcium Compounds, J. Nucl. Sci. Technol., 37, 970–978 (2000).CrossRefGoogle Scholar
Masuda, K., Kato, O., Tanaka, Y., Nakajima, S., Sakuragi, T., Yoshida, S., Development of Solidification Process of Spent Silver-Sorbent using Hot Isostatic Press Technique for Iodine Immobilization, Progress in Nuclear Energy Special issue for Scientific Basis of Nuclear Fuel Cycle II 2014 (to be published).Google Scholar
Latimer, W. M., The Oxidation States of Elements and their Potentials in Aqueous Solutions, Prentice Hall (1952).Google Scholar
Inagaki, Y., Imamura, T., Idemitsu, K., Arima, T., Kato, A., Nishimura, T., Asano, H., Aqueous Dissolution of Silver Iodide and Associated Iodine Release under Reducing Conditions with FeCl2 Solution, J. Nucl. Sci. Technol., 45(9), 859–866 (2008).CrossRefGoogle Scholar
Kodama, H., Dyer, A., Hudson, M. J., Williams, P. A., “Progress in Ion Exchange,” The Royal Society of Chemistry, Cambridge, UK, p. 39 (1997)Google Scholar
Kodama, H., Kabay, N., “Reactivity of Inorganic Anion Exchanger BiPbO2NO3 with Fluoride Ions in Solution,” Solid State Ionics, 141–142 (2001).Google Scholar
Yamashita, Y., Higuchi, S., Kaneko, M., Takahashi, R., Sakuragi, T., Owada, H., Iodine Release Behavior from Iodine-Immobilized Cement Solid under Geological Disposal Conditions, Progress in Nuclear Energy Special issue for Scientific Basis of Nuclear Fuel Cycle II 2014 (to be published).Google Scholar
Haruguchi, Y., Higuchi, S., Obata, M., Sakuragi, T., Takahashi, R., Owada, H., The Study on Iodine Release Behavior from Iodine-Immobilized Cement Solid, Mater. Res. Soc. Symp. Proc., 1518, 85–90 (2013).CrossRefGoogle Scholar