Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Phase analysis of simulated nuclear fuel debris synthesized using UO2, Zr, and stainless steel and leaching behavior of the fission products and matrix elements

  • Ryutaro Tonna (Department of Nuclear Engineering, Kyoto University) ;
  • Takayuki Sasaki (Department of Nuclear Engineering, Kyoto University) ;
  • Yuji Kodama (Department of Nuclear Engineering, Kyoto University) ;
  • Taishi Kobayashi (Department of Nuclear Engineering, Kyoto University) ;
  • Daisuke Akiyama (Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University) ;
  • Akira Kirishima (Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University) ;
  • Nobuaki Sato (Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University) ;
  • Yuta Kumagai (Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA)) ;
  • Ryoji Kusaka (Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA)) ;
  • Masayuki Watanabe (Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA))
  • Received : 2022.07.30
  • Accepted : 2022.12.14
  • Published : 2023.04.25
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Abstract

Simulated debris was synthesized using UO2, Zr, and stainless steel and a heat treatment method under inert or oxidizing conditions. The primary U solid phase of the debris synthesized at 1473 K under inert conditions was UO2, whereas a (U, Zr)O2 solid solution formed at 1873 K. Under oxidizing conditions, a mixture of U3O8 and (Fe, Cr)UO4 phases formed at 1473 K, whereas a (U, Zr)O2+x solid solution formed at 1873 K. The leaching behavior of the fission products from the simulated debris was evaluated using two methods: the irradiation method, for which fission products were produced via neutron irradiation, and the doping method, for which trace amounts of non-radioactive elements were doped into the debris. The dissolution behavior of U depended on the properties of the debris and aqueous solution for immersion. Cs, Sr, and Ba leached out regardless of the primary solid phases. The leaching of high-valence Eu and Ru ions was suppressed, possibly owing to their solid-solution reaction with or incorporation into the uranium compounds of the simulated debris.

Keywords

Acknowledgement

This work was supported by the JAEA Nuclear Energy S&T and Human Resource Development Project through concentrated wisdom, grant number JPJA18P18071886. The authors would like to acknowledge Dr. Shun Sekimoto and the staff at the Institute for Integrated Radiation and Nuclear Science, Kyoto University (KURNS), for their significant contributions to the experiments. The authors would also like to express their gratitude to the members of the research reactor group at KURNS for their help with the neutron irradiation experiments and for allowing us to use the KUR supported by Kyoto University.

References

  1. Tokyo Electric Power Company, Evaluation of the Status of the Reactor Core Damage at the Fukushima Daiichi Nuclear Power Station Units 1-3, 2017. http://www.tepco.co.jp/press/release/2017/pdf2/171225j0102.pdf.
  2. Tokyo Electric Power Company, Situation of the Primary Containment Vessel Based on Gas Measurement Results, 2012. http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120723_06-j.pdf.
  3. T. Sasaki, Y. Takeno, A. Kirishima, N. Sato, Leaching test of gamma-emitting Cs, Ru, Zr, and U from neutron-irradiated UO2/ZrO2 solid solutions in non-filtered surface seawater: Fukushima NPP Accident Related, J. Nucl. Sci. Technol. 52 (2015) 147-151. https://doi.org/10.1080/00223131.2014.935511
  4. N. Sato, A. Krishima, T. Sasaki, Behavior of fuel and structural materials in severely damaged reactors, Adv. Sci. Technol. 94 (2014) 93-96. https://doi.org/10.4028/www.scientific.net/AST.94.93
  5. P. Piluso, G. Trillon, C. Journeau, The UO2-ZrO2 system at high temperature (T > 2000 K): importance of the meta-stable phases under severe accident conditions, J. Nucl. Mater. 344 (2005) 259-264. https://doi.org/10.1016/j.jnucmat.2005.04.052
  6. Yu.B. Petrov, Yu.P. Udalov, J. Subrt, S. Bakardjieva, P. Sazavsky, M. Kiselova, P. Selucky, P. Bezdicka, C. Journeau, P. Piluso, Phase equilibria during crystallization of melts in the uranium oxide-iron oxide system in air, Glass Phys. Chem. 35 (2009) 298-307. https://doi.org/10.1134/S1087659609030109
  7. D. Akiyama, H. Akiyama, A. Uehara, A. Kirishima, N. Sato, Phase analysis of uranium oxides after reaction with stainless steel components and ZrO2 at high temperature by XRD, XAFS, and SEM/EDX, J. Nucl. Mater. 520 (2019) 27-33. https://doi.org/10.1016/j.jnucmat.2019.03.055
  8. V.I. Almjashev, M. Barrachin, S. Bechta, D. Bottomley, S.A. Vitol, V.V. Gusarov, F. Defoort, E.V. Krushinov, D.B. Lopukh, A.V. Lysenko, A.P. Martynov, L.P. Mezentseva, A. Miassoedov, Yu.B. Petrov, M. Fischer, V.B. Khabensky, S. Hellmann, Ternary eutectics in the systems FeO-UO2-ZrO2 and Fe2O3-U3O8- ZrO2, Radiochemistry 53 (2011) 13-18. https://doi.org/10.1134/S1066362211010024
  9. Yu.B. Petrov, Y.P. Udalov, J. Subrt, S. Bakardjieva, P. Sazavsky, M. Kiselova, P. Selucky, P. Bezdicka, C. Journeau, P. Piluso, Experimental investigation and thermodynamic simulation of the uranium oxideezirconium oxideeiron oxide system in air, Glass Phys. Chem. 37 (2011) 212-229. https://doi.org/10.1134/S108765961102012X
  10. A. Kirishima, D. Akiyama, Y. Kumagai, R. Kusaka, M. Nakada, M. Watanabe, T. Sasaki, N. Sato, Structure, stability, and actinide leaching of simulated nuclear fuel debris synthesized from UO2, Zr, and stainless-steel, J. Nucl. Mater. 567 (2022), 153842.
  11. Japanese Ministry of Economy Trade and Industry, Tokyo, Nuclear Accident Response Office, Agency for Natural Resources and Energy, Important Stories on Decommissioning 2018, Fukushima Daiichi Nuclear Power Station, Now and in the Future, 2018. https://www.meti.go.jp/english/earthquake/nuclear/decommissioning/pdf/20180827_roadmap.pdf.
  12. Industry JMoETa, Released Meeting Materials at Secretariat Meeting of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment, 2019.
  13. T. Sasaki, Y. Takeno, T. Kobayashi, A. Kirishima, N. Sato, Leaching behavior of gamma-emitting fission products and Np from neutron-irradiated UO2-ZrO2 solid solutions in non-filtered surface seawater, J. Nucl. Sci. Technol. 53 (2016) 303-311. https://doi.org/10.1080/00223131.2015.1055315
  14. A. Kirishima, M. Hirano, T. Sasaki, N. Sato, Leaching of actinide elements from simulated fuel debris into seawater, J. Nucl. Sci. Technol. 52 (2015) 1240-1246. https://doi.org/10.1080/00223131.2015.1017545
  15. A. Kirishima, M. Hirano, D. Akiyama, T. Sasaki, N. Sato, Study on the leaching behavior of actinides from nuclear fuel debris, J. Nucl. Mater. 502 (2018) 169-176. https://doi.org/10.1016/j.jnucmat.2018.02.018
  16. T. Sasaki, S. Sakamoto, D. Akiyama, A. Kirishima, T. Kobayashi, N. Sato, Leaching behavior of gamma-emitting fission products, calcium, and uranium from simulated MCCI debris in water, J. Nucl. Sci. Technol. 56 (2019) 1092-1102. https://doi.org/10.1080/00223131.2019.1641444
  17. S. Grazulis, A. Daskevic, A. Merkys, D. Chateigner, L. Lutterotti, M. Quiros, N.R. Serebryanaya, P. Moeck, R.T. Downs, A. Le Bail, Crystallography Open Database (COD): an open-access collection of crystal structures and platform for world-wide collaboration, Nucleic Acids Res. 40 (2012) D420-D427.
  18. R. Young, A.C. Larson, C. Paiva-Santos, Rietveld Analysis of X-Ray and Neutron Powder Diffraction Patterns, School of Physics, Georgia Institute of Technology, Atlanta (GA), 1998.
  19. Y. Takaya, T. Nakayama, C. Oguchi, T. Hatta, Experimental study on alteration of mortars attacked by seawateresecondary products on surface, J. MMIJ 125 (2009) 489-495. https://doi.org/10.2473/journalofmmij.125.489
  20. Y. Ikeda, Y. Yasuike, K. Nishimura, S. Hasegawa, Y. Takashima, Kinetic study on dissolution of UO2 powders in nitric acid, J. Nucl. Mater. 224 (1995) 266-272. https://doi.org/10.1016/0022-3115(95)00059-3
  21. F. Gronvold, High-temperature X-ray study of uranium oxides in the UO2-U3O8 region, J. Inorg. Nucl. Chem. 1 (1955) 357-370. https://doi.org/10.1016/0022-1902(55)80046-2
  22. F. Stein, G. Sauthoff, M. Palm, Experimental determination of intermetallic phases, phase equilibria, and invariant reaction temperatures in the Fe-Zr system, J. Phase Equilibria 23 (2002) 480-494. https://doi.org/10.1361/105497102770331172
  23. P. Nash, C. Jayanth, The Ni Zr (nickel-zirconium) system, Bull. Alloy Phase Diagrams 5 (1984) 144-148. https://doi.org/10.1007/BF02868950
  24. E. Hayes, A. Roberson, M. Davies, Zirconium-chromium phase diagram, JOM 4 (1952) 304-306. https://doi.org/10.1007/BF03397695
  25. L. Zhang, A. Shelyug, A. Navrotsky, Thermochemistry of UO2-ThO2 and UO2-ZrO2 fluorite solid solutions, J. Chem. Thermodyn. 114 (2017) 48-54. https://doi.org/10.1016/j.jct.2017.05.026
  26. R. Ploc, The lattice parameter of cubic ZrO2 formed on zirconium, J. Nucl. Mater. 99 (1981) 124-128. https://doi.org/10.1016/0022-3115(81)90146-X
  27. I. Cohen, B.E. Schaner, A metallographic and X-ray study of the UO2-ZrO2 system, J. Nucl. Mater. 9 (1963) 18-52. https://doi.org/10.1016/0022-3115(63)90166-1
  28. N.K. Kulkarni, K. Krishnan, U.M. Kasar, S.K. Rakshit, S.K. Sali, S.K. Aggarwal, Thermal studies on fluorite type ZryU1-yO2 solid solutions, J. Nucl. Mater. 384 (2009) 81-86. https://doi.org/10.1016/j.jnucmat.2008.10.015
  29. P. Evans, The system UO2-ZrO2, J. Am. Ceram. Soc. 43 (1960) 443-446. https://doi.org/10.1111/j.1151-2916.1960.tb13695.x
  30. A. Uehara, D. Akiyama, A. Ikeda-Ohno, C. Numako, Y. Terada, K. Nitta, T. Ina, S. Takeda-Homma, A. Kirishima, N. Satob, Speciation on the reaction of uranium and zirconium oxides treated under oxidizing and reducing atmospheres, J. Nucl. Mater. 559 (2022), 153422.
  31. I. Grenthe, X. Gaona, L. Rao, A. Plyasunov, W. Runde, B. Grambow, R. Konings, A. Smith, E. Moore, M.-E. Ragoussi, J.S. Martinez, D. Costa, A. Felmy, K. Spahiu, Second Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, americium and technetium Organisation for Economic Co-Operation and Development, Paris, 2020.
  32. C.F. Baes, R.S. Mesmer, The Hydrolysis of Cations, John Wiley & Sons, New York, London, Sydney, Toronto, 1976.
  33. R. Guillaumont, F.J. Mompean, Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium, Elsevier, Amsterdam, 2003.
  34. I. Grenthe, J. Fuger, R.J.M. Konings, R.J. Lemire, A.B. Muller, C. Nguyen-Trung, H. Wanner, Chemical Thermodynamics of Uranium, Elsevier, Amsterdam, 1992.
  35. M. Altmaier, E. Yalcintas, , X. Gaona, V. Neck, R. Muller, M. Schlieker, T. Fanghanel, Solubility of U (VI) in chloride solutions. I. The stable oxides/ hydroxides in NaCl systems, solubility products, hydrolysis constants and SIT coefficients, J. Chem. Thermodyn. 114 (2017) 2-13. https://doi.org/10.1016/j.jct.2017.05.039
  36. W.E. Browning Jr., C.E. Miller, R.P. Shields Jr., B.F. Roberts, Release of fission products during in-pile melting of UO2, Nucl. Sci. Eng. 18 (1964) 151-162. https://doi.org/10.13182/NSE64-1
  37. V.I. Paramonova, E.F. Latyshev, The ion exchange method in studies of the state of matter in solution. Vi. Complexing ruthenium (iv) in hydrochloric and perchloric acids, Radiokhimiya (1) (1959).
  38. M. Jimenez-Reyes, M. Solache-Rios, A. Rojas-Hern andez, Application of the specific ion interaction theory to the solubility product and first hydrolysis constant of europium, J. Solut. Chem. 35 (2006) 201-214. https://doi.org/10.1007/s10953-006-9363-z
  39. T. Fujino, K. Ouchi, Y. Mozumi, R. Ueda, H. Tagawa, Composition and oxygen potential of cubic fluorite-type solid solution EuyU1-yO2+x(x$_{<}^{\geqq}$0) and rhombohedral Eu6UO12+x'(x'< 0), J. Nucl. Mater. 174 (1990) 92-101.  https://doi.org/10.1016/0022-3115(90)90426-N