TY - JOUR
T1 - Leaching behavior of gamma-emitting fission products, calcium, and uranium from simulated MCCI debris in water
AU - Sasaki, Takayuki
AU - Sakamoto, Shunichi
AU - Akiyama, Daisuke
AU - Kirishima, Akira
AU - Kobayashi, Taishi
AU - Sato, Nobuaki
N1 - Funding Information:
This work was partly supported by the Japan Society for the Promotion of Science KAKENHI [grant number 16H02447]. The authors acknowledge Drs. Shun Sekimoto and Akihiro Uehara and the facility staff at the Institute for Integrated Radiation and Nuclear Science, Kyoto University for their great contributions to the experiments. The authors express their gratitude to the members of the research reactor group in KURRI for the preparation and operation in the neutron irradiation and to the program for the cooperative use of KUR supported by Kyoto University.
Publisher Copyright:
© 2019, © 2019 Atomic Energy Society of Japan. All rights reserved.
PY - 2019/12/2
Y1 - 2019/12/2
N2 - Gamma-ray radionuclides (Cs-137, Ba-140, I-131, Ru-103, and Zr-95) were produced by neutron irradiation of simulated molten core–concrete interaction (MCCI) debris, which was synthesized by the heat treatment of a mixture of UO2 with concrete components at a relatively low temperature of 1473 K under reducing and oxidizing conditions. The major uranium solid phases were unreacted UO2 and calcium uranate. The leaching ratio of the radionuclides in the powdered sample of the simulated MCCI debris was investigated under atmospheric conditions at 298 K in 0.1 mol/dm3 NaClO4 after filtration of the leachate through a 0.45-µm pore membrane. The uranium molar concentration in the filtrate was affected by the oxidation state in the solids. In the present study, however, the effect of various solid phase conditions on the leaching ratio normalized to that of uranium matrix could not be clarified. It was found that the leaching ratio of various fission products (RM) was proportional to that of Cs (RCs), and this trend did not depend on the oxidation state of uranium, the type of uranium complex (including a colloidal species), or the presence of Ca, Si, cement, or Zr.
AB - Gamma-ray radionuclides (Cs-137, Ba-140, I-131, Ru-103, and Zr-95) were produced by neutron irradiation of simulated molten core–concrete interaction (MCCI) debris, which was synthesized by the heat treatment of a mixture of UO2 with concrete components at a relatively low temperature of 1473 K under reducing and oxidizing conditions. The major uranium solid phases were unreacted UO2 and calcium uranate. The leaching ratio of the radionuclides in the powdered sample of the simulated MCCI debris was investigated under atmospheric conditions at 298 K in 0.1 mol/dm3 NaClO4 after filtration of the leachate through a 0.45-µm pore membrane. The uranium molar concentration in the filtrate was affected by the oxidation state in the solids. In the present study, however, the effect of various solid phase conditions on the leaching ratio normalized to that of uranium matrix could not be clarified. It was found that the leaching ratio of various fission products (RM) was proportional to that of Cs (RCs), and this trend did not depend on the oxidation state of uranium, the type of uranium complex (including a colloidal species), or the presence of Ca, Si, cement, or Zr.
KW - fission products
KW - fuel debris
KW - Fukushima Daiichi NPS
KW - MCCI
KW - static leaching
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U2 - 10.1080/00223131.2019.1641444
DO - 10.1080/00223131.2019.1641444
M3 - Article
AN - SCOPUS:85068799445
SN - 0022-3131
VL - 56
SP - 1092
EP - 1102
JO - Journal of Nuclear Science and Technology
JF - Journal of Nuclear Science and Technology
IS - 12
ER -