Protected plutonium production at fast breeder reactor blanket - Chemical analysis of uranium-238 samples irradiated in the experimental fast reactor Joyo

详细信息	查看全文 | 推荐本文 |

• 作者：Takashi Ohnishi^a ; ^{ohnishi.takashi@jaea.go.jp} ; Shin-ichi Koyama^a ; Tomooki Shiba^b ; Hiroshi Sagara^b ; Masaki Saito^b
• 关键词：Proliferation resistance ; Protected plutonium production ; Uranium-238 ; Plutonium-239 ; Experimental fast reactor Joyo ; Chemical analysis
• 刊名：Progress in Nuclear Energy
• 出版年：2012
• 期刊代码：42_01491970
• 类别：pw
• 出版时间：May, 2012
• 卷：57
• 期：Complete
• 页码：125-129
• 文件大小：396 K

摘要

For improvement of proliferation resistance, the protected plutonium production (PPP) concept has been proposed. The concept is to produce ²³⁸Pu which has high decay heat in fuels with appropriate ²³⁸Pu/²³⁹Pu ratio for higher proliferation resistance. Estimation of Pu production with high accuracy under various irradiation conditions should be needed for evaluation of fuel specification and its proliferation resistivity. In previous studies, ²³⁸Pu production from ²³⁷Np and ²⁴¹Am has been experimentally investigated in our group (, ; ). However, experimental data of ²³⁹Pu production from ²³⁸U is not enough opened. In this study, ²³⁹Pu production from ²³⁸U is investigated on the basis of experimental data. Nine small ²³⁸U samples were irradiated in the experimental fast reactor Joyo under various irradiation conditions. Isotopic composition of U, Pu and Nd was measured by chemical analysis with accuracy. Plutonium-239 production ratio (a ratio of ²³⁹Pu atoms to initial ²³⁸U atoms) and burnup were also determined. Behavior of ²³⁹Pu production depended on sample loading position (e.g. neutron spectrum), and the tendency is different between fuel stack and reflector region. In order to evaluate this spectrum dependence quantitatively, the ²³⁹Pu production rate is defined as the ratio of ²³⁹Pu production per 10²⁶ n/m² of neutron fluence. The ²³⁹Pu production rate was decreased linearly with increasing fast flux ratio (a ratio of fast flux with energy of more than 0.1聽MeV to the total flux). Therefore, the ²³⁹Pu production from ²³⁸U by neutron capture reaction could be evaluated under wide irradiation area and/or position based on experimental results.