Nuclear Data for Innovative Reactors Having Persistent Resistance to Nuclear Proliferation

摘要

The Protected Plutonium Production (P~3) project has been initiated in order to realize the proliferation-resistant plutonium. The first stage of this project is based on the idea to protect plutonium by ~(238)Pu generated from ~(237)Np doped in the fresh uranium fuel. Along with the burnup going on, the doped ~(237)Np is transmuted via ~(238)Np to ~(238)Pu, which is the intense neutron source of spontaneous fission (2.6x10~3 n/g/s). These neutrons will deteriorate the quality of the plutonium as the nuclear explosive material. In addition, high alpha-decay heat of ~(238)Pu (560W/kg) makes the processes of the explosive fabrication and its maintenance technologically difficult. In this background we surveyed the status of nuclear data relevant to the P~3-concept reactor design. The reliability of the capture cross section data for ~(237)Np and ~(238)Pu are far from satisfactory and more accurate experiments and evaluations are required. As fissions in these nuclides do not always play any decisive role in the P~3 concept LWR, we can be fairly tolerable about the uncertainty of the fission cross section data, but farther study is needed.