Quantitative evaluation of the plutonium proliferation resistance

The mathematical model presented in (Kulikov et al. 2018) can be used for the quantitative evaluation of the plutonium proliferation resistance. This requires the warm-up process of an implosion nuclear explosive device (NED) with a different structure to be analyzed with respect to various heat removal conditions and the option to be identified in which the NED remains operational for the longest time possible. The fraction of the 238Pu isotope with which, even in this case, the NED will prove to be operational only for quite a short time can be regarded as sufficient for the plutonium with such composition to be considered a proliferation resistant material. The purpose of the paper is to evaluate in quantitative terms the content of 238Pu in plutonium for ensuring its proliferation resistance and to identify the factors which influence significantly this evaluation. The data, procedures and findings from earlier works on the topic, as well as the authors’ own estimates and calculations were used for the study. It has been shown that the important factors involved in the plutonium proliferation resistance evaluation are the NED technology level and the required NED lifetime. Depending on the required lifetime, tougher requirements can be introduced with respect to the 238Pu content both from the standpoint of low-technology and high-technology NEDs. With a lifetime of five hours taken as the guide-mark (a NED is unlikely to be finally assembled, transported and used for such a short time), it is only plutonium containing 55% of 238Pu that can be considered a proliferation resistant fissile material.