Proliferation resistant plutonium: An updated analysis

Achieving a proliferation resistant, or possibly even proliferation proof, plutonium is a goal of the nuclear security and safeguards community. Considering that nearly all plutonium is under international safeguards, with the exception of plutonium with greater than 80 at.% Pu-238, reducing the necessity of these safeguards would be beneficial to both those in industry and in national and international security. Due to the Pu-238 high decay heat, establishing a technical limit for Pu-238 content in which rendering the plutonium useless for weapons purposes may be possible. Following the analysis done by Kessler, the authors analyzed two realistic models for hypothetical nuclear explosive devices seeking to establish this technical limit for Pu-238 content. The given plutonium vector used for this analysis was obtained through simulations of the Lightbridge fuel design in a pressurized water reactor. Calculating the temperature profile within the two hypothetical nuclear explosive device models showed that this plutonium vector would render the two models useless by causing the high explosives to undergo self-explosion.