Proliferation Resistance Evaluation of an Advanced Fuel Cycle Employing High Temperature Gas Cooled Reactors

摘要

The proliferation resistance (PR) evaluation of fresh and spent fuel blocks in transuranic (TRU) fuel cycle employing high temperature gas cooled reactors (HTGRs) was quantitatively carried out with PRAETOR (Proliferation Resistance Analysis and Evaluation Tool for Observed Risk) code. The total PR of the spent fuel block under International Atomic Energy Agency (IAEA) safeguards and physical protection is significantly higher than that for the fresh fuel block because of the large contributions not only from high radiation dose rate, but low plutonium concentration and depleted plutonium isotopic ratio due to the high fuel burn-up incineration. For the fresh fuel block which is relatively vulnerable material for diversion compared with the spent fuel block, it was found that the implementation of IAEA safeguards and physical protection system contribute to enhance the PR of the nuclear systems. It was also noticed that improvement of the PR of the fresh fuel block can be achieved by strengthening of IAEA safeguards using satellite imagery analysis and process monitoring, and designing the nuclear power plant with no space for modifications and a smaller storage capacity. The PR comparison of the HTGR and pressurized water reactor (PWR) spent fuel showed that the HTGR fuel cycle marginally has higher overall PR because of the difficulties in weaponization stage for the HTGR diverted SNM.