Preliminary Study on Transmutation of Plutonium and Minor Actinides in Accelerator Driven System

Abstract

As a free CO₂ emission energy source, nuclear energy can supply the world electricity for very long time, even for thousand years. However, to increase the public acceptance, nuclear spent fuel (high level nuclear waste) should be manage to minimize its radio-toxicity. There are several methods of processing nuclear spent fuel including geological repositories, reprocessing it to be used as fuel again or doing transmutation. In this preliminary study, the nuclear high level waste is transmuted by using an Accelerator Driven Subcritical System (ADS). ADS is a system consisting of a subcritical reactor core and a particle accelerator. Nuclear waste which will be transmuted is plutonium (Pu) and minor actinides (MA). Pu and MA are mixed in the ADS fuel that consists of U-ThO₂(NO₃)₂, PuMA(NO₃)₄ dan HNO₃. Two type of plutonium vectors have been evaluated, those are reactor grade Pu (RGPu) and weapon grade Pu (WGPu). The ADS can maintain it sub-criticality condition for RGPuMA and WGPuMA with the concentration of PuMA-Nitrate are above 62.6 kmol/m³ and 65.6 kmol/m³, respectively.