The Issue of Accelerator Beam Trips for Efficient ADS Operation

Abstract

International audienceThe development of accelerator-driven systems(ADSs) is motivated by the potential of these machines toreduce the volume and the radiotoxicity of accumulatednuclear waste, more particularly that of minor actinidescurrently generated by the operation of existing pressurizedwater reactors. The reduction of both volume andradiotoxicity of nuclear waste is achieved by transmutationand fission of minor actinides into less-active isotopesor shorter-lived by-products.Various technical challenges exist regarding designingreliable and efficient ADSs. The key points are verymuch linked to the design of the spallation module, theassurance that reactivity remains below criticality underany circumstances, and the accelerator reliability.This paper addresses the latter two challenges imposedon the accelerator in order to assure safe andreliable ADS operation. It discusses the possibility ofperforming online absolute reactivity measurements andthe limits in the number of allowable accelerator beamtrips, which might impede plant integrity and/or plantefficiency