Preliminary design of inner radius of spallation target of an accelerator driven subcritical reactor for waste transmutation (ADS-NWT)

This paper presented preliminary design studies of inner radius of spallation target for lead-bismuth cooled accelerator driven sub-critical reactor, aimed at reducing proton beam current while simultaneously maintaining high Minor Actinides transmutation performance. Lead-bismuth eutectic (LBE) and uranium-free metallic dispersion fuel were used as the coolant and the fuel for this 1000 MWt reactor. By taking Proton Transmutation Support Ratio (PTSR) as an evaluation index, the inner radius of the spallation target was designed for this reference reactor and the optimized design proposal could obtain the higher transmutation performance. The preliminary study found that when the inner radius of the spallation target ran up to a certain value, the spallation neutron yield would have greater influence on the transmutation performance.