Sensitivity of Moderator Thickness on the Detector Response in PGSFR

A Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR) has been developed by KAERI in collaboration with ANL and KEPCO E and C. This reactor will serve the testing and investigation of the TRU metallic fuel performance, and also will demonstrate the TRU transmutation capability of a burner reactor as a part of the sustainable nuclear power utilization. The moderating materials are normally considered to increase the counting rate in the neutron detectors. A moderator such as polyethylene has been successfully demonstrated in the thermal nuclear power plant for the same purpose. The sensitivity of the moderator thickness on the detector performance is presented in this paper for the PGSFR core. The effect of moderator thickness on detector response was invested in this work. In PGSFR, two types of neutron detectors are considered that are fission chambers for operation and boron lined proportional counter for the reactor shutdown.