Simulation and Sensitivity Study of the Rhodium Self-Powered Neutron Detector in PWR

Abstract

In this paper, taking the self-powered neutron detector (SPND) using rhodium as the emitter material as an example, simulations for SPNDs and calculations of neutron sensitivities are carried out by Bamboo-Lattice and Geant4 code. The neutron sensitivities with single-energy incident neutrons are validated by comparing with the experimental results. Effects of the incident neutron energy spectrum and the emitter burnup to the neutron sensitivity of the SPND are analyzed. Bamboo-Lattice is used to calculate the incident neutron energy spectrums and the emitter nucleus densities which are the environment of the SPND. Numerical results show the neutron sensitivity decreases due to the increase of the enrichment, the assembly average burnup, the boron concentration, the moderator temperature, the burnable poison rods and the control rod. The increase of the emitter burnup will lead to the decrease of the neutron sensitivity. Taking the incident neutron energy spectrum and the nucleus density into account together, the neutron sensitivity decreases with the increase of the assembly average burnup.