Derivation of Ex-Core Detector Response Functions for Sizewell B

Abstract

This paper describes neutron transport calculations carried out in order to predict the responses of the ex-core neutron detectors installed in the pressurized water reactor at Sizewell B in the UK. The calculations were performed in adjoint mode using the Monte Carlo radiation transport code MCBEND. The paper compares the new response functions with the response data used to date and tests the new response functions against the results of forward Monte Carlo calculations. It also describes the results of sensitivity calculations that underwrite key assumptions in the modeling.