Feasibility Test for Determination of Dosimeter Response for the Watts Bar Unit 1 Reactor Extended Belt-line Region Using the DRF Method

Abstract

New methods for solving 3-D reactor pressure vessel (RPV) dosimetry problems are emerging as the operating lifetimes of nuclear power reactors continue to increase. Accurately quantifying neutron fluence and its associated damage in RPV regions beyond the traditional beltline has become increasingly important. This work applies the detector response function (DRF) methodology to a 3-D RPV dosimetry problem using the TVA Watts Bar Unit 1 Benchmark as the reference model. A test problem consisting of four axial fuel segments is used to evaluate the effectiveness of the DRF approach for pressure vessel fluence calculations. DRF predictions are compared against reference MCNP Monte Carlo results. The good agreement between the two methods demonstrates the soundness of the DRF approach; however, additional analysis and optimization are required before extending the method to a full-core DRF solution.