Research on primary shielding calculation source generation codes

Primary shielding is composed of in-core internals surrounding the core (including baffle and barrel), water (including water between baffle and barrel, and water between barrel and Reactor Pressure Vessel (RPV)), and RPV and concrete surrounding RPV Primary Shielding Calculation (PSC) plays an important role in reactor shielding design and analysis. In order to facilitate PSC, a source generation code is developed to generate cumulative distribution functions (CDF) for the source particle sample code of the J Monte Carlo Transport (JMCT) code, and a source particle sample code is developed to sample source particle directions, types, coordinates, energy and weights from the CDFs. A source generation code is developed to transform three dimensional (3D) power distributions in xyz geometry to source distributions in rθz geometry for the J Discrete Ordinate Transport (JSNT) code. Validation on PSC model of Qinshan No.1 nuclear power plant (NPP), CAP1400 and CAP1700 reactors are performed. Numerical results show that the theoretical model and the codes are both correct. The source codes developed can be used to support other Monte Carlo codes and the Discrete Ordinate codes without large modification. We will extend the sources codes for other reactor types in the future