Neutronic calculation and power maps investigation of PWR critical lattice experiments using WIMSD-5B and CITVAP v3.1 codes

The calculation of integral parameters and power distribution is a very important task for fuel assembly design and whole core safety analysis. In this work, we used Monte Carlo (MCNP5) and deterministic lattice cell code WIMSD-5B with the diffusion code CITVAP v3.1 to assess the accuracy of neutronic calculations of three PWR lattice benchmark problems defined by the ANS Ad Hoc Committee on Reactor Physics Benchmarks. The code results for the integral parameters and relative pin power distribution are compared to measured values and the previous calculations obtained from some of organisations participated in this benchmark. The results demonstrate that the codes showed very good estimates of both the integral parameter and power distribution for the critical core and lattice configuration for the three different benchmarks selected.