Benchmarking of Monte Carlo model of PWR (CNPP-II) core against theoretical and experimental results

The purpose of this study is to develop a complete Monte Carlo model of Chashma Nuclear Power Plant Unit-2 (CNPP-II) core and benchmark against the theoretical (Final Safety Analysis Report FSAR) and experimental results. For this purpose, a comprehensive model of CNPP-II core is developed using Monte Carlo N-Particle (MCNP5) radiation transport code which is equipped with temperature dependent ENDF/B-VII.1 cross-section library. The model is validated against the reference results of CNPP-II at seven different operating conditions of the initial core. For Cold Zero Power (CZP) condition, the overall temperature is taken as 40 °C, while for Hot Zero Power (HZP) condition, the temperature is taken as 280 °C. In Hot Full Power (HFP), the fuel, cladding and coolant temperatures are taken as 873 °C, 340 °C and 302 °C respectively. To enhance the model validation from global level (keff) to local level (flux or power distribution), the simulated pin & assembly wise neutron flux and power distribution is compared with the available experimental results of CNPP-II. The comparison demonstrates a reasonable agreement between computational and reference results. This study infers that the criticality value and excess reactivity are within design limits of CNPP-II and the reactor has a symmetrical flat power distribution, ensuring the safe reactor operation. The deviations between the calculated and experimental results have been explained in this paper. This model is interesting in the sense that it presents a new full core benchmark with experimental validation. This research also reveals that CNPP-II, which is in SMR category, is a safe and reliable reactor.