Studies on the neutronics design of water-water energetic reactor

Abstract

The nuclear reactor core modeling is a challenging task, due to the many various interior and integrated physical phenomena included in the reactor core. The basic characteristic and neutronic parameters including both criticality and safety parameters as the multiplication factor, temperature coefficient of reactivity, neutron spectrum, and others are considered as fundamental and substantial parameters for design, safety, and control of nuclear power reactors. Subsequently, the calculation of these safety parameters with wide types of codes and data libraries is necessary firstly for verification and secondly for validation purposes, in addition further development of reactor core designs. As a result of the existence of only few analysis carried on the VVER-1200 reactor core, particularly using MCNP code, so the aim of this study is to make full analysis for the behavior of the nuclear criticality and safety parameters in different initial fuel loading prior startup of VVER-1200 core, in various conditions of operational modes, as cold, hot, and also normal states of reactor operation. The investigated criticality and safety parameters involve the effective multiplication factor, reactivity temperature coefficient that contains the effect of system temperature that represents in both fuel and coolant, void coefficient and concentration coeffi- cient, which are affected by the change in boric acid concentra- tion, fuel temperature and coolant temperatures and densities. In