MCU–RELAP Software Package for Analyzing Accidents and Non-Stationary Processes in the PIK Reactor

The purpose of this work is to elaborate the MCU-RELAP software package for modeling transient regimes in the PIK reactor by way of a self-consistent description of neutronics and thermohydraulic processes. The scheme of the developed MCU–RELAP software package is described, and the application of the package is shown for the example of a beyond design-basis accident in which an element of the CPS is ejected. The reactivity adjustment procedure implemented in the scheme makes it possible to detect and smooth the deviations that appear because of the imprecision of the reactivity characteristics used in dynamic calculations performed within the scope of the point-kinetics approximation used in the RELAP5/MOD3.2 code.