Estimate of the Possibility of a Self-Sustaining Nuclear Chain Reaction Accompanying Core Meltdown in a Research Reactor with IRT-M Type Fuel Assemblies

Computational estimates are made of the possibility of a self-sustaining nuclear chain reaction in beyond design basis accidents with core meltdown in a research reactor, where IRT-3M or IRT-4M fuel assemblies with high- and low-enrichment fuel are used. The certified MCU-PTR Monte Carlo code is used for the computational estimates. A conservative approach (estimaticphon from above) is used. It is shown that a selfsustaining nuclear chain reaction is impossible during core meltdown.