Nuclear Safety of an RBMK Spent Fuel Pool

Aspects of the nuclear safety of the spent fuel pools of RMBK reactors under normal conditions and design basis and beyond design basis accidents are studied using a three-dimensional model verified by comparing with Monte Carlo calculations. It is shown that the storage of spent fuel assemblies in pencil-shaped cases secures nuclear safety in the entire range of water density, lattice spacing, and fuel burnup, i.e., in all, including hypothetical, emergency situations. For compact case-free storage, nuclear safety is secured in real scenarios where the water density changes upon disruption of heat removal or flooding of a dewatered pool. The disruption of the lattice spacing of compact storage in design basis, including seismic action, and beyond design basis accidents is examined. The conditions under which nuclear safety is secured are shown.