The paper describes the organizational basis for computer simulation of complex physical processes at one of the most important Russian "weapon" computational institutions. The team passed a way of 50 years long from manual calculations to numerical simulation of various physical phenomena and processes in real, i.e. 2d and 3D, geometries. The paper presents the basic research fields and challenges, describes the generation and development steps of some new scientific approaches in simulation of solid mechanics, energy transfer and radiation transport, numerical studies of hydrodynamic instability etc. The paper addresses also the creation of high performance computers, organizational measures allowing the mathematicians to access the centralized computer kernel in a multiuser network.

An analysis is conducted of the possibility of retaining corium in the vessel of a VVER (PWR) reactor during a severe accident at a nuclear power station (NPS). A series of computational and experimental investigations was carried out, which showed that it is promising to work on the concept of an in-vessel catcher on the basis of a dioxide-zirconium ceramics for a reactor with a power capacity of 1000-1200 MW(e).