Simulation of the physical effects of the interaction of molten fuel with the coolant

Conclusions The method proposed makes it possible to obtain computational estimates of the intensity of a steam explosion inside a reactor vessel and in the space below the reactor inside the melt trap. The computational investigations of the intensity of a steam explosion inside a VVéR vessel in the most likely scenario of a serious accident with efflux of melt into the bottom pressurized chamber show that under certain conditions a high pressure capable of destroying separate structural elements can develop. The mass of the interacting melt, the initial temperature, the fragmentation time, and the final size of the fragments, as well as the type of contact realized, have the greatest effect on the intensity of the steam explosion. Local steam explosions in pipes of the melt trap have a relatively low intensity and cannot have a large effect on the construction in the space below the reactor and on the containment envelope. Deceased. State Science Center of the Russian Federation — Physics and Power Engineering Institute. Translated from Atomnaya énergiya, Vol. 80, No. 1, pp. 3–10, January, 1996.