Experimental modelling and computer simulation of core debris dispersal

Dispersal of core debris following a postulated high pressure failure of a PWR pressure vessel has been studied experimentally and by computer simulation. This two-part programme aims to improve estimates of the degree of dispersal and the containment pressurisation caused by rapid transfer of chemical and thermal energy from the dispersed debris. The experiments address only the fluid-dynamical aspects of dispersal using a 1/25-scale model of the reactor cavity. The computer model, CORDE, combines the fluid dynamics with the important oxidation and heat transfer processes which would take place in the event of hot debris being ejected into the cavity. The methods employed in the experimental modelling and computer simulation are outlined and some preliminary results from both parts of the programme are presented. (author). 9 refs, 4 figs, 2 tabs