STRUCTURAL RESPONSE OF A NUCLEAR-POWER-PLANT STEEL CONTAINMENT UNDER H2 DETONATION

At present studies are in progress at ENEA-DISP to assess the performa nce of a steel containment under hydrogen detonation. In this framewor k a number of topics needs to be investigated and they are considered in the present paper. To get a better understanding of the containment wall behaviour under a detonation a simple but complete model is anal ysed in order to study the fluid-structure interaction during the expl osion. The structure is represented by a single degree of freedom (SDO F) elastic-plastic system. This system is coupled to a monodimensional model of the containment atmosphere excited by hydrogen bursting. The atmosphere modeling allows to represent the shock propagation and the reflected wave effects. In the model a cylindrical geometry is used a s reference. The obtained results are compared with data adopted in It aly to assess the structural integrity of the Alto Lazio NPP steel con tainment in the case of a severe accident. The limits of the model as well as the possible extensions are discussed in the paper together wi th a possible application in an experimental program directed to the a ssessment of failure criteria under severe accident conditions.