CONTAINMENT PRESSURE LOADS FROM HYDROGEN COMBUSTION IN UNMITIGATED SEVERE ACCIDENTS

Forschungszentrum Karlsruhe conducted and sponsored a study on contain ment loads from hydrogen combustion pressures that could occur in case of an unmitigated severe accident in a future 1500-MW (electric) pres surized water reactor. The analysis of large-scale distribution tests leads to the conclusion that the full spectrum of combustion modes fro m slow deflagration to global detonation must be considered in the abs ence of any hydrogen control system. New experimental and theoretical results are presented for fast flames, deflagration-to-detonation tran sitions, and marginal and stable detonations in hydrogen-air mixtures on reactor relevant scale. Maximum possible combustion loads for sever e accidents are predicted for a typical dome geometry. The results pro vide a database on global combustion loads for design studies on futur e severe accident resistant containments.