Generic approach for designing and implementing a passive autocatalytic recombiner PAR-system in nuclear power plant containments

Abstract

PARSOAR project is one of the scientific projects on hydrogen risk in nuclear power plants co-sponsored by the European Commission in the Fifth Euratom Framework Program and the Swiss government. It is one of the components of the “Safety Accident Management” (SAM) cluster that is focusing on review of severe accident risks and on development of countermeasures for defence-in-depth. The first objective is to carry out a state-of-the-art on passive autocatalytic recombiners (PAR) to constitute a database helpful for the PAR-designers, nuclear power plant designers and utilities, and safety authorities. The second objective is to elaborate a handbook guide that defines an approach for implementing catalytic recombiners in nuclear power plants, and that proposes recommended practices to support the detailed implementation by individual nuclear actors. The third objective is to identify the needs in terms of complementary experimental qualification or computer code developments about the hydrogen risk in nuclear power plants. It is also recommended that future experimental tests and numerical modelling should concentrate on the remaining issues of (a) lowering of existing uncertainties about hydrogen sources as core reflood or the reactions between boron carbide and steam or uranium and steam, (b) completing the experimental qualification of catalytic recombiners for existing and future nuclear power plant applications, and (c) performing well-qualified couplings between computational fluid dynamics computer codes and numerical models simulating PAR-behaviour (thanks to some global and well-instrumented experiments reproducing a complete reference accident sequence in presence of catalytic recombiners). Such areas to be considered for future work could be integrated in the scope of a European hydrogen network of excellence, in the framework of the Sixth Euratom Framework Program (2002–2006).