PASSAM · Passive and Active Systems on Severe Accident source term Mitigation

In case of a severe accident in a Nuclear Power Plant (NPP) fission products are released from the degraded fuel and might reach the environment if their confinement is lost and/or bypassed. Given the high radio-toxic nature of fission products for environment and population, their release should be avoided at all costs. This highlights the importance of relying on efficient mitigation systems capable of reducing as much as possible any accidental release. This overall statement becomes even stronger after the accident of last year at Fukushima Daiichi NPP.Current NPPs are furnished with safeguards based on the Design Basis Accident and some extensions to cope with accidents beyond the design bases. So, there are a number of mitigation systems within a NPP, both to accommodate the energy release and to deplete most of potential radioactive emission to the environment. Sprays, suppression pools, high efficiency particle filters, etc. are among those contributing to source term attenuation.The PASSAM project is of an R&D experimental nature, aiming at:Exploring potential enhancement of existing source term mitigation devices,Demonstrating the ability of innovative systems to achieve larger source term attenuation.The understanding gained from in-depth analysis of experimental results will make it possible to produce simple models and/or correlations easy to be implemented in accident analysis codes, this way enhancing code capabilities to model Severe Accident Management guidelines, both for current NPPs and for future ones.The PASSAM project involves nine partners from six countries, coming from diverse organization types: Technical Safety Organizations (IRSN), applied research (CIEMAT, PSI, RSE, VTT), more academic research (CSIC, UniLor) and utilities/industry (EDF, AREVA). They have a strong experience and knowledge of severe accidents and more specifically of Filtered Containment Venting Systems and propose to share the work in a really complementary manner.