Coresoar Project On Update Of The Core Degradation State-Of-The-Art Report: Status Of Code Reviews

In 1991 the CSNI published the first State-of-the-Art Report on In-Vessel Core Degradation, which was updated to 1995 under the EC 3rd Framework programme. These covered phenomena, experimental programmes, material data, main modelling codes, code assessments, identification of modelling needs, and conclusions including the needs for further research. This knowledge is relevant to such safety issues as in-vessel melt retention of the core, recovery of the core by water reflood, H-2 generation and fission product release.In the following 20 years, there has been substantial progress in understanding, with major experimental programmes finished, e.g. the integral Phebus FP tests and the QUENCH series on reflooding degraded rod bundles, while others have many tests completed, e.g. LIVE on melt pool behaviour in the lower head. These is a similar situation regarding integral modelling codes such as MELCOR and MAAP (USA) and ASTEC (Europe), which encapsulate current knowledge in a quantitative way. After the two EC-funded projects on the SARNET network of excellence, now continuing in the NUGENIA association, it is timely to take stock of the knowledge gained both in the experimental and modelling areas.The CoreSOAR project in NUGENIA/SARNET draws together the experience of 11 European partners to update the state of the art in core degradation over the next two years. The review of available data being well advanced, attention is now focussed on summarising the status of the main modelling codes covering in-vessel core degradation, which enable the knowledge gained to be applied to reactor accident situations in light water reactors. The codes considered here include MAAP, MELCOR and ASTEC as well as other independent codes such as ATHLET-CD and SCDAPSIM. The final CoreSOAR report will serve as a reference point for ongoing research programmes in NUGENIA, in other EC research projects such as in Horizon2020, and in CSNI, e.g. the Fukushima benchmark BSAF2.