Review of Current Severe Accident Management Approaches in Europe and Identification of Related Modelling Requirements for the Computer Code ASTEC V2.1

The severe accident at Fukushima-Daiichi NPP has led to a worldwide review of nuclear safety approaches and is bringing a refocussing of R&D in the field. To support these efforts several new Euratom FP7 projects have been launched in 2013 like PASSAM and CESAM. The CESAM project (Code for European Severe Accident Management) in particular supports further improvement to the ASTEC (Accident Source Term Evaluation Code) computer code, the reference European code for Severe Accident Analyses which is developed by IRSN/GRS. The development of the ASTEC computer code was strongly supported during many years through the Euratom FP6 and FP7 SARNET I and SARNET II Network of Excellence to which 41 partners participated. Its development continues now through the Euratom FP7 CESAM (Code for European Severe Accident Management from 2013 to 2017) and JASMIN (Joint Advanced Severe Accidents Modelling and Integration for Na-cooled in fast neutron reactors from 2011 to 2015) projects. To cope especially with the situation that happened in Fukushima and the needs identified in Europe following the EU Stress Tests, it has become clear that the ASTEC capabilities should be extended to cover all types of EU NPPs and to model all plant statuses (from full power to shutdown states including the behaviour of the Spent Fuel Pool). This paper is based on the first task performed as part of the CESAM Work Package 40 "Plant applications and Severe Accident Management (SAM)". This task consisted in a review of Severe Accident Management strategies in place or under development on EU NPPs. The target of this review was to precisely identify necessary improvement to the ASTEC V2.1 computer code to ensure that the code can model accurately the different SAM strategies for the different types of EU NPPs. A detailed report on this topic was issued end of December 2013 as 1st deliverable of CESAM WP40. The paper describes work on identifying the requirements for future ASTEC versions in the domain of SAM. It sets out from looking at SAM as it is defined by NPP vendors, utilities or NPPs owner's Group and describes accepted strategies for the prevention and mitigation of accidents. For exemplary strategies, and dwelling on information from European LWR given in the EU stress tests, it provides the systems that are implemented in NPP and that ASTEC will need to model in order to provide full coverage for the inclusion of preventive and mitigative actions during an accident progression.

HERMSMEYER Stephan;  HERRANZ L.;  IGLESIAS R.;  REER B.;  NOWACK H.;  SONNENKALB M;  STEFANOVA A.;  CHATELARD P.;  FOUCHER Laurent;  RAIMOND E;  BARNAK M.;  MATEJOVIC P;  SANCHEZ V.;  LAJTHA G.;  TECHY Z.;  LIND T.;  GREMME Florian;  KOCH M.K.;  BUJAN Albert;  GRAH Aleksander;  PASCAL Ghislain;  PLA FREIXA Patricia;  SANGIORGI Marco;  STRUCIC Miodrag;  VELA GARCIA Monica; 

2015-08-24

INFORUM VERLAGS-VERWALTUNGSGESELLSCHAFT MBH

JRC91604

1431-5254,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC91604,