Methodology for reference accidents definition for RPrS
The safety assessment of ITER presented in the Rapport Prémilinaire de Sûreté (RPrS) for the French Regulator imposes the definition and the study of a limited set of incidental and accidental sequences selected on a deterministic ground. Ultimate safety margins have been analysed through hypothetical sequences conservatively extrapolated from the more significant accidents. The exhaustiveness of the final list of accidents has been independently checked by application of two complementary probabilistic methods (topdown and bottom-up methods). The results of these complementary studies are available in the Generic Site Safety Report (GSSR), but they are not reproduced in the RPrS which needs to be only deterministic and homogenous to the approach required by the French regulator for reprocessing plants and laboratories. In the present state of the ITER project, the only parts concerned by the analysis are the tokamak, the tritium plant and the hot cells. The rationale for event selection consists first to identify every radiological source and its confinement barriers; failure of one or several of these barriers may then be presumed and a scenario defined, following a standardized grid; in any case, the calculations and analysis are achieved following a unique logical scheme to assure consistency and exhaustiveness of the report. Nine accident families have been defined: plasma events, loss of power events, in-vessel events, ex-vessel events, cryostat events, magnet events, maintenance events, tritium plant and fuel events, hot cells events. Calculations with qualified computer codes have shown that the consequences of any postulated accident respect the safety guidelines.
Bibliographic Reference: An oral paper given at: 23rd Symposium on Fusion Technology Organised by: Consorzio RFX Held at: Fondazione Cini, Venice, Italy
Availability: Available from Association EURATOM-CEA, Département de Recherches sur la Fusion Contrôlée, CEA Cadarache, F-13108 St Paul-Lez-Durance, France Tel: (+33) 4 42 25 70 01; Fax: (+33) 4 42 25 64 21 E-mail: email@example.com
Record Number: 200518052 / Last updated on: 2005-04-06
Original language: en
Available languages: en