Application of reliability analysis methods to the Rapsodie reactor

A study has been made of the variation in the failure rate as a function of the total operating time of the Rapsodie fast reactor, for operation at 24 MW(th) from May 1967 to February 1970 and for operation at 37 MW(th) subsequently (Fortissimo version). In both cases, classical bathtub curves were obtained - without the rise characteristic of wear and tear. The failure rates for both Rapsodie and Fortissimo are very close to 4.3x10-3, giving a mean time between failures of 230 hours. On the other hand, the duration of teething troubles is considerably greater in the case of Rapsodie than in that of Fortissimo. These results relate only to incidents which occurred during reactor operation and which entailed a variation in power. For the classification of incidents, a degree of acuteness is assigned to failures of different componetns on the basis of a dimensionless number, A, defined for that purpose