Severe Accident Analysis of Stagnation Feeder Break Scenarios Using MAAP4-CANDU for Application to the Level 2 PSA for the POINT LEPREAU Station Refurbishment Project

Abstract

A Level 2 Probabilistic Safety Assessment was performed for the Point Lepreau Generating Station. The MAAP4‑CANDU code was used in this study to calculate the progression of postulated severe core damage accidents and fission product releases. Five representative severe core damage accidents were selected for this assessment: Station Blackout, Small Loss-of-Coolant Accident, Stagnation Feeder Break, Steam Generator Tube Rupture, and Shutdown State Accident. Analysis results for the reference Stagnation Feeder Break scenario are discussed in this paper. The major findings of this study are that the calandria vessel did not fail, containment did not fail, and therefore the release of fission products to the environment during this scenario is predicted to be very low.