Date of Award


Degree Type


Degree Name

Master of Applied Science (MASc)


Engineering Physics


J.C. Luxat




A methodology called the Multi-step Approach to Code-coupling for Progression Induced Severe Accidents in CANDU nuclear power plants (MACPISA-CANDU) was developed and applied. MACPISA-CANDU was used to couple a MATLAB single fuel channel model with a primary heat transport system model developed in MELCOR (MELCOR 1.8.5) to model a small break loss of coolant accident (SBLOCA) in conjunction with a loss of emergency coolant injection (LOECI) in a CANDU 6 nuclear power plant. The specific type of SBLOCA modelled was an individual reactor inlet feeder stagnation break (8.03cm2 ). The early stages of the SBLOCA-LOECI event were the focus of this thesis. 13 seconds after the initiation of the break it was predicted that the pressure tube would heat up to 1473 K and rupture. It is assumed that the calandria tube ruptures along with the pressure tube causing coolant to return to the fuel channel and flow out of the rupture into the calandria vessel. It predicted that the moderator within the calandria vessel would be able to act as an ultimate heat sink and end the transient at 298 seconds. In addition, the MATLAB single fuel channel modelĀ· was replaced by a single fuel channel model created in SCDAP/RELAP5 (RELAP/SCDAPSIM Mod 3.4 (bi7)). The coupled SCDAP/RELAP5-MELCOR simulation predicted that the pressure tube would rupture at 23 seconds and subsequently the transient would end at 403 seconds. The results from both code-coupled simulations are shown to be in reasonable agreement with the results of other validated computer models.

McMaster University Library

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