Degraded Cooling of Spent Fuel Bundles in Irradiated Fuel Bays

Abstract

The thermalhydraulic behaviour and heat transfer from fuel bundles to steam and air have not been examined experimentally in the context of a fuel bay accident. Following on from the heater bundle apparatus developed at Chalk River Laboratories in the 1980s and 1990s to examine fuel element temperatures, the Fuel Bay Heater Apparatus and experimental campaign has been designed at Canadian Nuclear Laboratories (CNL) to address the lack of thermalhydraulic data. The data generated by this campaign is planned to be used to further develop the heat transfer capabilities in the BAY Loss Of Coolant Accident (BAYLOCA) computer code. The experimental apparatus and capabilities, as well as the current modelling assumptions made in BAYLOCA concerning convective heat transfer, will be discussed. Example BAYLOCA calculations of the change in gas temperature within a tray of spent fuel will be used to provide context for further model developments using the data from the experimental program.