Source Term Calculations for Loss of Cooling Accident at CANDU Spent Fuel Pool

An investigation of the loss of cooling accident at a CANDU type spent fuel pool is presented. The analysis is intended to understand the potential of the accident to evolve towards a severe accident. The daily refuelling together with the relatively low burnup of the CANDU fuel ensure a large grace time for the intervention (around 2 weeks). Adding make-up water at a flow rate of 1.25 kg/s is sufficient to keep a constant level of water in the pool. However, in case of the refurbishment process (replacement of fuel channels to extend the plant life) a full core is discharged. The potential of a loss of cooling accident to evolve towards a severe accident was detailed investigated by numerical simulation using some of the modules of the ASTEC code. The main results consist of the transfer fraction for the most important elements of the source term. (author)