Analysis of Uncertainties in Power Pulse Calculations Following a LOCA

Abstract

A study has been carried out to assess the sensitivity of fuel power transients to variations in key physics and thermal hydraulic modelling input parameters. The purpose is to examine the influence of these parameters on the power pulse following a large LOCA. The predicted key results (such as bulk, hot bundle and hot channel energy deposition), thus obtained, are then compared with those of the reference case. The key parameters considered for this assessment are delayed neutron data, prompt neutron lifetime, decay power and the fuel to coolant heat transfer model. It is found that the maximum increase in power pulse is approximately 14 percent or lower. Therefore, the sensitivity of the power pulse to input modelling parameters does not change drastically for the variations considered in these parameters.