MUSA - Management and Uncertainties of Severe Accidents

The dominant contribution of Severe Accidents (SA) to the risk of Nuclear Power Plants (NPP), the complexity of the processes taking place during these events, and the inherent nature of numerical codes used to assess them, makes it mandatory to quantify the uncertainties associated to their estimates. Even though mathematical tools for quantification of code uncertainties and sensitivities have been under development for many years, their application into the SA to Best Estimate (BE) system codes, has not been extensive nor systematic so far. This is the challenge targeted in MUSA: to move beyond the state-of-the-art and facilitate the adoption of the Best Estimate Plus Uncertainty (BEPU) approach within the SA domain. Special emphasis is to be given to Source Term (ST) related figures and the effect on uncertainties on Severe Accident Management (SAM). Both in-reactor and in-Spent Fuel Pools (SFP) scenarios are being addressed.