Probabilistic approach for decay heat uncertainty estimation using URANIE platform and MENDEL depletion code

• A probabilistic approach for decay heat uncertainty assessment is presented.
• 235U and 239Pu fission pulse decay heat are investigated.
• Discrepancy of the yields uncertainties in both JEFF-3.1.1 and ENDF/B-VII.1 is pointed out.
• The effect of fission yields covariance data is highlighted.

The knowledge of the decay heat quantity and the associated uncertainties are important issues for the safety of nuclear facilities. Many codes are available to estimate the decay heat. ORIGEN, FISPACT, DARWIN are part of them. MENDEL is a new depletion code developed at CEA, with new software architecture, devoted to the calculation of physical quantities related to fuel cycle studies, in particular decay heat.The purpose of this paper is to present a probabilistic approach to assess decay heat uncertainty due to the decay data uncertainties from nuclear data evaluation like JEFF-3.1.1 or ENDF/B-VII.1. This probabilistic approach is based both on the MENDEL code and URANIE software which is a CEA uncertainty analysis platform. As preliminary applications, single thermal fission of Uranium 235 and Plutonium 239 are investigated.