Under the guidance of the Working Party on Nuclear Criticality Safety (WPNCS), this subgroup will perform a computational comparison exercise on decay heat from a specific Spent Nuclear Fuel assembly (SNF). The results' analysis will focus on the origins of differences between participants, and potential consequences for users of decay heat estimation.

The estimation of SNF decay heat (DH) with, or in the absence of measurement, is mandatory for the verification of wet/dry storage, canister requirements (with temperature limit) and for the design of long-term repositories. How well can we estimate such decay heat, what are the expected biases and potential uncertainties? This subgroup will derive such estimation in the case of a well-defined SNF with an extensive description (good quality experimental data, agreement with the published validation work). The impact from codes, users, inputs, and explicit/implicit parameters will be assessed.
This study will contribute to understanding simulation capabilities for SNF characterization.