Depletion system compression method with treatment of decay heat

Depletion system defined by the evaluated nuclear data library is usually unnecessarily complex for most reactor physics applications. The depletion system compression methods deal with the projection of the original complex depletion system to more compact ones, provided that the intended accuracy requirements are preserved. The huge number of compression possibilities and the consideration of neutronic-depletion coupling effects are the two major difficulties. Accordingly, a significance analysis based depletion system compression method is proposed in this paper. The analysis is carried out at a finer level, i.e. basic unit compression operations including not only the deletion of nuclides but also reduction of nuclides and deletion of reaction channels, compared with other existing methods. Since the decay heat accuracy requirement is expensive to consider in conventional treatment. A method that makes combined usage of decay heat precursors and target nuclides is proposed. Numerical results based on both thermal and fast spectrum systems demonstrated that the original depletion system can be reduced effectively while all intended accuracy requirements are satisfied.