Prediction of decay heat removal capabilities for LMFBRs and comparison with experiments

The decay heat removal capability of LMFBR plants is investigated in two steps: the transition phase and the established phase of natural circulation. Major parameters affecting the transition phase are briefly reviewed. This paper, then, considers two analytical approaches to study plant behaviour for the established phase, i.e., the long-term heat dissipation capability of the plant. Advanced thermohydraulic system simulation codes (SSC-L and SSC-P) are used to study the response of the CRBRP, FFTF and PHENIX plants. Simplified analyses were also performed for plants, as well as to interpret the actual whole plant test data from PFR, PHENIX and EBR-II. All of these studies have shown that the mixed mean reactor core temperature rise is proportional to the 0.58 exponent of the shutdown steady power level. (orig.)