The optimized initial set of LOCA surveillance system after refueling in Fangjiashan nuclear power plant

The LOCA surveillance system of the Fangjiashan unit is a system for reconstructing the core power distribution using real-time measurement data of the external power range channel. In order to ensure the accuracy of the LOCA surveillance system to reconstruct the calculation, it is necessary to periodically update relevant parameters of the LOCA surveillance system, especially the transfer-sensitivity matrix (TS matrix). This paper provides a reference to the revised ideas, refurbished after re-set relevant parameters to improve the LOCA surveillance system from 0% FP ∼ 30% FP monitoring accuracy. (authors)