Implementation and preliminary verification of 3D on-line core monitoring system: SOPHORA

A new on-line core monitoring software system (CMSS), named SOPHORA, is developed by China General Nuclear Power Corporation (CGN). Based on the measured fixing incore detector (FID) readings and on-line core status parameters, the best estimated 3D core power distribution is reconstructed, and the safety relative parameters such as peaking local power margin and minimum DNB margin can be also provided. Pseudo simulated FID signals, which are generated from the core movable incore detector (MID) measurement data, are used as input for SOPHORA to verify and to validate the system accuracy. Comparison results of core power peaking factors between SOPHORA and flux map processing code MAPLE show that the SOPHORA three dimensional core power distribution reconstruction function is reasonable and acceptable.