On Line Monitoring the Reactor Power Distribution Based on the Data Library of the Eigenfunctions

A method of on-line monitoring for commercial PWRs using eigenfunctions has been proposed in prevenient works. In this method, the eigenfunctions combine with the detector readings are used to reconstruct the real reactor power distribution. But it is very difficult to choose the eigenfunctions because the condition of the reactor is much complex. Therefore, some improvements on this method are studied in this paper. A number of representational conditions according to the reactor fuel management are picked up to create a data library of different eigenfunctions. On the monitoring process, the computer will judge that which represen6tational conditions most close to the real reactor condition and choose the eigenfunctions which will be used to reconstruct the reactor core power distribution combine with the detector readings. A reactor of Qinshan Nuclear Power Corporation is studied here as an example. The detector readings are from the simulator. The numerical result shows that this method can reconstruct the reactor power distribution with high speed (about 0.03 seconds for each step) and high accuracy (the relative errors are lower than 3% mostly).