Abstract
Reactor core status monitoring techniques have been developed to identify automatically the presence of a fuel assembly and double blade guide at each fuel exchanging step. This paper describes a method to identify the reactor core status using gray scale images obtained by a high resolution digital camera installed at the top of the reactor pool and test results obtained from images taken at an actual nuclear power generating plant. We developed a lattice mapping method for top guide positional data mapping on the reactor core images and a pattern matching method using the initial core image as the reference one. Evaluation testing of the system was carried out using more than 10 half reactor core images. We found the overall identification rate was about 96% for 1,825 image samples having the size of a fuel assembly. The processing time for identifying a half reactor core image including about 400 image samples was 60 to 90 seconds on a computer with 2.8 GHz CPU. This processing time is much smaller than the time for the shortest fuel exchanging interval.