STUDY ON NEUTRONICS CALCULATION METHOD OF SCWR WITH ANNULAR FUEL ASSEMBLY

摘要

Many Supercritical Water Reactor designs have beenproposed all over the world. Annular fuel was employedin SCWR by Xi’an JiaoTong University to achieve lowerfuel center temperature and lower cladding surfacetemperature. Different analysis codes have beendeveloped for these designs. In this article, a neutronicscalculation code for SCWR with annular fuel isdeveloped. This code is compared with Monte-Carlo codedoing both assembly and core calculation. The resultsshowed that the spectra difference of PWRs and SCWRs isthe main reason for assembly calculation errors andconventional assembly homogenization method is notsuitable for SCWRs. Thus the group-collapsing andspatial-averaging method were studied to improve theaccuracy. The few-group structure which contains 14energy groups is used. The “super-assembly” model isemployed to consider effect of reflector. The resultsshowed that the accuracy of effective multiplication factorand radial power was improved.