ANALYSIS OF CONTROL ROD REACTIVITY WORTHS FOR AVR POWER-PLANT AT COLDAND HOT CONDITIONS

The control rod worths of the AVR power plant for the cold and hot con ditions were analyzed to verify an analysis method of reflector contro l rod worths. In the analysis method, the neutron-flux-weighting metho d was used to obtain the effective group constants of the control rod inserted in the graphite nose. The control rod worths were calculated with the core analysis code system for the High Temperature engineerin g Test Reactor (HTTR). The experimental values of the control rod wort hs were 6.47 and 6.81%DELTArho for the cold and hot conditions, respec tively. The differences between the experimental and analytical values for the cold and hot conditions were 2 and 10%, respectively. From th ese results, it was made clear that the analysis method applied here p redicts well the control rod worth of the AVR power plant and is appli cable for the nuclear designs of reflector control rods of future smal l HTGRs.