Optimized 18-months low-leakage core loadings for uprated VVER-1000

Abstract

Abstract The VVER-1000 life extension and power uprating are important areas of research and development activities of JSC “Rosenergoatom”. Recent research has shown that the core baffle resource is one of the major limiting factors for the life extension of the Balakovo NPP unit 3. The core loading optimization is necessary to decrease the core baffle radiation dose for NPP life extension at uprated power. The paper contains the results of the optimization of 18-month low-leakage core loadings for the uprated to 104% Balakovo NPP unit 3. Moreover, the results of the radiation dose calculations at the reactor pressure vessel and core baffle are presented in the work. It is shown that the optimization of the core loadings reduces peaks of radiation doses and flattens its distributions along the core baffle, as well as gives the opportunity to extend the NPP life up to 60 years at the uprated power.