Flexibility study of core fuel management strategy in PWRs

The purposes of this paper are to investigate the capability and flexibility of the core fuel management strategy of a 193-assembly 2-loop reactor utilizing the 17 × 17 fuel assembly. Four different equilibrium cycle scenarios are designed including standard 12-month scheme, standard 18-month scheme, duplex scheme of 16 and 20 months and 24-month scheme. Key safety criteria and fuel economics are evaluated for every pattern. The important factors limiting the fuel management strategy flexibility of the high burnup core are studied. The result shows that the design criteria considered are all satisfied, the cycle length and fuel cost both increase with the feed assembly number and feed enrichment. A high economic performance will be achieved only when the fuel cycle length extension and discharge burnup increase are both set as the constraint conditions. At current high burnup fuel technology condition, the PWR is flexible in its ability to support economic fuel management schemes over a variety of cycle lengths from 12 months to 24 months by adjusting the feed size among a quarter to half of the core assemblies. (authors)