PWR Fuel Cycle Increased Enrichment, Combination of Burnable Absorbers

Assessment of the opportunity for development of various durability fuel cycles for PWR-type reactors using the increased enrichment fuel TVS-K. The combination of gadolinium oxide in U-Gd fuel rods and erbium oxide evenly distributed along regular fuel rods is used as a burnable absorber. The paper contains the calculation results for a great number of fuel cycles in the PWR-type reactor that differ in terms of the number of fresh fuel assemblies and average fuel enrichments, the analysis of such fuel efficiency indicators as durability of the fuel inventory operation at full power and burnup of the unloaded fuel. The estimations were obtained using the approximation models, which parameters had been identified based on three-dimensional calculations for a great number of fuel cycles in the PWR-type reactor. Using the combination of burnable absorbers enables to produce the fuel cycles of various durability. Varying the number of U-Gd fuel rods and content of erbium in regular fuel rods facilitates the control of such fuel cycle parameters as power distribution, reactivity coefficients, and critical concentration of boron acid. The completed studies resulted in characterization of properties for 18- and 24-months fuel cycles.