Comparative Analysis of Isotopic Composition of VVER-1000 Westinghouse and TVEL Spent Fuel

The paper considers the impact of different operational conditions on VVER-1000 spent fuel isotopic composition. Such operational conditions include the presence or absence of absorber rods in guide tubes of fuel assemblies, changing the concentration of boric acid dissolved in the moderator (water) during the campaign, fuel and/or moderator temperature. Moreover, the impact caused by manufacturing tolerance applied while manufacturing fuel assembly was analyzed by weight of fuel and by its enrichment. Calculations were made for reactor cells of fuel assemblies for VVER-1000. They were composed of the new fuel assemblies of Westinghouse Company and the typical fuel assemblies of Russian TVEL suppliers.