Spent VVER fuel storage subcriticality investigation

The experimental method used on the LR-0 critical assembly to estimate the subcriticality of the spent fuel compact storage configurations is described. The experimental results obtained both for the VVER-1000 and VVER-440 assemblies are presented. Several calculations supporting experiments on the LR-0 critical assembly with a driver zone and a subcritical part of the core related to a spent fuel storage design were carried out. Using the ANISN and DOT 4.2 codes one and two dimensional criticality calculations resulted in finding out both z-axis power density behavior and the range of its asymptotic part. These calculations justify the applicability of the experimental method. Subcriticality calculations for all the experimental configurations modeling compact storage pools were performed by the WIMS code. The comparison of numerical results and experimental data was done