UNCERTAINTY CONTRIBUTION TO FINAL IN-RACK K(95/95) FROM THE IN-CORE K.. CRITERION METHODOLOGY FOR SPENT FUEL STORAGE RACK CRITICALTY SAFETY ANALYSES

摘要

The in-core k∞, criterion methodology is identified as an appropriate technique for ensuring compliance with the 0.95 k_(eff) limit for spent fuel pool storage systems. Equations to define the uncertainty associated with a linear fit of the in-core to in-rack reactivity are presented. A method for determining an appropriate lattice for use in bias and tolerance studies is also reported. A study of 12 BWR lattices is used to establish the typical total contribution to the maximum K(95/95) of the rack system from the uncertainty associated with the in-core K∞ criterion methodology.