METHOD FOR REDUCING NONUNIFORMITY OF THERMAL RESOURCES DISTRIBUTION IN FUEL ASSEMBLIES OF NUCLEAR REACTOR CORE (ALTERNATIVES) Russian patent published in 2003 - IPC

FIELD: cores of water-cooled thermal reactors. SUBSTANCE: method for reducing nonuniformity of thermal resources distribution in reactor core fuel assemblies incorporating fuel elements of main enrichment with respect to fissionable isotopes includes insertion of thermal resources having lower enrichment in high- nonuniformity fuel elements. Fuel placed in fuel elements in vicinity of higher thermal resources has higher enrichment than in vicinity of lower thermal resources. As one of alternatives of this method, fuel used in lower part of peripheral fuel elements is of higher enrichment than that in their upper part. As another alternative of proposed method, fuel disposed in lower parts of peripheral and pre- peripheral fuel elements is of higher enrichment than that in their upper parts. EFFECT: enhanced thermal reliability of fuel assemblies. 3 cl, 5 dwg