Intranodal burnup gradient effects in rod power recovery

Conference · Thu Jan 01 04:00:00 EST 1987 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:5626662

Little, D C; Liu, Y S; Meliksetian, A

There are two types of heterogeneity in a light water reactor core-structural and burnup-induced heterogeneities. In modern nodal codes, the structural heterogeneity can be accurately accounted for by the advanced homogenization method. Frequently, however, the burnup-induced heterogeneity within a node is ignored. This approximation can introduce very large errors in rod power prediction in assemblies with significant burnup gradient, such as in-board assemblies shuffled from peripheral locations. The Westinghouse advanced nodal code (ANC) is intended as a stand-alone nuclear design code to replace the present discrete finite difference method code. To assure rod power prediction accuracy, a mesh size of four nodes per assembly is used and the burnup gradient is accounted for in the rod power prediction procedure. Considering the significant burnup gradients existing within pressurized water reactor fuel assemblies, the ANC methodology provides the required accuracy for design/licensing evaluations as well as fuel management decisions.

• OSTI ID: 5626662
• Report Number(s): CONF-870601-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 54
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
ACCURACY
BURNUP
ERRORS
FINITE DIFFERENCE METHOD
FUEL ASSEMBLIES
HOMOGENIZATION METHODS
ITERATIVE METHODS
KINETICS
MATHEMATICAL MODELS
NUMERICAL SOLUTION
POWER DISTRIBUTION
PWR TYPE REACTORS
REACTOR KINETICS
REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS