An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses—Isotopic Composition Predictions (NUREG/CR-7108, ORNL/TM-2011/509)

On this page:

Download complete document

Publication Information

Manuscript Completed: December 2011
Date Published:
April 2012

Prepared by:
G. Radulescu
I. C. Gauld
G. llas
J. C. Wagner

Oak Ridge National Laboratory
Managed by UT-Battelle, LLC
Oak Ridge, TN 37831-6170

Don Algama, NRC Project Manager

NRC Job Code V6005

Prepared for:
Division of Systems Analysis
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

Availability Notice


Taking credit for the reduced reactivity of spent nuclear fuel in criticality analyses is referred to as burnup credit. Criticality safety evaluations employing burnup credit require validation of the depletion and criticality calculation methods and computer codes with available measurement data. To address the issues of burnup credit criticality validation, the U.S. Nuclear Regulatory Commission initiated a project with Oak Ridge National Laboratory to (1) develop and establish a validation approach for commercial spent nuclear fuel criticality safety evaluations based on best-available data and methods and (2) apply the approach on representative spent nuclear fuel storage and transport systems and conditions to demonstrate its usage and applicability, as well as to provide reference bias and bias uncertainty results. This report describes an approach for establishing depletion code bias and bias uncertainty in terms of a reactivity difference based on comparison of measured and calculated nuclide concentrations.

Page Last Reviewed/Updated Thursday, March 25, 2021