Document: NUREG-0800
Document ID: a41f4aae-e975-45f3-aebc-5519bec72c6e
Document Type: srp
Title: CRITICALITY SAFETY OF FRESH AND SPENT FUEL STORAGE AND HANDLING
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070570006.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.1.1
CFR Part: 
CFR Title: 

Content:
c used to envelop one or more classes of normal conditions is sound. F. The reviewer evaluates the normal-conditions models to verify that normal conditions are modeled correctly and that all modeling approximations and assumptions are appropriate. 9.1.1-8 Revision 3 - March 2007 The normal-conditions computational models should be described. Such descriptions should include modeling assumptions and approximations; handling of dimensional and material tolerances and uncertainties; omitted materials; selection of computer code input options affecting the results; location of the fuel within the storage racks, including consideration of asymmetric fuel placement; and sensitivity studies performed to support normal-conditions model development. Sensitivity studies typically include center-to-center spacing between stored fuel, spacing between storage racks and other structures providing neutron reflection, asymmetric fuel placement, neutron absorber panel areal loading for poisoned racks, steel side-panel thickness for unpoisoned racks, fuel burnup for burnup credit racks, soluble boron concentration and worth for PWR spent fuel racks, and any other parameters used to justify the normal- conditions computational models. The reviewer verifies that normal-conditions models have been prepared for the full range of normal conditions. The reviewer verifies that normal-conditions models conservatively simulate the actual normal operating conditions and that all assumptions and approximations are appropriate. Where possible, detailed three-dimensional models should be used for criticality analyses. G. The reviewer evaluates the identification of abnormal conditions to verify that the scope of considered abnormal conditions is comprehensive. A description should be provided of abnormal conditions to be considered in the criticality analysis and of the process used to identify abnormal conditions. This description should include the credible range of parameter deviation from