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:
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 the normal-conditions model. For example, the consideration of seismic events and dropped loads should include descriptions of the credible rack deformation and/or relocation. The process for identifying abnormal conditions should include consideration of common-mode failures, whereby multiple criticality controls may be lost because of single initiating events such as a facility fire or dropped load. Fighting fires in and around the dry, fresh fuel storage racks should be identified as an abnormal condition. The range of parameter deviation for this event includes the consideration of optimum moderation by hydrogenous-based fire fighting techniques and moderation by full-density water. Accidental or erroneous placement of a fuel assembly outside of, but next to, the fuel storage racks should be considered as an abnormal condition. Abnormal conditions should include consideration of fuel assemblies loaded into storage racks not approved for their storage (e.g., fuel not meeting minimum burnup requirements stored in burnup credit storage racks). The reviewer verifies that the process used to identify abnormal conditions is sound, that the abnormal-conditions descriptions are comprehensive, and that the logic used to envelop or eliminate from consideration one or more classes of abnormal conditions is sound. The reviewer verifies that required abnormal conditions, such as consideration of optimum moderation in dry, fresh fuel storage racks, are identified as abnormal conditions. H. The reviewer evaluates the abnormal-conditions models to verify that abnormal conditions are modeled correctly and that all modeling approximations and assumptions are appropriate. The abnormal-conditions computational models should be described. Such descriptions should include, but are not