Document: NUREG-0800
Document ID: 2717fe7f-71fd-4f1e-bd08-7685b24763ba
Document Type: srp
Title: Standard Review Plans are prepared for the guidance of the Office of Nuclear Reactor Regulation staff responsible for th
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0301/ML030160606.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15
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Content:
ative. The degree of conservatism in the overall evaluation model must be quantified and documented for the particular application in order to justify a reduction in assessment requirements using this argument. 6.4 Extent of plant or operational changes that require a reanalysis The level of effort required to apply the process should be commensurate with the extent of changes made to the plant design or operation. Most of the changes to plant equipment or operations do not cause the plant to operate outside the range of validity of the evaluation model. In this case no additional development and assessment needs to be performed. This may not be the case for all changes. Examples of changes that may require changes to or additional assessment of the evaluation model are fuel bundle design changes (including grid spacer and intermediate flow mixer design changes), increases in the peak linear heat generation rate or operational changes that may cause reliance on a different safety grade trip which requires that accurate prediction of a quantity not required in the previous analysis. In these cases a limited application of the review process similar to that described in section 6.1 should be sufficient. IV. EVALUATION FINDINGS The reviewers should document all findings in an evaluation model safety evaluation report (SER) that either accepts the evaluation model for the intended use or rejects the evaluation model. Acceptance may be subject to limitations determined during the review. If the evaluation model is to be accepted, it must be clearly demonstrated that the model is getting the right answer for the right reasons. There must be no evidence of compensating errors or arbitrary code tuning that produces the desired result for a single parameter. Any errors found in the documentation or issues related to the technical adequacy of the model must be addressed through the review process. The review process and the results of communications with the code submitter