Document: NUREG-0800
Document ID: 3ea2f0ac-4d7e-464a-b1c4-390c3970f642
Document Type: srp
Title: provides specific thermal-hydraulic criteria.  The available radioactive fission product
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070740002.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.4
CFR Part: 
CFR Title: 

Content:
l and burnable poison rod growth • Fuel rod bowing • Fuel rod, spacer grid, and channel box oxidation and hydride levels • Fuel rod fretting • Fuel assembly growth • Fuel assembly bowing • Channel box wear and distortion • Fuel rod ridging (PCI) 4.2-15 Revision 3 - March 2007 • Crud formation • Fuel rod integrity • Holddown spring relaxation • Spacer grid spring relaxation • Guide tube wear characteristics In some cases, in-reactor testing of a new fuel assembly design or a new design feature cannot be accomplished before operation of the design’s full core. The inability to perform in-reactor testing may result from an incompatibility of the new design with the previous design. In such cases, special attention should be given to the surveillance plans (see Subsection II.4 below). C. Analytical Predictions Some design bases and related parameters can only be evaluated with calculational procedures. The analytical methods that are used to make performance predictions must be reviewed. Many such reviews have been performed establishing numerous examples for the reviewer. The following paragraphs discuss the more established review patterns and provide many related references. i. Fuel Temperatures (Stored Energy). Fuel temperatures and stored energy during normal operation serve as input to ECCS performance calculations. Temperature calculations require complex computer codes that model many different phenomena. RG 1.157 describes models, correlations, data, and methods to realistically calculate ECCS performance during a LOCA and to estimate the uncertainty in that calculation. Alternatively, an ECCS evaluation model may be developed in conformance with the acceptable features of Appendix K to 10 CFR Part 50. Phenomenological models that should be reviewed include the following: • Radial power distribution • Fuel and cladding temperature distribution • Burnup distribution in the fuel • Thermal conductivity of the fuel, cladding,