Document: NUREG-0800
Document ID: 28c03fd2-3542-41ec-bfd7-5df2087c4ee6
Document Type: srp
Title: FUEL SYSTEM DESIGN
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070407.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.2
CFR Part: 
CFR Title: 

Content:
and distortion Fuel rod ridging (PCI) 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 prior to operation of a full core of that design. This 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.D below). Although needed in fuel performance codes, this model is reviewed as described in SRP * Section 4.4. DRAFT Rev. 3 - April 1996 4.2-12 3. 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. (a) Fuel Temperatures (Stored Energy): Fuel temperatures and stored energy during normal operation are needed as input to ECCS performance calculations. The temperature calculations require complex computer codes that model many different phenomena. Regulatory Guide 1.157 describes models, correlations, data, and methods for a realistic calculation of ECCS performance during a LOCA and for estimating the uncertainty in that calculation. Alternatively, an ECCS evaluation model may be developed in conformance with the acceptable features of Appendix K of 10 CFR 50. Phenomenological models that should be 53 reviewed include the following: Radial power distribution Fuel and cladding temperature distribution Burnup distribution in the fuel Thermal conductivity of the fuel, cladding, cladding crud, and oxidation layers Densification of the fuel Thermal expansion of the fuel and cladding Fission gas