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:
ak that produced the peak fuel assembly loadings in the primary coolant system and reactor internals analysis) and (2) transient pressure differences that apply loads directly to the fuel assembly. If the earthquake loads are large enough to produce a nonlinear fuel assembly response, input for the seismic analysis should use structure motions corresponding to the reactor primary coolant system analysis for the safe-shutdown earthquake (SSE). If a linear response is produced, a spectral analysis may be used in accordance with the guidelines of RG 1.60. 2. Methods Analytical methods used in performing structural response analyses should be reviewed. The appropriateness of numerical solution techniques should be justified. Linear and nonlinear structural representations (i.e., the modeling) should also be reviewed. Experimental verification of the analytical representation of the fuel assembly components should be provided when practical. The applicant should work a sample problem of a simplified nature, which the reviewer will compare with either hand calculations or results generated with an independent code (NUREG/CR-1019). Although the sample problem should use a structural representation that is as close as possible to the design in question (and, therefore, would vary from one vendor to another), the applicant may make simplifying assumptions (e.g., one might use a three-assembly core region with continuous sinusoidal input). 4.2-30 Revision 3 - March 2007 The sample problem should be designed to exercise various features of the code and reveal their behavior. The sample problem comparison is not, however, designed to show that one code is more conservative than another, but rather to alert the reviewer to major discrepancies so that an explanation can be sought. 3. Uncertainty Allowances The fuel assembly structural models and analytical methods are likely to be conservative; input parameters are also conservative. However, to ensure that the fuel assembly