Document: NUREG-0800
Document ID: 855b2438-2ddf-48e9-8762-e39097109e12
Document Type: srp
Title: FUEL SYSTEM DESIGN
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340660.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.2
CFR Part: 
CFR Title: 

Content:
ydriding, and crud buildup might be addressed in this manner. 2. Prototype Testing When conclusive operating experience is pot available, as with the introduction of a design change, prototype testing should be reviewed. Out-of-reactor tests should be performed when practical to determine the characteristics of the new design. No definitive requirements have been developed regarding those design features that must be tested prior to irradiation, but the following out-of-reactor tests have been performed for this purpose and will serve as a guide to the reviewer: Spacer grid structural tests Control rod structural and performance tests Fuel assembly structural tests (lateral, axial and torsional stiffness, frequency, and damping) Fuel assembly hydraulic flow tests (lift forces, control rod wear, vibration, and assembly wear and life) In-reactor testing of design features and lead-assembly irradiation of whole assemblies of a new design should be reviewed. The following phenomena that have been tested in this manner in new designs will serve as a guide to the reviewer: Fuel and burnable poison rod growth Fuel rod bowing Fuel assembly growth Fuel assembly bowing Channel box wear 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 4.2-9 Rev. 2 - July 1981 testing may result from an incompatability 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). 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