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:
3 - April 1996 1. Operating Experience Operating experience with fuel systems of the same or similar design should be described, including the maximum burnup experience . When adherence to 51 specific design criteria can be conclusively demonstrated with operating experience, prototype testing and design analyses that were performed prior to gaining that experience need not be reviewed. Design criteria for fretting wear, oxidation, hydriding, and crud buildup might be addressed in this manner. 2. Prototype Testing When conclusive operating experience is not 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 maximum burnup experience associated with such tests should also be reviewed and considered in relation to the specified maximum burnup limit for the new design. The 52 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