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
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CFR Title: 

Content:
alculated using the Baker-Just equation (Argonne National Laboratory Report ANL-6548, May 1962). For non-LOCA applications, other correlations may be used if justified. These reaction rate models were originally developed based upon unirradiated Zircaloy test specimens. Zirconium alloy composition, manufacturing process, and in-reactor corrosion alter the reaction rate characteristics of the fuel cladding material. Rulemaking pursuant to 10 CFR 50.46 is planned to implement a performance-based test program to provide an acceptable means for establishing specific reaction rate models for new cladding materials. Future cladding alloys must comply with the new rules and the need to provide an empirical database to support applicable reaction rate models. ix. Fission Product Inventory. The assumptions in RG 1.3, RG 1.4, RG 1.5, RG 1.25, RG 1.77, RG 1.195, and RG 1.196, as they relate to fission product release for existing reactors (i.e., DC applications before January 10, 1997), currently specify the available radioactive fission product inventory in fuel rods (i.e., the gap inventory). RG 1.195 and RG 1.196 can be used in place of RG 1.3, RG 1.4, RG 1.5, RG 1.25, and RG 1.77. RG 1.183 and the requirements of 10 CFR 50.34 apply to fission product release for new reactors. An alternate source term (AST), specified in 10 CFR 50.67, can be applied to existing reactors as an alternative to 10 CFR Part 100 as defined in these documents. American Nuclear Society (ANS) 5.4 presents an approved method for release during non- LOCAs and situations that do not involve accidents in which the fuel temperature exceeds the temperature experienced during normal operation and AOOs. ANS 5.4 also provides an acceptable analytical model for calculating the release of volatile fission products from oxide fuel pellets during normal steady-state conditions. When used with nuclide yields, this model will define the inventory of volatile fission products that could be available for release