Document: NUREG-0800
Document ID: b3748a15-3b80-4626-a0a5-eb9f270739ad
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS ASSOCIATED
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340555.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
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CFR Title: 

Content:
uniformly distributed across the cross- sectional area of the jet, and only the portion intercepted by the target is considered. e. The break opening may be assumed to be a circular orifice of cross- sectional flow area equal to the effective flow area of the break. f. Jet expansion within a zone of five pipe diameters from the break location is acceptable if substantiated by a valid analysis or testing, i.e., Moody's expansion model (Ref. 6). However, jet expansion is applicable to steam or water-steam mixtures only, and should not be applied to cases of saturated water or subcooled water blowdown. 4. Analyses of pipe break dynamic effects on mechanical components and supports should include the effects of both internal reactor pressure vessel asym- metric pressurization loads and expand asymmetric compartment pressurization loads, as appropriate, as discussed for PWR primary systems in Reference 7. IV. EVALUATION FINDINGS The reviewer verifies that sufficient information has been provided and that his review supports conclusions of the following type, to be included in the staff's safety evaluation report: The staff evaluation concludes that the pipe rupture postulation and the associated effects are adequately considered in the plant design, and therefore are acceptable and meet the requirements of General Design Criterion 4. This conclusion is based on the following: 1. The proposed pipe rupture locations have been adequately assumed and the design of piping restraints and measures to deal with the subsequent dynamic effects of pipe whip and jet impingement provide adequate protection to the integrity and functionality of safety-related structures, systems, and components. 2. The provisions for protection against dynamic effects associated with pipe ruptures of the reactor coolant pressure boundary inside containment and the resulting discharging fluid provide adequate assurance that design basis loss-of-coolant accidents will not be aggravated by sequential