Document: NUREG-0800
Document ID: 645cc743-c9e4-428c-b05d-ead2517eb3fa
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070315.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
CFR Part: 
CFR Title: 

Content:
subcooled, nonflashing water. 3. Analyses of jet impingement forces are reviewed. These analyses should show that jet impingement loadings on nearby safety-related structures, systems, and components will DRAFT Rev. 2 - April 1996 3.6.2-10 not be such as to impair or preclude essential functions. Assumptions that are acceptable in modeling jet impingement forces are: a. The jet area expands uniformly at a half angle, not exceeding 10 degrees. b. The impinging jet proceeds along a straight path. c. The total impingement force acting on any cross-sectional area of the jet is time and distance invariant, with a total magnitude equivalent to the jet thrust force as defined in subsection III.2.c(4), above. d. The impingement force is 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 asymmetric pressurization loads and expanded asymmetric compartment pressurization loads, as appropriate, as 34 discussed for pressurized water reactor (PWR) primary systems in Reference 7. 35 For standard design certification reviews under 10 CFR Part 52, the procedures above should be followed, as modified by the procedures in SRP Section 14.3 (proposed), to verify that the design set forth in the standard safety analysis report, including inspections, tests, analysis, and acceptance criteria (ITAAC),