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
CFR Part: 
CFR Title: 

Content:
amic structural response. (3) The time variation of the jet thrust forcing function should be related to the pressure, enthalpy and volume of fluid in the upstream-reservoir, and the capability of the reservoir to supply a high energy flow stream to the break area for a significant interval. The shape of the transient function may be modified by considering the break area and the system flow conditions, the piping friction losses, the flow directional changes, and the application of flow limiting devices. (4) The jet thrust force may be represented by a steady state function if the energy balance model or the static model is used in the subsequent pipe motion analysis. In either case, a step function amplified as indicated in subsection III.2.b(2) or 2.b(3), above, is acceptable. The function should have a magnitude not less than T = KpA where p = system pressure prior to pipe break A = pipe break area, and K = thrust coefficient. To be acceptable, K values should not be less than 1.26 for steam, saturated water, or stream-water mixtures, or 2.0 for 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 not be such as to impair or preclude essential functions. Assumptions that are acceptable in modeling jet impingement forces are: 3.6.2-7 Rev. 1.- July 1981 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 equiv- alent to the jet thrust force as defined in subsection Ill.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-