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:
impact on the restraint, an amplification factor of 1.1 should be used to establish the magnitude of the forcing function in order to deter- mine the maximum reaction force of the restraint beyond the first quarter cycle of response. Amplification factors other than 1.1 may be used if Justified by more detailed dynamic analysis. (3) Static Analysis Model: The jet thrust force is represented by a conservatively amplified static loading, and the ruptured system is analyzed statically. An amplification factor can be used to establish the magnitude of the forcing function. However, the factor should be based on a conservative value obtained by 3.6.2-6 Rev. 1 - July 1981 comparison with factors derived from detailed dynamic analyses performed on comparable systems. (4) Other models may be considered if justified. c. Dynamic Analysis Models for Jet Thrust Justified. (1) The time-dependent function representing the thrust force caused by jet flow from a postulated pipe break or crack should include the combined effects of the following: the thrust pulse resulting from the sudden pressure drop at the initial moment of pipe rup- ture; the thrust transient resulting from wave propagation and reflection; and the blowdown thrust resulting from buildup of the discharge flow rate, which may reach steady state if there is a fluid energy reservoir having sufficient capacity to develop a steady jet for a significant interval. Alternatively, a steady state jet thrust function may be used, as outlined in subsec- tion III.2.c(4) below. (2) A rise time not exceeding one millisecond should be used for the initial pulse, unless a combined crack propagation time and break opening time greater than one millisecond can be substan- tiated by experimental data or analytical theory based on dynamic 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