Document: NUREG-0800
Document ID: 63f62189-691f-402d-9ac9-41fb60ec2261
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1423/ML14230A035.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
CFR Part: 
CFR Title: 

Content:
s should be limited to an allowable strain of 50 percent of the ultimate uniform strain (Xm) (see Figure 3.6.2-2(a)). Alternatively, the allowable strain value may be determined as the value of strain associated with 50 percent of the ultimate uniform energy absorption capacity as determined by dynamic testing at loading rates within +50 percent of the specified design loading rate (see Figure 3.6.2-2(b)). The method of dynamic analysis used should be capable of determining the inelastic behavior of the piping and restraint system within these design limits. 3.6.2-8 Draft Revision 3 – August 2015 Figure 3.6.2-1 Rated energy dissipating capacity Figure 3.6.2-2 Limitations on pure tension members A 10 percent increase of minimum specified design yield strength (Sy) may be used in the analysis to account for strain rate effects. Dynamic analysis methods and procedures presented should include: 3.6.2-9 Draft Revision 3 – August 2015 i. A representative mathematical model of the piping system or piping and restraint system. ii. The dynamic analytical method selected. iii. Solutions for the most severe responses among the piping breaks analyzed. iv. Solutions with demonstrable accuracy or justifiable conservatism. The extent of mathematical modeling and analysis should be governed by the method of dynamic analysis selected. B. Dynamic Analysis Models for Piping Systems. Analysis should be conducted of the postulated ruptured pipe and pipe-whip restraint system response to the fluid dynamic force. Acceptable models for the analysis of American Society of Mechanical Engineers (ASME) Class 1, 2, and 3 piping systems and other nonsafety-class high-energy piping systems include the following: i. Lumped Parameter Analysis Model: Lumped mass points are interconnected by springs to take into account inertia and stiffness properties of the system and time histories of responses are computed by numerical integration, taking into account clearances at restraints and inelastic