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:
dynamic response of the pipe run or branch should be performed for each longitudinal and circumferential postulated piping break. The loading condition of a pipe run or branch, prior to the postulated rupture, in terms of internal pressure, temperature, and inertial effects should be used in the evaluation for postulated breaks. For piping pressurized during operation at power, the initial condition should be the greater of the contained energy at hot standby or at 102% power. In the case of a circumferential rupture, the need for a pipe-whip dynamic analysis may be governed by considerations of the available driving energy. Dynamic analysis methods used for calculating piping and restraint system responses to the jet thrust developed followingafter the postulated rupture 30 should adequately account for the following effects: (a) mass inertia and stiffness properties of the system, (b) impact and rebound, (c) elastic and inelastic deformation of piping and restraints, and (d) support boundary conditions. If a crushable material, such as honeycomb, is used, the allowable capacity of crushable material shall be limited to 80% of its rated energy dissipating capacity DRAFT Rev. 2 - April 1996 3.6.2-6 as determined by dynamic testing, at loading rates within +50% of the specified design loading rate. The rated energy dissipating capacity shall be taken as not greater than the area under the load-deflection curve as illustrated in Figure 3.6.2-1. The portion of the curve in which the value of load vs. deflection has departed from the essentially horizontal portion shall not be used. Pure tension members shall be limited to an allowable strain of 50% of the ultimate uniform strain (X ) (see Figure 3.6.2-2(a)). Alternatively, the allowable strain m value may be determined as the value of strain associated with 50% of the ultimate uniform energy absorption capacity as determined by dynamic testing at loading rates within +50% of the specified design loading rate (see