Document: NUREG-0800
Document ID: e89cc26c-d19a-42b8-818a-fb598c05ccee
Document Type: srp
Title: PLANT DESIGN FOR PROTECTION AGAINST POSTULATED PIPING FAILURES IN FLUID
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340548.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.1
CFR Part: 
CFR Title: 

Content:
e. 3. Analyses and Effects of Postulated Piping Failures a. To show that the plant arrangement and design features provide the necessary protection of essential systems and components, piping failures should be postulated in accordance with BTP EMEB 3-1, attached to SRP Section 3.6.2. In applying the provisions of BTP EMEB 3-1, each longitudinal or circumferential break in high-energy fluid system piping or leakage crack in moderate- energy fluid system piping should be considered separately as a single postulated initial event occurring during normal plant conditions. An analysis should be made of the effects of each such event, taking into account the provisions of BTP EMEB 3-1 and of the system and component operability considerations of item B.3.b. below. The effects of each postulated piping failure should be shown to result in offsite consequences within the guidelines of 10 CFR Part 100 and to meet the provisions of items B.3.c and d below. b. In analyzing the effects of postulated piping failures, the following assumptions should be made with regard to the operability of systems and components: (1) Offsite power should be assumed to be unavailable if a trip of the turbine-generator system or reactor protection system is a direct consequence of the postulated piping failure. (2) A single active component failure should be assumed in systems used to mitigate consequences of the postulated piping failure and to shut down the reactor, except as noted in item B.3.b.(3) below. The single active component failure is assumed to occur in addition to the postulated piping failure and any direct consequences of the piping failure, such as unit trip and loss of offsite power. 3.6.1-:12 Rev. 2 - October 1990 (3) Where the postulated piping failure is assumed to occur in one of two or more redundant trains of a dual-purpose moderate-energy essential system, i.e., one required to operate during normal plant conditions as well as to shut down the reactor and mitigate the