Document: NUREG-0800
Document ID: 7ed8e5d3-fcfd-49cc-84ad-3b25caba06af
Document Type: srp
Title: STEAM SYSTEM PIPING FAILURES INSIDE AND OUTSIDE OF CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550006.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.1.5
CFR Part: 
CFR Title: 

Content:
ownstream of the main steam isolation valves, (MSIVs) due to a seismically initiated event, only safety related equipment should be assumed operative to mitigate the consequences of the break. 10. For postulated instantaneous pipe failures in seismically qualified portions of the main steam line (inside containment and upstream of the MSIVs), only safety related equipment should be assumed operative. If, in addition, a single malfunction or failure 15.1.5-7 Revision 3 - March 2007 of an active component is postulated, credit may be taken for the use of a backup nonsafety-related component to mitigate the consequences of the break. 11. During the initial 10 minutes of the transient, should credit for operator action be required (e.g., reactor coolant pump trip), an assessment for the limiting consequence must be performed in order to account for operator delay and/or error. Technical Rationale The technical rationale for application of these acceptance criteria to the areas of review addressed by this SRP section is discussed in the following paragraphs: 1. Compliance with GDC 13 requires the provision of instrumentation that is capable of monitoring variables and systems over their anticipated ranges to assure adequate safety, and of controls that can maintain these variables and systems within prescribed operating ranges. GDC 13 applies to this section because the reviewer evaluates the sequence of events, including automatic actuations of protection systems, and manual actions, and determines whether the sequence of events is justified, based upon the expected values of the relevant monitored parameters and instrument indications. 2. Compliance with GDC 17 requires (in part) that onsite and offsite electrical power systems be provided to ensure the functioning of structures, systems, and components important to safety. The safety function for each power system (assuming the other system is not functioning) shall be to provide sufficient capacity and capability to