Document: NUREG-0800
Document ID: ed948426-dd77-4047-be5e-2b7ab22de3f5
Document Type: srp
Title: FEEDWATER SYSTEM PIPE BREAK INSIDE AND OUTSIDE CONTAINMENT (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550009.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.2.8
CFR Part: 
CFR Title: 

Content:
tion. The SRP is not a substitute for the NRC’s regulations, and compliance with it is not required. However, an applicant is required to identify differences between the design features, analytical techniques, and procedural measures proposed for its facility and the SRP acceptance criteria and evaluate how the proposed alternatives to the SRP acceptance criteria provide acceptable methods of compliance with the NRC regulations. 1. Requirements for maintenance of adequate decay heat removal by the AFWS are in 10 CFR 50.34(f)(1)(ii), (TMI issue II E 1.1) and 10 CFR 50.34(f)(2)(xii), (TMI issue II E 1.2). Requirements for reactor coolant pump (RCP) operation are in 10 CFR 50.34(f)(1)(iii), (TMI issue 2 K 2). The reviewer should see Chapter 20 of the NRC FSAR for AP1000 to see how these post TMI requirements are met by the PRHR, the non-safety related start-up feedwater system (SUFWS) and the canned-motor RCPs of AP1000. 2. Pressure in the reactor coolant and main steam systems should be maintained below 110 percent of the design pressures (American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section III) for low-probability events and below 120 percent for very low-probability events like double-ended guillotine breaks. 3. The potential for core damage is evaluated for an acceptable minimum DNBR remaining above the 95/95 DNBR limit for pressurized-water reactors (PWRs) based on acceptable correlations (see SRP Section 4.4). If the DNBR falls below these values, fuel failure (rod perforation) must be assumed for all rods not meeting these criteria unless, from an acceptable fuel damage model (see SRP Section 4.2) including the potential adverse effects of hydraulic instabilities, fewer failures can be shown to occur. 15.2.8-6 Revision 2 - March 2007 Any fuel damage calculated to occur must be of sufficiently limited extent that the core remains in place and intact with no loss of core cooling capability. 4. Calculated doses at the site