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:
n acceptable fuel damage model (see SRP Section 4.2), which includes the potential adverse effects of hydraulic instabilities, that fewer failures occur. Any fuel damage calculated to occur must be of sufficiently limited extent that the core will remain in place and intact with no loss of core cooling capability. 3. The radiological criteria used in the evaluation of steam system pipe break accidents (PWRs only) appear in SRP section 15.0.3. 4. The integrity of the reactor coolant pumps should be maintained such that loss of ac power and containment isolation will not result in pump seal damage. 5. The auxiliary feedwater system or other means of decay heat removal must be safety related and, when required, automatically initiated. In the case of AP1000 the PRHR provides the safety related means of decay heat removal. 6. Tripping of the reactor coolant pumps should be consistent with the resolution to Task Action Plan item II.K.3.5. There are certain assumptions regarding important parameters used to describe the initial plant conditions and postulated system failures which should be used. These are listed below: 1. The reactor power level and number of operating loops assumed at the initiation of the transient should correspond to the operating condition which maximizes the consequences of the accident. These assumed initial conditions will vary with the particular NSSS design, and sensitivity studies will be required to determine the most conservative combination of power level and plant operating mode. These sensitivity studies may be presented in a generic report and referenced in the SAR. 2. Assumptions as to the loss of offsite power and the time of loss should be made to study their effects on the consequences of the accident. A loss of offsite power may occur simultaneously with the pipe break or during the accident, or offsite power may not be lost. Analyses should be made to determine the most conservative assumption appropriate to the particular plant