Document: NUREG-0800
Document ID: 42e7682f-df25-4a6a-94f4-7d44ea029702
Document Type: srp
Title: STEAM SYSTEM PIPING FAILURES INSIDE AND OUTSIDE OF CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070677.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.1.5
CFR Part: 
CFR Title: 

Content:
he requirements to maintain adequate decay heat removal and reactor coolant pump integrity and operation are Items II.E.1.2, II.K.2.1, II.K.2.8, II.K.3.5, II.K.2.16, II.K.3.25, and II.K.3.40 of NUREGs 0694, 0718, and 0737. Requirements for ensuring adequate decay heat removal and reactor coolant pump integrity and operation are specified in 10 CFR 50.34(f)(2)(xii) and 10 CFR 50.34(f)(1)(iii), respectively. In addition, Task Action Plan item II.K.3.5 of NUREG-0737 addresses automatic trip of reactor coolant pumps during a loss-of-coolant accident (LOCA). This issue was resolved in Generic Letters 83-10A through 83-10F, 85-12, 86-05, and 86-06. Specific criteria necessary to meet 34 the relevant requirements of the above regulations are as follows: 1. Pressure in the reactor coolant and main steam systems should be maintained below acceptable design limits, considering potential brittle as well as ductile failures. 2. The potential for core damage is evaluated on the basis that it is acceptable if the minimum DNBR remains above the 95/95 DNBR limit for 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 that do not meet these criteria unless it can be shown, based on an 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 the appendix to this SRP section. 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 must be safety grade and, when required, automatically