Document: NUREG-0800
Document ID: 6c5a07e2-91cf-49ae-a450-62551ed6bcef
Document Type: srp
Title: CONTAINMENT ISOLATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340703.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.4
CFR Part: 
CFR Title: 

Content:
it periodic oper- ability testing of the containment isolation system, and leak rate testing of isolation valves. 4. General Design Criteria 55 and 56 as it relates to lines that penetrate the primary containment boundary and either are part of the reactor coolant pressure boundary or connect directly to the containment atmo- sphere being provided with isolation valves as follows: a. One locked closed isolation valve' inside and one locked closed isolation valve outside containment; or b. One automatic-isolation valve inside and one locked closed isolation valve outside containment; or c. One locked closed isolation valve inside and one automatic isolation valve2 outside containment; or d. One automatic isolation valve inside and one automatic isolation valve2 outside containment. 5. General Design Criterion 57 as it relates to lines that penetrate the primary containment boundary and are neither part of the reactor coolant pressure boundary nor connected directly to the containment atmosphere being provided with at least one locked closed, remote-manual, or automatic isolation valve2 outside containment. 'Locked closed isolation valves are defined as sealed closed barriers (see Item II.3.f). 2A simple check valve is not normally an acceptable automatic isolation valve for this application. 6.2.4-3 Rev. 2 - July 1981 6. Appendix K to 10 CFR Part 50 as it relates to the determination of the extent of fuel failure (source term) used in the radiological calculations. The General Design Criteria identified above established requirements for the design, testing, and functional performance of isolation barriers in lines penetrating the primary containment boundary and, in general, required that two isolation in series be used to assure that the isolation function is main- tained assuming any single active failure in the containment isolation provisions. However, containment isolation provisions that differ from the explicit require- ments of General Design Criteria 55 and