Document: NUREG-0800
Document ID: c23d52ec-d83f-4468-b35e-e8c97fdf2f09
Document Type: srp
Title: CONTAINMENT ISOLATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070461.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.4
CFR Part: 
CFR Title: 

Content:
- April 1996 a. One locked-closed isolation valve inside and one locked-closed isolation valve 1 outside containment; or b. One automatic isolation valve inside and one locked-closed isolation valve 2 outside containment; or c. One locked-closed isolation valve inside and one automatic isolation valve outside containment; or d. One automatic isolation valve inside and one automatic isolation valve outside containment. 5. General Design Criterion 57 (GDC 57), as it relates to lines that penetrate the primary 35 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 valve outside containment. 3 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.36 The General Design Criteria identified above establish requirements for the design, testing, and functional performance of isolation barriers in lines penetrating the primary containment boundary and, in general, require that two isolation valves in series be used to ensure that the 37 isolation function is maintained assuming any single active failure in the containment isolation provisions. However, containment isolation provisions that differ from the explicit requirements of General Design Criteria 55 and 56 are acceptable if the basis for the difference is justified. Specific criteria necessary to meet the relevant requirements of the regulations identified above and guidelines for acceptable alternate containment isolation provisions for certain classes of lines are as follows: a. Regulatory Guide 1.11 describes acceptable containment isolation provisions for instrument lines. In addition, instrument lines that are closed both inside and outside containment, are designed to withstand the pressure and temperature conditions following a loss-of-coolant accident