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:
y Evaluation Report for construction permit application was issued prior to July 1, 1975, the methods described in Section B, Items B.1.a, b, d, e, 9, f, and 9, B.2 through B.4, and B.5.b, c, and d of Branch Technical Position CSB 6-4 should be implemented. For these plants, BTP Items B.1.c and B.5.a, regarding the size of the purge system used during normal plant operation and the justification by acceptable dose consequence analysis, may be waived if the applicant commits to limit the use of the purge system to less than 90 hours per year while the plant is in the startup, power, hot standby and hot shutdown modes of operations. This commitment should be incorporated into the Technical Specifications used in the operation of the plant.49 Item II.E.4.2 of NUREG-0737 and NUREG-0718 requires that containmentContainment purge valves that do not satisfy the operability criteria set 50 forth in Branch Technical Position CSB 6-4 or the Staff Interim Position of October 23, 1979 must be sealed closed as defined in SRP Section 6.2.4, Item II.3.fII.f, during 51 52 operational conditions 1, 2, 3, and 4 (Ref. 23). Furthermore, these valves must be 53 verified to be closed at least every 31 days. (A copy of the Staff Interim Position appears as Attachment 1 to Item II.E.4.2 in NUREG-0737.) These requirements should be 54 incorporated into the technical specifications for operation of the plant.55 o. The use of a closed system inside containment as one of the isolation barriers will be acceptable if the design of the closed system satisfies the following requirements: 1. The system does not communicate with either the reactor coolant system or the containment atmosphere. 2. The system is protected against missiles and pipe whip. 6.2.4-9 DRAFT Rev. 3 - April 1996 3. The system is designated seismic Category I. 4. The system is classified Safety Class 2Quality Group B (Ref. 1210).56 5. The system is designed to withstand temperatures at least equal to the containment design