Document: NUREG-0800
Document ID: c19cc314-2790-474c-a714-6a347e37ffb0
Document Type: srp
Title: Draft Revision 6 – August 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A592.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
plications). In these plants, a motor-operated isolation valve (MOIV) and two check valves are provided in series between each safety injection tank and the reactor coolant (primary) system. The MOIVs must be considered to be “operating bypasses” because, when closed, they prevent the safety injection tanks from performing the intended protective function. The Institute of Electrical and Electronics Engineers (IEEE) Standard (Std) 279-1971, “Criteria for Protection Systems for Nuclear Power Generating Stations,” has a requirement for “operating bypasses” which states that the bypasses of a protective function will be removed automatically whenever permissive conditions are not met. IEEE Std 603-1991, “IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations,” contains a similar requirement. This branch technical position (BTP) provides specific guidance in meeting the intent of IEEE Std 279-1971 or IEEE Std 603-1991 for safety injection tank MOIVs. It should be noted that SRP BTP 8-4, “Application of the Single Failure Criterion to Manually Controlled Electrically Operated Valves,” also applies to these isolation valves and should be used in conjunction with this position. B. Branch Technical Position The following features should be incorporated into the design of MOIV systems for safety injection tanks to meet the intent of IEEE Std 279-1971 or IEEE Std 603-1991: 1. Automatic opening of the valves when either primary coolant system pressure exceeds a preselected value (to be specified in the technical specifications), or a safety injection signal is present. Both primary coolant system pressure and safety injection signals should be provided to the valve operator. 2. Visual indication in the control room of the open or closed status of the valve. 3. Bypassed and inoperable status indication in accordance to RG 1.47, “Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety System.” 4. Utilization of a