Document: NUREG-0800
Document ID: 805f7e09-51a2-413b-92af-e23bb9073497
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070493.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
gle Failure Criterion to Manually-Controlled Electrically-Operated Valves 21 Supplemental Guidance for Application of Regulatory Guide 1.47Bypass and Inoperable Status Indication for Engineered Safety Features Systems7 BTP PSB 1 Adequacy of Shutdown ElectronicStation Electric Distribution System 8 Voltages 2 Criteria for Alarms and Indications Associated with Diesel-Generator Unit Bypassed and Inoperable Status 8A-3 DRAFT Rev. 3 - April 1996 BRANCH TECHNICAL POSITION 2 (PSB) DIESEL-GENERATOR RELIABILITY QUALIFICATION TESTING (BTP ICSB-2 (PSB) HAS BEEN SUPERSEDED BY IEEE-387)9 DRAFT Rev. 3 - April 1996 8A-4 BRANCH TECHNICAL POSITION ICSB-4 (PSB) REQUIREMENTS ON MOTOR-OPERATED VALVES IN THE ECCS ACCUMULATOR LINES A. BACKGROUND For many postulated loss-of-coolant accidents, the performance of the emergency core cooling system (ECCS) in pressurized water reactor plants depends upon proper functioning of the safety injection tanks (also referred to as "accumulators" or "flooding tanks" in some applications). 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. IEEE Std 279 (Reference 5) has a requirement for "operating bypasses" which states that the bypasses of a 10 protective function will be removed automatically whenever permissive conditions are not met. This Branch Technical Position provides specific guidance in meeting the intent of IEEE Std 279 for safety injection tank MOIVs. See Reference 3 for further background information regarding this issue.11 It should be noted that BTP ICSB 18 (PSB), "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