Document: NUREG-0800
Document ID: 7e9d3620-7a94-488e-b2d5-992282113080
Document Type: srp
Title: NUREG408OO
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350480.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
NTERLOCKS IN COMBUSTION ENGINEERING REACTORS [BTP has been deleted] ) 7A^12 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB 19 ACCEPTABILITY OF DESIGN-CRITERIA FOR HYDROGEN MIXING AND DRYWELL VACUUM RELIEF SYSTEMS [BTP.has been deleted] 7A-13 Rev. 2 - July 1981 - - BRANCH TECHNICAL POSITION ICSB 20 DESIGN OF INSTRUMENTATION. AND CONTROLS PROVIDED TO ACCOMPLISH CHANGEOVER FROM INJECTION-TO RECIRCULATION MODE A. BACKGROUND Designs are reviewed with regard to the automatic and manual initiation of protective actions, as set forth in paragraph 4.17 of IEEE Std 279; For some recent designs, the staff concluded that the proposed design of the circuits used to change over to the recirculation mode of operation following a loss-of-coolant accident did not conform to IEEE Std 279, and the complexity of the proposed changeover procedure raised questions as to whether the operator could be expected to perform correctly the required actions within the time and based on the information available to him. B. BRANCH TECHNICAL POSITION 1. A design that provides manual initiation at the system level of the transfer to the recirculation mode, while not ideal, is sufficient and satisfies the intent of IEEE Std 279 provided that adequate instrumenta- tion and information display are available to the operator so that he can make the correct decision at the correct time. Furthermore, it should be shown that, in case of operator error, there are sufficient time and information available so that the operator can correct the error, and the consequences of such an error are acceptable. 2. Automatic transfer to the recirculation mode is preferable to manual transfer, for the reasons cited above, and should be provided for standard plant designs submitted for review on a generic basis under the Commission's standardization policy. C. REFERENCES 1. IEEE Std 279, "Criteria for Protection Systems for Nuclear Power Generating Stations." 7A-14 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB 21