ML19308B704
| ML19308B704 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/23/1976 |
| From: | Shapaker J Office of Nuclear Reactor Regulation |
| To: | Tedesco R Office of Nuclear Reactor Regulation |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001160769 | |
| Download: ML19308B704 (2) | |
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NUCLEAR REGULATORY OCT."/.lsSION i'
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JUG L,' as Robert L. Tedesco, Assistant Director for Plant Systems, DSS 6 THP.U:
Gus C. Lainas, Chief, Containment Systems Branch, DSS, X PROF 0 SED POSITION ON B&W CONTAliciENT ISOLATION SYSTEM Standard Review Plan 6.2.4, Containment Isolation, specifies in Item II.6.
of the Acceptance Criteria that there should be diversity in the parameters sensed f ar the initiation of containment isolation.
We have noted that B&W plarts do not satisfy this criterion. With your concurrence, we plan to implemer.t this acceptance criterion on D&H plants beginning with the Greane Ccunty Nuclear Power Plant and BSAR 205 which is the B&W Standard NSSS design.
A brief description of the Engineered Safety Features Actuation System (ESFAS) for the Greene County Nuclear Power Plant will demonstrate the lack of diversity in the parameters used for B&W plants. The ESFAS is the pro-tection system that initiates action of various engineered safety feature devices to mitigate the consequences of a LOCA or secondary system rupture.
The ESFAS initiates, in part, the following:
1.
Emergency core cooling injection, and secondary system isolation and cooling (ECCI initiation), and 2.
Containment isolation and cooling (CIC initiation).
For ECCI initiation, the ESFAS monitors reactor coolant system pressure, containment pressure (4 psig), and steam line pressure. Upon detection of out-of-limit conditions for these variables, the only lines that will be isolated are the main steam and main feedwater lines, the decay heat removal systen return line, and the makeup and purification system letdown and seal return lines.
Also, safety related lines will open.
For CIC initiation, the ESFAS monitors containment pressure (4 psig). Upon detection of out-of-limit conditions for this variable, the remainder of the lines penetrating containment that are not safety related will be isolated.
It should be noted that the Westinghouse containment isolation philosophy is just the opposite of B&M's, in that the bulk of the lines penetrating contain-ment are isolated by diverse signals, including low containment pressure and safety in ection, and only a few lines are isolated on high containment s
pressure. We believe that B&W should adopt a similar approach and isolate 1,
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d ting the containment using diverse signals, t inment
' essentially all. lines penetra especially those lines that could potentially be open to the con a We therefore plar.
atmosphere such as the containment purge system lines.
l 6.2.4 and to enforce our position as stated in Standard Review P an i
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require ban plants to provide diverse containment isolat on s Greene With your spproval, we will infonn B&W of our intentions via the County and BSAR 205 applications.
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. James W. Shapaker, Section Leader
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Containment Systems Branch Division of Systems Safety cc:
J. Glynn G. Lainas J. Kudrick F. Eltawila T. Greene FILE: Greene County BSAR 205 M
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