ML20138B529
| ML20138B529 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 10/07/1985 |
| From: | Whittier G Maine Yankee |
| To: | Butcher E Office of Nuclear Reactor Regulation |
| References | |
| 635OL-FWS, GDW-85-250, MN-85-169, NUDOCS 8510150387 | |
| Download: ML20138B529 (2) | |
Text
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o MAIRE HARHEE ATOMIOPOWERComPARUe avausu0*S"a%
h (207) 623-3521 October 7, 1985 g
MN-85-169 GDW-85-250 Director of Nuclear Reactor Regulation United States Ntclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. Edward J. Butcher, Jr.
Acting Branch Chief Operating Reactors Branch No. 3 Division of Licensing
References:
(a) License No. OPR-36 (Docket No. 50-309)
( b) WAPCo Letter to USNRC dated April 23, 1985 -
Containment Isolation Valves Under Adninistrative Controls (MN-85-76) - Proposed Chang 9 #114 (c) USNRC Letter to WAPCo dated December 26, 1984 - Safety Evaluation for Amendment 80
Subject:
Significant Hazard Considerations for Proposed Change #114 Gentlemen:
In Reference (b), Maine Yankee submitted Proposed Changes to our Technical Specification to add certain manual containment isolation valves to the list of those which may be repositioned under administrative controls without corrpensatory measures being taken to isolate the penetration. This submittal was based upon the need to test our post accident sampling system. Subsequent discussions with our Project Manager, Mr. P. Sears, indicate that you require additional discussion of the matter of significant hazards consideration in order to complete your review of this application.
All five valves which we request to be added to the list control
, containment air flow through small bore piping. Should a design basis accident occur while these valves are aligned to permit discharge of containment gas to the atmosphere, all flow would be through the safety class deep bed charcoal filters and the HEPA filters.
In addition, the valves IA-212 and 213, when opened for the purpose of flow testing, result in a closed loop being formed in which flow is returned to the containment atmosphere via the air particulate detector line.
Each of these valves is opened only briefly to verify flow during the periodic surveillance testing of the containment hydrogen monitoring system and an operator is stationed nearby during the period of time that the valve remains open. Should an abnormal event occur during the time that these valves are open, the operator would be instructed to promptly close them.
Additionally, these valves were installed in a system that was designed to be opened in the post accident time period in order to obtain samples.
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MAINE YANKEE ATOMIC POWER COMPANY l
United States Nuclear Regulatory Commission Page Two Attention: Mr. Edward J. Butcher, Jr.
MN-85-169 In Reference (c), the Staff evaluated the original list of valves which may be repositioned under administrative control without compensatory measures taken to isolate the penetration and found that for a variety of reasons that it was an acceptable practice.
In. addition, such repositioning of valves is permitted in standard technical specifications (NUREG-0212).
Since the potential consequences of an accident occurring with these valves open is essentially identical to the consequences of an accident with other valves.in the list.open, this change would not significantly increase the consequences of a previously analyzed accident.
Since none of the:s valves is an active component of the reactor coolant system, the operation or-failure of any of these valves would not, of itself, result in an accident. Therefore, this change will not increase the probability of an accident occurring. Neither does it create the possibility of a new or unanalyzed accident nor result in a significant reduction in a margin of safety. Therefore, we conclude that this Proposed Change does not involve a significant hazard consideration as defined by 10 CFR 50.92.
If you have any questions, please feel free to contact me.
Very truly yours, MAINE YANKEE ATOMIC POWER COWANY bhN G. D. Whittier, Manager Nuclear Engineering.& Licensing 3
GDW/bjp cc: Dr. Thomas E. Murley Mr. Cornelius F. Holden 1
6350L-FWS-
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