ML19254F632
| ML19254F632 | |
| Person / Time | |
|---|---|
| Site: | Perkins, Cherokee  |
| Issue date: | 11/05/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Dail L DUKE POWER CO. |
| References | |
| NUDOCS 7911160116 | |
| Download: ML19254F632 (2) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION g
' iIj 8 REGION il r
o 101 MARIETTA ST N.W.. SulTE 3100 V
ATLANTA. GEORGIA 30303 o
In Reply Refer To:
NOV 5 7979 RII:JPO 50-488, 50-489 50-490, 50-491 50-492, 50-493 Duke Power Company Attn:
L. C. Dail, Vice President Design Engineering
' Post Office Box 33189 Charlotte, North Carolina 28242 Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular, Bulletin, or NRR Generic Letter will be issued to recommend or request specific licensee actions.
If you have questions regarding the matter, please contact the Director of the appropriate h3C Regional Office.
Sincerely,
?em' James P. O'Reill Director
Enclosures:
1.
IE Information Notice No. 79-26 2.
List of IE Information Notices Issued in the Last Six Months l
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Duke Power Company.
cc w/ encl:
J. T. Moore, Project Manager Post Office Box 422 Gaffney, South Carolina 29340 134/
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SSINS:
6870 Accession No:
7908220133 UNITED STATES NUCI. EAR REGUI.ATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 November 5, 1979 IE Information Notice No. 79-26 BREACH OF CONTAINMENT INTEGRITY
' Description of Circumstances:
On September 14, 1979, the Consumers Power Company (CPC) notified the NRC of discovery at the Palisades Nuclear Generating Plant of a valve misalignment that had resulted in containment integrity being breached for an indeterminate length of time.
While preparing to perform a Type "C" leak test between two manual valves in a 3" bypass line around the main 48" containment purge valve, plant personnel dis-covered that both of these manual isolation valves were locked in the open posi-tion. These valves should have been locked closed.
Investigation by the licensee indicated that the valves may have been improperly positioned since April, 1978, when an efficiency test of the bypass line filters was performed. The plant has operated at power for the major portion of that time period.
The valve misalignment had no actual impact on the public health. Hcwever, in the event of a design basis accident wherein fuel damage and release of primary coolant inside the containment are postulated, the open valves would provide a significant path for a radioactive release from the containment.
The initial design purpose for the bypass system was to provide a long term hydrogencontro}jcapability for the containment atmosphere following a design basis accident.- It was intended that after approximately 30 days following an accident, when containment pressure and activity levels dropped sufficiently to permit venting, this system would be manually valved to vent the containment atmosphere, through high efficiency and charcoal filters, to the exhaust stack.
Thus the components in the bypass line beyond the two manual isolation valves were not designed for the severe service they would be exposed to with the valves 6 ~
open during the initial pressure surge of the design basis accident, and signif-icant uncontrolled release would result. High radiation in th's vicinity of the bypass line would also make immediate closing of the manual isolation valves, even if identified as the source of leakage, an extremely hazardous operation.
The principal cause for this event wa proper use and positioning of these v valve line-up checklist, which is per DUPLICATE DOCUMENT Entire document previously 1/ Current NRC requirements call for entered into system under:
hydrogen buildup. Palisades has recos 7,@fSO/R xNo m
.H 4 No. of pages:
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