ML19254F663
| ML19254F663 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 11/05/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Hines E DETROIT EDISON CO. |
| References | |
| NUDOCS 7911160211 | |
| Download: ML19254F663 (1) | |
Text
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/ Sa arogo UNITED STATES 8 A(
NUCLEAR REGULATORY COMMISSION n
E REGION lli
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799 ROOSEVELT ROAD 8
g,.....,o GLEN ELLYN. ILLINOIS 60137 Docket No. 50-341 NOV 5 1979 The Detroit Edison Company ATTN:
Mr. Edward Hines, Assistant Vice President and Manager Quality Assurance 2000 Second Avenue Detroit, MI 48226 Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the infor-mation for poscible applicability to their facilities. No specific action or response is requected at this time.
If further NRC evaluations so indi-cate, 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 NRC Regional Office.
Sincerely, s.b /\\
zyN-u e' James G. Keppler Director
Enclosure:
IE Information Notice No. 79-26 cc w/ encl:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Ronald Callen, Michigan Public Service Commission Eugene B. Thomas, Jr.,
Attorney 1347 305 7911160 25
SSINS:
6870 9
Accession No:
7908220133 UNITED STATES NUCLEAR REGULATORY 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.
However, 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{capabilityforthecontainmentatmospherefollowingadesign 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 open during the initial pressure surge of the design basis accident, and signif-icant uncontrolled release would result.
High radiation in the 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 was inadequacy of the procedures addressing proper use and positioning of these valves.
The master enntainmont intanc h valve line-up checklist, which is per 1/ Current NRC requirements call for DUPLICATE DOCUMENT liydrogen buildup.
Palisades has reco Entire document previously entered into system under:
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