ML20004F831
| ML20004F831 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Cooper, Arkansas Nuclear, River Bend, Waterford, South Texas, Comanche Peak, Fort Calhoun, Fort Saint Vrain, Perkins  |
| Issue date: | 03/13/1981 |
| From: | Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| NUDOCS 8106220491 | |
| Download: ML20004F831 (1) | |
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UNITE 3 STATES I-
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,r NUCt. EAR REGULATORY COMMISSION REGloN IV 611 RYAN Pt.AZA DRIVE, SulTE 1000
,8 ARUNGTON. TEXAS 76011 March 13, 1981 MEMORANDUM FOR: Tbae' Listed Bekw FROM:
G. L. Madsen, Chief. Reactor Projects Branch, IE:RIV
SUBJECT:
IE INr0RMATION NOTICE NO. 81-05 Subject IE Information Notice has been sent to the following listed licensees. A copy of the letter to the licensee and the IE Information Notice is attached for your information.
Arkansas Power & Light Company Gulf States Utilities ANO-1 & 2 (50-313; 50-368)
River Bend (50-458; 50-459)
- Nebraska Public Power District Houston Lighting & Power Company Cooper Nuclear Station (50-298)
South Texas (50-498; 50-499)
Omaha Public Power District Kansas Gas & Electric Company Ft. Calhoun (50-285)
Wolf Creek (STN 50-482)
Public Service Company of Colorado Louisiana Power & Light Company Fort St. Vrain (50-267)
Waterford 3 (50-382)
Texas Utilities Generating Company Comanche Peak (50-445; 50-446) bY'$/hd?ln/
G. L. Madsen, Chief Reactor Projects Branch Attachnients:
As stated DISTRIBUTION:
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NUCLEAR REGULATORY COMMISSION OFFICE 0F INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
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IE Information Notice No. 81-05 March 13, 1981 Page 1 of 2 DEGRADED OC SYSTEM AT PALISADES p
Purpose:
The intent of this notice is to enhance nuclear power plant safety by improving the reliability of the direct current (de) distribution system in nuclear power plants.
Toward this end, this information notice alerts holders cf operating licenses and construction permits of an event that degraded the l
de system at the Palisades facility and jeopardized plant safety.
Description of Circumstances:
On January 6, 1181, wh!1e performing monthly surveillance tests on both station batteries, maintenance perJonnel inadvertently opened the breakers from both station batteries to their 125. volt dc buses and left them open for approxi-mately one hour. We view this personnel error as a common-mode failure that, if left uncorrected, would ler.d to a complete station blackout (i.e., total loss of both alternating current (ac) and dc power).
Since the plant was in a normal mode of operatica, de power was being supplied by the ac system via the battery chargers; therefore, de power was never interrupted during this period.
Nevertheless, as described late, the safety of th9 plant was jeopardized.
A loss of offsite power during this ceriod would, in the absence of manual action, result in the loss of all control power, blocking the automatic transfer of power to the onsite diesel generators.
In many designs, such losses would also block the starting of the diesels.
In contrast, the Calisades design would not block the starting of the diesels; however, the loss of control power would block the connecting of the generators to their emergency buses so that a complete station blackout would still result.
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'In either case, the blackout would persist until the battery breakers were manually reclosed or manual actions taken, o.g., manually closing tne breakers from the diesel generators to tneir emergency buses anc tne recuirec down stream load breakers.
During this time the ability of the plant to remove cecay heat wou M be severely restricted.
Since the tripping of tne battery creaKers is not annunciated in the Palisades control room, a subsequent loss of offsite
~ power would lead to an undetected common-mode failure.
Such a failure would be difficult to diagnose, thereby limiting the operator's Mility to take timely i
corrective action.
Consequently, an inordinate amount of th.
muld ce recuired to br.ing the plant to a normal moce of decay heat removal.
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.3-tf-IN 81-05 March 13, 1981 Page 2 of 2 Plants designed to conform with Regulatory Guide 1.47, " Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety," will automatically Elert the operator whenever a battery is disconnected from its bus, thereby precluding a Palisades type of event. As a corrective measure, Palisades is planning to install annunciators in the control room that will alert the operator whenever a station battery has been disconnected from its bus.
The information herein is being provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
Recipients should review the information for p7ssible applicability to their facilities.
If NRC evaluations so indicate, further licansee actions may be requested.
No written response to this Information Notice is required.
If you desire additional information regarding this matter, contact the Director of the appropriate NRC Regional Office.
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J IE Informa!. ion Notice No. 81-05 March 13, 1981 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject'
.Dete Issued To Notice No.
Issued 80-42 Effect Radiation 11/24/80 All power reactor on Hydraulic Snubber Fluid facilities with an Operating License (OL) or Construction Permit (CP) 80-43 Failures of the Continuous 12/5/80 All power roactor Water Level Monitor for facilities with an.
the Scram Discharge Volume Operating License (OL)
- at Dresden Unit No. 2 or Construction Permit (CP) 80-44 Actuation of ECCS in the 12/16/80 All power reactor Recirculation Mode While facilities with an in Hot Shutdown Operating License-(OL) or Construction Permit (CP) 80-45
- Potential Failure of 12/17/80 All pressurized water BWR Backup Manual Scram reactor facilities with Capability an Operating License (0L)
Construction Permit (CP) 81-01 Possible Failures of 1/16/81 All power reactor facilities General Electric Type with an Operating License HFA Relays (OL) Construction Permit (CP) 81-02 Transportation of 1/23/81 All Radiography licensees Radiography Devices t
81-03 Checklist for Licensees 2/12/81 All power reactor Making Notifications of facilities with an Significant Events in Operating License (OL) and Accordance with Near-term Applicants 10 CFR Part 50.72 81-04 Cracking in Main Steam 2/27/31 All power reactor facilities Linos witn an Operating License (OL) or Construction Permit (CP) l 81-06 Failure of ITE Model 3/11/81 Ai1 power reactor facilities K-600 Circuit Breaker
- with an Operating License (OL) or Construction Permit (CP)
Enclosure I
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