ML20097B274
| ML20097B274 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 01/30/1996 |
| From: | Kraft E COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF ENFORCEMENT (OE) |
| References | |
| ESK-96-010, ESK-96-10, NUDOCS 9602060396 | |
| Download: ML20097B274 (5) | |
Text
Commonwcalth Edhon Company g
e.
Quad Cities Generating $tahon 22710 2f 6th Asenue North
. Cordos a, II. 612 i2-9740 Tei 3mu>st22 ii ESK-96-010 January 30,1996 Mr. James Lieberman, Director Office of Enforcement U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738
Subject:
Quad Cities Power Station Units 1 and 2; NRC Docket Number 50-254 and 50-265; NRC Inspection Report Numbers 50-254(265)/95007
)
Reference:
A. B. Beach to M. J. Wallace dated January 2,1996, transmitting Notice of Violation and Proposed Imposition of Civil Penalty -
$50,000 (Severity Level III)
Dear Mr. Lieberman:
Enclosed is Commonwealth Edison's (Comed) response to the Notice of Violation transmitted with the referenced letter. The NOV cited one violation involving the failure to promptly correct the potential for safety-related MCCs to trip on current overload.
This violation has been classified in the aggregate as a Severity Level III problem, and assessed a civil penalty of $50,000. Comed's response and payment of the civil penalty is attached.
Ik 9602060396 960130 ful als/
PDR ADOCK 05000254 nesu y
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____.. ~ ~ _ _
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Mr. James Lieberman, Director i
Page 2 l
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We appreciate the NRC's acknowledgement of Quad Cities corrective actions for this violation.
If there are any questions or comments concerning this letter, please refer them to Nick Chrissotimos, Regulatory Assurance, at (309) 654-2241 ext. 3100.
1 Sincerely, Od 4i E. S. Kraft J.
Site Vice > esident Quad Cities Station i
Attachment cc:
II. Miller, Regional Administrator, RIII R. Pulsifer, Project Manager, NRR C. Miller, Senior Resident Inspector, Quad Cities 1
D. C. Tubbs, MidAmerican Energy Company R. J. Singer, MidAmerican Energy Company
1 l
VIOIATION During an NRC inspection conducted on September 2 through October 18,1995, a j
violation of NRC requirements was identified. In accordance with the " General Statement of Policy and Procedure for NRC Enforcement Actions," NUREG-1600, the Nuclear Regulatory Commission proposes to impose a civil penalty pursuant to Section 234 of the Atomic Energy Act of 1954, as amended (Act),42 U.S.C. 2282, and 10 CFR 2.205. The particular violation and associated civil penalty are set forth below:
10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Action," requires, in part, that measures be established to assure that conditions adverse to quality are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition. The identification of the significant condition adverse to quality, the cause of the condition, and the corrective action taken shall be documented and reported to the appropriate levels of management.
Contrary to the above, from June 1994 until October 4,1995, the licensee failed to promptly correct the potential for safety-related 480 VAC motor control centers (MCCS) to trip on current overload, a significant condition adverse to quality. Specifically:
1.
Commonwealth Edison Corporate Engineering performed a study in June 1994 to compare each Quad Cities feed breaker trip settings to its calculated maximum current. The study identified maximum currents of 300,343,472,304,299 amps for MCCs 29-2,18-1B,18-2,28-1B, and 28-2, respectively, which were greater than each breaker's trip setting lower end tolerance of 270 amps.
2.
NRC Unresolved Item 50-254/265/94014-03(DRP) for Quad Cities, issued July 15,1994, stated, in part, that three MCCs at Dresden were found, under certain conditions, to be carrying loads in excess of the setpoint for the long time delay trip of the MCC feed breaker. One safety related feed breaker (MCC 18-2) at Quad Cities Unit 1 was determined to be set too low.
3.
The Dresden Lessons Learned Initial Notification (LLIN 94-059), issued June 20, 1994, alerted Commonwealth Edison Nuclear Stations of the potential that engineered safeguards features (ESF) bus overcurrent relay settings may be too low for all postulated loading conditions (i.e., LOCA with no LOOP).
4.
Dresden's LER 237/94018, " Potential Trip of Motor Control Centers Due to
)
Improper Feed Breaker Settings," was issued July 7,1994. Additionally, Revision 1 to LER 237/94018 was issued December 29,1994, which stated, in part, that the cause of the overloaded condition was a failure to assure that the addition of plant loads over time (load growth) were reviewed for impact on breaker settings, and a failure to review plant operating conditions during the USNRC - Attachment - Page 1 of 3
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development of protective device settings. The LER also alerted the licensee of the need to consider overcurrent trip setting tolerances. Specifically, the LER stated,"The setting of this breaker was 400 amps +10% due to the tolerance of the EC-2A device."
5.
On October 4,1995, the Quad Cities feed breaker for MCC 29-2 tripped from current overload. (01013) i This is a Severity Level III violation (Supplement I). Civil Penalty - $50,000.
Reason for Violation:
Quad Cities performed a review of the safety related MCC loading following the trip of 1
MCC 39-2 at Dresden. This study did not indicate any potential for a feed breaker trip other than for MCC 18-2, which was reset in response to the Dresden event. The review identified maximum current levels of 287 and 298 amps for MCCs 28-2 and 29-2 that were greater than each breaker's trip setting lower end tolerance of 270 amps.
l The review was deficient in that it considered the degraded voltage currents the worst case and breaker tolerances were not used. The worst-case loading for many of the MCCs occurs when surveillances are being performed. The maximum currents for MCC 28-2 and 29-2 should have also been identified as a problem when Revision 1 to Dresden LER 237/94018 was issued December 29,1994. This LER identified the failure to review plant operating conditions during the development of protective device settings.
The LER also alerted the need to consider over current trip settings tolerances.
The notice of violation was incorrect in that it identified maximum amps from the 1994 study of 300,343,472,304,299 amps for MCCs 29-2,18-1B,18-2,28-1B and 28-2 respectively. The numbers from the 1994 study were 298,66,392,7, and 287 amps respectively. The numbers in the 1994 study were from the degraded voltage calculation.
The numbers from your report were from a maximum loading calculation. The numbers in the maximum loading calculation were considered invalid. First the LOCA cases did not include lessons learned from the degraded voltage studies and for non-LOCA cases the ELMS data was overly conservative because it was much higher than actually measured.
Corrective Action Takem Engineering has reviewed the loading for all the safety related MCCs. To prevent any trips administrative limits were imposed and breaker settings were changed.
A level 2 investigation was completed for this issue. The root cause and corrective actions identified by the investigation were forwarded under Revision 1 to LER 265/95006.
USNRC - Attachment - Page 2 of 3
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w Actions to Prevent Further Occurrence j
To ensure the proper review of Nuclear Operating Notifications (NON), a policy has been instituted to write PIFs on all notifications. The PIF process requires an investigation that is reviewed by station management. (THIS ITEM IS COMPLETED)
)
Engineering is evaluating the need for modifications to replace the feed cables for overloaded MCCs with larger cables. (NTS #'s 265-180-95-00601 AND 02)
The responsibility for maintenance of the Electrical Load Monitoring System (ELMS) will be turned over to site design engineering by December 31,1996. Site Engineering will perform a self assessment to be completed by July 31,1997. (NTS # 265-180 00604)
Corporate Engineering has formed an Auxiliary Power Peer Group. The purpose of this group is to ensure electrical power problems are conveyed between the sites. Quad Cities has and will attend this group. (THIS IS COMPLETED)
Date when Full Compliance will be met Full compliance will be met by July 31,1997.
USNRC - Attachment - Page 3 of 3