ML20216B540
| ML20216B540 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/08/1998 |
| From: | Sorensen J NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-282-98-03, 50-282-98-3, 50-306-98-03, 50-306-98-3, NUDOCS 9804130500 | |
| Download: ML20216B540 (4) | |
Text
o, Northern states Power Company Prairie island Nuclear Generating Plant 1717 Wakonade Dr. E.
Welch, MN 55089 April 8,1998 10 CFR Part 2 U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 l
PRAIRIE ISLAND NUCLEAR GENERATING STATION Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Response to Notice of Violation (Inspection Report 98003)
Inadequate Review of Logic Circuits During Test and Maintenance Activities Your letter of March 12,1998, which transmitted Inspection Report No. 98003, required a response to a Notice of Violation. Our response to the notice is contained in the attachment to this letter, j
Your letter of March 12,1998 made reference to three documented previous events in which an inadequate review of logic circuits led to problems during maintenance or testing activities. These three events: (1)"D2 Diesel Generator Functional Test" on 9-25-96, (2)" Transfer Buses 21 and 22 from 2RX to 1RX Transformer" on 5 97, and (3) " Unit 1 Turbine Torsional Testing" on 12-15-97 have been reviewed I
against the corrective actions described in the attached Response to Notice of Violation, We believe that the proposed corrective actions when complete will prevent the future occurrence of events similar to these three events.
I in addition to the actions which led directly to the violation, construction work at the Training Center was identified by the Prairie Island Error Reduction Task Force (ERTF) as a contributing event. Two questions related to this contributing event that were raised in the final report, ERTF 98-02, are being pursued to identify if further actions exist that would provide effective assurance that safety significant switchyard i
errors will not occur:
(1)
An NSP corporate task force, that is evaluating the conduct of substation work, will examine the issues associated with the application of the nuclear station modification process to substation equipment outside the jurisdiction of the plant.
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9804130500 980408 PDR ADOCK 0500o282 G
USNRC NORTHERN STATES POWER COMPANY April 8,1998 Page 2 (2)'
System Control Center (SCC) management and Prairie Island plant management are examining the issues associated with moving the I
Jurisdiction boundary in the switchyard.
In this response we have made two new NRC commitments as noted by bold Italics j
under Corrective Steps to Avoid Further Violations. If you have any questions i
concerning this response, please contact John Stanton at 612-388-1121 x4083.
l Joel P. Sorensen Plant Manager Prairie Island Nuclear Generating Plant c:
Regional Administrator-Ill, NRC l
NRR Project Manager, NRC Senior Resident inspector, NRC State of Minnesota, Attn: Kris Sanda J. E Silberg Attachment Response to Notice of Violation (Inspection Report 98003) l l
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Attachment I
Response to Notice of Violation (Inspection Report 98003)
Violation:
Criterion V, " Instructions, Procedures, and Drawings," of Appendix B of 10 CFR Part 50 requires in part, that activities affecting quality be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances.
Contrary to the above, on January 21,1998, the Instructions in Work Order 9800310, " Isolate Breaker 1H3," were not appropriate to the circumstances because following the instructions resulted in an unexpected loss of one offsite power source to Unit 2, temporary loss of safeguards Bus 26, and actuation of the automatic bus sequencer, part of an engineered safety feature system.
Reason for Violation:
The cause of this event was an inadequate review of breaker protection logic by the system engineer, that resulted in inappropriate instructions in a work order. The uniqueness of the breaker failure scheme for breaker 1H3 was not identified when preparing the Work Order.
Determining the combined effect of the tripped ground fault lockout relays and the opening of the breaker DC control power supply switch on the breaker failure protective relaying scheme required branching from one electrical drawing to another. An incorrect conclusion was reached when all referenced electrical drawings and protection logic diagrams were not used.
The review of the 1H3 breaker failure logic did not detect that this logic used an auxiliary relay versus a breaker position auxiliary contact for the breaker failure scheme. More details of this event have been described in LER 29801.
Corrective Actions Taken and Results Achieved:
Procedure 5AWI 3.2.2," Work Control Package Preparations and Review," has been revised to add an additional review for work orders issued for substation equipment under plant jurisdiction. Revision 17 was issued on 2/13/98.
I Procedure SAWI 3.12.3, " Substation Work Control," has been revised to add a detailed second level engineering review for work orders issued for substation equipment under plant l
jurisdiction. ACDM 1998-0005 to Revision 2 was issued on 2/13/98.
Since the occurrence of this violation, two w. orders have been executed in the switchyard l
without any further adverse events.
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E Attachment Pags 2 l-Corrective Stoos To Avoid Further ViolationRI l
As a short term action, a memo will be issued to the electrical system engineering l
section that communicates the management expectations for the preparation and review of work orders.
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As a long term action, a study of the review requirements in Work Control AWIs will be l
conducted to Identify the scope of reviews and define the criteria required of each review.
Date When Full Comollance Will Be Achieved; Full compliance has been achieved.
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