ML20116F927
| ML20116F927 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 03/29/1985 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-335, REF-PT21-85, REF-PT21-85-207-000 130, PT21-85-207, PT21-85-207-000, NUDOCS 8505010307 | |
| Download: ML20116F927 (4) | |
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CD&L Carolina Podet[f tigpt Company nj{.
P. O. Box 101, New Hill, NC [2/562 March 29,1985 Dr. J. Nelson Grace NRC-335 United States Nuclear Regulatory Commission Region 11 101 Marietta Street, Northwest (Suite 2900)
Atlanta, GA 30323 CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 MAIN REACTOR TRIP BREAKERS, SHOP ORDER 386, ITEM 130
Dear Dr. Grace:
Attached is our final report on the subject item which was deemed reportable per the provisions of 10CFR50.55(e) and 10CFR, Part 21, on April 27,1983. With this report, Carolina Power &
Light Company considers this matter closed.
if you have any questions regarding this matter, please do not hesitate to contact me.
Yours very truly,
??7ke =~w1--
R. M. Parsons Project General Manager Completion Assurance Shearon Harris Nuclear Power Plant RMP/m]
Attachment cc:
Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)
Mr. R. C. DeYoung (NRC)
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8505010307 850329 PDR ADOCK 05000400 S
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CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO.1 FINAL REPORT MAIN REACTOR TRIP BREAKERS ITEM 130 March 29,1985 REPORTABLE UNDER 10CFR50.55(e) AND 10CFR 21 XEX-se3/3-OS3
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SUB3ECT:
SHNPP Unit 1 Main Reactor Trip Breakers, Westinghouse Model DS-416 purchased under NSSS contract with Westinghouse NY-435002, Shop Order 386.
ITEM:
Misoperation of the undervoltage attachments.
SUPPLIED BY:
Westinghouse Electric Corporation Switchgear Division.
NATURE OF DEFICIENCY:
A design discrepancy existed concerning a retaining ring on the undervoltage attachment pivot shafts.
Specifically, a design change increased the width of a retaining ring, while the groove in which the retaining ring seats was not changed. This allowed improper seating of the retaining ring. The result is that the retaining ring may detach itself from the pivot shaft with the potential for misoperation of the undervoltage attachment.
DATE PROBLEM OCCURRED:
On April 12,1983, Westinghouse informed CP&L (CQL-7343) of a potential problem concerning minimum gap clearances on the same item. On April 21, 1983, Westinghouse informed CP&L (CQL-7360) of a potential problem concerning a retaining ring design discrepancy on the undervoltage attachment.
DATE PROBLEM REPORTED:
On April 18,1983, CP&L (Mr. N. 3. Chiangi) notified the NRC (Mr. C. Hehl) that this item was potentially reportable per 10CFR50.55(c) and 10CFR, Part 21.
On April 27,1983, CP&L (Mr. N. 3. Chiangi) notified the NRC (Mr. A. Hardin) that this item was reportable per 10CFR50.55(e) and 10CFR, Part 21.
SCOPE OF PROBLEM:
This deficiency involves two Unit I reactor trip breakers and two Unit I reactor trip bypass breakers.
SAFETY IMPLICATIONS:
The potential for misoperation of the undervoltage attachment could create a condition wherein the reactor trip breakers might not open on automatic demand from the reactor protection system. This could prevent a safe shutdown of the reactor unless prompt operator action is taken to " manually" trip the reactor.
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-REASON DEFICIENCY IS REPORTABLE: This item was reportable because the deficiency report?d could have affected the ability of safety-related equipment to perform its intended function.
CORRECTIVE ACTION:
Westinghouse provided the replacement undervoltage attachments which included a replacement pivot shaf t with wider grc >ves to accommodate the new retaining ring.
The replacement of the undervoltage attachments has now been accomplished in accordance with approved design documents and work procedures.
PREVENTIVE ACTION:
Westinghouse has informed CP&L that they have revised manufac-turing drawings and quality control procedures to assure that critical design dimensions are maintained during manufacture.
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