ML20107C520
| ML20107C520 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 01/23/1985 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| CON-NRC-316, REF-PT21-85, REF-PT21-85-126-000 130, PT21-85-126, PT21-85-126-000, NUDOCS 8502210365 | |
| Download: ML20107C520 (4) | |
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CD&L Carolina Power & Ught Company ill!, N 27562 January 23,1985 Mr. James P. O'Reilly NRC-316 United States Nuclear Regulatory Commission Region II 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 Mr. O'Reilly:
Attached is our fourth interim report on the subject item which was deemed reportable per the provisions of 10CFR50.55(e) and 10CFR, Part 21, on April 27, 1983. CP&L is pursuing this matter, and it is currently projected that corrective action and submission of the final report will be accomplished by April 1,1985.
Thank you for your consioeration in this matter.
Yours very truly, R. M. Parsons Project General Manager Completion Assurance Shearon Harris Nuclear Power Plant RMP/sae Attachment cc:
Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)
Mr. R. C. DeYoung (NRC).
8502210365 950123 gDR ADOCK05ooggo COPY -
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.4-CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO. I FOURTH INTERIM REPORT MAIN REACTOR TRIP BREAKERS ITEM 130 3ANUARY 23,1985 REPORTABLE UNDER '10CFR50.55(e) AND l'0CFR 21 p-e-
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J SUB3ECT:
SH'NPP Unit 1 Main Reactor Trip Breakers, Westinghouse Model DS-416 purchased under NSSS contract with Westinghouse NY-435002, Shop Order 336.
ITEM:
Misoperation of the undervoltage attachments.
SUPPLIED BY:
Westinghouse Electric Corporation Switchgear Division NATURE OF DEFICIENCY:
A design discrepancy exists concerning a retaining ring on the undervoltage attachment pivot shaf ts. Specifically, a design change increased the width of a retaining ring, while the groove in which the retaining ring seats was not changed. This allows improper seating of the retaining ring. The result is that the retaining ring may detach itself from the pivot shaf t 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(e) 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 DROBLEM:
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 is reportable because the deficiency reported may i
affect the ability of safety-related equipment to perform its intended function.
- CORRECTIVE ACTION:
Westinghouse has provided replacement undervoltage attachments which includes a replacement pivot shaf t with wider grooves to accommodate the new retaining ring. Work packages p,
if have been prepared for the change out of the undervoltage trip n
assemblies and work is in progress. The change out necessitates determination /retermination of vendor cables and splices. Since vendor cable splices are unique to approved design specifications, an alternate method is being proposed to the Harris Plant Engineering Section for approval.
- PREVENTIVE ACTION:
1.
Westinghouse has revised manufacturing drawings and quality control procedures to assure.that critical design dimensions are maintained during manufacture.
2.
To prevent trip breaker failure as.a result of any undervoltage attachment malfunction, CP&L is reviewing industry information as a precursor to initiating a design -
change for the automatic dual trip. operation by activating both the undervoltage attachment and the shunt coil-
. attachm6nt on receipt of an automatic undervoltage signal
. from the reactor protection system.
FINAL REPORT: The final report is now pending engineering approval concerni,ng,
the vendor cable splices, receipt of documentation not received -
with replacement assemblies and work completion and -
verification. It is currently projected that the final report will.
be issued by April 1,'1985.
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