ML20090A672
| ML20090A672 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 06/27/1984 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-235, REF-PT21-84-309-000 180, PT21-84-309, PT21-84-309-000, NUDOCS 8407120070 | |
| Download: ML20090A672 (4) | |
Text
..
CP&L Gicac "
}$
Carolina Power & Light Company p dbu -
P. O. Box 101, New Hill, N. C. 27562 June 27, 1984 Mr. James P. O'Reilly NRC-235 United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Georgia 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 second 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 September 30, 1984.
Thank you for your consideration in this matter.
Very truly yours,
?))?
! f +='
R. M. Parsons Project General Manager Shearon Harris Nuclear Power Plant RMP/j am Attachment cc: Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)
Mr. R. C. DeYoung (NRC) 8407120070 840627 DR ADOCK 05000400 PDR
[OFFICI AL COPY, y}GSY\\
\\
e, CAROLINA POWER & LIGHT COMPANY SHEARON HAL.!: NUCLEAR POWER PLANT UNIT 1 SECOND INTERIM REPORT MAIN REACTOR TRIP BREAKERS ITEM 130 JUNE 27, 1984 REPORTABLE UNDER 10CFR50.55(e) AND 10CFR21
i
SUBJECT:
SHNPP Unit 1 Main Reactor Trip Breakers, Westinghouse Model DS-416 purchased under NSSS contract with
}
Westinghouse NY-435002, Shop Order 386 t
ITEM:
Misoperation of the undervoltage attachments SUPPLIED BY:
Westinghouse Electric Corporation Switchgear Division i
r NATURE OF DEFICIENCY:
A design discrepancy exists concerning a retaining f
ring on the undervoltage attachment pivot shafts.
Specifically, a design change increased the width of I
a retaining ring, while the groove in which the i
retaining ring. seats was not changed. This allows i
improper seating of the retaining r.4ng.
The result is that the retaining ring may detach itself from the pivot shaft with the potential for misoperation of the undervoltage attachment.
i 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. J. Chiangi) notified the NRC (Mr. C. Hehl) that.this item was potentially reportable.
On April 27, 1983, CP&L j
(Mr. N. J. Chiangi) notified the NRC (Mr. A. Hardin) that this item was reportable under 10CFR50.55(e) and 10CFR21.
{
L SCOPE OF PROBLEM:
This deficiency involves two Unit I reactor trip i'
breakers and two Unit I reactor trip bypass breakers.
l t
?
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.
REASON DEFICIENCY:IS REPORTABLE:
This item is reportable because the deficiency reported may affect the ability of safety-related equipment to perform its intended function.
4 -
CORRECTIVE ACTION:
Westinghouse has committed to replacing the undervoltage attachments which includes a replaccment pivot shaft with wider grooves to accommodate the new retaining ring. An installation and alignment procedure has already been provided for the replacement attachments.
T 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 attachment on receipt of an automatic undervoltage signal from the reactor protection system.
FINAL REPORT: Final action on this item could not be completed by June 30, 1984 due to a delay in the delivery of the replacement attachments. CP&L expects to complete the corrective action plan and submit a final report by September 30, 1984.