ML19305C202
| ML19305C202 | |
| Person / Time | |
|---|---|
| Site: | Perkins, Cherokee  |
| Issue date: | 03/14/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Dail L DUKE POWER CO. |
| References | |
| NUDOCS 8003260157 | |
| Download: ML19305C202 (2) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION n
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.r REGION 11 o
101 MARIETTA ST N.W SUITE 3100 g
ATLANTA, GEORGIA 30303 In ep y Refer To:
50-4 50-492
@J 50-488 50-489 50-490 Duke Power Company Attn:
L. C. Dail, Vice President Design Engineering P. O. Box 33189 Charlotte, NC 28242 Gentlemen:
The enclosed Circular No. 80-04 is forwarded to you for information.
No written response is required.
Should you have any questions related to your understanding of the recommendations on this matter, please contact this office.
Sincerely, James P. O'Reill Director
Enclosures:
1.
IE Circular No. 80-04
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2.
List of Recently Issued IE Circulars
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800326015
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MAR 141980 0
Duke Power Company O cc w/ encl:
J. T. Moore, Proje'et Manager' Post Office Box 422 Gaffney, South Carolina 29340 l
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ENCLOSURE 1 SSINS NO. 6830 i
Accession No.:
UNITED STATES 7912190662 l
NUCLEAR REGULATORY COMMISSION
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OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Circular No. 80-04 Date:
March 14, 1980 Page 1 of 3 SECURING OF THREADED LOCKING DEVICES ON SAFETY-RELATED EQUIPMENT Description of Circumstances:
In recent months, several licensee event reports have been submitted that address the inoperability of safety-related equipment caused by loosened threaded locking devices.
Some of the events are listed below:
MAIN STEAM CHECK VALVE HEX NUT LOCKING DEVICES, TURKEY POINT NO. 3 I.
REPORTABLE OCCURRENCE 250-79-31 (Oct. 22, 1979)
During a planned outage of Turkey Point Unit No. 3 on October 7,1979, a two-inch ir.ternal diameter hex nut was discovered in the internals of a steam supply valve for a moisture separator-reheater.
Investigation revealed that the nut was missing from the disc stud of the 3A main steam check valve.
The disc and disc stud were in the proper position and the The 3B and 3C main steam check valves were valve was fully operable.
inspected and the disc stud, nut and locking washer were in place although some distress was noted on the 3C locking washer in that the tack welds en the locking pin had separated.
The licensee installed an improved locking device on the disc stud on each of the three main steam check valves.
The locking device consists
'sf a tab washer that is prevented from rotating by a pin and by fingers that extended on either side of the valve arm; the tabs are bent up against two faces of the hex r.ut.
The main steam isolation valves (MSIV) have the same type of hex nut locking device.
The valves are Schutte and Koerting SK Type 828.
SLIPPAGE AND MISALIGNMENT OF VALVE LINKAGES, DAVIS-BESSE LICENSEE EVENT II.
REPORT NOS78-101 (Nov. 1, 1978),78-126 (Jan. 26, 1979),79-068 (July 1
19, 1979), and 79-098 (Oct. 30, 1979) f f two service water s stem These reports involve the inope i
valves and one component cooli declared inoperable because th missinq or had loosened to the DUPLICATP DOCUMEl:T ment of the valve linkage. Th The supplier has provided the 1 Entire document previously manual that defines the torque entered into system under:
used to retain the actuator li No. of pages:
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