ML19305C118
| ML19305C118 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 03/14/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8003260016 | |
| Download: ML19305C118 (1) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
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REGION I
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631 PARK AVENUE Kino oP PnusslA, PENNSYLVANIA 19408 March 14, 1980 Docket Nos. 50-317 50-318 Baltimore Gas and Electric Company ATTN:
Mr. A. E. Lundvall, Jr.
Vice President, Supply P. O. Box 1475 Baltimore, Maryland 21203 Gentlemen:
The enclosed IE Circular No. 80-04, " Securing of Threaded Locking Devices on Safety-Related Equipment," is forwarded to you for information.
No written response is required. If you desire additional information regarding this matter, please contact this office.
Sincerely, e
~~ /
Boyce H. Grier
- Director
Enclosures:
1.
IE Circular No. 80-04 2.
List of Recently Issued IE Circulars CONTACT:
L. E. Tripp (215-337-5232) cc w/encls:
R. M. Douglass, Manager, Quality Assurance L. B. Russell, Chief Engineer T. Sydnor, General Supervisor, Operations QA R. C. L. Olson, Senior Engineer K. H. Sebra, Principal Engineer 8003260016
ENCLOSURE 1 SSINS NO. 6830 Accession No.:
UNITED STATES 7912190662 NUCLEAR REGULATORY COMMISSION 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-RELATEC CTIIPMENT 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:
I.
MAIN STEAM CHECK VALVE HEX NUT LOCKING DEVICES, TURKEY POINT NO. 3 REPORTABLE OCCURRENCE 250-79-31 (Oct. 22, 1979)
During a planned outage of Turkey Point Unit No. 3 on Octcber 7, 1979, a two-inch internal 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 valve was fully operable.
The 3B and 3C main steam check valves were 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 on 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 of 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 nut. The main steam isolation valves (MSIV) have the same type of hex nut locking device.
The valves are Schutte and Koerting SK Type 828.
II.
SLIPPAGE AND MISALIGNMENT OF VALVE LINKAGES, DAVIS-BESSE LICENSEE EVENT REPORT NOS78-101 (Nov. 1, 1978),78-126 (Jan. 26, 1979),79-068 (July 19, 1979), and 79-098 (Oct. 30, 1979)
These reports involve the inop service water s stem valves and one component cooli declared inoperable because th missing cr had loosened to the DUPLICATE DOCUbunEP ment of the valve linkage.
Th The supplier has provided the 1 Entire document previously manual that defines the torque entered into system under:
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