ML19323F521
| ML19323F521 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 05/14/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| References | |
| NUDOCS 8005290124 | |
| Download: ML19323F521 (2) | |
Text
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IJNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
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REGION 11 o,
101 MARIETTA ST N.W SUITE 3100
%.....o ATLANTA GEOROBA 30303 In Reply Refer To:
MAY 141980 R3J 0 QO-395,
South' Carolina Electric and Gas Company Attn:
T. C. Nichols, Jr., Vice President Power Production and System Operations Post Office Box 764 Columbia, South Carolina 29218 Gentlemen:
The enclosed Circular No. 80-12, is forwarded to you for information.
If there are any questions related to your understanding of the suggested actions, please contact this office.
Sincerely,
~
2 James P. O'Reilly Director
Enclosures:
1.
IE Circular No. 80-12 2.
List of Recently 1ssued IE Circulars 44
.. - - - -.....8 005290 /Q /
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SSINS No.: 6830 UNITED STATES Accession No.:
NUCLEAR REGULATORY COMMISSION 8005050052 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555
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May 14, 1980
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IE Circular No. 80-12 VALVE-SHAFT-TO-ACTUATOR KEY MAY FALL OUT OF PLACE WHEN MOUNTED BELOW HORIZONTAL AXIS Description of Circumstances:
Tennessee Valley Authority has identified and reported to the NRC a nonconformance on a Bettis Robot-Arm actuator installed on a Pratt Butterfly valve at the Sequoyah nuclear plant.
It is reported (ref. attached 10 CFR 50.55(e) report) that a valve became inoperable when the valve-shaft-to-actuator key fell out of place.
It is further noted that the orientation of this valve assembly was such that the operator was on the bottom of the valve (below the horizontal axis).
The Pratt Butterfly Valve furnished with Battis actuator is designed with a press-fit keyway connection valve / actuator. We believe other manufacturer's connections may be of similar construction and therefore subject to this failure mode.
On May 1, 1980, Pratt Company sent letters to their customers who have these connec-tions (enclosed list). They recommended that their customers review their installa-tion of such connections, and if the keyway is oriented below horizontal, make one of the following field modifications:
1.
Add a spacer bushing, or shim plate to fill the vrn between the top of the shaft and the indicating plate on the actuator.
2.
Locally upset the end of the valve shaft in the area of the keyway using a hand punch in such a way that the key could not work loose.
3.
Install new keys of longer length which extend above the end of the valve shaft whereby the key is up to the actuator plate and could not slip down if inverted.
Recommended Action for Licensee Consideration:
We request that all plants make the above recommended inspection of all connections similar to the above described Bettis/Pratt connection, whether or not supplied by those particular manufacturers.
If connections are found that are susceptible to failtre, one of the above recommended actions or other appropriate action should be taken to correct the potential problem.
No written response to this Circular is required.
If you desire additional informa-tion regarding this matter, contact the Director of the appropriate NRC Regional Office.
{
Attachments:
1.
10 CFR 50.55(e) Report
~
2.
List of Addresses l
ATTACHMENT 1 SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 NCR 19P 10 CFR 50.55(e)
REPORT NO. 1 (FINAL)
LOOSE KEY IN BETTIS ROBOT-ARM VALVE ACTUATORS Description of Condition A containment isolation valve in Unit 1 became inoperable when the key which locks the actuator to the valve shaft fell out of place.
This problem could occur with Bettis Robot-Arm valve actuators (model numbers 732C-SR80, 721C-SR60, 521C-SR60, CB525-SR60) when installed upside down or sideways. With the valve shaft mounted below horizontal, there is a potential for the key to work itself loose.
Safety Implications If the valve actuator were to fall out, it would result in a loss of valve control. Since these valve actuators are on safety-related valves, this condition could have adversely affected or reduced the redundancy of safety-related systems.
Corrective Action TVA has identified 51 suspect operators in the Purge Air System, Emergency Gas Treatment System and the Chilled Water System. Those operators that are installed so that the key can work loose will have spacer bushings installed in the actuator as recommended by the vendor.
Installation of the spacer buchings will be completed before fuel loading. All TVA design project managers are being asked to ensure that this problem does not occur at other TVA nuclear plants.
_ ~
ATTACHMENT 2 LIST OF ADDRESSEES FOR MAY 1 LETTER FROM HENRY PRATT COMPANY Metropolitan Edison - Three Mile Island #2 Arkansas Power & Light Arkansas Nuclear One 1 Wisconsin Public Service - Pioneer Service Kewaunee Northern States Power - Prairie Island I & 2 t
. Baltimore Gas & Electric - Calvert Cliffs 1 & 2 Florida Power Corporation - Crystal River #3 Florida Power & Light - St.
Lucie #1 & 2 Toledo Edison - Davis-Besse #1 Alabama Power Company - Joseph M. Farley 1 & 2 Tennessee Valley Authority - Sequoyah 1 & 2 Pennsylvania Power & Light - Susquehanna 1 & 2 Mississippi Power & Light - Grand Gulf I & 2
' Cleveland Electric Illuminating Company - Perry 1 & 2 Commonwealth Edison Company - Zion 1 & 2 Rochester Gas & Electric - Robert E. Ginna 1 Westinghouse Hanford/FFTF Westinghouse - Phillipines Northeast Utilities - Millstone #3 Tennessee Valley Authority - Stride l
p IE Circular No. 80-12 Enclosure May 14, 1980 RECENTLY ISSUED IE CIRCULARS Circular Subject Date of Issued to No.
Issue 80-12 Valve-Shaft-To-Actuator Key 5/14/80 All holders of a power May Fall Out of Place when reactor OL or CP Mounted Below Horizontal Axis 80-11 Emergency Diesel Generator 5/13/80 All holders of a power Lube Oil Cooler Failures reactor OL or CP 80-10 Failure to Maintain 4/29/80 All holders of Reactor Environmental Qualification OLs and cps of Equipment 80-09 Problems With Plant Internal 4/28/80 All holders of a power Communications Systems reactor OL or CP 80-08 BWR Technical Specification 4/18/80 All General Electric Inconsistency - RPS Response BWR's holding a power Time reactor OL 80-07 Problems with HPCI Turbine 4/3/80 All holders of a power Oil System reactor OL or CP 80-06 Control and Accountability 4/14/80 Medical licensees in Systems for Implant Therapy Categories G and G1 Sources 80-05 Emergency Diesel-Generator 4/1/80 All holders of a power Lubricating Oil Addition and reactor OL or CP Onsite Supply 80-04 Securing of Threaded Locking 3/14/80 All holders of a power Devices on Safety-Related reactor OL or CP Equipment 80-03 Protection from Toxic Gas 3/6/80 All holders of a Hazards power reactor OL 80-02 Nuclear Power Plant Staff 2/1/80 All holders of Reactor Work Hours OLs, including research and test reactors, and
- cps L