ML20028E059
| ML20028E059 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 01/10/1983 |
| From: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 82-023, 82-23, L-83-11, NUDOCS 8301200309 | |
| Download: ML20028E059 (4) | |
Text
. P. O. BOX 14000, JUNO BEACH, FL 33408 FLORIDA POWER & LIGHT COMPANY January 10, 1983 L-83-11 f.$
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Mr. James P. O'Reilly 'c Regional Administrator, Ogion II s U. S. Nuclear Regulator,' Commission 101 Marietta Street, Suit: 300 g Atlanta, Georgia 30303 ,7 N
Re: RII:JP0 ~
Docket No. 50-389, 10 CFR 50.55(e),82-023 Micro-Switch PTK Selector Switches ,
Dear Mr. O'Reilly:
On November 10, 1982, Florida Power & Light Company notified NRC Region II (via telecon between J. Orlowski, FPL, and K. Landis) of a potential 10 CFR 50.55(e) condition existing at St. Lucie Unit 2 Site involving PTK Switches manufactured by Micro Switch.
Pursuant to the requirement of 10 CFR 50.55(e) a final report is attached.
Very truly yours, Robert E. Uhrig Vice President Advanced Systems & Technology REU/J0/ cab cc: Director of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 l
l OFFICLtL_.._. Col'Y.
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8301200209 Ar A PEOPLE. .SER ING PEOPLE
/ Final Deficiency Report Name of Station:
St Lucie Plant - Unit 2 .
Florida Power & Light Company Owneri Architect / Engineer:
Ebasco Services Incorporated November 10, 1982 NRC Notification:
Final Report Filed:
January 10, 1983 W
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'I. Summary To prevent inadvertent actuation of certain systems, which are not recuired during normal reactor power operation, the control circuits are provided with key operated control switches. The key operated switches, type PTK, manufactured by Micro-Switch a Division of Honeywell, are utilized in the St Lucie No. 2 control boards.
II. Description During functional testing' the key operated Micro Switch Type PTK for the pressurizer auxiliary spray valve f ailed.
The key lock operator pulled out of the metal bushing hous-ing, during removal of.the key in the actuate mode, render-ing the switch inoperable. This condition has.occured in more than one instance indicating a possiblity of generic problems. Therefore, the switch manufacturer Micro Switch a Division of Honeywell and the switch supplier Systems Control a Division of MJ Electric Incorporated were con-tacted to evaluate failures.
An investigation by the vendor (Micro Switch) has determined that the plastic barrel which sets inside the metal bushing is dislodged when stress is created frcm removing the key.
The investigation also indicates that d'u ring assembly this plastic barrel is not being properly seated. The barrel doesn't catch enough material (plastic) in the switch as-sembly to hold the key operator securely.
III. Corrective Action Def ective switches have been replaced with spare Class IE switches having the same contact development as the original switches. The plastic barrel is secured to the metal bush-ing by two small pl.,s and only a very thin. layer of plastic which prevents the key assembly from being dislodged, during key removal. To insure the integrity of the PTK switch, shim collars were installed in all Micro Switch Type PTK switches be-ween the plastic key barrel and the outer switch assembly re-taining nut to prevent a recurrence of disengaging the key mechanism.
IV. Safety Implications The key lock switches are employed in the 17 different safety systems. Five (5) of these systems would have to be used in-termittently during safe shutdown, loss of the abi-lity to engage and disengage these systems could create a safety hazard 9
,' IV. (cont'd) and if.left uncorrected could affect plant safety.
V. Conclusion -
The corrective action identified in item III sbove has be'en completed. All pertinent documentation in reference to this condition will be maintained at the site. Our evaluation indicates that the above condition is reportable t*
10CFR5 0. 55 (e) .
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