ML20079P198
| ML20079P198 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/24/1983 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SDR-38, NUDOCS 8303040554 | |
| Download: ML20079P198 (4) | |
Text
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4 PHILADELPHIA ELECTRIC COMPANY 23O1 M ARKET STREET P.O. BOX 8699 PHILADELPHIA PA.19101 FEB 241983
- osu s. -, m VIC E-PR ESID E NT ENGINEE RING A40 RESE ARCH Mr. Ronald C. Haynes, Director United States Nuclear Regulatory Ceramission Office of Inspection and Enforcement, Region I 631 Park Avenue King of Prussia, PA 19406
SUBJECT:
Significant Deficiency Report No. 38 Final Report on Defects in Limitorque Motor Operator (Revised)
Limerick Generating Station, Units 1 and 2 88 ' M )I NRC Construction Permits Nos. CPPR-106 & 107
REFERENCE:
J. S. Kemper (PECO) Letter to NRC dated December 19, 1981 FILE: QUAL 2-10-2 (SDR 38)
Dear Mr. Haynes:
In accordance with the above referenced letter, attached is our revised final report on the subject deficiency. It has been revised to give a more definitive description of the corrective actions being taken. We do not anticipate that these corrective actions will impact our construction schedule or fuel load dates.
If there are any questions on this matter we would be pleased to discuss them with you.
Sincerely,
.YS$f Copy to: Director of Inspection and Enforcement United States Nuclear Regulatory Commission Washington, D.C.
20555 S. K. Chaudhary, Resident NRC Inspection (Limerick) 8303040554 830224 PDR ADOCK 05000352 S
PDR h
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Limerick Generating Station-Units 1 and 2 Final Significant Deficiency Report No. 38
. Defects in Limitorque Valve Motor Operators December, 1981
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Revised January, 1983
1.0 INTRODUCTION
This is our final report'regarding certain deficiencies in Limitorque valve motor operators supplied for use at Limerick Generating Station.-
Previous information was forwarded to the USNRC via Interim Reports 1, 2, and 3 dated May 28, July 28 and September 29, 1981, respectively.
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This revised Final Report is being submitted.to give a more definitive description of the corrective actions being taken in the Limitorque motor operator rework program.
2.0 DESCRIPTION
OF PROBLEM Upon notification of potential deficiencies with Limitorque operators on the Limerick project, a sample inspection of 39 out of approximately 450 safety-related motor operated valves was performed by Bechtel Power j
Corporation.
2.1 A sammary of the deficiencies found by this sample inspection is as follows:
2.1.1 Improper attachment of terminal lugs to wires (on 37 valves).
2.1.2 Disconnected and improperly routed wires (on 5 valves).
2.1.3 Damaged terminal blocks and loosely connected wires at terminal blocks (on 2 valves).
2.1.4 Unqualified splices in wiring (on 14 valves).
2.1.5 Cracked or overdrilled limit switch rotors (on 27 valves).
2.1.6 Loose contact screws on torque switches (on 1 valve).
2.1.7 Damaged gaskets (on 20 valves).
2.2 Other Items not covered in Item 2.1 which might prevent the motor operator valves from functioning correctly are as follows:
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2.2.1 Installation of unqualified heaters in limit switch compartment.
(No heaters are located in motor compartment.)
2.2.2 Lindt switch and motor compartment breathers and drain arrangements are not in accordance with arrangements during qualification testing.
SDR-38-1
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2.2.3 Missing torque switch limiter plates.
hh 2.2.4 Deleted (The grease in the limit switch gear box is qualified.)
2.2.5 Qualification of grease in main gear box is indeterminate.
2.2.6 Fiber shims under torque switch contact screws which relax and allow the screws to loosen.
3.0 ANALYSIS OF SAFETY IMPLICATIONS Poorly terminated or disconnected wires (Item 2.1.2) can be postulated to fail in service and thereby render the motor operator inoperable. Also excessive elongation of the roll pin hole in the limit switch rotor (Item 2.1.5) and loose contact screws in the torque switches (Item 2.1.6) can render the motor operator inoperable. Presence of unqualified components in the operators could result in premature operator failure. Therefore, safe operation of Limerick could have been compromised had these
-conditions gone undetected and uncorrected.
4.0 CORRECTIVE ACTION All safety related operators will be inspected and the following corrective action will be taken:
4.1 The terminal blocks will be eliminated and external cables will be wired directly to the motor operator elements. This will correct the problem of Items 2.1.1, 2.1.2 and 2.1.3 above.
4.2 All existing splices will be replaced with qualified splices.
(Corrective action for Item 2.1.4.)
4.3 All limit switch rotors found cracked or overdrilled will be replaced with new rotors.
(Corrective action for Item 2.1.5.)
4.4.1 All fiber shims under torque switch contact screws will be replaced with metallic shims.
(corrective action for Item 2.2.6.)
4.4.2 All torque switches with stripped threads in the contact screws will be replaced.
(corrective action for Item 2.1.6.)
4.5 All damaged gaskets will be replaced.
(corrective action for Item 2.1.7.)
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4.6 All heaters in limit switch compartments will be removed.
(Corrective action for Item 2.2.1.)
4.7 All motor units will be checked for installation of drain plugs in accordance with the recommendations of Limitorque. All drains and breathers will be removed from limit switch units.
(Corrective action for Item 2.2.2.)
SDR-38-2 o
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w 4.8.- All. calibration charts will be checked for clear and proper setting ~
- markings and to determine if~a' limiter plate is required. Where required, new calibration charts and missing' limiter plates will be installed.
(Corrective action for Item 2.2.3.)
-@'l'4.9.1
- Deleted.
4.9.2 All grease in the main gear box housing will be replaced with new grease, the type to be Exxon Nebula EPO.
(Corrective Action for Item 2.2.5.).
- 4. 9. 3' Internals.of all safety' related motor operators will be examined. Any other failures or defects will be identified and corrected. This corrective action will be complete by January 1984 for Unit I and January 1988 for Unit II.
5.'O CONCLUSIONS The corrective action described in Section 4.0 will correct all deficiencies which exist in the motor operated valves.
SDR-38-3
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