ML20039G245
| ML20039G245 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 12/29/1981 |
| 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, NUDOCS 8201150416 | |
| Download: ML20039G245 (5) | |
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PHILADELPHIA ELECTRIC COMPANY 23O1 M ARKET STREET g
ggQ P.O. BOX 8699 M
PHILADELPHI A. PA.19101
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JOHN $ KEMPER v ic t PR E SID E N T DEC 29 Mr. Ronald C. Haynes, Director Office of Inspection and Enforcement, Region I United States Nuclear Regulatory Commission 631 Pa k Avenue King of Prussia, PA 19406
SUBJECT:
Significant Deficiency Report No. 38 Final Report on Defects in Limitorque Valve Motor Operators Limerick Generating Station Units 1 and 2 NRC Construction Permit Nos. CPPR-106, 107
REFERENCE:
Interim Report No. 1, J. S. Kemper (PECO) to B. H. Grier (USNRC), May 28, 1981 3)
Interim Report No. 2, J. S. Kemper (PECO) to B. H. Grier (USNRC), July 28, 1981 4)
Interim Report No. 3, J. S. Kemper (PECO) to B. H. Grier, (USNRC), Sept. 29, 1981 FILE: QUAL 2-10-2 (SDR 38)
Dear Mr. Haynes:
Attached is our final report regarding certain deficiencies in Limitorque valve motor operators supplied for use at Limerick Generating Station. Previous information was forwarded to you via the references.
8201150416 811229 PDR ADOCK 05000352 97 S
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Mr. Ronald C. Haynes l l
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If there are any questions on the matter we wuld be pleased to discuss them with you.
l Sincerely, fM L I
Copy to:
J. P. Durr, LGS Resident USNRC Inspector Director of Inspection and Enforcement United States Nuclear Regulatory Commission Washington, DC 20555
Limerick Generating Station-Units 1 and 2 Final Significant Deficiency Report No. 38 Defects in Limitorque Valve Motor Operators December, 1981
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.
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 Co rporation.
2.1 A summary 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).
b 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). t 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:
i 2.2.1 Installation of unqualified heaters in motor compartment l
and limit switch compartment.
2.2.2 Limit switch and motor compartment breathers and drain arrangements are not in accordance with arrangements during qualification testing.
- 2.2.3 Missing torque switch limiter plates.
2.2.4 Qualification of grease in limit switch gear box is indeterminate.
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 fall in service and thereby render the motor operator Lmoperable. 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 problems 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.'.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.)
4.6 All heaters in motor units and limit switch compartment 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.)
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4.8 All calibration charts will be checked for clear and proper i
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.)
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4.9.1 All grease in limit switch gear' boxes will be replaced with Mobi1~28..
(Corrective action for Item 2.2.4.)
4.9.2 All grease in the main gear box housing will be replaced with new grease, the type to be determined at a later date.
(Corrective action for Item 2.2.5.)
h This corrective action will be complete by January 1984 for Unit 1 and January 1986 for Unit II.
5.0 CONCLUSION
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The corrective action described in Section 4.0 will correct all deficiencies I
which exist in the motor operated valves.
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