U-600651, Final Deficiency Rept 55-86-02 Re Electrical Lugs Installed on Vendor Leads of Limitorque Operators.Initially Reported on 860508.Affected safety-related motor-operated Valves Verified Acceptable or Reworked Using Listed Methods

Final Deficiency Rept 55-86-02 Re Electrical Lugs Installed on Vendor Leads of Limitorque Operators.Initially Reported on 860508.Affected safety-related motor-operated Valves Verified Acceptable or Reworked Using Listed Methods

ML20207K738
Person / Time
Site:	Clinton
Issue date:	07/17/1986
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
55-86-02, 55-86-2, U-600651, NUDOCS 8607300009
Download: ML20207K738 (6)

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U- 600651 M[

Ll4-E- 97 -17 )-L 1A.120

/LLINOIS POWER OOMPANY CLINTON POAER STATION. P.O. BOX 678. CLINTON. ILLINOIS 61727 Docket No. 50-461 JUL 171986 Mr. James G. Keppler Regional Administrator Region III U. S. Nuclear Regulator 71ssion 799 Roosevelt Road Glen Ellyn, Illinois 60) '

Subject:

Reportable 10CFR50.55(e) Deficiency 55-86-02:

Electrical Lugs Installed on Vendor Leads of Limitorque Operators

Dear Mr. Keppler:

On May 8, 1986, Illinois Power Company (IP) notified Mr. Jablonski, NRC Region III (Ref: IP Record of Coordination Y-200269 dated May 8, 1986) of a potentially reportable deficiency under the provisions of 10CFR50.55(e) concerning electrical lugs installed on the motor leads of certain Limitorque valve operators. Objective evidence was obtained which documents that the lugs installed on the motor leads of certain Limitorque valve operators were not the correct size.

Our investigation of this matter is complete. Illinois Power has reviewed and evaluated the findings associated with this investigation and has determined that the lugs which were above the circular mil range of the lug size required by the vendor for the associated wire size invalidated the lug qualification. An extensive engineering evaluation would be required to determine the effect of these deficiencies on the associated systems to gerform their required safety function if uncorrected. On this basis the issue is considered to be reportable under the provisions of 10CFR50.55(e). This letter represents a final report in accordance with the requirements of 10CFR50.55(e). Attachment A provides the details of our investigation.

We trust that this final report provides you sufficient background information to perform a general assessment of this reportable deficiency and adequately describes our overall approach to resolve this issue.

S i, erely yours, B607300009 e60717 PDR S

ADOCK 05000461 PDR

, P. Hall Vice President RLC/ckc Attachment t JUL 211986

U- 600651 L14-86(07 -17 )-L 1A.120 cc: NRC Resident Office Illinois Department of Nuclear Safety INPO Records Center

ATTACHMENT A ILLINOIS POWER COMPANY CLINTON POWER STATION Docket No. 50-461 Reportable 10CFR50.55(e) Deficiency 55-86-02 Electrical Lugs Installed on Vendor Leads of Limitorque Operators Final Report Statement of Reportable Deficiency / Background The CPS design for terminations of power cables to the motors of valve operators requires a lug-to-lug connection of the field cable to the motor leads for A.C. valve operators and allows either a lug-to-lug connection or termination at the power terminal block for D.C. valve operators. Where lug-to-lug connections were made, it was necessary that the vendor supplied lugs on the motor leads be replaced to provide compatability with the lugging on the field cables.

Illinois Power Company Quality Assurance Department initiated Condition Report (CR) No. 1-86-04-042 which documented a potential problem with the lugs installed on the motor leads of Limitorque valve operators. Preliminary investigation of CR l-86-04-042 identified motor leads for Limitorque valve operators which had incorrectly sized field lugs. Two (2) operators confirmed deficient (by disassembly of the terminations) involved 18 gauge motor leads with 14-16 gauge lugs applied. Consultation with the lug manufacturer determined that this application was unacceptable.

Two hundred eighty-seven (287) safety related Limitorque valve operators may have had field lugs installed on the motor leads. Although lug sizes were generally available through site

documentatica, motor lead sizes were not furnished with vendor documentation. Additionally, the motor leads were not physically marked with the wire size, and the terminations were covered with insulating tape or " heat shrink" which precluded direct observation of the lug / wire size.

Investigation Results/ Corrective Action Preliminary findings indicated that, due to the nature of the application of the lugs, size 18 gauge motor leads were most likely to have the wrong lugs applied. Conversely, due to the ranges of lugs for larger wire sizes (16 gauge and larger), these lugs were judged to be more likely acceptable, although verification was required.

The 287 safety related motor operated valves were verified or reworked with one or more of the following methods:

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ATTACHMENT A (continued)

METHOD I VALVES:

These valves were verified or reworked by:

1) Opening valve limit switch compartment.

2) Removing tape / heat shrink from one termination.

3) Determining stranding and circular mil value of wire.

4) Verifying correct lug application or reworking all leads.

Work documents were written for 183 valves (with motors equal to or less than 1/3 horsepower) initially judged to have a significant chance of having #18 gauge motor leads.

Work documents were later written for 12 additional valves which could not be verified with other methods.

METHOD II VALVES:

By review of termination cards, these valves were determined to be acceptable because lugs used were of a range (16-22 gauge) which are acce7 table for either 16 or 18 i gauge wire. The horsepowers for these motors are all 1/3 or less.

It should be noted that these lugs were applied after a

! limited recognition of this issue in the spring of 1985.

The generic implications of the problem were not seen and r addressed. .

METHOD III VALVES:

l For these valves, documentation was obtained from Reliance Electric, primary supplier to Limitorque for the Clinton Proj ect, for motor lead sizes of motors in this category. This was accomplished by walkdown of the motors, obtaining motor serial numbers and submitting these numbers ta Limitorque/ Reliance. The resultant motor lead sizes which were documented by Limitorque/ Reliance were compared with termination records. Twelve motors were found to be deficient or lacked complete information to assure correct application of lugs, and were reworked by Method I. Motors by vendors other than Reliance (Paramount and Peerless) were verified / reworked in Method I.

METHOD IV VALVES:

These valves, although in safety related piping runs, do not have a safety related function and were not addressed as part of this issue.

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. ATTACHMENT A (continued)

To summarize, the following shows a breakdown of the verification of the 287 safety related valves:

Physical verification / rework (Method I) 195 Verification by documentation (Methods II & III) 72 Non safety function (Method IV) 20 Total 287 Of the 195 valves physically inspected, 44 were found deficient and reworked.

REMEDIAL CORRECTIVE ACTION:

All safety related valves were reworked or verified as described in the investigation.

GENERIC CORRECTIVE ACTION:

It was determined that no further work was to be performed under the Baldwin Associates procedure which covered these original terminations.

CPS Procedure 8492.01 which now governs any work on these terminations was reviewed. A revision to this procedure was initiated to require that each vendor lead of unknown size be verified for wire gauge / circular mil value by specific means. This revision is presently in the approval cycle, with an anticipated issue date of July 31, 1986.

ROOT CAUSE The root cause of the misapplication of lugs on Limitorque operators may be attributed to a series of factors which resulted in an overall misunderstanding regarding the Limitorque motor operator leads furnished. These factors are described below:

1) Various Specifications (K2866A, K2866B, K2882, etc.) under which the valves were furnished, required 14 gauge minimum for " control and power Wiring". Based upon this statement, Baldwin Associates apparently assumed that small horsepower motors had 14 gauge motor leads. Therefore, lugs with a range of 14-16 gauge were specified generally for use. Quality control confirmed that the specified lug was used, but did not generally confirm the associated lead size.

2) Vendor documentation provided with valve operators

(drawings, manual) did not document actual lead size or type.

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ATTACHMENT A (continued)

3) The valve operator motor leads are not physically marked with the information frequently provided (wire size, type, temperature rating, etc.).

4) Although electrical installation Specification K2999 calls for using "the correct lug for the size and type of cable being terminated," there was not a procedure used by Baldwin to describe how an unknown wire size was to be determined. The wire used for these motor leads is multi-stranded type of a class intended for extra flexibility. The visual difference between 18 gauge and 16 gauge is slight and the use of a device which checks the overall diameter of the conductor is not sufficiently accurate for this situation.

5) The motors used for these actuators were built over a

, period of se"3ral years. During this period there was not always consistency in providing the same lead size for similarly rated motors, although all leads used are acceptable for the application.

SAFETY IMPLICATION / SIGNIFICANCE:

The use of lugs which were above the circular mil range of the size required by the vendor for the associated wire size invalidated the lug qualification. An extensive engineering evaluation would be required to determine the effect of these deficiencies on the associated systems to perform their required safety function if uncorrected. On this basis the issue is considered to be reportable under the provisions of 10CFR50.55(e).

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