ML19309H615

Final Deficiency Rept Submitted for Snupps, Rept on Improperly Crimped Lugs on Electrical Penetration Assemblies Supplied by Bunker Ramo Corp.

ML19309H615
Person / Time
Site:	Wolf Creek, Callaway, 05000586
Issue date:	05/05/1980
From:	BECHTEL GROUP, INC.
To:
Shared Package
ML19309H609	List: ML19309H608 ML19309H615
References
NUDOCS 8005130563
Download: ML19309H615 (7)

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8005130565 REPORT g ON IMPROPERLY CRIMPED LUGS ON ELECTRICAL PENETRATIO9 ASSEMBLIES SUPPLIED BY BUNKER RAM) CORPORATION FOR CALLAWAY PLANT UNIT NO. 1 (UNION ELECTRIC)

AND WOLF CREEK (KANSAS GAS AND ELECTRIC CO.)

Bechtel Power Corporation Gaithersburg, Maryland May 5, 1980

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J TABLE OF CONTnTS l

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{ 1.0 Introduction 1

2.0 Description of Deficiency 3.0 Analysis of Safety Implications l

4.0 Corrective Action I

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1.0 INTRODUCTION

In accordance with the requirements of 10CFR50.55(e), this report is prepared to provide a summary of the improperly crimped lugs in the Bunker Ramo electrical penetration assemblies shipped to Callaway Unit 1 and Wolf Creek Jobsites.

On February 26, 1980, Bechtel and the Utilities were advised that the Constructor found that some penetration wires had pulled out of their associated crimped lugs at Callaway Jobsite. Based on preliminary engineering assessment it was determined that this deficiency was reportable to the NRC per 10CFR50.55(e) and was reported by Union Electric to the NRC I&E Region III on February 26, 1980.

Bunker Ramo was immediately notified of the deficiency and requested to provide a Service Engineer to inspect the penetrations and report on the magnitude, cause of the problem, and corrective action.

Subsequent information supplied by Bunker Ramo indicated that the deficiency could be applicable to the Penetrations at the Wolf Creek l

Jobsite. It was then reported as a SNUPPS generic 10CFR50.55(e)

I deficiency to the NRC I&E Region I oc harch 24, 1980, by SNUPPS QA l 1

Manager. Prior to this generic notification, KGE informed NRC Region IV that a 10CFR Part 21 report was being prepared by Bunker Ramo on this matter.

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2.0 DESCRIPTION

OF DEFICIENCY Hollingsworth ring tongue terminal lugs HDR 22B are used on all #14 and #16 AWG wires in the electrical penetrations. These lugs are I screwed to terminal points on terminal blocks in boxes mounted on either side of the penetrations. Lugs with uninsulated ferrules are crimped on to their associated wires and shrink tubing is then used to insulate the fa.rrule.

Improper crimping can cause wires to pull out (undercrimped) or be cut (overcrimped). Proper crimping tools and procedures are required to assure that the wire and its terminal lug are correctly and permanently attached. Bunker Ramo has procedures for lugging and tool calibration.

l however, implementation problems resulting in undercrimping were not identified until discrepancies were later discovered at the Callaway Jobsite. Bunker Ramo procedures, however, did not provide for inspection for overcrimping.

l At the Callaway Jobsite six or more wires pulled out of their lugs during installation and subsequent hand pull tests by Bechtel and the Constructor. Bunker Ramo's Service Engineer made a partial inspection j I

of 27 penetrations and found at least 32 wires that separated from their lugs during a hand pull test.

Bunker Ramo's assessment of the cause of the deficiency indicates two problems - overcrimping and undercrimping.

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Overeriepics - The Hollingsworth lug used with either #14 or #16 AWG wire is a heavy duty type and the manufacturer requires it to be crimped in the 12-10 tool nest, not the 16-14 nest as would be normally expected.

Bunker Ramo used the 16-14 nest which resulted in overcrimping. The extent of overcrimping has yet to be determined at the jobsites.

Undercrimping - Bunker Ramo used a T & B Sta-Kon crimper for a period of time when the SNUPPS penetrations were being manufactured. This tool is not a full cycle crimper. A full cycle crimper physically requires that a full compression stroke be made once it has been started. The Sta-Kon crimper is dependent on the operator to apply enough compressive force. Bunker Ramo has stated that the operators became fatigued and improperly crimped the lugs resulting in wires that subsequently pulled out of their terminal lugs at the jobsite.

Improper positioning of the conductor in the lug also contributed to the problem with the Sta-Kon crimper. When the penetration assemblers complained of fatigue due to crimping, Bunker Ramo switched to a power cperated crimper which eliminated the undercrimped lugs. Full cycle crimpers were used on all other wire sizes.

During the investigations at Callaway Jobsite of loose lugs, additional possible problems related to suspected improper lug ferrule insulation, loose terminal screws and damaged cables were identified. The lug insulation is as specified and and is not a problem. The loose screws and the damaged cables appcar to be random site related problems which have been resolved in accordance with the existing nonconformance control procedures.

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3.0 ANALYSIS OF SAFETY IMPLICATIONS Had the improperly crimped lugs gone undetected, wires .ould have pulled out or broken rendering Class IE control and instrumentation circuits inoperable. The ability of Class IE circuits to perform their safcty function could have been significantly degraded. The degree of degradation and impact on Safe Shutdown Systems is a function of the number and locations of improper crimps.

4.0 CORRECTIVE ACTION All #14 and #16 terminal lug connections at Callaway Unit 1 and Wolf Creek will be tension tested with a mechanical pull tester, in accordance with written and approved test procedures. All wires that pull out will be relugged and reinsulated. Overcrimped lugs will also be replaced as required.

The rework will be done by Bunker Ramo's Service Engineer and subject to Site QA surveillance and/or inspection. Attachment "A" lists the affected penetrations requiring inspection.

Correction of deficiencies at the jobsites will be monitored by the site and is expected to be completed during the next three months.

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• I ATTACHMENT "A" l

The following electrical penetration assemblies (EPA) have f14 and #16 AWG wires with crimped Hollingsworth lugs:

l EPA No. EPA No. i ZNE 291 I ZSE 296 ZSE 215 ZSE 255 ZSE 297 ZNE 287  !

ZSE 298 ZSE 252 ZNE 285 ZSE 254 ZNE 276 ZNE 284 ZNE 282 ZNE 294 ZNE 275 ZSE 223 ZSE 234 ZSE 216 ZSE 253 ZSE 217 ZNE 279 ZNE 293 ZSE 240 ZNE 277 ZNE 278 ZNE 292 l ZSE 233 ZSE 295 j l

ZSE 224 ZSE 250  !

l ZNE 222 ZNE 288 ZSE 249 ZSE 258 ZSE 243

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