ML20010G926

Final Deficiency Rept Re Defective Terminations in Ite/Brown Boveri Electric Breakers & Switchgears,Initially Reported on 800703.Insp Also Covered Breakers Identified in IE Info Notice 81-06

ML20010G926
Person / Time
Site:	Grand Gulf
Issue date:	09/15/1981
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, AECM-81-338, IEIN-81-06, IEIN-81-6, IEN-81-6, NUDOCS 8109220667
Download: ML20010G926 (5)

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MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi E dellaliddE P. O . B O X 1640, J A C K S O N, MIS SIS SlP PI 3 9 2 05

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Office of Inspectie Enforcement gr s/$

U. S. Nuclear Reg .t.ory Commission g yff ,

Region II 101 Marietta Street, N.W.

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Suite 3100 2_" SEP2 2 1933, gj Atlanta, Georgia 30303 - u. s. i,u , , , , ,

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Attention: Mr. J. P. O'Reilly, Director

Dear Mr. O'Reilly:

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SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/39, Final Repc .

Defective Terminations in ITE/ Brown Boveri Electric Breakers and Switchgear AECM-81/338

References:

1) AECM-80/177, 8/1/80

2) AECM-80/276, 11/6/80

3) AECM-81/70, 2/17/81 On July 3, 1980, Mississippi Power & Light Company notified Mr. R.

Wright, of your office, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns defective terminations in ITE/ Brown Boveri Electric breakers and switchgear.

We have determined that this deficiency, had it remained uncorrected, cotid adversely affect the safety of operations of the nuclear power plant and is reportable under the provisions of 10CFR50.55(e). The systems containing the deficient equipment have been turned over to MP&L, but the affected equip-ment lad been identified prior to turnover so the deficiency is not reportable under 10CFR21.

Atteched is our final report giving all necessary information.

Yours truly, 7

J. P. McGaughy, Jr. TO y KDS/ MAL:dr ll ATTACHMENT cc: See page 2 8109220667 810915 PDR ADOCK 05000416 g PDR Member Middle South Utilities System J

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Mr. J. P. O'Reilly AECM-81/338 NRC Page 2 I

cc: Mr. N. L. Stampley Mr. R. B. McGehee Mr. T. B. Conner j

Mr. Victor Stello, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 2055.'3 Mr. G. B. Taylor South Miss. Electric Power Association P. 0.. Box 1589.

Hattiesburg, MS 33401

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. . Atts:chment to AECM-81/338 Paga 1 of 2 FINAL REPORT FOR PRD-80/39 I. Description of Deficiency _

Vendor terminations (ring tongue terminal lugs) in the 4.16 KV metal clad switchgear and 480 volt load centers manufactured by Brown Boveri Electric, Inc. were found to have faulty crimps.

After this deficiency was noted, our Constructor undertook, with the equipment vendor, Brown Boveri Electric, Inc., an inspection of all lugs in the switch-gear to verify that the conductors are visible inside the lug barrel, and that a crimp has been placed properly on each barrel.

During this inspection program several other deficiencies were noted such as:

1. Lugs for #10 and #12 wire were used on #14 wire.

2. Some lugs were bent and/or deformed.

3. Some terminal lugs had been trimmed ar cut to fit into the terminal strips.

4. Wires were inserted too far and protruded past the end of the lug barrel.

5. Individual strands were bent back and protruded from the rear of the lug barrel.

t Several other problems were also identified during the inspection of the circuit breakers on nine (9) of the breakers. These included deficient vendor wires , cables , contacts, and lugs. The scope of this PRD was expanded to

! include these breakers.

The deficient equipment is in the 4.16 KV Switchgear and Load Shedding and Sequencing Panels, (R21). Most of the other plant systems are affected also.

i The deficiency affects both Unit 1 and Unit 2. .

The cause of the deficiency was improper workmanship at the manufacturer's shop. This deficiency does not apply to the NSSS supplier.

l II. Analysis of Safery Implications Approximately fifteen (15) lugs were noted which had wire not visible in the end of the barrel, and/or which had loose wires. One of these deficient tera-inations could have af fected the overcurrent protection of the equipment and cause a failure. Therefore, these deficiencies are reportable under the pro-visions of 10CFR50.55(e).

- The deficient ' equipment had been identified prior to turnover to MP&L by our Constructor, so this deficiency-is not reportable under 10CFR21.

Brown Boveri Electric Inc. has reported this condition to the NRC under the I

provisions of 10CFR21. - This was by letter from D. D. Duvall, Vice President and General Manager, to Mr. Victor Stello, Jr., Director, Office of Inspection

, and Enforcement, U. S. Nuclear Regulatory Commission, Washington, D. C., April 3, 1981.

Attcchment to AECM-81/338

. . pig 2 2 cf 2 III. Corrective Actions Taken The cause of the deficiency was improper workmanship at the manufacturer's shop. All safety-related medium voltage switchgears and 480 volt load centers supplied by Brown Bove:1 Electric for Unit 1 (4.16 KV Buses 15AA and 16AB and 480 Volt Load Centers 15BA1 through 15BA6 and 16BB1 through 16BB6) have been inspected and reworked as necessary. In all cases where a defective lug was found, the affected lug was cut off and reworked to our Constructor's standards. The dravout circuit breakers in the 480 volt load centers were given an inspection of al' lugs which could be readily seen without disassembly of the breaker. It was decided that full breater disassembly was not required since most deficient terminations were in the cabinets, not in the breakers.

Further, the breakers were manufactured in a different factory under a more rigid QA/QC program. This inspection also covered the breakers for the deficiencies noted in IE Information Notice No. 81-06, March 1,1981.

All corrective actions for Unit I with the exception of nine (9) circuit breakers have been completed. These will be repaired during future plant switchgear outages prior to Unit i fuel load. Our Constructor has issued Nonconformance Report (NCR) 5173 to track this.

Brown Boveri Electric Switchgears and Load Centers for Unit 2 will be inspected at a future date. Management Corrective Action Report (MCAR) 117 will track this inspection. All corrective actions for Unit 2 will be completed prior to Unit 2 fuel load.

Actions to preclude future recurrence have been undertaken by Brown Boveri, Inc. as outlined in their letter of April 3, 1981, to the Nuclear Regulatory Commission, which is attached.

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bbe: Mr. D. C. Lutken Mr. J. Leatherman.

Dr. D. C. Gibbs Manager of BWR-6 Licensing Mr. J. N. Ward General Electric Company Mr. J. P. McGaughy, Jr. 175 Curtner Avenue i Mr. J. D. Heaton San Jose, CA. 95125 Mr. R. .

Trickovic Mr. J. W. Yelverton Mr. L. F. Dale -Mr. D. M. Houeton Mr. C. K. McCoy

. U. S. Nuclear Regulatory Commission '

Mr. T. H. Cloninger Division of Licensing f.

Mr. R. A. Ambrosino Washington, D. C. 20555 ,

Mr.'A. J. Iosue /

Mr. G. B. Rogers Mr. S. H. Hobbs Mr. J. Matore Mr. L. E. Ruhland U. S. Nuclear Regulatory Commission Mr. D. L. Hunt Division of Licensing. / '

Mt. A. G. Wagner Washington, D. C. 20555 Mr. P. A. Taylor PRD File File

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Brown B(. :n. Electn.c, Inc.

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Manufacturer of I.T E Ek ctrical Pc,wer Eoucment YTSIf April 3, 1981 b N- k i

RECEVED .

Mr. Victor Stello, Jr. APR - 61981 Director, Region II -

Of fice of Inspection & Enforcement U. S. Nuclear Regulatory Cor:r.iission t e D.O. ;

. Washington, D. C. 20555

Dear Mr. Stello:

This report is a follow-up to a 10CTR50.55(e) report issued by the Mississippi Power & Light Company on the Crand Culf Nuc] car Station with respect to problems noted with ring tongued wire terminals in medium vol-tage metal-clad switchgear and 480V load centers supplied by Brown Boveri Electric, Inc., (formerly known as I-T-E). -

This ondition was documented in NCR 4851 by Bechtel who is both Engineer s and Constnictor for the Crand Culf Nuclear Station. Initially, it was .

reported that two (2) crimped wire teminals came loose from their control wires in safety related switchgear. BBEL and Bechtel mutually agreed that an inspection should be made to detemine that there were no other loose wire teminals in the s,afety related switchgear wiring. Prior to this inspection an inspection criteria was established. This inspection criteria was to make a visual inspection of the crimped wire terminals to determine 'that the stranded wire was visible in the barrel of the terminal.

If the wire were not visible, this crimped termination was not acceptable.

This criteria was verified by tests performed by BBEL. ,

The results of this inspection which was performed by Bechtel show that there were approximately 15 wire teminals in which the wire was not virible e l

in the end of the barrel, or which had loose wires. Bechtel reported that l

one of these wires could have affected the overcurrent protection of the

equipment.

During the course of this equipment inspection program at the jobsito, there were other wire terminal anomalies which were detected. These included the items listed below.

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1. No.10-12 wire teminals had been crimped to a No. 14 wire.

l 2. Some wire teminals were bent or deformed.

3. Some wire teminals had been trimmed or cut to fit into a teminal board connection.

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Page 2 April 3, 1981

4. Wire was protruding too far from the end of the barrel.

5. In some cares, individual wire strands were bent back and protrudinr, from the rear end of the wire terminal.

Although the wire terminal anomalics listed above do not represent perfect workmanship, the nature of these anomalies is such that they would not result in a safety related problem. It should be noted that the equipment inspection reference so far, and the deficiencies and annmalics noted sere found in Unit #1 switchgear which was manufactured during the period of late 1975 through carly 1977 at the EBEL Chalfent, Pa. Switchgear Systems Division Operation.

On the average, during the manufacturing of a single cubic 3e of lou-voltage switchgear there are some 282 wite terminal connections which are crimped.

In the metal-clad switchgear there are some 240 connections per cubicle in the SHK equipment and some 297 connections per cubicle in 15HK equipment.

In the Unit 1 switchgear at Grand Gulf there are approximately 36,000 wire terminal connections and approximately one-half of these are in safet?

related circuits. These figures are based on the "as built" drawings for the switchgear but there have been many additional circuits added te the equipment during field modifications.

Although the deficient wire terminal connections at Crand Gulf are less than 0.1 of one percent, other users should determine the need for inspecting the safety related cirtufts to assure that wire terminals are not loose and that wirc strands are visible when looking into the end of the crimped wire

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terminal. ,

The cause of the deficiency at Grand Gulf is improper workmanship. During the time sp,an of manufacturing of the switchgear for Grand Gulf, inspec-tion was performed on a sampling basis. Early in 1977 BBEL procured new and improved crimping tools. These tools were identified by individual serial numbers and were issued to wiring personnel in accordance with a controlled plan. Wiring personnel were retrained in accordance with the tool manufacturers instructions.

Wire terminal inspection procedures were revised and updated. Crimping tool calibration and procedures were revlacd and updated and during the second quarter of 1977, the wire terminal inspection criteria was changed from a sampling inspection to a 100% inspection for safety related switch-gear. .

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April 3, 1981 Unit #2 switchgear at Grand Culf has also been furnished by BBEL. This equipment was manufactured during 1978 and early 1979. A cursory inspection of the equipment was performed at the jobsite during a recent visit and a few minor ancmalies such as a single strand of wire protruding from the rear of the wire terminal were no.ted. BBEL will propose r.o Bechtel to per-form a sample inspection of Unic A2 switchgear wire terminals to determine if any further action is required.

Although the majority of the safety related switchgear has been manufac-tured at the BBEL Chalfont, ?a. Operation, equipment of the same design has been manufactured at the BBEL Tulsa, Oklahoma Operation and a small amount of equipment has been manufactured at the BBEL Sanford, Florida Operation.

If you require any additional details in this matter, please feel free to contact Mr. E. W. Rhoads at 215-628-7660.

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\ *< t 4 ;1L ff1 LL Vic'e President & General Managcr Switchgear Systems Division EWR/ja ec: J. P. O'Reilly Director, Region II ,

Office of Inspection and Enforcement

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