United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #: 9809140193


Northeast
Nuclear Energy
      Northeast Rope Ferry Rd. (Route 156),
Waterford, CT 06385

Millstone Nuclear Power Station
Northeast Nuclear Energy Company
P.O. Box 128
Waterford, CT 06385-0128
(860) 447-1791
Fax (860) 444-4277

The Northeast Utilities System

Docket No. 50-245

B17414

Re: 10CFR21.21

U.S. Nuclear Regulatory Commission
Attention: Document Control Desk
Washington, DC 20555

Millstone Nuclear Power Station, Unit No. 1
10CFR21 Report Concerning Berkeley Model 466 Tachometer Transducer
Supplied by Eitel Manufacturing

Northeast Nuclear Energy Company (NNECO) is providing this letter to inform the Commission, in accordance with 10CFR21.21(c)(4), that a defective Berkeley Model 466 Tachometer Transducer, supplied by Eitel Manufacturing, was received at Millstone Unit No. 1. The tachometer transducer was procured commercially and was' dedicated by NNECO. The information required by 10CFR21 is provided in Attachment 1 to this letter.

Initial notification of this matter was provided, via facsimile notification to the NRC Operations Center in accordance with 10CFR21.21 (c)(3), on August 7, 1998.

There are no commitments made within this letter as indicated in Attachment 2.

If there are further questions on the information provided in this letter, please contact Peter J. Miner at (860) 440-2085.

NORTHEAST NUCLEAR ENERGY COMPANY

Martin L. Bowling, Jr.
Recovery Officer - Technical Services


Sworn to and subscribed before me this _______ day of ________, 1998

Notary Public

My Commission expires LORETTA F. GOODSON, NOTARY PUBLIC

Commission Expires November 30, 2001


U.S. Nuclear Regulatory Commission

B17414\Page 2



Attachments:
1. 10CFR21 Report Concerning Berkeley Model 466 Tachometer Transducers, Manufactured by Eitel
2. List of Regulatory Commitments
 
cc: H. J. Miller, Region I Administrator
S. Dembek, NRC Project Manager, Millstone Unit No. 1
T. A. Easlick, Senior Resident Inspector, Millstone Unit No. 1

Docket No. 50-245

B17414


Attachment 1
Millstone Nuclear Power Station, Unit No. 1
10CFR21 Report Concerning Berkeley Model 466 Tachometer Transducers Supplied by Eitel Manufacturing

September 1998

U.S. Nuclear Regulatory Commission
B17414\Attachment 1\Page 1

10CFR21 Report Concerning Berkeley Model 466 Tachometer Transducers, Manufactured by Eitel

In accordance with 10CFR21.21 (c)(4), NNECO is providing the following information:

(i) Name and address of the individual or individuals informing the Commission.

Mr. Martin L. Bowling, Jr.
Recovery Officer - Technical Services
Northeast Nuclear Energy Company
P.O. Box 128
Waterford, Connecticut 06385-0128

 
(ii) Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect. Berkeley Model 466 Tachometer Transducers
 
(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.
Eitel Manufacturing, Inc.
P.O. Box 7353
34052 Doheny Park Road Number 1
Capistrano Beach, CA 92624
Commercial Grade Dedication by:
Northeast Nuclear Energy Company
P.O. Box 128
Waterford, CT 06385-0128
(iv) Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.
Millstone Unit No. 1 uses one diesel generator and one gas turbine generator (GTG) for dedicated onsite emergency power. Millstone Unit No. 1 has certified that it has permanently ceased power operation, however, the GTG provides station blackout power for Millstone Unit No. 2. The GTG is a General Electric LM1500, that utilizes tachometer transducers to provide the governor with the speed signals from the gas turbine and the electric generator.
On January 16, 1998, tachometer transducer, ID number TG-25-5 failed during a surveillance test. A replacement tachometer transducer was ordered and U.S. Nuclear Regulatory Commission delivered by Eitel. Following inspection, the installation of the "finger spring washer" in the transducer was questioned; however, it was determined to be acceptable as a result of assurances from the manufacturer. The serial number of this tachometer transducer is 108-3.
On April 8, 1998, during a surveillance test the GTG was manually tripped due to a loss of the electric generator speed signal. The failure resulted in significant load transients and was traced to the failure of tachometer transducer TG-25-1, which is the same design as TG-25-5. Tachometer TG-25-5 is mounted on the GTG in tandem with TG-25-1. TG-25-1 provides feedback to the governor for generator frequency control. The GTG cannot perform its safety function without this signal. TG-25-5 provides the generator speed signal that is used for the overspeed trip circuit. The GTG can perform its safety function without this signal.
A second tachometer transducer, serial number 298-2, had been delivered by Eitel and questions on manufacturing quality were raised by the Procurement Engineering and Nuclear Receiving Group(NRG). These included the improper orientation of the "finger spring washer' used to hold the tachometer shaft bearing in place and the machining tolerances of the tachometer stator bearing housings which resulted in improper bearing fit. As a result, the tachometer transducer was shipped to Schulz Electric for an inspection which was performed on April 10, 1998. The results of the inspection showed that it should not be installed on the GTG; thus, Schulz Electric was authorized to rebuild it.
A third tachometer transducer, serial number 498-1, was subsequently delivered by Eitel. Inspection showed that this tachometer transducer had the "finger spring washer" installed in the correct orientation; however, because of manufacturing deficiencies observed on the tachometer transducers previously received from Eitel, it was shipped to Schulz Electric for rebuild.
While replacement tachometer transducer serial number 108-3, installed in location TG-25-5, had not failed, its manufacturing quality was in question. Therefore, it was replaced with a rebuilt tachometer using the stator from the Eitel tachometer transducer, serial number 298-2.
The possibility that the failure of the bearings in TG-25-5 could affect the operation of TG-25-1 was evaluated. Possible scenarios for failure are:
1. Bearing failure could cause the shaft to seize and break.
2. Bearing failure could increase the vibration in the assembly of the tachometer transducers.
In view of the above, it is possible to postulate that in the event of an accident, failure of TG-25-5 could have caused the failure of TG-25-1, rendering the GTG unavailable to mitigate the consequences of an accident.
 
(v) The date on which the information of such defect or failure to comply was obtained.
A Condition Report (CR) addressing the issue was initiated on April 10, 1998. A 10CFR Part 21 evaluation of the issue was initiated on June 4, 1998.
 
(vi) In the case of a basic component which contains a defect or fails to comply, the number and location of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations of this Part.
The basic component of concern is a Berkeley Model 466 tachometer transducer, manufactured by Eitel, provided under NNECO purchase order 02062807 for use at Millstone Unit No. 1. The three modules ordered arrived on site with the defects described above. One was installed in the GTG and later replaced upon discovery of the defects. The remaining two were not accepted by NNECO and were shipped to a third party for inspection and rebuild.
 
(vii) The corrective action which has been, is being, or will be taken; and the length of time that has been or will be taken to complete the action.
One defective tachometer transducer was removed from service and replaced. It will be rebuilt within the next month. The remaining two were not accepted and were shipped to a different vendor for inspection and rebuild.
(viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.
A visual inspection for proper "finger spring washer orientation and for correct machining tolerances of the tachometer stator housing should be performed prior to commercial grade dedication.

Docket No. 50-245

B17414

Attachment 2
Millstone Nuclear Power Station, Unit No. 1
Regulatory Commitments

September 1998


U.S. Nuclear Regulatory Commission

B17414\Attachment 2\Page 1

Regulatory Commitment Enclosure List of Regulatory Commitments

The following table identifies those actions committed to by NNECO in this document. The Manager - Regulatory Compliance Millstone Unit No. 1 should be notified of any questions regarding this document or any associated regulatory commitments.



REGULATORY COMMITMENT COMMITTED DATE OR OUTAGE
None None


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