Information Notice 2009-10, Official Exhibit - NYS000019-00-BD01- NRC Information Notice 2009-10, Transformers Failures - Recent Operating Experience (Jul. 7, 2009) (NRC in 2009-10)

Official Exhibit - NYS000019-00-BD01- NRC Information Notice 2009-10, Transformers Failures - Recent Operating Experience (Jul. 7, 2009) (NRC in 2009-10)

ML12334A490
Person / Time
Site:	Indian Point
Issue date:	07/07/2009
From:	Dan Dorman, Mcginty T NRC/NMSS/FCSS, Division of Policy and Rulemaking
To:	Atomic Safety and Licensing Board Panel
SECY RAS
References
RAS 21523, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 IN-09-010
Download: ML12334A490 (4)

United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of

Entergy Nuclear Operations, Inc. (Indian Point Nuclear Generating Units 2 and 3)

ASLBP #:07-858-03-LR-BD01 Docket #:05000247 l 05000286 Exhibit #:

Identified:

Admitted: Withdrawn:

Rejected: Stricken: Other: NYS000019-00-BD01

10/15/2012

10/15/2012 NYS000019 Submitted: December 12, 2011 u .... 0 I./l I '

0-" ,-.* ..... UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, DC 20555-0001 July 7,2009 NRC INFORMATION

NOTICE 2009-10: TRANSFORM

ER F AI LU RES-RECENT

OPERA TI NG EXPERI ENCE

ADDRESSEES

All holders of operating

licenses for nuclear power reactors under the provisions

of Title 10 of the Code of Federal Regulations

(10 CFR) Part

50, "Domestic

Licensing

of Production

and Utilization

Facilities," except those who have ceased operations

and have certified

that fuel has been permanently

removed from the reactor vessel. All holders of licenses or certificates

of fuel cycle facilities.

All holders of and applicants

for nuclear power plant construction

permits under the provisions

of 10 CFR Part 50. All holders of licenses or certificates

for fuel cycle facilities.

PURPOSE

The U.S. Nuclear Regulatory

Commission (NRC) is issuing this information

notice (IN) to inform addressees

of recent operating

experience

involving

failures of large transformers.

The NRC expects that recipients

will review the information

for applicability

to their facilities

and consider actions, as appropriate, to avoid similar problems.

However, suggestions

contained

in this IN are not NRC requirements;

therefore, no specific action or written response is required.

DESCRIPTION

OF CIRCUMSTANCES

For several years, available

industry operating

experience

has indicated

an increasing

trend in transformer

failures, and has provided recommendations

to reduce the chances of failure. Improved preventive

maintenance

and monitoring

practices

have helped to identify some problems before they developed

to the point of failure, but the number of large transformers

events has not decreased

and in fact continues

to rise. The following

are relatively

recent examples involving

main power transformers:

• Indian Point, Unit 3-0n April 6,2007, while operating

at 92-percent

power, a fault occurred on the No. 31 main transformer

resulting

in an automatic reactor trip and transformer

fire. Licensee Event Report (LER) 50-286/2007-002, which can be found on the NRC's public Web site using Agencywide

Documents

Access and Management

System (ADAMS) Accession

No. ML071620122, provides additional

information.

• River Bend Station-On

May 4,2007, an unplanned

manual reactor scram was initiated

following

the loss of cooling on the No.2 main transformer (see LER 50-458/2007-002, ADAMS Accession

No. ML071840161, for more information).

• Grand Gulf Nuclear Station-On

January 12, 2008, a manual reactor scram was initiated

following

a loss of cooling to the main transformers (see LER 50-416/2008-001, ADAMS Accession

No. ML080700702, for more information).

M L090540218 OAG 10000526_

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• Limerick Generating

Station, Unit 2-0n February 1, 2008, a low voltage bushing connection

failed on the 2A main transformer

resulting

in a turbine trip and reactor scram.

• Diablo Canyon, Unit 2-0n August 16,2008, an automatic reactor trip occurred resulting

from the failure of the main electrical

transformer

C phase. Plant operators

subsequently

declared a Notification

of Unusual Event due to an observed fire at the C phase transformer (see LER 50-323/2008-001, ADAMS Accession

No. ML082970221, for more information).

• North Anna, Unit 2-0n October 29, 2008, while attempting

to place the unit on line, the turbine tripped on a generator

lockout relay actuation.

The C main transformer

was discovered

to be spraying oil.

• Oyster Creek-On November 28,2008, an electrical

fault internal to the M1A main transformer

led to an automatic reactor scram due to load reject. The transformer

was replaced with the spare, and on February 1, 2009, this transformer

failed due to a bushing failure, resulting

in a reactor scram, fire, and declaration

of a Notification

of Unusual Event (see LER 50-219/2008-001, ADAMS Accession

No. ML090260082, and LER 50-219/2009-001, ADAMS Accession

No. ML090970735 for more information).

A review of licensees'

root cause evaluations

for the large transformer

failures shows that the events are often the result of ineffective

implementation

of the transformer

maintenance

program.

DISCUSSION

The events described

above illustrate

instances

in which the loss or tripping of large transformers

resulted in plant transients, reactor trips, unnecessary

starting of the emergency

diesel generators (EDGs), and declaration

of plant events. Transformer

failures have resulted in eight declared plant events from January, 2007, to February, 2009, making them the second leading reason for such declarations.

While the large transformers

discussed

in this I N are generally

non-safety

related, they are within the scope of the Maintenance

Rule (Title 10 of the Code of Federal Regulations, Section 50.65, "Requirements

for Monitoring

the Effectiveness

of Maintenance

at Nuclear Power Plants").

A relatively

high incidence

of transformer

failures has occurred in the last few years, the majority of which could have been avoided had the licensee fully evaluated

and effectively

implemented

corrective

actions and recommendations

identified

in industry operating

experience.

These corrective

actions included a more effective

maintenance

program and a more proactive

approach to addressing

abnormal indications.

In particular, some utilities

have installed

online automated

oil analysis and monitoring

system to support decisions

regarding

preventive

and corrective

maintenance

to improve transformer

reliability.

The Institute

of Electrical

and Electronics

Engineers (IEEE) provides industry guidance on this matter in Standard C57.140-2006, "IEEE Guide for the Evaluation

and Reconditioning

of Liquid Immersed Power Transformers." However, it should be noted that the NRC has not endorsed this document, and the recommendations

it contains do not constitute

NRC requirements.

OAG 10000526_

000002

CONTACT

This I N requires no specific action or written response.

Please direct any questions

about this matter to the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager. IRAI Timothy J. McGinty, Director Division of Policy and Rulemaking

Office of Nuclear Reactor Regulation

IRAI Daniel H. Dorman, Director Division of Fuel Cycle Safety and Safeguards

Office of Nuclear Materials

Safety and Safeguards

Technical

Contacts:

Rebecca Sigmon, NRR/DIRS (301) 415-4018 Prem Sahay, NRR/DE (301) 415-8439 E-mail: Rebecca.Sigmon@nrc.gov

E-mail: Prem.Sahay@nrc.gov

NRC generic communications

may be found on the NRC public Web site, httQ:llwww.nrc.gov.

To access this information, select "Electronic

Reading Room" and then "Document

Collections." OAG 10000526_

000003

CONTACT

This I N requires no specific action or written response.

Please direct any questions

about this matter to the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager. IRAI Timothy J. McGinty, Director Division of Policy and Rulemaking

Office of Nuclear Reactor Regulation

IRAI Daniel H. Dorman, Director Division of Fuel Cycle Safety and Safeguards

Office of Nuclear Materials

Safety and Safeguards

Technical

Contacts:

Rebecca Sigmon, NRR/DIRS (301) 415-4018 Prem Sahay, NRR/DE (301) 415-8439 E-mail:

E-mail: p..r.§f.D.,$.§!.O.9Y.@.oJ.g:.9Q'y'

NRC generic communications

may be found on the NRC public Web site, httr;:rllwww.nrc.gov.

To access this information, select "Electronic

Reading Room" and then "Document

Collections." Distribution:

IN Reading File Hard Copy to Elizabeth

Doolittle (Mail Stop EBB 6003 1-0 2-M) ADAMS Accession

Number* ML090540218 TAC NO ME0392 OFFICE 10EBIDIRS

ACIDIRS/IOEB

D/NRRIDIRS

TECH EDITOR NRRIDE/EEEB

BC/EEEBIDE

NAME RSigmon JThorp FBrown KAzariah-Kribbs

PSahay GWilson DATE 05/08/09 05/13/09 06/02/09 04/03/09 email 05/12/09 05/12/09 OFFICE A/NRRIDE DPR/PGCB DPR/PGCB BCIDPR/PGCB

D/NRRIDPR

D:FCSS NAME ABoland DBeaulieu

CHawes MMurphy TMcGinty DOorman DATE 05/18/09 06/03/09 06/03/09 07/01/09 07/07/09 06/19/09 OFFICIAL RECORD COPY OAG 10000526_

000004