ML032760180

Preliminary White Finding; NRC Inspection Report 50-255/03-05

ML032760180
Person / Time
Site:	Palisades
Issue date:	10/03/2003
From:	Reynolds S Division Reactor Projects III
To:	Domonique Malone Nuclear Management Co
References
EA-03-180, IR-03-005
Download: ML032760180 (5)

See also: IR 05000255/2003005

Text

October 3, 2003

EA-03-180

Mr. Daniel J. Malone

Site Vice President

Palisades Nuclear Plant

Nuclear Management Company, LLC

27780 Blue Star Memorial Highway

Covert, MI 49043-9530

SUBJECT: PALISADES PRELIMINARY WHITE FINDING;

NRC INSPECTION REPORT 50-255/03-05

Dear Mr. Malone:

On March 25, 2003, with the plant in Mode 6 (Refueling), plant maintenance workers were

installing signs in the parking lot designating parking spaces. One of the signposts was driven

into a conduit and damaged a cable which contained a combination of energized indication

circuitry and de-energized protective relay circuitry. The metal signpost cut and shorted

together several of the conductors within the cable which resulted in a loss of offsite power and

loss of shutdown cooling. An Alert was initially declared based on the loss of offsite power

combined with the loss of shutdown cooling and was subsequently downgraded to an Unusual

Event after about one hour when shutdown cooling was restored. Your staff secured from the

Unusual Event on March 27, 2003, when offsite power was reliably restored.

As discussed in NRC Special Inspection Report 50-255/03-05, we reviewed the circumstances

surrounding this event and identified a finding with a significance which was to be determined.

As described in Section 02.2 of the subject report, the finding involved the failure to have

established controls in place in the form of administrative policies and procedures for digging or

excavating activities and the failure to address previous problems involving digging and

excavating activities.

We have recently completed our preliminary assessment of this finding. This finding was

assessed based upon the best available information, including influential assumptions, using

the applicable Significance Determination Process (SDP) and was preliminarily determined to

be a White finding which means the finding has a low to moderate safety significance. This is

due to the increase in initiating event likelihood (IEL) which resulted from the loss of the

preferred source of offsite power and the reliance on the onsite emergency diesel generators to

provide power to needed mitigating systems.

The preliminary significance of the finding is based on a Phase 3 SDP assessment that used

the plant-specific Phase 2 SDP worksheets and assigned a value to the change in IEL based

on a best estimate. The Palisades loss of offsite power event caused by digging on March 25,

2003, was treated as a random, plant-centered event. However, this particular event was the

result of a performance deficiency that would increase the IEL over that which would be

D. Malone -2-

expected to cause plant-centered occurrences, such as random equipment failures. Therefore,

from a significance determination process viewpoint, the IEL associated with the March 25,

2003, event was treated by the NRC as a new mechanism that should be additive to the loss of

offsite power IEL expected from all other plant-centered causes. The NRC concluded that an

appropriate estimate of the change in plant-centered loss of offsite power IEL, resulting from

this deficiency, was about 1 event in 32.1 years or 3.11 E-2/year. When the change in

plant-centered loss of offsite power event frequency is considered, the resulting change in Core

Damage Frequency value is on the order of 1E-6/year for this finding, or White. To validate this

result, the NRC used the Standardized Plant Analysis Risk (SPAR) model for Palisades. This

model produced results that were consistent with the results using the plant-specific Phase 2

worksheets discussed above.

Before we make a final decision on this matter, we are providing you an opportunity to:

(1) present to the NRC your perspectives on the facts and assumptions, used by the NRC to

arrive at the finding and its significance, at a Regulatory Conference; or (2) submit your position

on the finding to the NRC in writing. If you request a Regulatory Conference, it should be held

within 30 days of the receipt of this letter; and we encourage you to submit supporting

documentation at least one week prior to the conference in an effort to make the conference

more efficient and effective. If a Regulatory Conference is held, it will be open for public

observation. If you decide to submit only a written response, such submittal should be sent to

the NRC within 30 days of the receipt of this letter.

Please contact Eric Duncan at (630) 829-9628 within 10 business days of the date of your

receipt of this letter to notify the NRC of your intentions. If we have not heard from you within

10 days, we will continue with our significance determination and enforcement decision and you

will be advised by separate correspondence of the results of our deliberations on this matter.

In accordance with 10 CFR 2.790 of the NRCs "Rules of Practice," a copy of this letter will be

made available electronically for public inspection in the NRC Public Document Room or from

the Publicly Available Records (PARS) component of NRCs document system (ADAMS).

ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the

Public Electronic Reading Room).

Sincerely,

/RA by Patrick L. Hiland acting for/

Steven A. Reynolds, Acting Director

Division of Reactor Projects

Docket No. 50-255

License No. DPR-20

See Attached Distribution

(*See Previous Concurrence)

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OFFICE RIII RIII RIII RIII

NAME EDuncan:ags * MParker * Bclayton*KJL for SReynolds PLH for

DATE 09/26/03 09/26/03 10/02/03 10/03/03

OFFICIAL RECORD COPY

D. Malone -3-

cc: J. Cowan, Executive Vice President

and Chief Nuclear Officer

R. Fenech, Senior Vice President, Nuclear

Fossil and Hydro Operations

L. Lahti, Manager, Regulatory Affairs

J. Rogoff, Esquire, Nuclear Management Company, LLC

A. Udrys, Esquire, Consumers Energy Company

R. Remus, Plant Manager

P. Harden, Site Director

S. Wawro, Nuclear Asset Director, Consumers Energy Company

W. Rendell, Supervisor, Covert Township

Office of the Governor

L. Brandon, Michigan Department of Environmental Quality -

Waste and Hazardous Materials Division

Department of Attorney General (MI)

D. Malone -4-

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