ML102500641

NRC000019-Final Significance Determination for a White Finding and Notice of Violation; NRC Inspection Report No. 05000282/2008008; Prairie Island Nuclear Generating Plant, Unit 1

ML102500641
Person / Time
Site:	Prairie Island
Issue date:	01/27/2009
From:	Caldwell J Region 3 Administrator
To:	Wadley M Northern States Power Co, Atomic Safety and Licensing Board Panel
SECY RAS
Shared Package
ML102500629	List: IR 05000282/2008008 IR 05000282/2008009 IR 05000282/2009008 IR 05000282/2009010 IR 05000282/2010003 IR 05000306/2009013 ML102500631 ML102500632 ML102500633 ML102500636 ML102500638 ML102500639 ML102500640 ML102500641 ML102500644 ML102500646 ML102500647 ML102500648 ML102500650 ML102500653
References
50-282-LR, 50-306-LR, ASLBP 08-871-01-LR-BD01, EA-08-272, RAS 18573
Download: ML102500641 (8)

See also: IR 05000282/2008008

Text

January 27, 2009

EA-08-272

Mr. Michael D. Wadley

Site Vice President

Prairie Island Nuclear Generating Plant

Northern States Power Company-Minnesota

1717 Wakonade Drive East

Welch, MN 55089

SUBJECT:

FINAL SIGNIFICANCE DETERMINATION FOR A WHITE FINDING AND

NOTICE OF VIOLATION; NRC INSPECTION REPORT NO. 05000282/2008008;

PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 1

Dear Mr. Wadley:

The purpose of this letter is to provide you the final results of our significance determination of

the preliminary White finding identified in the subject inspection report. The inspection finding

was assessed using the Significance Determination Process and was preliminarily

characterized as White, a finding with low to moderate increased importance to safety that may

require additional U.S. Nuclear Regulatory Commission (NRC) inspections. This White finding

is associated with your staffs failure to adequately control the position of a normally open valve

used to isolate the 11 turbine-driven auxiliary feedwater pumps (TDAFWP) discharge pressure

switch. The valve was left closed, causing the 11 TDAFWP to fail to operate as required

subsequent to a Unit 1 reactor trip which occurred on July 31, 2008. The pump was rendered

inoperable for a time period that significantly exceeded the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> time limit allowed by the

Technical Specifications.

In a letter dated December 5, 2008, your staff provided information stating your staffs position

on this issue. Your staff acknowledged the violation, described the issue, the root cause, the

corrective actions taken, and your assessment of the risk significance. Your staff performed a

human reliability analysis for operator recovery of 11 TDAFWP discharge pressure trip remotely

from control room and locally after the control room is abandoned. The analysis included

detailed modeling and assessment of risk contribution from a postulated fire and concluded that

the issue was of very low risk significance.

After considering the information developed during the inspection and the additional information

you provided in your letter dated December 5, 2008, the NRC has concluded that the inspection

finding is appropriately characterized as White, a finding with low to moderate increased

importance to safety that may require additional NRC inspections. Enclosure 1 to the letter

provides a detailed description of the NRC final risk significance determination with the issue.

You have 30 calendar days from the date of this letter to appeal the staffs determination of

significance for the identified White finding. Such appeals will be considered to have merit only

if they meet the criteria given in the NRC Inspection Manual Chapter 0609, Attachment 2.

NRC000019

M. Wadley

-2-

The NRC has also determined that the Unit 1 TDAFWP inoperability is a violation of Technical

Specification 3.7.5, as cited in the enclosed Notice of Violation (Notice). The circumstances

surrounding the violation are described in detail in the subject inspection report.

In accordance with the NRC Enforcement Policy, the Notice is considered escalated

enforcement action because it is associated with a White finding.

The NRC has concluded that the information regarding the reason for the violation, the

corrective actions taken, and the date when full compliance was achieved is already

adequately addressed on the docket in the subject inspection report and your letter dated

December 5, 2008. Therefore, you are not required to respond to this letter unless the

description therein does not accurately reflect your corrective actions or your position.

Because plant performance for this issue has been determined to be in the regulatory response

band, we will use the NRC Action Matrix to determine the most appropriate NRC response for

this event. We will notify you, by separate correspondence, of that determination.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its

enclosures, and your response, if you choose to provide one, will be made available electronically

for public inspection in the NRC Public Document Room or from the NRCs document system

(ADAMS), accessible from the NRC Web site at http://www.nrc.gov/readingrm/adams.html. To

the extent possible, your response should not include any personal privacy, proprietary, or

safeguards information so that it can be made available to the public without redaction.

Sincerely,

/RA/

James L. Caldwell

Regional Administrator

Docket No. 50-282

License No. DPR-42

Enclosures:

1. Final Significance Determination

2. Notice of Violation

cc w/encl:

D. Koehl, Chief Nuclear Officer

Regulatory Affairs Manager

P. Glass, Assistant General Counsel

Nuclear Asset Manager

J. Stine, State Liaison Officer, Minnesota Department of Health

Tribal Council, Prairie Island Indian Community

Administrator, Goodhue County Courthouse

Commissioner, Minnesota Department of Commerce

Manager, Environmental Protection Division

Office of the Attorney General of Minnesota

Emergency Preparedness Coordinator, Dakota

County Law Enforcement Center

NRC000019

M. Wadley

-2-

The NRC has also determined that the Unit 1 TDAFWP inoperability is a violation of Technical

Specification 3.7.5, as cited in the enclosed Notice of Violation (Notice). The circumstances surrounding

the violation are described in detail in the subject inspection report. In accordance with the NRC

Enforcement Policy, the Notice is considered escalated enforcement action because it is associated with

a White finding.

The NRC has concluded that the information regarding the reason for the violation, the corrective actions

taken, and the date when full compliance was achieved is already adequately addressed on the docket in

the subject inspection report and your letter dated December 5, 2008. Therefore, you are not required to

respond to this letter unless the description therein does not accurately reflect your corrective actions or

your position.

Because plant performance for this issue has been determined to be in the regulatory response band, we

will use the NRC Action Matrix to determine the most appropriate NRC response for this event. We will

notify you, by separate correspondence, of that determination.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosures,

and your response, if you choose to provide one, will be made available electronically for public

inspection in the NRC Public Document Room or from the NRCs document system (ADAMS), accessible

from the NRC Web site at http://www.nrc.gov/readingrm/adams.html. To the extent possible, your

response should not include any personal privacy, proprietary, or safeguards information so that it can be

made available to the public without redaction.

Sincerely,

/RA/

James L. Caldwell

Regional Administrator

Docket No. 50-282

License No. DPR-42

Enclosures: 1. Final Significance Determination

2. Notice of Violation

cc w/encl:

D. Koehl, Chief Nuclear Officer

Regulatory Affairs Manager

P. Glass, Assistant General Counsel

Nuclear Asset Manager

J. Stine, State Liaison Officer, Minnesota Department of Health

Tribal Council, Prairie Island Indian Community

Administrator, Goodhue County Courthouse

Commissioner, Minnesota Department of Commerce

Manager, Environmental Protection Division

Office of the Attorney General of Minnesota

Emergency Preparedness Coordinator, Dakota

County Law Enforcement Center

DISTRIBUTION:

See next page

DOCUMENT NAME: G:\\EICS\\ENFORCEMENT\\Enforcement Cases 2008\\EA-08-272 Prairie Island Mispositioned Valve\\EA-08-272

Prairie Island Draft final action WHITE NOV.doc

Publicly Available

Non-Publicly Available Sensitive

Non-Sensitive

OFFICE

RIII

RIII

RIII

RIII

D: OE

D: NRR

RIII

RIII

NAME

Gryglak

Lougheed

Lerch for

Giessner

Pederson

Hilton for

Carpenter1 Cunningham2 OBrien

Caldwell

DATE

01/22/09

01/22/09

01/22/09

01/23/09

01/21/09

01/21/09

01/23/09 01/26/09

OFFICIAL RECORD COPY

1 OE concurrence received via e-mail from G. Bowman on January 21, 2009.

2 NRR concurrence received via e-mail from G. Bowman on January 21, 2009.

NRC000019

Letter to Michael D. Wadley from James L. Caldwell dated January 27, 2009

SUBJECT: FINAL SIGNIFICANCE DETERMINATION FOR A WHITE FINDING AND NOTICE OF

VIOLATION; NRC INSPECTION REPORT NO. 05000282/2008008; PRAIRIE ISLAND

NUCLEAR GENERATING PLANT, UNIT 1

DISTRIBUTION:

ADAMS (PARS)

RidsSecyMailCenter Resource

OCA

Bill Borchardt, EDO

Bruce Mallett, DEDR

Cynthia Carpenter, OE

Nick Hilton, OE

Gregory Bowman, OE

James Caldwell, RIII

Mark Satorius, RIII

Catherine Marco, OGC

Marvin Itzkowitz, OGC

Eric Leeds, NRR

Bruce Boger, NRR

Daniel Holody, RI

Carolyn Evans, RII

Kenneth OBrien, RIII

William Jones, RIV

MaryAnn Ashley, NRR

Karla Stoedter, RIII

Paul Zurawski, RIII

Eliot Brenner, OPA

Hubert Bell, OIG

Guy Caputo, OI

Mona Williams, OCFO

John Giessner, RIII

Scott Thomas, RIII

Laura Kozak, RIII

Diana Betancourt, RIII

Viktoria Mitlyng, OPA RIII

Prema Chandrathil, OPA RIII

Allan Barker, RIII

Paul Pelke, RIII

Patricia Lougheed, RIII

Magdalena Gryglak, RIII

RidsNrrDirsIrib

OEMAIL Resource

OEWEB Resource

NRC000019

Enclosure 1

FINAL SIGNIFICANCE DETERMINATION

In NRC Inspection Report No. 05000282/2008008; 05000306/2008008, an apparent violation

of Technical Specification (TS) 3.7.5 was identified associated with the inoperability of the

11 turbine-driven auxiliary feedwater pump (TDAFWP) for approximately 138 days, a time

period which significantly exceeded the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> time limit allowed by the TS. Based upon

the NRCs consideration of information provided by the licensee in a letter dated

December 5, 2008, the NRC has determined that the preliminary finding is appropriately

characterized as White, a finding with low to moderate increased importance to safety that

may require additional NRC inspections.

Apparent Violation: (AV)05000282/2008001-01

Final Significance: White

The NRC reviewed the information provided in the letter dated December 5, 2008, and

concluded that it was generally acceptable for use in the final significance determination with

several exceptions as detailed below.

With respect to the analysis of control room fires that could result in control room abandonment,

the NRC disagreed with the results of the licensees evaluation of the time available for fire

suppression activities before intolerable environmental conditions would develop. Specifically,

the NRC found that the licensees estimate relied on the assumption that the control room

ventilation system would continue to operate during a fire. The NRCs review of the control

room ventilation system operation and fire response procedures indicated that the system may

isolate during a fire or that operators may secure the system as directed by procedures.

Additionally, the licensee did not consider the potential for smoke to obscure the operators

vision during a control room fire. As a result, the NRC concluded that the time available for fire

suppression could be shorter than 25 minutes and used a best estimate of 15 minutes in the

final Significance Determination Process (SDP) evaluation. The NRC also disagreed with the

licensees consideration of both prompt suppression of a fire by the control room operators

and suppression by the fire brigade. The guidance of NUREG/CR-6850 indicates that prompt

suppression should only be considered for hot work fire scenarios where a fire watch is

present.

Regarding the analysis of main control board fires that affect redundant trains of equipment and

require control room abandonment, the NRC found that the licensee did not consider a fire

affecting the Unit 2 main control board. The NRC determined that Procedure F5, Appendix B,

Control Room Evacuation (Fire), would require control room abandonment for both units if

either main control board was significantly affected by a fire. As a result, the NRC determined

that the fire frequency for this scenario should have been multiplied by two to reflect a fire in

either units main control board.

The relay room fire analysis assumed that the Unit 2 motor driven auxiliary feedwater (AFW)

pump could be cross-tied to provide for decay heat removal. The NRC determined that the

licensees control room evacuation procedure did not specify the use of the cross-tie and that

NRC000019

Enclosure 1

2

other operating procedures would have to be modified to use the cross-tie. Additionally, the

licensees operations training program specifies the use of Procedure F5 for control room

abandonment situations rather than emergency or other operating procedures. The NRC

concluded that the successful use of the AFW cross-tie was unlikely and should not be credited

in the final significance determination.

Consistent with the NRCs preliminary SDP evaluation, the licensees analysis considered the

possibility of recovering the 11 TDAFWP. The NRC agreed that the estimate of the time

available to recover the pump was reasonable. However, the NRC found the timeline for the

operator actions for recovery in control room abandonment scenarios to be overly optimistic. As

an example, the licensee did not consider the time impact of required actions, such as

announcements and notifications to personnel, on the control room abandonment which would

cause delays in arriving at the Hot Shutdown Panel. Also, the timeline was largely based on

existing estimates of individual tasks, rather than a walk-through demonstration of the current

procedure. The NRC concluded that individual task time estimates may not adequately capture

the overall timeline of the coordinated crew response required in a control room abandonment

fire scenario. Because of concerns with the timing analysis, the NRC determined that it was not

appropriate to consider that the operator had extra time available for recovery. In the final

significance determination, the NRC used a modified version of the licensees human error

probability (HEP) by using the estimated HEP without recovery.

The NRC developed several other concerns with the risk analysis but did not consider the

quantitative impacts on the risk estimate due to the complexity involved and the low likelihood

that rigorous evaluation would cause the risk of the finding to be greater than low to moderate

safety significance. The NRC noted that the licensees evaluation credited the automatic fire

suppression system in the relay room fire analysis without evaluating whether the system would

actuate for those specific scenarios. In three scenarios, the time to target damage was

estimated at 6 minutes or less. The assumption that the system would automatically actuate in

these scenarios may not be appropriate given the short time to target damage.

The NRC also noted that the licensee did not consider any dependency between the failure of

the automatic suppression system and the failure of manual fire suppression which could be

particularly important in the short time to damage fire scenarios. Lastly, the horizontal flame

spread rate used in the analysis to determine the times to target damage was not adequately

justified.

In summary, the NRC considered the licensees information in the final significance

determination with the exceptions noted above, where modified inputs were used in the

quantitative analysis. The NRC analysis using the licensees information, with the modifications

described above, resulted in a change in core damage frequency of approximately 2E-6/yr. The

dominant core damage sequence was a control room fire which results in abandonment of the

control room, followed by the failure of the 11 TDAFWP, and a failure of the operator to recover

the pump. The dominant sequence was consistent with both the NRCs preliminary significance

determination and with the licensees risk evaluation.

NRC000019

Enclosure 2

NOTICE OF VIOLATION

Northern States Power Company - Minnesota

Docket No. 50-282

Prairie Island Nuclear Generating Plant, Unit 1

License No. DPR-42

EA-08-272

During an NRC inspection conducted from August 4 through October 6, 2008, a violation of

NRC requirements was identified. In accordance with the NRC Enforcement Policy, the

violation is listed below:

Technical Specification 3.7.5 requires, in part, that two auxiliary feedwater trains be

operable during plant operation in Modes 1, 2, and 3.

Technical Specification 3.7.5.B requires, in part, that if one auxiliary feedwater train is

inoperable in Modes 1, 2, and 3, the affected train shall be restored to operable status

within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or the plant placed in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Contrary to the above, from March 15, 2008 to July 31, 2008, the 11 turbine-driven

auxiliary feedwater pump was inoperable for a period of greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and the

licensee did not restore the pump to operable status or place the plant into Mode 3 or

Mode 4 within the required time periods. Specifically, the pump was inoperable for

approximately 138 days due to the discharge low pressure switch being isolated and no

actions were taken to restore the pump to operable status or to place the plant in Mode 3

or 4.

This violation is associated with a White Significance Determination Process finding.

The NRC has concluded that information regarding the reason for the violation, the corrective

actions taken and planned to correct the violation and prevent recurrence, and the date when

full compliance was achieved, is already adequately addressed on the docket in Inspection

Report No. 05000282/2008008, and your letter dated December 5, 2008. However, you are

required to submit a written statement or explanation pursuant to 10 CFR 2.201 if the

description therein does not accurately reflect your corrective actions or your position.

In that case, or if you choose to respond, clearly mark your response as a "Reply to a

Notice of Violation," EA-08-272, and send it to the U.S. Nuclear Regulatory Commission,

ATTN: Document Control Desk, Washington, DC 20555-0001 with a copy to the Regional

Administrator, Region III, and a copy to the NRC Resident Inspector at the Prairie Island

Nuclear Generating Plant, within 30 days of the date of the letter transmitting this Notice of

Violation (Notice).

If you contest this enforcement action, you should also provide a copy of your response, with

the basis for your denial, to the Director, Office of Enforcement, United States Nuclear

Regulatory Commission, Washington, DC 20555-0001.

NRC000019

Enclosure 2

Notice of Violation

-2-

If you choose to respond, your response will be made available electronically for public

inspection in the NRC Public Document Room or from the NRC=s document system (ADAMS),

accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html. Therefore, to

the extent possible, the response should not include any personal privacy, proprietary, or

safeguards information so that it can be made available to the public without redaction.

In accordance with 10 CFR 19.11, you may be required to post this Notice within two working

days.

Dated this 27th day of January 2009

NRC000019