ML102500641
| 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: |
| 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
NRC000019
January 27, 2009
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
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
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
2
NAME Gryglak Lougheed Lerch for Pederson Hilton for Cunningham OBrien Caldwell
1
Giessner Carpenter
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:
RidsSecyMailCenter Resource
Bill Borchardt, EDO
Bruce Mallett, DEDR
Cynthia Carpenter, 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
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
Enclosure 1
NRC000019
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.
2 Enclosure 1
NRC000019
Northern States Power Company - Minnesota Docket No. 50-282
Prairie Island Nuclear Generating Plant, Unit 1 License No. DPR-42
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.
Enclosure 2
NRC000019
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
Enclosure 2