ML081990534
| ML081990534 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 07/14/2008 |
| From: | O'Keefe N NRC/RGN-IV/DRS/EB2 |
| To: | Minahan S Nebraska Public Power District (NPPD) |
| References | |
| EA-07-204, IR-08-008 | |
| Download: ML081990534 (5) | |
See also: IR 05000298/2008008
Text
UNITED STATES
NU C LE AR RE G ULATO RY C O M M I S S I O N
R E GI ON I V
612 EAST LAMAR BLVD , SU ITE 400
AR LIN GTON , TEXAS 76011-4125
July 14, 2008
EA 07-204
Stewart B. Minahan
Vice President-Nuclear and CNO
Nebraska Public Power District
P.O. Box 98
Brownville, NE 68321
SUBJECT: ERRATA FOR FINAL SIGNIFICANCE DETERMINATION FOR A WHITE
FINDING AND NOTICE OF VIOLATION, NRC INSPECTION
REPORT 05000298/2008008, COOPER NUCLEAR STATION
Dear Mr. Minahan:
This Errata corrects the decision basis for the significance determination for the subject
violation. Table 4 in Enclosure 2 of our letter (ML081650090) (Caniano to Minahan, dated
June 13, 2008) erroneously provided data that had been used in a sensitivity study as opposed
to the probabilities calculated to support the final determination of significance. Please replace
Page E2-13 of Enclosure 2, Final Significance Determination Summary, with the enclosed
revised page. We regret any inconvenience this may have caused.
In accordance with 10 CFR 2.390 of the NRCs "Rules of Practice," a copy of this letter, its
enclosure, and your response (if any) 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), accessible from the NRC Web site at
http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Neil F. OKeefe, Chief
Engineering Branch 2
Division of Reactor Safety
Docket: 50-298
License: DPR-46
Nebraska Public Power District -2-
EA 07-204
cc w/enclosure: as stated
Gene Mace
Nuclear Asset Manager
Nebraska Public Power District
P.O. Box 98
Brownville, NE 68321
John C. McClure, Vice President
and General Counsel
Nebraska Public Power District
P.O. Box 499
Columbus, NE 68602-0499
David Van Der Kamp
Licensing Manager
Nebraska Public Power District
P.O. Box 98
Brownville, NE 68321
Michael J. Linder, Director
Nebraska Department of
Environmental Quality
P.O. Box 98922
Lincoln, NE 68509-8922
Chairman
Nemaha County Board of Commissioners
Nemaha County Courthouse
1824 N Street
Auburn, NE 68305
Julia Schmitt, Manager
Radiation Control Program
Nebraska Health & Human Services
Dept. of Regulation & Licensing
Division of Public Health Assurance
301 Centennial Mall, South
P.O. Box 95007
Lincoln, NE 68509-5007
H. Floyd Gilzow
Deputy Director for Policy
Missouri Department of Natural Resources
P. O. Box 176
Nebraska Public Power District -3-
EA 07-204
Jefferson City, MO 65102-0176
Director, Missouri State Emergency
Management Agency
P.O. Box 116
Jefferson City, MO 65102-0116
Chief, Radiation and Asbestos
Control Section
Kansas Department of Health
and Environment
Bureau of Air and Radiation
1000 SW Jackson, Suite 310
Topeka, KS 66612-1366
Melanie Rasmussen, State Liaison Officer/
Radiation Control Program Director
Bureau of Radiological Health
Iowa Department of Public Health
Lucas State Office Building, 5th Floor
321 East 12th Street
Des Moines, IA 50319
John F. McCann, Director, Licensing
Entergy Nuclear Northeast
Entergy Nuclear Operations, Inc.
440 Hamilton Avenue
White Plains, NY 10601-1813
Keith G. Henke, Planner
Division of Community and Public Health
Office of Emergency Coordination
930 Wildwood, P.O. Box 570
Jefferson City, MO 65102
Paul V. Fleming, Director of Nuclear
Safety Assurance
Nebraska Public Power District
P.O. Box 98
Brownville, NE 68321
Ronald L. McCabe, Chief
Technological Hazards Branch
National Preparedness Division
DHS/FEMA
9221 Ward Parkway
Suite 300
Kansas City, MO 64114-3372
Nebraska Public Power District -4-
EA 07-204
Daniel K. McGhee, State Liaison Officer
Bureau of Radiological Health
Iowa Department of Public Health
Lucas State Office Building, 5th Floor
321 East 12th Street
Des Moines, IA 50319
Ronald D. Asche, President
and Chief Executive Officer
Nebraska Public Power District
1414 15th Street
Columbus, NE 68601
Nebraska Public Power District -5-
EA 07-204
Electronic distribution by RIV:
Regional Administrator (Elmo.Collins@nrc.gov)
DRP Director (Dwight.Chamberlain@nrc.gov)
DRP Deputy Director (Anton.Vegel@nrc.gov)
DRS Director (Roy.Caniano@nrc.gov)
DRS Deputy Director (Troy.Pruett@nrc.gov)
Senior Resident Inspector (Nick.Taylor@nrc.gov)
Resident Inspector (Michael.Chambers@nrc.gov)
Branch Chief, DRP/C (Geoffrey.Miller@nrc.gov )
Senior Project Engineer, DRP/C (Wayne.Walker@nrc.gov)
Public Affairs Officer (Victor.Dricks@nrc.gov)
Team Leader, DRP/TSS (Chuck.Paulk@nrc.gov)
RITS Coordinator (Marisa.Herrera@nrc.gov)
OEDO RIV Coordinator (Patricia.Lougheed@nrc.gov )
ROPreports
CNS Site Secretary (Sue.Farmer@nrc.gov)
OEMail.Resource@nrc.gov
OEWeb.Resource@nrc.gov Mike.Franovich@nrc.gov
Doug.Starkey@nrc.gov Jeff.Circle@nrc.gov
Maryann.Ashley@nrc.gov Joseph.Anderson@nrc.gov
Michael.Vasquez@nrc.gov Tim.Kobetz@nrc.gov
Victor.Dricks@nrc.gov Thomas.Hiltz@nrc.gov
Bill.Maier@nrc.gov Carl.Lyon@nrc.gov
Linda.Smith@nrc.gov Undine.Shoop@nrc.gov
Neil.OKeefe@nrc.gov Richard.Borchardt@nrc.gov
John.Mateychick@nrc.gov Melissa.Wyatt@nrc.gov
Karla.Fuller@nrc.gov Paul.Lain@nrc.gov
Michael.Cheok@nrc.gov Bruce.Boger@nrc.gov
John.Grobe@nrc.gov Harold.Barrett@nrc.gov
Mark.Cunningham@nrc.gov Frederick.Brown@nrc.gov
Alexander.Klein@nrc.gov Christine.Tucci@nrc.gov
Christi.Maier@nrc.gov Amy.Powell@nrc.gov
SUNSI Review Completed: _TWP__ ADAMS: Yes Initials: _TWP__
Publicly Available Non-Sensitive ML081990534
C:EB2 DD:
Neil OKeefe Troy Pruett
M.Runyan for /RA/
7/14/08 7/14/08
OFFICIAL RECORD COPY T=Telephone E=E-mail F=Fax
The analyst used the main control room abandonment freql \encies documented in
Table 3. In addition, sensitivities were run using the Iicense~'s values.
Recovery Following Failure of Valve RHR-MO-25B
As documented in Assumption 5, the analyst calculated a combined non-recovery
probability using the event tree shown in Figure 2 in the Attachment.
Table 4 documents the 'final split fractions used in quantifying this event tree.
Table 4
Split Fractions for RECOVERY-PATH
Top Event How Assessed Failure Probability
LEVEL-DOWN SPAR-H Diagnosis Only) 8.8 x 10-4
SRV-STATUS Best Estimate of Fraction 1.0 x 10-1
CLOSE-SRVS SPAR-H Action Only) 5.7 x 10-4
RESTORE-HPCI SPAR-H Combined) 1.9 x 10-2
OPEN-MO-25B-3 SPAR-H Combined) 6.7 x 10-1
OPEN-MO-25B-5n SPAR-H Combined) 6.7 x 10-1
Using the event tree in Figure 2 and the split fractions in Table 4, the analyst calculated
a combined non-recovery probability of 7.9 x 10.2 . The licensee's combined non
3
recovery probability was 4.0 x 10- * The licensee used a similar approach to quantify this
value. However, the licensee assumed that operators would always shut the safety
relief valves upon determining that reactor pressure vessel water level was decreasing.
The analyst assumed that some percentage of operators would continue to follow the
procedure and attempt to recover from the failed RHR valve or try alternate methods of
low-pressure injection. In addition, the analyst identified the following issues that
impacted the licensee's analysis: .
- The inspectors determined that it would require 112 ft-Ibs of force to manually
open Valve RHR-MO-25B. The analyst determined that this affected the
ergonomics of this recovery. Some operators may assume that the valve is on
the backseat when large forces are required to open it. Some operators might
be incapable of applying this force to a 2-foot diameter hand wheel.
- The analyst noted that the following valves would be potential reasons for lack
of injection flow and/or may distract operators from diagnosing that
Valve RHR-MO-025B is closed:
RHR-81 B, RHR Loop B Injection Shutoff Valve, could be closed.
RHR-27CV, RHR Loop B Injection Line Testable Check Valve,
couid be stuck ciosed.
E2-13 Enclosure 2