IR 05000298/2008008

Download: ML081990534

Text

July 14, 2008

EA 07-204

Stewart 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 NRC's "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 NRC's 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. O'Keefe, 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) DRS STA (Dale.Powers@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 Doug.Starkey@nrc.gov Maryann.Ashley@nrc.gov Michael.Vasquez@nrc.gov Victor.Dricks@nrc.gov Bill.Maier@nrc.gov Linda.Smith@nrc.gov Neil.OKeefe@nrc.gov John.Mateychick@nrc.gov Karla.Fuller@nrc.gov Michael.Cheok@nrc.gov John.Grobe@nrc.gov Mark.Cunningham@nrc.gov Alexander.Klein@nrc.gov Christi.Maier@nrc.gov Mike.Franovich@nrc.gov Jeff.Circle@nrc.gov Joseph.Anderson@nrc.gov Tim.Kobetz@nrc.gov Thomas.Hiltz@nrc.gov Carl.Lyon@nrc.gov Undine.Shoop@nrc.gov Richard.Borchardt@nrc.gov Melissa.Wyatt@nrc.gov Paul.Lain@nrc.gov Bruce.Boger@nrc.gov Harold.Barrett@nrc.gov Frederick.Brown@nrc.gov Christine.Tucci@nrc.gov Amy.Powell@nrc.gov SUNSI Review Completed: _TWP__ ADAMS: Yes Initials: _TWP__ Publicly Available Non-Sensitive ML081990534 C:EB2 DD: Neil O'Keefe 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 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 recovery probability was 4.0 x 10-3* The licensee used a similar approach to quantify this value. However, the licensee assumed that operators would always shut the 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. Enclosure 2