ML032340014

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Nebraska Public Power District, Meeting Summary Re. Main Steam Line Isolation Leakage Pathway Seismic Evaluation
ML032340014
Person / Time
Site: Cooper Entergy icon.png
Issue date: 08/21/2003
From: Thadani M
NRC/NRR/DLPM/LPD4
To:
Thadani M, NRR/DLPM, 415-1476
Shared Package
ML032340020 List:
References
TAC MB7376
Download: ML032340014 (9)


Text

August 21, 2003 LICENSEE: Nebraska Public Power District FACILITY: Cooper Nuclear Station

SUBJECT:

SUMMARY

OF MEETING WITH NEBRASKA PUBLIC POWER DISTRICT TO DISCUSS ISSUES RELATED TO MAIN STEAM LINE ISOLATION LEAKAGE PATHWAY SEISMIC EVALUATION (TAC NO. MB7376)

On July 23, 2003, the Nebraska Public Power District (the licensee), met with the U. S. Nuclear Regulatory Commission (NRC) staff at the NRC Headquarters. The purpose of the meeting was to discuss the issues related to main steam line isolation valve (MSIV) leakage pathway seismic adequacy for iodine plate-out credit in radiological dose assessment of design basis accidents. Enclosure 1 is a list of meeting attendees. Enclosure 2 contains the licensees view-graphs. Enclosure 3 is a drawing that the licensee used to discuss the modifications to ensure seismic ruggedness of the leakage pathway. Enclosure 4 is a list of the NRC staffs questions related to seismic concerns that were discussed at the meeting The licensee outlined the history of the issue since 1994, summarizing the sequence of actions related to seismic considerations of the MSIV leakage pathway during the NRC staff reviews related to four successive license amendments. The amendments were issued to support the Cooper Nuclear Station (CNS) control room emergency filtration system fan capacity increase, and approve revisions to design basis dose assessment calculations methodologies. During each amendment review process the NRC staff raised concerns regarding the licensees assumptions and the licensee partially addressed the NRC staffs concerns. In each case the NRC staff did not approve all the changes requested and permitted continued operation of CNS for one successive operating cycle. The staff required the licensee to maintain potassium iodide (KI) supplements in the control room to mitigate potential accident radiological dose consequences.

The licensee stated that, with the exception of one, all concerns raised in the NRC staff reviews have been addressed. The remaining issue relates to demonstration of seismic ruggedness of MSIV pathway to justify iodine depletion credit due to plate-out in MSIV pathway. This credit is assumed in the licensees revised dose assessment methodology. The licensee went on to describe the design and function of the MSIV pathway that would provide adequate seismic ruggedness.

The licensee described the modifications that have already been made to ensure seismic ruggedness. New valves have been installed to isolate the vulnerable segments of the MSIV pathway. Structural improvements have been installed and emergency lighting provisions have been made to permit the operators to align the MSIV leakage to a seismically rugged pathway.

Procedures have been revised and validated. Implementation has been deferred pending the NRC staffs approval of the changes. The licensee stated that when the changes are accepted

by the staff, the licensee will submit an application for the staff to approve the final loss-of-coolant accident dose assessment methodology, and removal of the license condition 2.C.(6) which requires the licensee to maintain KI in the CNS control room.

The NRC staff stated that it plans to submit a request for additional information (RAI) addressing the remaining seismic, design, and human performance considerations of the proposed modifications as well as operator actions and operating procedures. The NRC staff requested that the licensee provide the responses expeditiously after the receipt of the RAI.

The licensee requested that the NRC staff should submit all RAI in writing.

There were no public comments or questions and the meeting was adjourned.

/RA/

Mohan C. Thadani, Senior Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-298

Enclosures:

As stated cc w/encls: See next page

ML032340014 NRC-001 OFFICE PDIV-1/PM PDIV-1/LA PDIV-1/SC NAME MThadani:sab MMcAllister RGramm DATE 8/21/03 8/21/03 8/21/03 MEETING WITH NEBRASKA PUBLIC POWER DISTRICT (NPPD)

JULY 23, 2003 LIST OF ATTENDEES NAME AFFILIATION Mohan Thadani NRC Kamal Manoly NRC Yong Kim NRC Gary Kline NPPD Dan Buman NPPD Paul Fleming NPPD Bill Victor NPPD Robert Gramm NRC James Tatum NRC Enclosure 1

Viewgraphs of the Licensees Presentation ADAMS Accession No.: ML032340733 Enclosure 2

Modification Drawing ADAMS Accession No.: ML032340735 Enclosure 3

QUESTIONS PROVIDED TO NEBRASKA PUBLIC POWER DISTRICT AT JULY 23, 2003 PUBLIC MEETING REQUEST FOR ADDITIONAL INFORMATION ON THE SUPPLEMENTAL INFORMATION SUBMITTED BY NEBRASKA PUBLIC POWER DISTRICT FOR COOPER NUCLEAR STATION LICENSE CONDITION 2.C.(6)

DOCKET NO.: 50-298, DPR-46

1. You stated in Reference 1 that ... Five manual isolation valves to be installed on Main Steam branch lines in order to limit the amount of piping to be credited for the MSIV leakage flowpath (and hence, maintained as seismically robust). Post-accident Operator action will be required to close these valves (which will be located in the Turbine Building)... We request your responses to the following:

C Explanation as to how those five manual isolation valves will be seismically qualified.

C Provide a comparison between the Coopers MSIV leakage path proposed manual isolation valves and the earthquake experience database concerning seismic performance of this class of equipment.

C Indicate whether the leakage path with the manual isolation valves installed meets the provisions in the SQUG-GIP 2 (Reference 2). If it does not, identify how the outlier conditions were resolved.

C Indicate whether the five manual valves will be part of the Coopers in-service testing (IST) program. If they are not, provide justification as to why they should not be part of the IST program.

2. You stated in Reference 3 that ... The cross-sectional leakage area is being reduced by mechanically adjusting the Stop Valve actuator/control shaft positions through use of a special pre-staged tool, applied as a post-Loss Coolant Accident manual action... We request your response to the following:

C Explanation as to how the mechanically adjusted Stop Valve actuator/control shaft with a special pre-staged tool will be seismically robust.

C Provide a comparison between the MSIV leakage path Stop Valve actuator with the proposed adjustment and the earthquake experience database concerning seismic performance of the equipment class that encompasses the reconfigured Stop Valve.

References C Letter, Nebraska Public Power District to U.S. NRC, License Condition 2.C.(6) Seismic Evaluation, Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46, dated February 26, 2002.

Enclosure 4

C Seismic Qualification Utility Group, Generic Implementation Procedure (GIP) for Seismic Verification of Nuclear Power Plant Equipment, Revision 2, corrected February 14, 1992.

C Letter, Nebraska Public Power District to U.S. NRC, Additional Information Related to License Condition 2.C.(6) Seismic Evaluation, Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46, dated December 19, 2002.

Enclosure 4

Cooper Nuclear Station cc:

Mr. William J. Fehrman Senior Resident Inspector President and Chief Executive Officer U.S. Nuclear Regulatory Commission Nebraska Public Power District P. O. Box 218 1414 15th Street Brownville, NE 68321 Columbus, NE 68601 Regional Administrator, Region IV Mr. Thomas J. Palmisano U.S. Nuclear Regulatory Commission Site Vice President 611 Ryan Plaza Drive, Suite 1000 Nebraska Public Power District Arlington, TX 76011 P. O. Box 98 Brownville, NE 68321 Jerry Uhlmann, Director State Emergency Management Agency Mr. John R. McPhail, General Counsel P. O. Box 116 Nebraska Public Power District Jefferson City, MO 65101 P. O. Box 499 Columbus, NE 68602-0499 Chief, Radiation and Asbestos Control Section Mr. Paul V. Fleming, Licensing Manager Kansas Department of Health Nebraska Public Power District and Environment P.O. Box 98 Bureau of Air and Radiation Brownville, NE 68321 1000 SW Jackson Suite 310 Mr. Michael J. Linder, Director Topeka, KS 66612-1366 Nebraska Department of Environmental Quality Mr. Daniel K. McGhee P. O. Box 98922 Bureau of Radiological Health Lincoln, NE 68509-8922 Iowa Department of Public Health 401 SW 7th Street Chairman Suite D Nemaha County Board of Commissioners Des Moines, IA 50309 Nemaha County Courthouse 1824 N Street Mr. Scott Clardy, Director Auburn, NE 68305 Section for Environmental Public Health P.O. Box 570 Ms. Cheryl K. Rogers, Program Manager Jefferson City, MO 65102-0570 Nebraska Health & Human Services System Mr. Clay C. Warren Division of Public Health Assurance Chief Nuclear Officer Consumer Services Section Nebraska Public Power District 301 Centennial Mall, South P. O. Box 98 P. O. Box 95007 Brownville, NE 68321 Lincoln, NE 68509-5007 Mr. Ronald A. Kucera, Director of Intergovernmental Cooperation Department of Natural Resources P.O. Box 176 Jefferson City, MO 65102