ML060580176

Summary of Meeting with Duke Energy Corporation High Energy Line Break and Tornado Mitigation at Oconee, Units 1, 2 and 3

ML060580176
Person / Time
Site:	Oconee
Issue date:	03/06/2006
From:	Olshan L Plant Licensing Branch III-2
To:	Duke Energy Corp
Olshan L N, NRR/DORL, 415-1419
Shared Package
ML060580201	List: ML060580176
References
Download: ML060580176 (5)

Text

March 6, 2006 LICENSEE: DUKE ENERGY CORPORATION (DUKE)

FACILITY: OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 (OCONEE)

SUMMARY

OF FEBRUARY 7, 2006, MEETING TO DISCUSS HIGH ENERGY LINE BREAK (HELB) AND TORNADO MITIGATION On February 7, 2006, the Nuclear Regulatory Commission (NRC) met with Duke (the licensee) to discuss HELB and tornado mitigation at Oconee. Enclosure 1 is a list of the attendees. is the handouts provided by the licensee during the meeting.

By letter dated January 31, 2006, the licensee had provided information on planned modifications related to HELB and tornado events. In that letter, the licensee stated, Following that meeting, absent verbal or written notification from the Staff that this approach is not sufficient, Duke will proceed with the understanding that implementation of the activities described in the Attachment will resolve the NRC staffs concerns regarding Oconees CLB

[current licensing basis] for tornado and HELB events outside containment. The NRC staff stated that it did not have enough specific details to reach a conclusion regarding the CLB for tornado and HELB events. The NRC staff also stated that the licensee should not conclude that the absence of verbal or written notification from the NRC staff constitutes NRC approval of the licensees approach. The licensee stated that it did not intend for the NRC staff to approve the CLB for tornado and HELB based on the information provided in the January 31, 2006, letter and during this meeting; the licensee was instead asking the NRC staff to identify any problems the NRC staff had with the licensees general approach thus far.

The NRC staff requested that the licensee provide a listing of systems, components, and structures (SSCs) needed to mitigate tornado and HELB events and to specify for which SSCs protection from these events will be provided and for which SSCs the licensee will provide analyses to demonstrate that these events can be adequately mitigated. The NRC staff also recommended that the licensee provide a failure modes and effect analysis (FMEA) for tornado and HELB events. The licensee agreed to provide the listing of SSCs requested by the NRC staff, and the licensee stated that it would consider providing the FMEA.

The licensee discussed the modifications that it is currently planning to implement to mitigate tornado events. The licensee may propose additional plant modifications after completing its review of risk insights for the remaining SSCs. The planned modifications will be designed to the tornado criteria specified for the Standby Shutdown Facility (SSF) in the Updated Final Safety Analysis Report. The licensee also stated that the upgrade to station auxiliary service water (ASW) will be designed to Quality Assurance I requirements. The licensee stated that when the upgrade to station ASW has been completed, it will provide an alternate means from the SSF for shutting down the plant. For SSCs not covered by these modifications, the licensee intends to provide risk insights, some of which will be based on TORMIS, a computer model for analyzing tornado-induced missiles. In addition, the licensee is reviewing a draft regulatory guide, Draft Regulatory Guide DG-1143, Design-Basis Tornado and Tornado Missiles for

Nuclear Power Plants, that has recently been made available for public comment. The licensee stated that it will reach a decision by March 1, 2006, regarding possible use of DG-1143.

The licensee stated that it will be using Fiber Reinforced Polymer (FRP) technology for application in strengthening selected masonry walls against the effects of tornado wind and differential pressure loads. The licensee will be submitting a license amendment request (LAR) by June 1, 2006, for use of FRP technology. The NRC staff stated that the use of this technology will be a first-time review for the NRC staff.

The NRC staff also discussed some concerns with tornado mitigation, including the availability of steam generator level control and indication after a tornado.

For HELB events, the licensee agreed that it will confirm by analysis that cold shutdown can be achieved, but that certain repairs may be needed. The licensee has not yet determined what criterion it will use for the time required to reach cold shutdown. The NRC staff agreed with the concept of making repairs to achieve cold shutdown, but stated that it would need more details regarding these repairs and the time needed to make these repairs.

The licensee stated that it intends to incorporate NUREG/CR-2913, Two-Phase Jet Loads, and Branch Technical Position MEB 3-1 into the Oconee licensing basis for jet impingement from critical cracks. The NRC staff stated that NUREG/CR-2913 was intended for full circular breaks of pipe and that the licensee would have to justify the use of this NUREG for pipe cracks. The NRC staff also stated the licensee should not just address selected items in MEB 3-1, but should address all the items in MEB 3-1.

The licensee provided its schedule for implementing the planned modifications and stated that it would provide additional justification for modifications that are scheduled to be completed later than December 31, 2007. The NRC stated that it was encouraged by the licensees plans for resolving these issues.

/RA/

Leonard N. Olshan, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287

Nuclear Power Plants, that has recently been made available for public comment. The licensee stated that it will reach a decision by March 1, 2006, regarding possible use of DG-1143.

The licensee stated that it will be using Fiber Reinforced Polymer (FRP) technology for application in strengthening selected masonry walls against the effects of tornado wind and differential pressure loads. The licensee will be submitting a license amendment request (LAR) by June 1, 2006, for use of FRP technology. The NRC staff stated that the use of this technology will be a first-time review for the NRC staff.

The NRC staff also discussed some concerns with tornado mitigation, including the availability of steam generator level control and indication after a tornado.

For HELB events, the licensee agreed that it will confirm by analysis that cold shutdown can be achieved, but that certain repairs may be needed. The licensee has not yet determined what criterion it will use for the time required to reach cold shutdown. The NRC staff agreed with the concept of making repairs to achieve cold shutdown, but stated that it would need more details regarding these repairs and the time needed to make these repairs.

The licensee stated that it intends to incorporate NUREG/CR-2913, Two-Phase Jet Loads, and Branch Technical Position MEB 3-1 into the Oconee licensing basis for jet impingement from critical cracks. The NRC staff stated that NUREG/CR-2913 was intended for full circular breaks of pipe and that the licensee would have to justify the use of this NUREG for pipe cracks. The NRC staff also stated the licensee should not just address selected items in MEB 3-1, but should address all the items in MEB 3-1.

The licensee provided its schedule for implementing the planned modifications and stated that it would provide additional justification for modifications that are scheduled to be completed later than December 31, 2007. The NRC stated that it was encouraged by the licensees plans for resolving these issues.

/RA/

Leonard N. Olshan, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287 Distribution:

Public BWetzel, Rgn II CDoutt LPL2-1 r/f RidsRgn2MailCenter(MErnstes) JShea RidsNrrDorlLplc(EMarinos) RidsNrrAdro(BBoger) RCarroll RidsOgcRp JTatum RSchin RidsAcrsAcnwMailCenter JFair MShannon RidsNrrDorl(CHaney/EHackett) MTschiltz RJasinski RidsNrrPMLOlshan EImbro SJones RidsNrrLAMOBrien BHarvey Package: ML060580201 Meeting Handouts: ML060580237 Meeting Summary: ML060580176 Meeting Notice: ML060240613 NRC-001 OFFICE NRR/LPL2-1/PM NRR/LPL2-1/BC NAME LOlshan EMarinos DATE 3/6/06 3/6/06 OFFICIAL RECORD COPY

LIST OF ATTENDEES MEETING TO DISCUSS OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 HIGH ENERGY LINE BREAK AND TORNADO MITIGATION FEBRUARY 7, 2006 NRC DUKE B. Boger R. Jones C. Haney B. Hamilton E. Hackett M. Glover E. Marinos G. Davenport J. Tatum J. Fuller L. Olshan G. McAninch J. Fair L. Kanipe M. Tschiltz J. Robertson E. Imbro L. Nicholson B. Harvey J. Fisicaro S. Jones R. Freudenberger C. Doutt M. Ernstes*

J. Shea*

R. Carroll* OTHER R. Schin*

M. Shannon* T. Bacon, Areva

• By phone

Oconee Nuclear Station, Units 1, 2, and 3 cc:

Ms. Lisa F. Vaughn Mr. R. L. Gill, Jr.

Duke Energy Corporation Manager - Nuclear Regulatory 526 South Church Street Issues and Industry Affairs P. O. Box 1006 Duke Energy Corporation Mail Code = EC07H 526 S. Church St.

Charlotte, North Carolina 28201-1006 Mail Stop EC05P Charlotte, NC 28202 Manager, LIS NUS Corporation Division of Radiation Protection 2650 McCormick Dr., 3rd Floor NC Dept of Environment, Health, & Natural Clearwater, FL 34619-1035 Resources 3825 Barrett Dr.

Senior Resident Inspector Raleigh, NC 27609-7721 U.S. Nuclear Regulatory Commission 7812B Rochester Highway Mr. Peter R. Harden, IV Seneca, SC 29672 VP-Customer Relations and Sales Westinghouse Electric Company Mr. Henry Porter, Director 6000 Fairview Road Division of Radioactive Waste Management 12th Floor Bureau of Land and Waste Management Charlotte, NC 28210 Dept. of Health and Env. Control 2600 Bull St. Mr. Henry Barron Columbia, SC 29201-1708 Group Vice President, Nuclear Generation and Chief Nuclear Officer Mr. Michael A. Schoppman P.O. Box 1006-EC07H Framatome ANP Charlotte, NC 28201-1006 1911 North Ft. Myer Dr.

Suite 705 Mr. Bruce H. Hamilton Rosslyn, VA 22209 Vice President, Oconee Site Duke Energy Corporation Mr. B. G. Davenport 7800 Rochester Highway Regulatory Compliance Manager Seneca, SC 29672 Oconee Nuclear Site Duke Energy Corporation ON03RC 7800 Rochester Highway Seneca, SC 29672 Ms. Karen E. Long Assistant Attorney General NC Department of Justice P.O. Box 629 Raleigh, NC 27602