ML071510552

Commitment for Hydrogen Igniter Backup Power Supply & Closure Process for Generic Issue 189, Susceptibility of Ice Condenser & Mark III Containments to Early Failure from Hydrogen Combustion During a Severe Accident

ML071510552
Person / Time
Site:	River Bend
Issue date:	06/15/2007
From:	Catherine Haney Plant Licensing Branch III-2
To:	Venable J Entergy Operations
Vaidya B, NRR/DORL/LP4, 415-3308
References
TAC MB7245
Download: ML071510552 (4)

Text

June 15, 2007 Mr. Joseph E. Venable Vice President of Operations Entergy Operations, Inc.

River Bend Station 5485 US Highway 61 N St. Francisville, LA 70775

SUBJECT:

RIVER BEND STATION, UNIT 1 - COMMITMENT FOR HYDROGEN IGNITER BACKUP POWER SUPPLY AND CLOSURE PROCESS FOR GENERIC ISSUE 189, SUSCEPTIBILITY OF ICE CONDENSER AND MARK III CONTAINMENTS TO EARLY FAILURE FROM HYDROGEN COMBUSTION DURING A SEVERE ACCIDENT (TAC MB7245)

Dear Mr. Venable:

This letter acknowledges your February 15, 2007, letter committing to changes at the River Bend Station that will enhance plant capabilities to mitigate the potential for early containment failure from hydrogen combustion. In addition to existing procedures to power one train of igniters through a cross-tie from the Division 3 diesel generator, you proposed changes involving procurement of portable equipment to power one train of igniters and development of associated procedures and training.

The Nuclear Regulatory Commission (NRC) staff agrees that the proposed changes will resolve concerns related to Generic Issue 189 (GI-189), Susceptibility of Ice Condenser and Mark III Containments to Early Failure from Hydrogen Combustion During a Severe Accident, and provide benefits for certain security scenarios. The NRC staff understands that the changes will enhance the electrical independence of the containment hydrogen igniter system. This action is warranted for boiling water reactors with Mark III containments because many systems that prevent core damage rely on the same power supplies and electrical distribution system as the hydrogen igniters. This enhancement mitigates the potential for early containment failure by allowing control of hydrogen within containment following certain beyond-design-basis events that may progress to core damage and preclude operation of the hydrogen igniters from their normal power supply. The NRC staff expects this enhancement will provide hydrogen igniter system electrical independence commensurate with the expected frequency, challenges, and uncertainties associated with these beyond-design-basis events.

Consistent with the guidelines of NRC Management Directive 6.4, Generic Issues Program, the NRC staff will perform a verification inspection at River Bend. These inspections will include elements to verify that you establish procedures to provide back-up power to the hydrogen igniters, train appropriate staff in the procedures, and institute appropriate controls on the reliability and availability of necessary equipment. Procedures that allow trained personnel to establish backup power to the igniters within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> are fully consistent with goals to mitigate potential hydrogen accumulation. The NRC staff understands that implementation of vendor recommended maintenance and existing procedures will ensure adequate availability and

J. E. Venable reliability of the backup power supplies. In addition, NRC licensing project managers may verify the integrity of your commitments over time through established review procedures for your commitment management program.

Verification of your committed actions and those of other affected licensees will provide the basis by which the NRC will close out GI-189. The NRC staff will perform the verification inspection at a time consistent with the implementation date specified in your letter.

Accordingly, please keep the NRC staff informed of any changes in the scope of modifications or the implementation date.

Sincerely,

/RA by John Lubinski for Catherine Haney/

Catherine Haney, Director Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.: 50-458 License No.: NPF-47 cc: See next page

ML071510552 OFFICE DSS/SBPB DSS/SBPB:BC DSS:D DPR/PGCB DIRS:D NAME SJones JSegala JWermiel JGolla ECollins DATE 6/5/07 6/5/07 6/5/07 6/5/07 6/8/07 OFFICE DORL/LPLIV/PM DORL/LPLIV/LA DORL/LPLIV/BC DORL/D NAME BVaidya JBurkhardt THiltz JWL for CHaney DATE 6/12/07 6/12/07 6/12/07 6/15/07 River Bend Station cc:

Mr. Michael L. Kansler Executive Vice President and President and Chief Nuclear Officer Chief Operating Officer Entergy Operations, Inc. Entergy Operations, Inc.

1340 Echelon Parkway P.O. Box 31995 Jackson, MS 39213 Jackson, MS 39286-1995 Manager, Licensing General Manager Plant Operations Entergy Operations, Inc. Entergy Operations, Inc.

River Bend Station River Bend Station 5485 US Highway 61N 5485 US Highway 61N St. Francisville, LA 70775 St. Francisville, LA 70775 Director, Nuclear Safety & Licensing Director, Nuclear Safety Assurance Entergy Operations, Inc. Entergy Operations, Inc.

1340 Echelon Parkway River Bend Station Jackson, MS 39213-8298 5485 US Highway 61N St. Francisville, LA 70775 Louisiana Department of Environmental Quality Vice President, Operations Support Radiological Emergency Planning and Entergy Operations, Inc.

Response Division P.O. Box 31995 P.O. Box 4312 Jackson, MS 39286-1995 Baton Rouge, LA 70821-4312 Mr. Jim Calloway Louisiana Department of Environmental Public Utility Quality Commission of Texas Office of Environmental Compliance 1701 N. Congress Avenue P.O. Box 4312 Austin, TX 78711-3326 Baton Rouge, LA 70821-4312 Attorney General Senior Resident Inspector State of Louisiana P.O. Box 1050 P.O. Box 94095 St. Francisville, LA 70775 Baton Rouge, LA 70804-9095 President of West Feliciana Brian Almon Police Jury Public Utility Commission P.O. Box 1921 William B. Travis Building St. Francisville, LA 70775 P.O. Box 13326 1701 North Congress Avenue Regional Administrator, Region IV Austin, Texas 78701-3326 U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Richard Penrod, Senior Environmental Arlington, TX 76011-8064 Scientist/State Liaison Officer Office of Environmental Services Ms. H. Anne Plettinger Northwestern State University 3456 Villa Rose Drive Russell Hall, Room 201 Baton Rouge, LA 70806 Natchitoches, LA 71497 November 2006