ML071510562
| ML071510562 | |
| Person / Time | |
|---|---|
| Site: | Clinton  (NPF-062) |
| Issue date: | 06/15/2007 |
| From: | Catherine Haney Plant Licensing Branch III-2 |
| To: | Crane C AmerGen Energy Co |
| Sands S,NRR/DORL, 415-3154 | |
| References | |
| GSI-189 | |
| Download: ML071510562 (4) | |
Text
June 15, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
CLINTON POWER STATION, UNIT NO. 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
Dear Mr. Crane:
This letter acknowledges your February 28, 2007, letter committing to changes at the Clinton Power Station, Unit No. 1 (Clinton), that will enhance plant capabilities to mitigate the potential for early containment failure from hydrogen combustion. In addition to existing procedures to power the hydrogen igniters from alternate power supplies, you described changes involving procurement of portable equipment to power one train of igniters using a portable generator and through a cross-tie from the Division 3 electrical distribution system, and development of associated procedures and training.
The Nuclear Regulatory Commission (NRC) staff agrees that the proposed enhancements 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 Clinton. These inspections will include elements to verify that you establish procedures to provide backup 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
C. M. Crane potential hydrogen accumulation. Implementation of vendor recommended maintenance for portable equipment and existing procedures for maintenance of installed equipment will ensure adequate availability and 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/
Catherine Haney, Director Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461 License No. NPF-62 cc: See next page
C. M. Crane potential hydrogen accumulation. Implementation of vendor recommended maintenance for portable equipment and existing procedures for maintenance of installed equipment will ensure adequate availability and 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/
Catherine Haney, Director Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461 License Nos. NPF-62 cc: See next page DISTRIBUTION:
PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsNrrPMSSands RidsNrrLAEWhitt RidsRgn3MailCenter RidsNrrDorl RidsNrrDss RidsNrrDssSbpb RidsNrrDprPgcb RidsOgcRp RidsAcrsAcnwMailCenter ADAMS Accession Number: ML071510562 OFFICE DSS/SBPB DSS/SBPB/BC DSS/D DPR/PGCB DIRS/D NAME SJones JSegala JWermiel JGolla ECollins DATE 06/5/07 06/5/2007 06/5/2007 06/5/2007 06/8/2007 OFFICE LPL3-2/LA LPL3-2/PM LPL3-2/BC DORL/D NAME EWhitt SSands RGibbs CHaney DATE 6/12/2007 6/12/2007 6/12/2007 6/15/2007 OFFICIAL RECORD COPY
Clinton Power Station, Unit No. 1 cc:
Senior Vice President - Operations Support Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness 1035 Outer Park Dr Springfield, IL 62704 Director - Licensing and Regulatory Affairs AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Manager Licensing - Dresden, Quad Cities and Clinton Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Manager Regulatory Assurance - Clinton AmerGen Energy Company, LLC Clinton Power Station RR 3, Box 228 Clinton, IL 61727-9351 Vice President - Regulatory Affairs AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Document Control Desk - Licensing AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Site Vice President - Clinton Power Station AmerGen Energy Company, LLC Clinton Power Station RR 3, Box 228 Clinton, IL 61727-9351 Plant Manager - Clinton Power Station AmerGen Energy Company, LLC Clinton Power Station RR 3, Box 228 Clinton, IL 61727-9351 Senior Vice President - Midwest Operations Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Resident Inspector U.S. Nuclear Regulatory Commission RR 3, Box 229A Clinton, IL 61727 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 2443 Warrenville Road, Suite 210 Lisle, IL 60532-4352 Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Chairman of DeWitt County c/o County Clerks Office DeWitt County Courthouse Clinton, IL 61727 J. W. Blattner Project Manager Sargent & Lundy Engineers 55 East Monroe Street Chicago, IL 60603