ML022470024

Severe Accident Mitigation Alternatives

ML022470024
Person / Time
Site:	Mcguire, McGuire
Issue date:	08/19/2002
From:	Barron H Duke Energy Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML022470024 (4)

Text

Duke S Duke Energy Corporation McGuire Nuclear Station SEnergy 12700 Hagers Ferry Road Huntersville, NC 28078-9340 (704) 875-4800 OFFICE H. B. Barron (704) 8754809 FAX Vice President August 19, 2002 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Duke Energy Corporation McGuire Nuclear Station, Units 1 and 2 Docket Numbers 50-369 and 50-370 Severe Accident Mitigation Alternatives

REFERENCE:

1) Letter, U.S. Nuclear Regulatory Commission to Duke Energy Corporation Dated May 6, 2002,

SUBJECT:

Request for Comments on the Draft Plant-Specific Supplement 8 to the Generic Draft Environmental Impact Statement Regarding McGuire Nuclear Station, Units 1 and 2 (TAC NOS. MB2021 and MB2022).

Section 5.2.7 of Reference 1 identifies one Severe Accident Mitigation Alternative (SAMA) that would provide back-up power to the hydrogen igniters for Station Blackout (SBO) event. The NRC staff states that since this SAMA does not relate to adequately managing the effects of aging during the period of extended operation, it does not need to be implemented as part of license renewal pursuant to 10 CFR 54. The NRC staff intends to pursue this SAMA as a current operating license issue. McGuire concurs with the NRC that this SAMA is not within the scope of license renewal and should be addressed separate from any license renewal proceedings.

McGuire concurs with the NRC staff that there may be a cost beneficial plant design modification that can provide alternative power to the hydrogen ignition system during a SBO event. The NRC staff has determined that the hydrogen control issue is sufficiently important for PWRs with ice-condenser containment and BWR Mark III containments that the NRC has made the issue a Generic Safety Issue (GSI), GSI-189 - Susceptibility of Ice Condenser and Mark III Containments to Early Failure from Hydrogen Combustion During a Severe Accident. McGuire has begun evaluating possible plant design and procedure changes to find a cost-beneficial resolution for this SAMA issue.

U.S. Nuclear Regulatory Commission August 19, 2002 Page 2 Duke Energy has performed plant-specific probabilistic risk assessments (PRA), individual plant examinations, and system/component reliability studies to evaluate severe accidents at McGuire. Various design and procedure changes have been identified and implemented as a result of the above efforts.

These changes have reduced the risk associated with major contributors identified by the McGuire PRA and have enhanced overall plant safety. Resolution of the SAMA issue identified in Reference 1 is consistent with the effort by Duke Energy to use risk insights to continuously improve the safety of McGuire Nuclear Station. McGuire is cooperating with the NRC in resolving GSI-189 as a current operating license issue.

If you have any questions regarding this submittal, please contact P.T. Vu at 704-875-4302.

Very Truly Yours, H.B. Barron HBB/PTV/s

U.S. Nuclear Regulatory Commission August 19, 2002 Page 3 xc:

L.A. Reyes U.S. Nuclear Regulatory Commission Regional Administrator, Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, GA 30303 S.M. Schaffer Senior Resident Inspector (MNS)

U.S. Nuclear Regulatory Commission McGuire Nuclear Station R.E. Martin (Addressee Only)

NRC Senior Project Manager (MNS)

U.S. Nuclear Regulatory Commission Mail Stop 08-G9 Washington, DC 20555-0001 R.L. Franovich Senior Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 12-G15 Washington, DC 20555-0001 J.H. Wilson Senior Project Manager Office of Nuclear Reactor Regulation Mail Stop 12-D3 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Anne Cottingham, Esquire Winston and Strawn 1400 L Street, NW Washington, DC 20005 R.M. Frye Director, N.C. Division of Radiation Protection 3825 Barrett Drive Raleigh, NC 27609-7221

bxc:

L. F. Vaughn (ECIIX)

B. J. Dolan C. J. Thomas T. M. Burgess (MG05EE)

K. Crane R. D. Hart (CNO1RC)

M. T. Cash (ECO50)

R. L. Gill (EC12R)

H. D. Brewer (EC08I)

ELL (EC050)

MNS Master File 1.3.2.11