ML13056A128

DHS Briefing Slides on Oconee Flood Protection and the Jocassee Dam Hazard

ML13056A128
Person / Time
Site:	Oconee
Issue date:	09/19/2008
From:	Office of Information Services
To:
References
FOIA/PA-2012-0325
Download: ML13056A128 (6)

Text

Offcia ý- Sensi`,1yve I all to~r Uio~n ftle~Kse 0 ,f, en,, e j;1!ý.SNR Oconee Flood Protection and the Jocassee Dam Hazard DHS Briefing September 19, 2008 10/4/2012 Official e 1,!y enive 1 SNRC Overview

• Objective

- Provide background information for issue

- Provide status and path forward

• Success

- Understanding of the regulatory and safety issues

- Understanding of NRC planned actions

- Identify any NRC/DHS issues that need further action 10/4/2012 1 / 2Y -Seoy e2 2

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Offic, se Only

,ye- Sen In nal 4t*fo*atib*

(N -ecia~se~$1y- kns' ve US.NR.C ',Inhih-I *nforat n Oconee Nuclear Station

" Three pressurized water reactors located in Seneca, South Carolina

- Owned and operated by Duke Energy Corporation

- Operational in 1973-74

- Located down river of lake Keowee (just north of site) and lake Jocassee (11 miles upriver)

" Only nuclear plant in the United States that relies on hyrdo-electric generators as emergency power source (Keowee Hydro Station)

• Plant relies on the Standby Shutdown Facility (SSF) to maintain reactor shutdown in case of fires, floods, or sabotage events.

- SSF contains its own electric power source (diesel generators, batteries, etc..), control room.

- SSF is a retrofit to the original plant design.

6 10/4/2012 Okciaiu ve 3 Itmal Infofr.~i Officj~4seQnIyjSei~iti~e

___ In a lrmatioM

- The Flood Scenario Rupture of Jocassee Dam

ýa Lake Jocasee

-385-ft Ocne Sitein 10/4/2012 0 Us ensie 4 ell Inform~ioh' 2

Official U ensiti ntenal InFrmation

-t,,U.S.NRC SD Or2ýnow e Sen ye

=nfb*vAInternal Inforion Jocassee Dam Aerial 10/4/2012 W,,IX Zse~of. -SennSI 5 U.S.NRC 10/4 12 6 10/4 12 6 3

Ofial Ue Oly - SensitiveI I rmat n OiciaI Use - Sens ve

-ýtUSNRC The SSF FioodBarriers Five-foot flood wall 10/4/2012 10/4/2012 Use 0 "ySe tive 7

\jtii4ftrrri"6i Oeffical Use On Sen *e U.S.NRC Key Insights from Reactor Oversight Process

" In 2007, NRC concluded that the Jocassee dam failure issue had not been adequately resolved.

• Duke Hydro/FERC Inundation Study completed in early 1990s. Estimated flood heights up to 16.8 ft above SSF grade level.

• Floods in excess of 5 ft lead to three-unit core damage event and ultimate failure of each containment building.

" Staff identified an under-estimate in licensee's dam failure frequency.

10/4/2012 8 eon 4

orm'bti "n yJ nterna, Official Use ONi - niti

-1U.S.NRC ter form Issuance 50.54(f) Letter

• On August 15, 2008, NRC issued letter to licensee requiring information to determine if NRC should modify, suspend, or revoke the license.

• Letter seeks information to assure protection of public and elevates NRC's regulatory and safety concerns.

• Letter states that Jocassee Dam Failure Inundation Study indicates flood heights up to 16.8 feet above SSF grade.

• Licensee to respond to NRC by September 29, 2008.

10/4/2012 Use - Sens, 9e lnt~tT 1fnfor. ai TTC1.T1ial~ aI U OnWI-Sens e Actions Concurrent with 50.54(f) Letter

• Backfit evaluation: external flooding within licensing basis. Licensee did not address Jocassee dam failure.

" "Adequate Protection" based backfit best approach.

- No defense-in-depth: three unit core damage event with ultimate failure of each containment.

- Regulatory expectations for external flood protection includes dam hazards.

" Cost-benefit estimate of $3 million in modifications.

Modifications on the order of $13 million justified.

10/4/2012 c. l Use -Sensiti*e 10 Ie.l nfo atioo 5

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ý-:jU'JS.NRC -uQ" nse *~Se* *ve.lyfrt Ve Actions Concurrent with 50.54(f) Letter (continued) o In early September 2008, NRC staff notified Congressional staffers regarding the issue.

" NRC anticipates interaction with Congressional staffers on the issue and NRC resolution.

o Generic issue preliminary assessment completed.

- Twenty five sites have a dependency on dam performance. Seven sites (including Oconee) have dams up river of the site.

- Draft Information Notice has been written.

10/4/2012 0fi6 I r Senale 11 Inera "forrnam o

-':)AJ.S.NRC USn

!ROfficial NRCIDHS Interface o NRC staff is providing this information to DHS should it affect the ranking of the Jocassee Dam from a security oversight standpoint.

o NRC has not determined how or if security issues may affect the NRC's regulatory actions.

o Are there any additional actions that DHS could take, if necessary, to further protect the dam?

10/4/2 012 140Use ly S ive 12

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