ML14058A031

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DHS Briefing on Oconee Flood Protection and the Jocassee Dam Hazard
ML14058A031
Person / Time
Site: Oconee  Duke energy icon.png
Issue date: 11/26/2008
From:
Office of Nuclear Reactor Regulation
To:
Shared Package
ML14055A421 List: ... further results
References
FOIA/PA-2012-0325
Download: ML14058A031 (16)
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Text

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, .Official F se Only ecurity USS.NRC hznrti~up~dhEwiiromt o w In elate form iýý Oconee Flood Protection and the Jocassee Dam Hazard DHS Briefing November 26, 2008 10/3/2012 I

-Se rity

- ,US.NRC Official VOMEMCA, ERLTOACOMM.ated In rf ation 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 10/3/2012 2

USNRC fteU.S ;*'opkendoh,,'w.mNR fcaUe0 Se ur Related Infr n.

Oconee Nuclear Station

- Owned and operated by Duke Energy Corporation

- Operational in1973-74

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

, Only nuclear plant inthe 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 incase of fires, floods, or sabotage events.

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

- SSF isa retrofit to the original plant design.

10/3/2012 0 jal Use nly Sec 3 SRte nforma ion

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10/3/2012 4

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~US.NRC 0f) fW1TAM%.%W UGJWYMOSM PAourgxPeopIkW~ (AtEnzironewsi Jocassee Dam Aerial 10/3/2012 5

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Five-foot flood wall protecting the doorway.

10/3/2012 7

Ký3US.NRC a ~ng ople andi&w[wimmenmI ImProen Key Insights from Reactor Oversight Process

  • In2007, NRC concluded that the Jocassee dam failure issue had not been adequately resolved.

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

, Floods inexcess of 5ff lead to three-unit core damage event and ultimate failure of each containment building.

, Staff identified an under-estimate inlicensee's dam failure frequency, 10/3/2012 8

(TU.S.RC cam.0 UMcNeR Rated n

-vmciaseyecr formation7 Issuance 50.54() Letter On August 15, 2008, NRC issued letter to licensee requiring information to determine ifNRC 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 responded to NRC on September 26, 2008.

10/3/2012 9

$US.NRC 0icial Use Only - urity IPr*-JqPn~L~o~p~eand thr Emi-zrunmD Actions Concurrent with 50.54(f Letter

  1. 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.

s Cost-benefit estimate of $3million inmodifications.

Modifications on the order of $13 million justified.

10/3/2012 10

4*US,NRC Official Use nly

"*,,.*ae ~*- Security Actions Concurrent with 50,54(1 Letter (continued)

  • Inearly September 2008, NRC staff notified Congressional staffers regarding the issue.
  • NRC anticipates interaction with Congressional staffers on the issue and NRC resolution.

, Generic issue preliminary assessment completed.

- Twenty five sites have adependency on dam performance. Seven sites (including Oconee) are vulnerable to dams up river of the site.

- Draft Information Notice has been written.

10/3/2012 11

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.N U niy Scr-Related I rmati NRC/DHS Interface

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@NRC staff isproviding this information to DHS should itaffect the ranking of the Jocassee Dam from a security oversight standpoint.

s NRC has not determined how or ifsecurity issues may affect the NRC's regulatory actions.

e Are there any additional actions that DHS could take, ifnecessary, to further protect the dam?

10/3/2012 12

  • USNRC O° nf r

%UIi MIMU UTjcIM RhWI CMMN theUwawwm xPeops and Pvoktec Other Vulnerable Sites Of the 24 Nuclear plant sites located on rivers that contain upstream dams, 7were identified that did not have obvious protective features.

Several sites had as many as 5upstream dams with no provision for cascading failures, 10/3/20112 13

- Sequffy AU.S.NRC I~ll~

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(Official nly Related Info tin Nuclear Plant Location River Upstream Dams Local Dams (Regulator)

Arkansas Nuclear One I LAT Arkansas River Ozark Dam Dardarielle (N)

&2 3518'36" (COE) 66' LONG Concrete/Gravity 9313'53" Cooper Nuclear Station LAT Missour River Gavins Point, Fort Randall, Big (COE) 40 21'44" Bend, Oahe, Garrison, Fort Peck LONG 95 38'30.4" Ft. Calhoun Station LAT Missouri River Gavins Point, Fort Randall, Big (COE) 41 31'14* Bend, Oahe, Garrison, Fort Peck LONG 96 39" McGuire Nuclear Station, LAT Catawba River Lookout Shoals Dam, Cowans Ford (N)(FERC)

Units I &2 35 25'59" Bridgewater. Rhodhiss. Oxford 115' Gravity/Earth LONG 80 56'55" Oconee, Units 1,2,and 3 LAT Keowee River Jocassee Dam, (Bad Creek Dam Jocasse 34 47'38.2" -not analyzed) 385' Rockfill LONG Lake Keowee (N) 82 53'55.4" 70' Gravity/Earth Little River (N) 155' Earthfill (FERC)

Waterford Unit #3 LAT Mississippi River Many Dams on or feeding (COE) 29 59'42" Mississippi River LONG 90 28'26" Watts Bar Nuclear Plant LAT Tennessee River Wafts Bar Dam Wafts Bar, 35 367" Chickarnauga (N)

LONG (both TVA) 105' 85 47'21" Gravity/Earth 10/3/2012 Official se ly-Se dty 14

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I)UOS.NRC andIkeEmnnuonmexi FrokedmPkopku O~ffial Use Only - Sec ity Relate( fo ation 1656 Ozark Lock &Dam Ozark Lake AR00164 -93.81 35,47333 Arkansas CESWL 41465 Lookout Shoals NC00394 -81.0908 35.7575 Catawba DUKE POWER 41205 Rhodhiss NC00104 -81.4381 35.77417 Catawba DUKE POWER 41405 Oxford Lake Hickory NC00329 -81.1922 35.82139 Catawba DUKE POWER 65679 Wafts Bar Watts Bar Lake TN12102 -84.7833 35.62 Tennessee River TVA 65754 Wafts Bar Nuclear Holding Pond Temporary Holding Pond TN14306 -84.783 36 Tennessee River IVA 65757 Wafts Bar/Kingston Backwater Dike Wafts Bar Lake TN14503 -84.517 35.875 Clinch River TVA 65680 Walls Bar/Saddle Dam No. 1 Wafts Bar Lake TN12103 -84.783 35.62 Tennessee River TVA 63599 Gavins Point Dam Lewis And Clark Lake SD01094 -97.4817 42.84833 Missouri River CENWO 63598 Fort Randall Dam Lake Francis Case SD01093 .98.555 431065 Missouri River CENWO 37855 Fort Peck Dam Fort Peck Lake MT00025 .106.417 48 Missouri River CENWO 63597 Big Bend Dam Lake Sharpe SD01092 -99.4467 44.03833 Missouri River CENWO 63600 Oahe Dam Lake Oahe SD01095 -100.387 44.45 Missouri River CENWO 43989 Garrison Dam Lake Sakakawea ND00145 -101.432 47.50167 Missouri River CENWO 1013/2012 cial Use ly - Se 15 dlnf rm 'on

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-L Related tion /

Analysis Concerns with Jocassee Dam

, NRC staff feels that Jocassee Dam isrobust

- Discussions with licensee and FERC

- FERC inspection reports

  • Licensee's analysis may lack necessary conservatism for nuclear licensing basis
  • Areas where further analysis isrequired:

- Inundation analysis e Breach size parameters s Timing of breach e Probable Maximum Precipitation s Spillway gates

- Seismic Analysis s Soil liquefaction

  1. Settlement of foundation 10/3/2012 1
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