ML102710338

E-Mail from Lake to Franke Et Al., Update on Crystal River

ML102710338
Person / Time
Site:	Crystal River
Issue date:	12/10/2009
From:	Lake L NRC/RGN-II
To:	Mark Franke, Farideh Saba, Marvin Sykes Office of Nuclear Reactor Regulation, NRC/RGN-II
References
FOIA/PA-2010-0116
Download: ML102710338 (3)

Text

Sengupta, Abhijit From:

Lake, Louis Sent:

Thursday, December10, 2009,11:54 AM To:

Franke, Mark; Saba, Faridel; Sykes, Marvin; KhannaMeena; Reyes, Luis; Kennedyý, Kiss; Wert, Leonard; Munday, Joel; Morrissey, Thomas; Reyes, Rogerio; Dan naus; Lake, Louis;-

Masters, Anthony; Carrion, Robert Thom as,. George SUbject:

Update on Crystal River Attac-hahments:

QC Inspection of SGR Opening

`Oýpdf; Root Cause Update for NRC pptx I receivedithe following update on three, areas from Garry Miller this morning:

Field Work While removing grout (that was temporarily instailed to provide a level surfac6 for the SGR platform) from the bottom of the SGR opening cracks were identified in the containment concrete close to the containment liner.

Further inspections identified similar cracks which are also close to the containment liner. See -attached photo. By examining photos taken soon after the SGR opening was made, it was determined that these cracks were not there at that time. Initial thoughts are that they are somehow linked to the activities associated with the SG movementand/or containment liner replacement. Furtherinvestigation is UndaerswaY.

Desigqn Basis Analysis With input from root cause analysis, MPR is evaluating two plans for de4ensioning tendons in preparation for the removal of the de-lamination.

One plan consists of 164 horizontal and 36 vertical tendons. Another plan being considered, taking into account specific information provided by PHl (rootcause) on the effects of creep, consists of,35 horizontal and 35 Vertical tendons..

There has been no change in the estimated time for de-tensioning starting around mid January-Root.Cauase Garry plansto share preliminary root cause information by the end of December. The latest Open Failure Mode Status chart is attached. PII is ini the process of using two computer programs, NASTAN and ABAQUS, to evaluate the effects of creep vs de-tensioning with results within next week and a half.

Louis Lake Crystal River SIT Team Lead Louis.La ke @ n rc.gov 404-562-4683

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Root Cause: Analysis -P1 Metrics as of Dec 3rd 2009 Open Failure Modes

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,r 80 I1 5,0, 40 30

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External Events

• (I)Operational Events I

h -! dequate.Co ain ment

.. -I Inadequate Concrete-Tendon intoeactions.

.i.r.) Chemically or Ehvironmentally du~edAging (4) Sh rinkage.: Cr~eep and 2 Yj) Inadequate-Use-of Concrete Matei als-10 I

S(i Iladequate Choicrete

ýqonstruction P,(1) Inadequate Concrete Design

'due to High Local Stress r~OO~d&#Vý,

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