ML12200A246
| ML12200A246 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/14/2011 |
| From: | Rajender Auluck Division of License Renewal |
| To: | Cuadradodejesus S, Dennis Morey Division of License Renewal |
| References | |
| FOIA/PA-2012-0121 | |
| Download: ML12200A246 (2) | |
Text
7 CuadradoDeJesus, Samuel From:
Sent:
To:
Cc:
Subject:
Attachments:
Auluck, Rajender '61M Wednesday, December 14, 2011 10:27 AM CuadradoDeJesus, Samuel; Morey, Dennis Sheikh, Abdul; Lehman, Bryce; Li, Rui DB Containment Crack RAI-abdul-RA.docx DB Containment Crack RAI-abdul-RA.docx
- Sam, This is a new RAI regarding shied building cracks at Davis Besse.
- Thanks, Raj
"" q I
RAI B.2.39-X
Background:
In order to perform a scheduled reactor head replacement, a construction opening was made in the concrete shield building. During hydro-demolition of the concrete shield building, cracks were identified in the 'architectural shoulders' of the shield building. While investigating the extent of the cracking, additional cracks were identified around the shield building. These additional cracks were identified using an Impulse Response (IR) technique and core bores were used to verify the IR results.
Issue:
Extensive cracking in the shield building could affect the and may impact its ability to perform its intended functior operation.
Request:
- 1. Summarize the shield building degradationAhe n actions.
- 2. Explain how the recent plant-specific operating. e:
ability to perform its intended'functions during I*h'e a list of any additional aging *ff #s that may req operating experience.
'f",
of the shield building of extended expected corrective thf',h5ield Building's on this
- 3. Explain how the recent pla Structures Monitoring P-rq to manage aging'of thefzhi this operating.experience;>
,xperiEncehwill be incorporated into the lthe curnpnt program will be adequate enperiodiof extended operation, based on the f6*l*
ing:
Details of testr.pl rdo deterr"i'"
he long term effect of the concrete cracks on-tPiotnbl~ityof the.
- to car X'*!design flos.
It.
i~f.
tny,o trpair the crackbr_ ie orce the shield building concrete.
Detailed'plans to mp tor the extentvand thickness of cracks, and corrosion of the r6bars over the long,termi.
\\
iv.
, ýPlans, if any, to:
rm~de6taIled structural analysis, with explicit modeling of rebar Iracks, and co r" nete, to demonstrate that the shield building will perform its intended 'design function,,Over the long term. This analysis should also consider the effect of shrinkape and environment on the concrete and rebar during the period of extended operation.
- 4. Identify and explain '
changes to the license renewal application based on the recent plant specific operating experience.