ML19329D684
| ML19329D684 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 04/21/1976 |
| From: | FLORIDA POWER CORP. |
| To: | |
| Shared Package | |
| ML19329D683 | List: |
| References | |
| NUDOCS 8003160304 | |
| Download: ML19329D684 (1) | |
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u Florida Power co.,,,....e April 21, 1976 Mr. Ernes t Volganeat:, Director Directorate of Regulatory Operations U.S. Nuclear Regulatory Commission Washington, D. C.
20545
Subject:
Docket No. 50-302
Dear Mr. Volganeau:
Pursuant to 10CFR50.55E, we wish to follou up our verbal (telephone) notification of 4/19/76 regarding a separation in the concrete of the Crystal River Un:t 43 containment structure dome.
We have now documented the apparent extent of this separation.
To recap,the following is the sequence of events of the investigation.
Cn Wednesday, April 14, 1976, while placing cinch anchors in the done concrete of the Reactor Duilding, it was noted that there appeared to be a hollow area acout one inch beneath the surface.
Investigation on Friday, April 16, e
and removing a section of concrete approximately one footby saw cutting wide by three feet long, showed that the depth of the hollow area went deeper as it went higher on the dome.
By core drill-ing on Saturday and Sunday, April 17 and 18, it was further determined that the separation continued across the done and went as deep as 15" and separated as much as 1-3/4 inche.s.
By using acoustic methods, the lower perimeter of the separated area was determined to extend all around the dome in pours "G", "H" and "J".
Our engineers are now evaluat ng the present condition of the structure.
S' ches marked I, II, III, IV, V, and VI illustrate the apparent extent of the separation as indicated by the limited data available at this time.
e 9
8003160 3 0 /
, Genomi (ilfico wu T*
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