ML20084L206
| ML20084L206 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/06/1968 |
| From: | Philleo R ARMY, DEPT. OF, CORPS OF ENGINEERS |
| To: | Reinmuth G US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML17198A202 | List: |
| References | |
| NUDOCS 8305200347 | |
| Download: ML20084L206 (6) | |
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ENCCW-EC 9 Septc:6cr 1968 i
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Mr. G. W. Reinmuth 1
i Reactor Inspector Division of Compliance 1
U. 3.' Atemic Energy Cocaicsion Washington, D. C.
20545
Dear Mr. Reinmuth:
Inclosed is a ccpy cf ry rc"itw of the "Rcpert on I!oneyec Oing 1
Turkey Point Unit 3 Centsirsent P.at."
Plcnc let na knau if I can bo of further help.
l
> My copy of the report is returned hercuith.
3 Sincorcly yours, i
l 2Inb1 nonrar :. PHILLEO, Chief an' l'ccearch and Development and 5 tcadards Sectica Concretc Ercnch, Za;inecrin3 Div l
Civil Wrh3 l
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.r. Frank Iona "i
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8305200347 700209 PDR ADOCK 05000250 A
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Cor.cnts on l
" Report on Honeycombing, Turkey Point Unit 3 Containment Mat"
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- The. report prepared by Lechtel Associates for the Florida Power a'nd Light Company is quito complete, particularly in the inves tiga tive phase, and generally satisfactory. However, the following ec=.ents are I
in~ order:
i Investication.
The investigation by coring, chipping, and scniscope i
was adequate for dealing with the indicated problem. The soniscope survey l
9 II in particula'r was thorough and helpful in assessing the condition of the l
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There is, however, one discrepancy in the interpretation of the mat.
3 data which tends to weaken the conclusions.
In most of the cases in which a readable signal was not received, it has been demonstrated that obstructions other than accidcatal voids were present.
Hence, the absence of a strong signal did not necessarily indicate the presence of voids.
.i At el vation 3.0 it was concluded that many received signals were weak becauke, as a result of a surveying error, the signal paths passed I
through tendon trumpets. Those which were not through trumpets generally I
produced good results. HowcVer, in one sector cf the mat these conclu:.icn; I
arc in disagreement with the path locations shown in Appendix E (Drawin;;
i No. 5610 C-148).
According to Figure 12 of the Whitchurst reporg high horizontal velocities were obtained at the 3.0 ft level in test positions 19 througn 28' and position 30 in Section 4-5; and according to Figure 13 1
high velocities were obtained in test positions 1 through 3.
Appendix C i,
shows that all those pa ths pass through trumpets. Either the plotted i
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i locations ar'c in error or the conclusion that trumpets interrupt signal-is invalid. A personal conta = by telcphone with Professor Wnitcherut j
did not succeed in resolving this matter.
It would be well if it cou t,:
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be cleared up.
Otherwis e, the cenclusicrs of the Whitehurst report are 1
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consistent with Appendix E.
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j Although details of the structural design are not available, the
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i mat appears to be sufficiently intact to carry the wall loads provided 1
l the concrete adjacent to the tendons has the quality and continuity l
assumed in design.
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Proposed Remedial Measure s.
The grcuting procedure outlined in the
' report should prove adequate. During the execution of the work frequent l
samples should be taken to check expansion of the grout since it is sensitive to field conditions.
I l The report is not clear as to how much of the repair will be by f
grouting and how much by shoterete. Shotcrete should be applicabic to.i significant portion of the werk.
i jPreventive Measures.
In paragraph V-2.0 it is stated that a low slump; was required to minimize shrinkage and creep effects. Actually, very little shrinkage can occur in so lar2e a mass; and any sort of cra d-ing resulting' from volume change is unlikely with the large amount of
, steel which is incorporated. In = cst mass concrete structures emphasis is placed on 'he icwest possible water and cement contents for the pur-t pose of minimizing temperature rise and the subsequent thermal stresses I
which accompany cooling. Such structures are normally unreinforced,,,m:
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I these measures are taken to prevent cracking. None of these control measures appear important in thaso heavily reinforced mats. Emphasis i
should be placed primarily on strength and workability. If an extra
' inch of slump is needed for proper placement, there is no reason why it should not be used. There is also no need for two types of concrete.
)
Apparently, some difficulty could have been prevented on Unit 3 if it had l
been possible to divert some of the concrete frcm the inside to the out-t i
I side. Honeycomb should be prevented by:
i Considering placing problems when setting s tacl, a.
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bf Providing an adequate nurler of trcaics to restrict the t
' horizontal flow of concrete, and p.
Using a very workable concretc with a slump higher than c.
3 inches if necessary.
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4 1.
A very good investigation was carried out which, except for one inconsistent group of conclusions, adequately detailed the extcut of i
the problem.
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The grouting repair precedure, which was developed in tha f
manufacturer's shop is adequate.
3.
In future work more c:nphasis should be placed on concrete j
workability.l i
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j ROBE 2T E. PHILLEO 9 Septe:rber 1968 l
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