ML19209A592
| ML19209A592 | |
| Person / Time | |
|---|---|
| Issue date: | 07/19/1979 |
| From: | Richart F, Scott R Advisory Committee on Reactor Safeguards |
| To: | Fraley R Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1154, NUDOCS 7910050030 | |
| Download: ML19209A592 (4) | |
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' g u.cCMM-July 19, 1979 U.
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g Mr.
R.
F.
Fraley, Executive Secretary Advisory Committee on Reactor Safeguards U.S. Nuclear Regulatory Commission Washington, D.C.
20555 RE:
231st ACRS Committee Meeting:
Discussion of BAILLY Piles, July 12, 1979, Washington, D.C.,
and ACRS Sub-committee Meeting, July 9, 1979, Portage, Indiana.
Dear Mr. Fraley:
In accordance with requests by telephone from Mr. R. Muller of ACRS and with the authorizations for Official Tra'rel, the undersigned visited the BAILLY Site and attended the ACRS Subcommittee Meeting on July 9, and attended the evening portion of the ACRS Committee Meeting on July 12.
Previ-ously, we had been sent the Reference Documents (noted at the end of this report) for study.
As a result of our study of documents, and from information obtained at the site and answers to our questions, we pre-sented com. Tents at the ACRS Meeting, July 12, 1979.
These comments and additional notes are included in the following paragraphs.
1.
We noted that the NRC Staff had not yet completed its analysis of the behavior of piles to the interbedded glacial lacustrine deposit.
Therefore our relatively brief study of the problem would contribute to only a few of the topics covered in the NRC Staff's exhaustive study.
2.
It was not clear from the documents we studied as to the amount of settlement which might be developed by compression of the soils between the pile tips and bedrock.
Professor Richart suggcsred that it would be most useful if personnel from Sargent and Lundy and/or Dames and Moore would spend a day with Profes-sor Scott in Pasadena to review and clarify the method of evaluating the settlement below the pile tips.
This settlement and the associated deformation of the con-tinuous pile cap mat under the entire facility were also to be discussed.
7910050
- 5 J l 0.8 J21_
t Mr.
R.
F.
Fraley July 19, 1979 Page Two 3.
On July'16, 1979, r.
A.
K.
Singh from Sargent and Lundy and Mr. Demetrious Koutsoftas from Dames and Moore visited Professor Scott in Pasadena.
They dis-cussed methods of calculating the settlements and the values obtained until about 6:00 p.m.
At the end of this discussion period Professor Scott was satisfied that the methods of calculation, and selection of soil properties from laboratory and field data, were satisfactory.
Following further study alone, Profes-sor Scott concluded that their estimates of settle-ment were also satisfactory, and tha* the settlement should not be more than two inches.
4.
With adequate design of the piling system, we believe that satisfactory load-bearing systems can be devel-oped with piles bearing in the interbedded glacial lacustrine deposit.
5.
The soil regions disturbed during previous construc-tion have been termed "Sof t Spots. "
These zones will be identified, recompacted by driving additional dis-placement piles, and the effectiveness of the recom-paction will be verified.
We suggested the use of a Dutch Cone Penetrometer as a rapid method for iden-tifying the zone of loose soil at each soft spot and the effect!.veness of compaction.
The consultants to NIPSCO will look into use of this p ocedure.
There is no major problem in recompacting these soft spots.
6.
The new Pile Load Test Program appears satisfactory.
We questioned the limiting load of 600 tons and sug-gested that a number of piles ba tested to failure even if the load exceeds 600 tons.
This would pro-vide field verification of Dr. Lymon Reese's analyti-cal procedures.
7.
We had requested information concerning the combined static and dynamic loads to be developed in the piles.
This was given to us at the end of the ACRS Meeting by Sargent and Lundy personnel as copies of Tables 130.4-1 and 130.4-2.
Further discussions on the structural integrity of the pile cap-base mat assured us that there ein be minimal articulation of the base mat and it must move essentially as a single unit, after appropriate detailed design studies assure con-tinuity of the structure.
Thus the base mat motions, during earthquakes, control the loading in each pile, and extreme loadings on any one pile are not probable.
I108 324
Mr.
R.
F.
Fraley July 19, 1979 Page Three 8.
At the July 9 meeting there was some discussion of the settlements at the Burns Harbor Bethlehem Steel Plant following the oral statement by Mr. George M. Wilson of United Steel Workers Local 6787.
Information was requested for the July 12 meeting concerning the amount of settlements actually observed and the types of foundations used at the Burns Harbor Plant.
NIPSCO agreed to try to obtain this information.
An excellent public ation on settlements at the Burns Harbor Steel Plant is, " Settlement of Spread Footings on Sand," by D.
J.
D'Appolonia, E.
D'Appolonia, and R. F. Brissette, J. Soil Mechanics and Foundations Division, Proc. Am. Soc. Civil Engineers, v. 94, No. SM3, May, 1968, pp. 735-760.
Settlement measure-ments were made on over 300 colv n footings over a period of roughly four years.
i ese were all spread footings and the maximum settlement was on the order of 3/4 inch.
It was also noted in this paper that,
" Heavy machinery ir supported on individual footings not considered in this study."
Consequently, in our comments we noted that settle-ments at the Burns Harbor Plant provide no useful information for evaluating settlements of pile-sup-ported facility at the NIPSCO site.
Mr. Lynch from NRC Staff confirmed that the Burns Harbor Plant was supported by spread footings and that piles were not used to suf9 ort the major structures.
We recommend that no frcther effort be devoted to study of settle-ments o,f ti.e Burns Harbor Bethlehem Steel Plant.
Our conclusion is that properly designed piles supported by the interbedded glacial lacustrine deposit are satis-factory for carrying the applied loads.
This type of pile system represents no significant design change from that incorporating piles to hardpan or bedrock.
Very truly yours, (i
b F.
E. ~ Ric ha r t, /U r.
R. F. Scott ACRS Consultant ACRS Consultant FER:dap i108 325
Mr.
R.
F.
Fraley July 19, 1979 Page Four
~ '
Reference Documents 1.
Supplementary Information on Driven H-Pile Foundations, Docket No. 50-367, BAILLY, DeceTler 4, 1978.
2.
Docket File 130.1 130.6 130.11 130.16 130.2 130.7 130.12 130.17 130.3 130.8 130.13 130.18 130.4 130.9 130.14 130.19 130.5 130.10 130.15 362.1 362.8 362.13 362.18 362.2 362.9 362.14 362.19 362.3 362.10 362.15 362.20 362.4 362.11 362.16 362.21 362.7 362.12 362.17 3.
Soil Report, Bailly Generating Station Unit #7, Soil Testing Services, Inc., April 12, 1960.
4.
Analysis of Pile Driving Tests, Bailly Generating Station-Nuclear I, Report SL-3205, Sargent and Lundy, September 15, 1975.
5.
Design Analysis and Installation of Driven H-Pile Foundations, Bailly Generating Station-Nuclear I, Report SL-3629, Sargent and Lundy for NIPSCO, March 8, 1978.
6.
Indicator Pile Program, Bailly Generating Station-Nuclear I for NIPSCO, Sargent and Lundy and Dames and Moore, September 26, 1978.
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