ML19225C925
| ML19225C925 | |
| Person / Time | |
|---|---|
| Site: | Bailly |
| Issue date: | 06/28/1979 |
| From: | Vassallo D Office of Nuclear Reactor Regulation |
| To: | Lyle H NORTHERN INDIANA PUBLIC SERVICE CO. |
| References | |
| NUDOCS 7908030284 | |
| Download: ML19225C925 (3) | |
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7, UNITED STATES 8
'i NUCLEAR REGULATORY COMMISSION 5 ";,'o,
S WASHINGTON. D. C. 20555
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50-367 Mr. H. P. Lyle, Vice President Electric Production & Engineering Northern Indiana Public Service Company 5265 Hohman Avenue Hammond, Indiana 46325
Dear Mr. Lyle:
SUBJECT:
REVIEW 0F THE SHORTER PILE PROPOSAL FOR THE BAILLY SAFETY-RELATED STRUCTURES In reviewing your proposal for implementing the design criteria for the Bailly foundation piles, submitted on March 8,1978, and subsequently supplemented in September and December of 1978, we find that your March 1978 proposal for shorter piles has considerable merit but that you have not submitted sufficient infor-mation to permit us to conclude our review.
To date, we have identified a need for information related to three fundamental concerns:
(1) an acceptable pro-posal for correcting the "sof t spots" in the foundai. ion (i.e., those portions of the site degraded by the jetting of test piles)' (2) the piles chosen for load testing should be representative of the production piles; and (3) a sheeting and bracing pl2n to minimize pile disturbance adjacent to the deeper excavation planned for the reactor building.
With respect to your proposed fix of the "sof t spots," gravity grouting appears to be unacceptable.
We suggest, instead, that redensification may be accomplished by use of compaction piles driven to the depth of native soil disturbed by you-previous jetting procedures.
Additionally, the compaction piles might he installed so that:
(1) the production piles in the region of the soft spots attain a high level of driving resistance well before reaching either the underlying glacial till or bedrock; (2) the compaction piles do not interfere in any way with the driving of the production piles; and (3) the compaction pile, are cut off well below the bottom of the fourdatio,1 mat.
With respect to the piles which have been load tested, we note that only those piles you designate as " Type A" (i.e., those piles which did not break through a " bearing" sand layer) were load tested. Accordingly, we believe that your pile load tests establish tne upper bounds of the load-bearing capacity of piles at this site rather than typical capacities of production piles.
We suggest that pile load tests should be performed on " Type B" piles (i.e., those piles whose driving records indicate a potentially low load-bearing capability) and thereby establish a conservative bound for pile load capacities.
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Mr. H. P. Lyle JUN 2 81979 Finally, we note that none of your submittu.; to date addresses the adverse consequences to the piles which will be adjacent to the reactor building..nen the soil under this particular building is excavated an additional ten feet af ter first having driven the adjacent piles.
We suggest that a sheeting and bracing plan which minimizes the effect of disturbances on the adjacent piles, should be developed and submitted.
For y,ur guidance on these three issues, we suggest that you give careful consideration to our thoughts expressed above in implementing the basic re-quirement that the Bailly safety-related piles be designed, tested and installed in accordance with high construction industry standards.
In particular, all aspects of your three reports on the shorter pile proposal should be reviewed and modified to ensure that they are well documented and thoroughly justified.
If you have any questions on these matters, please contact us.
Sincerely,
/
D. B. Vassallo, Acting Director Division of Project Management Office of Nuclear Reactor Regulation cc:
See next page 403 i81
140rthern Indiana Public Service Con.pany cCs.
fieredith Hemphill, Jr. Esq.
Assistant General Counsel Bethlehem Steel Corporation 701 East Third Street c
Bethlehem, Pennsylvania 18016 William H. Eichhorn, Esq.
Eichhorn, Morrow & Eichhorn 5243 Hohman Avenue Hdluniond, Indidna 46320 Edward W. Osann, Jr., Esq.
Wolfe, Hubbard, Leydio, Voit & Osann, Ltd.
- l-Suite 4600 One IBM P1aza Chicago, Illinois 60611 Robert J. Vollen, Esq.
109 North Dearborn Street Chicago, Illinois 60602
-w Porter County, Izaak Walt in
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League of America, Inc.
Box 438 Chesterton, Illinois 46304 Michael I. Swygert, Esq.
25 East Jackson Boulevard Chicago, Illinois 60604 Richard L. Robbins, Lsq.
Lake Michigan Federation 53 West Jackson Boulevard Chicago, Illinois 60604 p.,
yf Maurice Axelrad, Esq.
Oy Lowr ein, Ne wan, Heis & Axelrad I;
- 102, necticut Avenue, N. W.
C. ;
Wach
.on, D. C. 20036
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Dean Hansell, Esq.
Russell Eggert, Esq.
Of fice of the Attorney General 7
State of Illinois 168 W. Randolph Street Chicago, Illinois 60601 408 182 4
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