ML19224C421

Forwards Suppl Info,Clarifications & Alternatives to Foundation Pile Design.Proposals Developed for Improving Subsoil Conditions within Preconstruction Areas & for Defining Criteria for Pile Placement,Splices & Load Tests

ML19224C421
Person / Time
Site:	Bailly
Issue date:	05/29/1979
From:	Shorb E NORTHERN INDIANA PUBLIC SERVICE CO.
To:	Vassallo D Office of Nuclear Reactor Regulation
References
NUDOCS 7907020310
Download: ML19224C421 (6)

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Northern Indiana Public Service Company General Offices l 5265 Hohman Avenue l Harrynond. Indiana 46325 lTel: 853 GOO (219)

EUGEN E M. SHO99

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June 29,1979 Mr. Dominic B. Vassallo, Acting Director Division of Project Management Office of Nuclear Reactar Regulations U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Re: Northern Indiana Public Service Company Bailly Generating Station - Nuclear 1 Docket No. 50-367

Dear Mr. Vassallo:

To facilitate the staff's review of the foundation design for Bailly Generating Station - Nuclear 1, the following reports and responses have previously been submitted:

- Design Analysis and Installation of Driven H-Pile Foundation, Report SL-3629, submitted on March 8,1978

- NIPSCO's Responses to NRC Staff Questions, sub-mitted on July 14 and July 20, 1978

- Indicator Pile Program, submitted on September 26, 1978

- Supplenwntary Information on Driven H-Pile Foundation on December 4,1978 Subsequent to these submissions, NIPSCO has had discussions with the NRC Staff and continued to evaluate foundation pile design. On the basis of these further evaluations, we have developed alternative proposals for improving subsoil conditions within preconstruction 271 148 7907020 M

Northern Indianam PublIo Servloe Cornpang Mr. Dominic B. Vas sallo Hammond, Indiana U. S. Nuclear Reg,~ 1 tory Commission June 29,1979 Page Two areas and for defining criteria for pile placement, pile splices, and pile load tests. As a result, enclosed are forty (40) copies of the document, " Supplementary Information, Clarifications, and Alterna-tives to the Foundation Pile Design, " which presents these alternatives and further details of our proposed pile installation techniques.

We believe that this enclosure may serve to resolve some of the staff's questions and clarify our positions with regard to:

Remedial measures in preconstruction areas; Delineation of load test procedures; Tolerance criteria for placement of production piles; Pile splices.

These clarifications are intended t 3 aid the staff in finalizing review of the Bailly foundation design. We shall appreciate receiving staff views concerning the alternatives outlined in the enclosure, which in our opinion, are equally acceptable to our previous proposals.

Very truly yours, EMS: cgs Enclosure 271 149

SUPPLEMENTARY INFORMATION, CLARIFICATIONS, AND ALTERNATIVES TO THE FOUNDATION PILE DESIGN

1. Preconstruction Areas During the fall of 1978, Northern Indiana Public Service Company conducted an extensive program of investigations within the areas that were influenceo ay preconstruction activities to evaluate soil conditions within these areas and te collect sufficient data to develop a program of remedial measures to improve these areas.

The results of these studies were submitted to the NRC for review in the form of a supplementary report titled:

" Supplementary Information on Drivin H-Pile Foundations, Bailly Generating Station -

Nuclear 1" December 4, 1978, Chapter 2 The proposed remedial programs included grouting in the bnmediate vicinity of the source of disturbance, as explained in detail in the December 4, 1978, report, and driving H-piles to densify soils encountered within the areas which were influenced by the precon-struction activities.

On the basis of further evaluations, we suggest the following, equally acceptable, alternative program for improving the subsoil conditions within the preconstruction areas:

a. Ten-inch nominal diameter pipe piles would be driven within the preconstruction areas. The piles would be driven with 271 150

a Vulcan 016 hammer with a rated energy of 48,750 f t.-lbs. or equivalent.

b. Grouting would te eliminated. The original intent of grouting was to fill the holes that could have been created by the extraction of test piles, anchor piles, jet pipes, or holes created by drilling. The same objectives would be achieved by the compaction resulting from the dirplacement of soil by the 10-inch nominal diameter pipe piles.

c. Other specific details of the program would be defined within the general guidelines provided in Chapter 2 of the December 4, 1978, report for each of the preconstruction areas.

2. Pile Driving Criteria As part of the driving criteria for the production H-piles that will be seated in the glacial lucustrine interbedded dense sand /hard clay deposit, we submit the following alternative criteria, which would supplant the criteria presented in Chapter 4 of the December 4, 1978, report.

The piles would be driven in accordance with the following criteria:

a. A minimum pile tip elevation, as defined by Figure 5 of the Indicator Pile Program report (September 26, 1978.)

b. A minimum of 500 blows for the last five feet

c. A m' imum of 100 blows for the last one foot

d. A m ;.imum of 30 blows for the last three inches Item a. has been added for clarification and Item d. would replace the previously proposed criteria of a min'. mum of 10 blows for the last inch.

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3.  : lle Placement Tolerance Criteria The installation of the proposed H-piles would satisfy the following criteria with respect to placement tolerances as an alternative to the proposed tolerance criteria in Chapter 5 of the December 4, 1978 report:

a. Tolerance Acceptable Deviation, Deviation, Consulting Engr.'s Consulting Engr.'s Approval Required, NRC Approval will be Informed of the Required Deviation and the Resolution Location 0 - 3" 3" - 6" > 6" Rotation 0 - 10 100 - 200 > 200 Plumbness 0 - 2% 2% - 4% > 4%

4. Pile Splices This alternative would revise the criteria presented in Chapter 5 of the December 4, 1978 report.

The occurrence of a splice within the top 30 feet of the pile ahall be reviewed by the Consulting Engineers, who will determine the resolution and the nature of remedial measures, if required.

5. Pile Load Test A minimum of six production piles would be load tested as follows:

a. The load test would be conducted using ASTM D1143-74, quick optional procedure, up to a tctal load of 400 tons.

b. The 400-ton load would be maintained for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and deflection readings will be obtained during this time.

c. At the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the load would be increased further in accordance with the quick optional procedure to failure or to a maximum loa,d of 600 tons.

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These criteria are alternatives to the informat:.on presented in Chapters 3 and 4 of the December 4, 1978 reporc.

271 153