ML19262B926

Forwards Applicant Analysis of Need to Overexcavate Unit 2 Foundation.Activity Raises No Significant Relationship to ALAB-573 Issues of Site Suitability & Environ Matters

ML19262B926
Person / Time
Site:	Black Fox
Issue date:	01/02/1980
From:	Gallo J ISHAM, LINCOLN & BEALE
To:	Johnson W, Salzman R NRC ATOMIC SAFETY & LICENSING APPEAL PANEL (ASLAP)
References
NUDOCS 8001220136
Download: ML19262B926 (2)

Text

.. . ..

ISHAM, LINCOLN & BEALE COUNSELORS AT LAW 1050 9 71** ST R E E T, N . W. $[VE NTH FLOOR WAS HINGTON, D. C. 2OO 36 T E LE PHON E 202-833-9730 CHICAGO OFFICE ONE FIRST NAf 80NAL PLA2A FORTV SECOND FLOOR CH'CAGO,ILLINotS 60803 T E LE PHON E 312-S58-7500 TELEX:2-8288 January 2, 1980 Richard S. Salzman, Esquire Dr. W. Reed Johnson Chairman, Atomic Safety and Member, Atomic Safety and Licensing Appeal Board Licensing Appeal Board U.S. Nuclear Regulatory U.S. Nuclear Regulatory Commission Commission Washington, D.C. 20555 Washington, D.C. 20555 Re: In the Matter of the Application of Public Service Company of Oklahoma, Associated Electric Cooperative, Inc. and Western Farmers Electric Cooperative (Black Fox Station, Units 1 and 2), Docket Nos. STN 50-556 and STN 50-557 Gentlemen:

Applicants advised the Appeal Board and the parties on October 22, 1979 of the need to overexcavate the foundation area of Black Fox Station, Unit 2. Overexcavation was neces-sary to remove certain underlying soft siltstone material which Applicants propose to replace with concrete fill to bring the excavation to design grade.

It was stated in the October 22 notification that further analyses were being conducted by Applicants and that these analyses would be furnished to all concerned. The in-formation is now available and it is enclosed with this letter.

Applicants continue to believe this information has no sig-nificant relationship to any site suitability or environmental matters reviewed by the Appeal Board in ALAB-573.

1784 142 gggggg,3g

. _ _ . .__ .._...__m.___

We are also mindful that the issuance of ALAB-573 may have caused the Appeal Board to lose jurisdiction in this matter. Nevertheless we are erring on the side of full disclosure. This information is also being furnished to the Licensing Board under separate cover (copy enclosed),

Sincerely, osep Gallo One of the Attorneys for the Applicants cy: Serv.ce List except letter to Licensing Board dated January 2, 1980 m

\18k \43

• 6212 DIN 8-019-767 PUBUC SERVlCE COMPANY OF OKLAHOMA m A CENTRAL AND SOUTH WEST COMPANY .

PO. BCX 2o1/ TULSA CKlh0MA 741o2 / (918) 5834611 k _g Public Service Company of Oklahoma December 12,1979 Black Fox Station Units 1 and 2 File 6212.125.3500.21L Excavation Seal Unit 2 U.S. NRC Docket No. STN50-556, 50-557 Mr. Steven A. Varga, Assistant Director Division of Project Management Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20002

Dear Mr. Varga:

As promised in our letter of October 19, 1979, we are transmitting herewith, for staff review, analyses we have done regarding the excavation seal on Unit 2 of the Black Fox Station. These analyses involve an assessment of the strength of a mass fill of lean concrete as a foundation material as compared with the natural rock structure and the effect of this relatively thick con-crete fill on the dynamic responses of the safety related structures. The attached material is in the format of the BFS PSAR, Subsection 3.8.5. We intend to submit this material as a PSAR Amendment in conjunction with a TMI related amendment which will be filed prior to the cocinencement of the safety hearings.

The purpose of the concrete fill is, of course, to replace the excavated silt-stone with concrete which meets the design basis established for the under-lying competent siltstone during the NRC's Site Suitability Evaluation. The attached analysis demonstrates that the design basis is met and that there will be no soil structure interaction as a result of seismic events and that the impact on the dynamic response of the safety related structures is insigni-ficant.

Since a concrete fill represents a relatively large concrete pour, PS0 will utilize full quality procedures and quality control concrete in this activity even though this work cannot be construed as safety related. This has been done with all of the concrete poured as a part of the excavation seals for Unit 1 and Unit 2. In addition, the computed value of the shear wave velocity for the lean concrete backfill will be verified by actual tests in the field to insure that it is not lower than 35 ' ~

This transmittal fulfills our commitme descriptions prior to commencing the m DUPLICATE DOCUMENT panying analysis demonstrates acceptab Entire document previously entered into system under:

4

}]0k k ANO No. of pages:

% CENTAAL ANO SOUTH WEST SYSTEM

. Central Power ard Lignt Puchc.Sennce Comcany of Oktanoma Soutnwestern E'ectnc Power glestj,egas,Utmes