ML19253A162

Confirms 790628 Telcon Re Reactor Containment Bldg Exterior Shell Wall Concrete Placements.Partial Release of Stop Work Order Will Be Issued,Allowing Placement of All safety-related Concrete Except for Exterior Shell Walls

ML19253A162
Person / Time
Site:	South Texas
Issue date:	06/28/1979
From:	Eric Turner HOUSTON LIGHTING & POWER CO.
To:	Seidle W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
ST-HL-AE-356, NUDOCS 7908170358
Download: ML19253A162 (2)

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- /J C-IlotsTox LicitTtxo & Powru Go>te.cv Iforsrox.TrxAs 77001 M2.U.1", June 28, 1979 ST-HL-AE-356 SFN: C0510 Mr. W. C. Seidle Branch Chief Nuclear Regulatory Comission Region IV 611 Ryan Plaza Drive Suite 100 Arlington, Texas 76012

Dear Mr. Seidle:

This document is written to confirm our telephone conversation of this date. -

With reference to our stop work order of June 22,1979, on the placement of safety-related concrete at the South Texas Project, please be advised that we have completed an extensive review of the items identified in said letter.

As a result of this review and because of the confidence developed on past non-RCB exterior shell wall placements we intend to issue a partial release of our stop work notice which will allow for placement of all safetv-related concrete with the exception of the RCB exterior shell walls.

We will continue our hold on the RCB exterior shell wall placements because of the complexity and configuration of this type concrete placement. Also, our evaluation of the RCB exterior wall has not been completed. We intend to release the stop work on the RCB exterior shell walls only af ter the results of our evaluation '

are known and corrective action, if any, is presented.

Our decision is the restilt of a thorough review of the areas of concern identified in the stop work noti' of June 22, 1979, as they relate to non-RCB exterior shell wal' placements of safety-related concrete. Specifically: l

1. Engineering has reviewed the design mixes currently used on site and have found them to be acceptable for the various safety-related structures.

2. The pre-placement meetings and the topics addressed in these sessions have been reviewed and have been found adequate for non-RCE exterior shell walls.

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3. The present method of providing lighting for non-RCB exterior shell walls has been reviewed and found adequate especially for those personnel who must be inside the formed area.

4. The present methods and equipment utilized to conso-lidate concrete have been re-examined as well as the QA/QC inspection techniques and both are achieving adequate results in r.on-RCB exterior shell walis.

5. The present systtoi for training both construction and QA/QC personnel is adequate to ensure proper implementa-tion of specification requirements. Additionally, special sessions were held June 26, 1979, to re-emphasize the procedural details of concrete placement to both construction and QA/QC personnel.

6. The ratio of construction supervision to placement personnel has been evaluated and has been found adequate for non-RCB exterior shell wall placements. However, no fixed ration of QC inspection personnel to placement personnel exists. Rather an evaluation on many factors is conducted to determine the appropriate number of QC inspection personnel for any given concrete placement.

This present method has been reviewed and is adequate for non-RCB exterior shell wall placements.

If you have any questions and/or comments on the above, please advise.

Yours very trul ,

Y c( /-

EAT:rpv cc: Messrs. M. Borchelt (CP&L)

J. Poston (CPS)

R. Hancock (C0A)

G. Oprea 803 150