ML19345H279
| ML19345H279 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 02/27/1981 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML19345H278 | List: |
| References | |
| ST-HL-AE-625, NUDOCS 8105010490 | |
| Download: ML19345H279 (3) | |
Text
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O The Light PHY sees ee i;shties & ee-er eo. 8ex i700 sees ee. rexes 77ooi <7is> 22s-92ii February 27, 1981 ST-HL-AE-625 SFN: V-0530 Mr. Karl Seyfrit Director, Region IV Nuclear Regulatory Comission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012
Dear Mr. Seyfrit:
South Texas Project Units 1&2 Docket Nos. STN 50-498, STN 50-499 Expert Comittee's Final Report Concerning Show Cause Item 2 Structural Backfill Investigation Please find attached the Independen'. Expert Committee's " Final Report on the Adequacy of Category I Structural Backfill for the South Texas Project."
The attached Independent Expert Review Comittee's Final Report incorporates and supersedes the previous C5mmittee Interim Reports, submitted to your office on July 28, 1980 and December 12, 1980, respectively. The Brown & Root Technical Reference Document (TRD), " Category I Structural Backfill Placement and Quality Control Data" has been completed. The TRD provides a basis for the engineering evaluation of the adequacy of the South Texas Project Category I Structural Backfill, as requ0 red by Item 2 of the NRC Show Cause Order. The information contained within the TRD includes in-place and laboratory density test results, placement locations and associated data, as obtained from the Construction Quality Control Reports.
The TRD also contains the various field requests for engineering action, Nonconformance Reports as well as the Corrective Action Reports pertaining to the Category I Structural Backfill. The TRD is available for reviewing in the Houston office on Clinton Drive.
The overall conclusion of the Excert Comittee's Final Report is that the condition of the Structural Backfill as it now exists is entirely adequate for the design requirements of the South Texas Project.
The following is a summari-zation of the Expert Committee's conclusions:
- 1) "The Comittee has performed special studies relating to the presence of four small, isolated zones in the backfill for which the results of Standard Penetration Tests indicated a relative density less than construction quality control cri-WO5010 %D
Houston Lighting & Power Company February 27, 1981 ST-HL-AE-625 SFN: V-0530 Page 2 teria. The studies establish that these zones have adequate factors of safety against liquefaction and that the negligible pore pressures which might build up in these zones during the Safe Shutdown Earthquake are not significant with respect to the adequacy and safety of the overall structural backfill."
- 2) " Detailed studies were made which showed that the probable pres-ence of a thin surface layer of low density backfill immediately under mat foundations would have no significant effect on the performance of Category I buildings."
- 3) "The June 1980 test fill data were reviewed and the Committee finds that the project vibratory rollers, the specified thick-ness of lifts, and the number of passes actually accomplished were adequate to assure a unifomly compacted structural back-
' fill of the specifiea density. The Committee further concludes that the actual field control procedures used during Category I backfilling were properly accomplished."
- 4) " Statistical analyses support the judgment of the Comittee that the boring results obtrined to date are representative for assess-ing the overall backfill condition and that further investigations are not needed."
HL&P concurs with the conclusions reached by the Independent Expert Committee and thus considers this letter to constitute our final submittal con-cerning Shew Cause Item 2, Structural Backfill Investigation.
If there are any questions concerning this matter, please contact Mr. Michael E. Powell at (713) 676-8592.
Very truly yours, C/
7 N. $$rd,~ N.
7 Execufive Vtc~ President e'
MEP/RRH/mf Attachment
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[fouston Lighting & Power Company cc:
J. H. Goldberg Februark2762$
1981 ST-HL-A D. G. Barker SFN: V-0530 Howard Pyle Page 3 R. L. Waldrop H. R. Dean D. R. Beeth J. D. Parsons G. B. Painter L. K. English J. W. Briskin R. A. Frazar H. S. Phillips (NRC)
J. O.
Read (Read-Poland,Inc.)
M. D. Schwarz (Baker & Botts)
R. Gordon Gooch (Baker &Botts)
J. R. Newman (Lcwenstein, Newman, Reis & Axelrad)
Director, Office of Inspection & Enforcement Nuclear Regulatory Comission Washington, D. C.
20555 M. L. Borchelt Charles Bechoefer, Esquire Executive Vice President Chainnan, Atomic Safety & Licensing Board Central Power & Light Company U. S. Nuclear Regulatory Comission P. O. Box 2121 Washington, D. C.
20555 Corpus Christi, Texas 78403 R. L. Range Dr. James C. Lamb, III Central Power & Light 313 Woodhaven Road P. O. Box 2121 Chapel Hill, North Carolina 27514 Corpus Christi, Texas 78403 R. L. Hancock Dr. Emeth A. Luebke Director of Electrical Utilities Atomic Safety & Licensing Comission City of Austin U. S. Nuclear Regulatory Comission P. O. Box 1088 Washington, D. C.
20555 Austin, Texas 78767 T. H. Muehlenbeck Citizens for Equitable Utilities City of Austin c/o Ms. Peggy Buchorn P. O. Box 1088 Route 1, Box 1684 Austin, Texas 78767 Brazoria, Texas 77422 J. B. Poston Pat Coy Asst. General Manager of Operations Citizens Concerned About Nuclear Power City Public Service Board 5106 Casa Oro P. O. Box 1771 San Antonic, Texas 77422 San Antonio, Texas 78296 A. vonRosenberg Betty Wheeler City Public Service Board Hoffman, Steeg & Wheeler P. O. Box 1771 1008 S. Madison San Antonio, Texas 78296 Amarillo, Texas Brian E. Berwick Bernard M. Bordenick Asst. Attorney for the State of Texas Hearing Attorney l
P. O. Box 12548 Office of the Executive Legal Director i
Capitol Station U. S. Nuclear Regulatory Comission j
Austin, Texas 78711 Washington, D. C.
20555 i
L