ML19329C480

Seismological & Geological Review.

ML19329C480
Person / Time
Site:	Davis Besse
Issue date:	10/31/1969
From:	JOHN A. BLUME & ASSOCIATES, ENGINEERS
To:	US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML19329C478	List: ML19329C477 ML19329C480
References
CON-AT(49-5)-4011 NUDOCS 8002140858
Download: ML19329C480 (4)

Text

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(] SEISMOLOGICAL AND GEOLOGICAL REVIEW w

OAVIS-BESSE NUCLEAR POWER STATION THE TOLEDO EDISON COMPANY (Docket No. 50-346)

The following are additional comments and questions resulting from a preliminary review of the PSAR reference documents (see attached list) for the Davis-Besse Plant and are primarily directed toward seismo-logical and geological considerations.

1. Reference is made to "significant solution fissures or solution cavities". What is the definition of a significant cavity or fis-sure? How is this distinction made when cavities or voids are en-countered in drilling?

2. How was it determined that the boring grid used was adequate to detect all "significant" solution fissures or cavities?

3. We note that it is recommended that additional rock probes be made during construction to further investigate the possibility that the bedrock may contain significant voids. Will this recommenda-tion be followed? If so, what are the specifications for this addi-tional exploration wor 47

4. Has the seismic reflection method for detection of voids been evaluated?

5. The bar logs and the design log do not centain sufficient infor-mation to evaluate subsurface conditicns. Please submit complete logs of all borings, probes, and drill holes which penetrate bed-rock beneath or adjacent to critical structures. Also submit the 3426 JCHN A. SLUME & ASSCCIATES. ENGINEEAS s o o 2140 M l

procedures and standards (such as ASTM D1452-63T, D1586-64T, D1587-63T,02113-62T) followed. In particular, the information listed in Section 4 of D2113-62T would be helpful in the eval-uation including loss of drilling fluid.

6. What were the qualifications of the field supervisory personnel under which field investigations were performed?

7. Please discuss the possible causes and significance of the depression in the ground surface at the site of drill hole B3-10. Data obtained by drilling and conclusions reached should be included in the discussion.

.8. Please submit the results of the broadside seismic survey and the shear wave refraction profiles. Include an evaluation of these results.

9. It is stated that the foundation level of the east wing of the auxiliary building will be of elevation 585 which is approximately 7 ft. above the existing grade. However, the contour map shows existing grades of 562 which is 23 ft. below foundation grade.

Please clarify this.

10. The applicant states that the auxiliary building is to be founded at three elevations: 545 ft, 565 ft, and 585 ft. The response spectra presented are presumably for bedrock conditions. What are the response spectra for the top of the glacial deposits and fill on which portions of the auxiliary building will be founded? How will the different spectral responses at these various foundation elevations be treated in the seismic analyses and design? How will differential settlements under normal and/or earthquake conditions be evaluated and accounted for in the design?

11. The maximum ground acceleration due to the Operating Basis Earth-ouake hould be equal to at least v...-half of that due to the Design Basis Earthquake.

JCHN A. BLt.;ME & ASSOC!ATES. ENGINEERS

12. Elastic parameters for bedrock are given (plate 2C-61) and it is stated that they are valid only for very low stress levels existing in seismic surveys. It is further stated that parameters pertaining to earthquake induced forces would be determined by laboratory tests. Please present these laboratory determined values and the final values to be used as representative of the fcundation materials.

Please provide the bases for selection of these final values.

13. Please provide detailed design considerations for canal embankments and supporting data (Page 2C-36). Will the design provide for re-sistence to earthquake forces under saturated conditions?

14. Please discuss possible liquefactic, of the sandy soils underlying site.

- 3 .lC H N A. BLUME & ASSOCIATES. ENGINEERS

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SEISMIC REVIEW REFERENCE DOCUMENTS Davis-Besse Nuclear Power Station The Toledo Edison Company Docket No. 50-346 Construction Permit Preliminary Safety Analysis Report, Volume l Preliminary Safety Analysis Report, Volume 11 Preliminary Safety Analysis Report, Volume lll

.;OHN A. BLUME & ASSCCIATES. ENGINEERS