ML17362A089
| ML17362A089 | |
| Person / Time | |
|---|---|
| Site: | HI-STORE |
| Issue date: | 12/18/2017 |
| From: | Leathers F GEI Consultants |
| To: | Thomas P Holtec, Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML17362A097 | List: |
| References | |
| 5025021 | |
| Download: ML17362A089 (4) | |
Text
www.geiconsultants.com 400 Unicorn Park Drive Woburn, MA 01801 781.721.4000 fax 781.721.4073 Memo To:
Paul Thomas Holtec International From:
Francis D. Leathers, P.E.
Date:
December 18, 2017 Re:
Results of One-Dimensional Consolidation and Swell Tests Proposed Holtec HI-STORE CISF, Lea County, New Mexico GEI Project No. 1703345 In this memorandum, we summarize the results of two one-dimensional consolidation and swell tests, SW1 and SW2, performed on core samples of the Chinle Formation mudstone. The test results are shown in the attached plots. The samples were obtained from HQ rock core in B107 at depths of about 74 and 101 feet below the ground surface.
Sample Preparation and Testing Procedure The consolidation - swell tests were performed in accordance with GEIs Laboratory Test Procedures 239 and 244. The samples were taken from visually intact specimens of rock core. We used a one-dimensional consolidation ring with a diameter of 6.35 cm which was slightly larger than the diameter of the rock cores (5.67 cm and 6.24 cm, respectively) so that we did not have to trim the diameter of the friable rock samples. We trimmed the ends parallel and as flat as practical. The annular space between the sides of the sample and consolidation ring was backfilled with rounded fine quartz (Ottawa) sand, gently vibrated as it was place. A thin layer of the sand was placed on the top and bottom faces of the sample, just thick enough to even out any small irregularities in the trimmed surface.
The samples were consolidated and partially unloaded in a dry state, i.e., at their natural water content without addition of water to the container surrounding the sample and ring. Loading increments were applied up to a maximum of 16 tons per square foot (tsf), and then unloaded to 4 tsf.
During the dry increments, the consolidation or rebound occurred very quickly, typically in less than 1 minute. Each increment was held for approximately 30 to 60 minutes. The dry consolidation and rebound load curve and the coefficient of consolidation values are shown on the plots.
After unloading to 4 tsf, the sample in SW1 was flooded with water. The swell as the sample absorbed water was measured for a period of about 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, and then the sample was further unloaded in increments with each swell increment held for about 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. In test SW2, the swelling at 4 tsf was measured for a period of about 22.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. The swelling stopped after a period of about 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, with no swell during the last 14.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> of the test. No further unloading steps were performed for SW2.
Discussion of Test Results These tests demonstrate that the Chinle mudstone has a potential to swell about 0.3% to 0.4% in the presence of free water, with confinement ranging from 0.125 tsf to 4 tsf, equivalent to the vertical stress at depths of about 2 feet to over 60 feet. Potential swell at greater depths is expected to be less due to the increase in confining pressure.
ATTACHMENT 6 TO HOLTEC LETTER 5025021 Page 1 of 4
Paul Thomas, Holtec International December 18, 2017 Based on available literature, the measured swell would classify the Chinle mudstone as having a low potential for both probability and amount of significant swell (reference: Expansive Soils, Problems and Practice in Foundation and Pavement Engineering, by John D. Nelson and Debora J. Miller, John Wiley and Sons, New York, 1992).
Although most of the existing residual soil will be removed from beneath the ISFSI pads, it is our opinion that these test results are also indicative of the expected behavior of the remaining residual soil below foundation level.
We note that the potential for swell is not likely to actually occur in the field, because the presence of the ISFSI pads and improvements to site drainage means that there will be less water infiltration from the surface than occurs presently. Even with reduced evapotranspiration, we anticipate that the water content of the rock in the ground will not increase significantly with time, and certainly will not approach a state of saturation. Therefore, it is our opinion that the ISFSI pad will not experience heave due to swell of the foundation soils and rock.
Limitations The evaluations and recommendations provided above are based on our current understanding of the proposed project, and the currently available data on subsurface conditions. We will update our evaluations and recommendations as the project design is further developed by Holtec.
Attachments One-Dimensional Consolidation and Swell Test Results, SW1 and SW2 FDL:mrb O:\\Nuclear Program\\Nuclear QA Projects\\1703345 - Holtec HI-STORE\\1703345 - Final\\Admin\\Correspondence\\2017-12-18 Memo\\Memo - Results of One-Dimensional Consolidation and Swell Tests - Dec 18, 2017.docx ATTACHMENT 6 TO HOLTEC LETTER 5025021 Page 2 of 4
SAMPLE INFORMATION Boring:
B107 Sample:
C4 Depth (ft):
73.9-74.6 Test:
SW1 Type:
HQ-diameter core
==
Description:==
Reddish-brown mudstone SPECIMEN INFORMATION Specific Gravity 2.75 (assumed)
TEST
SUMMARY
Estimated preconsolidation stress (tsf):
Compression Ratio (strain per log cycle stress):
0.007 (4 to 8 tsf)
Swell Ratio (strain per log cycle stress):
Recompression Ratio (strain per log cycle stress):
Swell after flooding at 4 tsf (% Strain):
0.25 REMARKS Results Computed per Square Root of Time Method Test Date:
LEGEND:
Tested By:
End of primary Check By:
Loading Check Date:
Unloading End of stage GEI Consultants, Inc., 400 Unicorn Park Drive, Woburn, MA 01801 NA NA FDL ONE DIMENSIONAL CONSOLIDATION AND SWELL TEST SW1 Holtec Hi-Store CISF Site Characterization Lea County, New Mexico Holtec International Camden, New Jersey Project 1703345 12/5/2017 DJA 12/18/2017 December 2017 Form 239.7 rev.0 0.002 (8 to 4 tsf) 2.054 cm 2.061 cm 25.25 sq. cm 25.25 sq. cm 51.86 cc 52.03 cc 13.74 %
14.80 %
2.211 gm/cc 2.224 gm/cc 1.944 gm/cc 1.937 gm/cc 97.0 %
0.415 0.419 Specimen consolidated " in the dry" and then flooded at 8 minutes into the 4 tsf unload stage.
Dry Unit Weight Saturation Void Ratio Initial Final Specimen Height Specimen Area Specimen Volume Water Content Total Unit Weight 91.1
-0.5
-0.4
-0.3
-0.2
-0.1 0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Vertical Strain (%)
1 10 100 Coeff. of Consol, Cv (cm2/min.)
0 0.02 0.04 0.06 0.08 0.1 0.1 1
10 100 Coeff. of Sec. Comp., CD (strain/log cycle time)
Vertical Stress (tons/ft2)
Swell after flooding ATTACHMENT 6 TO HOLTEC LETTER 5025021 Page 3 of 4
SAMPLE INFORMATION Boring:
B107 Sample:
C9 Depth (ft):
100.5-101.1 Test:
SW2 Type:
HQ-diameter core
==
Description:==
Reddish-brown mudstone SPECIMEN INFORMATION Specific Gravity 2.75 (assumed)
TEST
SUMMARY
Estimated preconsolidation stress (tsf):
Compression Ratio (strain per log cycle stress):
Swell Ratio (strain per log cycle stress):
Recompression Ratio (strain per log cycle stress):
Swell after flooding at 4 tsf (% Strain):
0.40 REMARKS Results Computed per Square Root of Time Method Test Date:
LEGEND:
Tested By:
End of primary Check By:
Loading Check Date:
Unloading End of stage GEI Consultants, Inc., 400 Unicorn Park Drive, Woburn, MA 01801 Specimen consolidated "in the dry" and then flooded at 8 minutes into the 4 tsf unload stage.
Dry Unit Weight Saturation Void Ratio Initial Final Specimen Height Specimen Area Specimen Volume Water Content Total Unit Weight 73.7 %
105.7 %
0.299 0.274 2.287 gm/cc 2.386 gm/cc 2.118 gm/cc 2.158 gm/cc 73.55 cc 72.17 cc 8.00 %
10.54 %
2.409 cm 2.364 cm 30.53 sq. cm 30.53 sq. cm NA 0.014 0.003 NA FDL ONE DIMENSIONAL CONSOLIDATION AND SWELL TEST SW2 Holtec Hi-Store CISF Site Characterization Lea County, New Mexico Holtec International Camdem, New Jersey Project 1703345 12/8/2017 DJA 12/18/2017 December 2017 Form 239.7 rev.0 0
1 2
3 4
5 Vertical Strain (%)
Swell after flooding 1
10 100 Coeff. of Consol, Cv (cm2/min.)
-0.1
-0.05 0
0.05 0.1 0.1 1
10 100 Coeff. of Sec. Comp., CD (strain/log cycle time)
Vertical Stress (tons/ft2)
ATTACHMENT 6 TO HOLTEC LETTER 5025021 Page 4 of 4