ML012420328

Draft Regulatory Guide DG-1109 (Proposed Revision 1 of Regulatory Guide 1.138), Laboratory Investigations of Soils and Rocks for Engineering Analysis and Design of Nuclear Power Plants

ML012420328
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Issue date:	08/31/2001
From:	Office of Nuclear Regulatory Research
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Philip J (301)415-6211
References
-nr, DG-1109 RG-1.138
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U.S. NUCLEAR REGULATORY COMMISSION August 2001 OFFICE OF NUCLEAR REGULATORY RESEARCH Division 1 Draft DG-1109 DRAFT REGULATORY GUIDE

Contact:

J. Philip (301)415-6211 DRAFT REGULATORY GUIDE DG-1109 (Proposed Revision 1 of Regulatory Guide 1.138)

LABORATORY INVESTIGATIONS OF SOILS AND ROCKS FOR ENGINEERING ANALYSIS AND DESIGN OF NUCLEAR POWER PLANTS A. INTRODUCTION This guide describes laboratory investigations and testing practices acceptable for determining soil and rock properties and characteristics needed for engineering analysis and design for foundations and earthworks for nuclear power plants. The state of the art of laboratory testing practices of soils and rocks is reflected in existing standards, and, where appropriate, this guide discusses and references such standards.

In 1996, the Nuclear Regulatory Commission (NRC) issued new regulations concerning site evaluation factors and geologic and seismic siting criteria for nuclear power plants (10 CFR Part 100),

Reactor Site Criteria, in Subpart B, Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997"). In particular, 10 CFR 100.20(c), 100.21(d), and 100.23 establish requirements for conducting site investigations for nuclear power plants for site applications submitted after January 10, 1997, to permit an evaluation of the site and provide information needed for seismic response analyses and engineering design. This evaluation should include the development of information relative to the static and dynamic engineering properties of soil and rock materials of the site.

Safety-related site characteristics are identified in detail in Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants. Regulatory Guide 4.7, General Site Suitability Criteria for Nuclear Power Stations, discusses site characteristics that affect site suitability. Regulatory Guide 1.132, Site Investigations for Foundations of Nuclear Power Plants, discusses programs of field studies, exploratory borings, and sampling needed to provide geotechnical data for site evaluation and engineering analysis and design.

The technical basis for this regulatory guide is contained in NUREG/CR-5739 (1999).

NUREG/CR-5739 was developed to reflect current and state-of-the-art techniques related to laboratory testing of soils and rock. It summarizes the processes required in a laboratory testing program ranging This regulatory guide is being issued in draft form to involve the public in the early stages of the development of a regulatory position in this area. It has not received complete staff review or approval and does not represent an official NRC staff position.

Public comments are being solicited on this draft guide (including any implementation schedule) and its associated regulatory analysis or value/impact statement. Comments should be accompanied by appropriate supporting data. Written comments may be submitted to the Rules and Directives Branch, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. Comments may be submitted electronically or downloaded through the NRCs interactive web site at <WWW.NRC.GOV> through Rulemaking. Copies of comments received may be examined at the NRC Public Document Room, 11555 Rockville Pike, Rockville, MD. Comments will be most helpful if received by December 10, 2001.

Requests for single copies of draft or active regulatory guides (which may be reproduced) or for placement on an automatic distribution list for single copies of future draft guides in specific divisions should be made to the U.S. Nuclear Regulatory Commission, Washington, DC 20555, Attention:

Reproduction and Distribution Services Section, or by fax to (301)415-2289; or by email to DISTRIBUTION@NRC.GOV. Electronic copies of this draft guide are available through NRCs interactive web site (see above), on the NRCs web site <www.nrc.gov> in the Reference Library under Regulatory Guides, and in NRCs Public Electronic Reading Room at the same web site, under Accession Number ML012420328.

from storage, selection, and handling of test specimens to static and dynamic testing methods and equipment.

Regulatory guides are issued to describe to the public methods acceptable to the NRC staff for implementing specific parts of the NRCs regulations, to explain techniques used by the staff in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations, and compliance with regulatory guides is not required. Regulatory guides are issued in draft form for public comment to involve the public in developing the regulatory positions. Draft regulatory guides have not received complete staff review; they therefore do not represent official NRC staff positions.

The information collections contained in this draft regulatory guide are covered by the requirements of 10 CFR Parts 50 and 100, which were approved by the Office of Management and Budget, approval numbers 3150-0011 and 3150-0093. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

B. DISCUSSION

1. PURPOSE In the course of site investigations and analyses for nuclear power plant facilities, the purpose of a laboratory testing program is to identify and classify soils and rocks and to evaluate their physical and engineering properties. The NRC staff reviews the information obtained from the site investigations and laboratory tests and considers the safety aspects of the application of the data to the design and construction of nuclear plants. Consideration of public safety imposes particularly stringent requirements on the design and construction of nuclear power plant facilities. Therefore, it is essential that all phases of a site investigation program and associated field and laboratory testing be carefully planned and carried out to ensure that soil and rock properties are realistically estimated.

The course of site and laboratory investigations will depend on actual site conditions, the nature of problems encountered or suspected at the site, and design requirements for foundations and earthworks. Therefore, a program should be made flexible and tailored to each site and plant design as the site and laboratory investigations proceed. The program should be under the direction of experienced engineers and geologists that have demonstrated competence in the field of soil and rock mechanics testing and are familiar with the site. Specific testing requirements and details of testing procedures will depend on the nature of the soils and rocks encountered. It is normally desirable to follow testing procedures that are generally known and accepted since they are easily reproduced. Also, the effects of standard procedures on test results are better understood. Depending on the nature of the soil and rock material, it may be more appropriate and desirable to modify existing standard procedures, however, it is important that such test procedures be fully described so that the test may be reproduced and the results verified. Laboratory procedures for some of the most common tests are shown in Appendix A with related references.

C. REGULATORY POSITION 2

1. LABORATORY TESTING PROGRAM 1.1 Laboratory Facilities The basics for a laboratory facility for soil and rock testing include adequate test space, temperature controlled areas, adequate ventilation and air flow. Separate areas, and preferably separate rooms, are desirable for dust- and vibration-producing activities such as sieve analyses, compaction tests, and sample processing. Normally, samples should be tested on arrival from the field. If storage is required, consideration should be given to storing samples in a separate room with the relative humidity maintained at or near 100%.

The facility should be equipped with the proper equipment (from calipers and sieves to triaxial testing devices) necessary to perform the types of tests for which the facility was designed.

1.2. Laboratory Equipment 1.2.1 Apparatus When standard laboratory testing procedures are used, the test apparatus should conform to the published specifications. When the testing apparatus does not satisfy published specifications, a complete description of the essential characteristics of the apparatus is needed, with appropriate references to published papers, reports, or monographs. To ensure that essential characteristics (such as dimensions, mating of parts, piston friction, and fluid seals) are not significantly altered by wear, handling, corrosion, dirt, or deterioration of materials, all testing apparatus should be inspected and maintained regularly.

Use and care of laboratory equipment are discussed in detail in EM 1110-2-1906, Das (1992) and Head (1992). Specifications for balances and scales are described in ASTM D 4753. EM 1110-2-1906 provides valuable discussions of common problems, precautionary measures, and control of errors when engaged in the testing of soils. Scholey et al. (1995) present a review of instruments for measuring small strain. Germaine and Ladd (1988) discuss problems associated with triaxial testing of saturated cohesive soils, including errors caused by the equipment or the procedures used.

1.2.2 Calibration All test apparatus and instruments used for quantity measurement should be calibrated against certified calibration standards before being put into service. Calibrations can be verified at regular intervals thereafter. The necessary frequency for recalibration varies according to the susceptibility of the apparatus to change and the required precision of measurement. Physical length or volume measuring apparatus such as metallic tapes, rules, pycnometers, cylinders, or graduated cylinders need not be calibrated unless altered by visible wear or damage. Weights and other equipment used as standards to calibrate test instruments are normally recalibrated periodically by an external agency with equipment directly traceable to the National Institute of Standards and Technology. Instrument calibrations may be performed in-house using the specific laboratorys own standards of references. EM 1110-2-1909 provides procedures recommended for the calibration of testing equipment. ASTM D 3740 and Sallfors (1989) provide information on equipment calibration and its importance, respectively.

1.2.3 Reagents and Water 3

Chemical testing in a soil laboratory is usually limited to routine tests. These tests determine such constituents as organic matter, chlorides, pH value, and sulfates. Head (1992) provides information on the most widely used clinical test for soils and groundwater.

2. HANDLING AND STORAGE OF SAMPLES The identification markings of all samples are verified immediately upon their arrival at the laboratory, and an inventory should be maintained of all samples received.

2.1 Disturbed Samples It is important that disturbed samples be examined and tested as soon as possible after arrival in the laboratory; however, for a large testing program, storage of the samples may be required for several days or weeks. Samples to be used for fluid content determinations, however, should be protected against change in water content.

2.2 Undisturbed Samples Undisturbed samples should be protected from vibration, shock, significant temperature changes, and changes in water content. Moisture seals should be checked periodically and renewed as needed. Even the most careful sealing and storing of undisturbed samples cannot prevent physical and clinical changes. Therefore, the samples should not be retained for long periods, particularly if in contact with unprotected steel tubes.

Storage for long periods of time may discredit any subsequent determination of their engineering properties. The duration of storage before testing should be recorded for each sample test. Samples that have been stored for long periods of time should not be considered to have the characteristics of undisturbed samples. Therefore, they should not be tested as undisturbed samples. For clay specimens, the delay between sampling and testing and the control kept over their volumes during storage are known to affect the strength and compressibilities measured in the laboratory. These measured properties will also be affected by the reconsolidated procedures (see Graham et al., 1990, and Brown and Chow, 1988).

Further information on handling and storage of soil samples can be found in ASTM D4220.

2.3 Rocks Rock samples should be transported as fragile material and protected from excessive changes in humidity and temperature. Like soil samples, rock samples should be examined and tested as soon as possible. For a large testing program, the rock specimens may be stored, but every effort should be made to protect the stored samples against damage.

3. INITIAL IDENTIFICATION AND EXAMINATION OF SAMPLES The initial description of a sample should include but not be limited to what is seen, felt, and smelled.

ASTM D2488 describes procedures necessary for the description and identification of a soil sample based primarily on visual identification and manual test. ASTM D4452, on x-ray radiography of soil samples, describes procedures before testing for the detection of inherent abnormalities and disturbances; it is especially useful for undisturbed samples. ASTM D 2487 4

describes the various soil groups in detail and discusses the method of identification in order that a uniform classification procedure may be followed by those who use the system. RTH 102-93 describes procedures used in the petrographic examination of rock core samples.

Petrographic examinations are made to determine the physical and chemical properties of a material, to describe and classify a sample, and to determine the amount of specific materials that may affect the specimens intended use.

4. SELECTION AND PREPARATION OF TEST SPECIMENS 4.1 General The selection of soil and rock specimens for laboratory testing requires careful examination of boring records and available samples. It is important that test specimens be representative of the soil or rock unit to be tested and be accurately described to permit establishment of the soil profile. Average test values of material properties need to be identified as well as the range of values identifying their variability. This requires the testing of not only the most representative samples, but also of those with extreme properties and those representative of critical zones. Guidelines for spacing of borings and frequency of sampling are given in Regulatory Guide 1.132. Additional boring and sampling may be required when laboratory examination of the samples reveals an inadequate number or distribution of suitable samples to meet testing requirements.

Undisturbed test samples should be prepared to preserve the natural structure and water content of the material. The sample should always be prepared in a humid room.

Trimming instruments should be sharp and clean and the sample adequately supported.

4.2 Undisturbed Samples Undisturbed tube samples of soils should be examined for evidence of disturbance. A serious source of damage to undisturbed soil samples is the extrusion of the samples from the sample tubes. One method that may minimize damage during the removal of samples from thin-wall tubes is to split the tube longitudinally by milling. An alternative may be to saw the tube transversely into segments of sufficient length to extrude a single test specimen from each and trim off the ends. The fact that milling may cause disturbance and changes in the void ratio in some soils, particularly in loose sand, is an important consideration in the assessment of the best way to remove samples from tubes. Dressing the cut tube edges before extruding samples from the tube sections reduces disturbance of the sample. Reuse of thin-walled sample tubes is not recommended if they have been damaged during retrieving or extruding samples.

Undisturbed tube samples should satisfy the following criteria:

(1) The specific recovery ratio should be between 90 and 100 percent; a tube with less recovery may be acceptable if it appears that the sample may have been broken off and otherwise appears undisturbed. The actual recovery obtained should be recorded and documented.

(2) On the surface of or in sliced sections of the sample, there should be no visible distortions, planes of failure, pitting, discoloration, or other signs of disturbance that can be attributed to the sampling operation or handling of the sample.

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(3) The net length and weight of the sample and the results of other control tests should not have changed during shipment, storage, and handling of the sample.

In addition to the above, samples that have been subjected to violent mechanical shocks or to accidental freezing and thawing should not be considered to be undisturbed even if other evidence of disturbance is absent Test specimens should be representative of each discrete soil or rock unit to be tested and should be accurately described on the basis of classification tests to permit establishment of the soil and geologic profiles. The best quality and most representative undisturbed samples available should be used in physical and engineering property tests of in situ soils, whether cohesive or cohesionless.

Trimming and shaping of test specimens of soils require great care to prevent disturbance and changes in water content. Frozen samples should be prepared under conditions that will prevent premature thawing. Details of procedures depend on the nature of the test and the specimen. EM 1110-2-1906 describes procedures for preparing soil samples for testing, while ASTM-D-4452 can be used to determine the quality of a sample before testing.

4.3 Reconstituted or Remolded Samples High-quality undisturbed samples are preferred for all tests of strength and dynamic responses of in situ soils, whether cohesive or cohesionless. However, in some instances, reconstituted or remolded samples should be used when representative undisturbed samples cannot be obtained. Remolded samples are also used as representative of compacted fill or backfill material for new construction. Undisturbed samples of earth fill are taken for confirmatory testing during construction. Undisturbed samples are also taken in the testing and reevaluation of existing structures. Reconstituted specimens representative of in situ material should be molded to the in situ density and moisture content as determined from actual field measurements. Regulatory Guide 1.132 discusses methods of determining the in situ density of cohesionless soils. Samples representative of fill material should be molded to the range of densities and water contents expected or obtained under field conditions.

Laboratory personnel should record a complete detailed description of the specimen that should include but not be limited to identification of the material, color, consistency, brittleness of the material, and indication of disturbance of boring samples. Disturbed samples should not be used for any test other than classification, specific gravity, or water content (see EM 1110-2-1906).

4.4 Scalping of Large Particles Standard-size laboratory testing equipment will not readily accommodate gravel and large particles. Such materials are typically scalped, or removed from the total sample, and the finer fraction tested. Fractional analysis of density for compaction control measures to account for scalped gradation are discussed by Torrey and Donaghe (1991), while Evans and Zhou (1995) report the effects on cyclic strength caused by the inclusion of gravel size particles in various gradations of granular soils.

4.5 Laboratory Testing Program 6

The study of soil and rock mechanics covers the investigation, description, classification, testing, and analysis of soil and rock to determine their interaction with structures built in or upon them, or built with them. The physical properties of soils and rocks should be determined by carrying out tests on samples of soil in a laboratory. These tests can be divided into two main categories: classification tests and engineering properties tests.

Classification tests indicate the general type of soil and the engineering category to which it belongs. Engineering properties are determined by specific tests that require careful considerations of field conditions, various design loading conditions, material properties, and possible problems at the site. The focus of laboratory investigations should depend on the design requirements and nature of problems encountered or suspected at the site.

In addition to the usual geotechnical engineering considerations, the investigation and evaluation of sites for nuclear power plants require an evaluation of the site response to earthquake loading as well as other dynamic loading conditions. Such analyses include the evaluation of wave propagation characteristics of subsurface materials with interaction effects of structures, analysis of the potential for soil liquefaction, settlement under dynamic loading, and analysis of the effects of earthquake loading on the stability of slope and embankments.

The basic parameters required as input for dynamic response analyses of soils include total mass density, relative density, Poissons ratio, static soil strength, initial stress conditions, shear and compressional wave velocities, and the dynamic shear modulus and damping ratio. The variation of strength, moduli, and damping with strain is also needed for such analyses.

5. TESTING PROCEDURES FOR DETERMINING STATIC SOIL PROPERTIES 5.1 General Laboratory tests on soil and rock material should be thorough and of documented quality that permits a realistic estimate of soil and rock properties and subsurface conditions.

Personnel experienced in laboratory practices for soil testing should be responsible for handling samples, preparing test specimens, specifying testing procedures and operations, with all related documentation.

5.2 Soil Testing Classification tests and determination of engineering properties should be performed according to an accepted and published method. Laboratory procedures for some of the most common tests along with other related references, are shown in Appendix A. These include:

Water Content Permeability Unit Weights Consolidation Void Ratio Direct Shear Test Porosity Triaxial Compression Tests Saturation Unconfined Compression Tests Atterberg Limits Relative Density Specific Gravity Grain Size Analysis Erodibility Tests Compaction 7

The number of tests required in a laboratory investigation program will depend on the type of material, the quality of samples, the purpose and relative importance of the test, and the scatter of test data. In general, all soils and rocks sampled at the site should first be identified and classified using appropriate index and classification tests. The Unified Soil Classification System (ASTM D 2487) should be used in describing soils and in preparing soil profiles, while ASTM D 5878 should be used for the classification of rock mass for specific engineering purposes. Further tests required to establish physical and engineering properties should be sufficient to define the range of values for material properties. A sufficient number of tests should be completed to cover the range of values expected under field conditions.

Standard test procedures that are followed without deviation and performed on standard equipment require documentation by reference only. For tests for which there are no standard procedures available or for which it is appropriate to use modified or alternative procedures, the details of the test procedures should be documented for evaluation and future referencing. The technical basis for deviating from standard testing procedures should be documented. Use of other than standard equipment, even if it is used with standard testing procedures, should also be documented.

5.3 Tests of Ground Water or Surface Waters Testing of ground water and surface water depends on the nature of potential problems identified at the site. Acid water, for example, may cause the degradation of carbonate rocks and concrete foundations. Standard methods of testing water for physical, chemical, radioactive, and microbiological properties are described in Standard Methods for the Examination of Water and Wastewater (1998). This reference also describes methods of testing polluted water, wastewaters, effluents, bottom sediments, and sludges. Standard testing methods should be used unless special problems are encountered that require modifications or alternative methods.

6. TESTING PROCEDURES FOR DETERMINING DYNAMIC SOIL PROPERTIES 6.1 General It is important that the laboratory tests represent field conditions as closely as practical to ensure a realistic assessment of soil properties. Before dynamic tests are performed, the initial state of stress in the soil should be determined, and a series of static consolidated-drained and consolidated-undrained triaxial compression tests should be made to determine static strength. The dynamic testing program should include tests to determine the soil parameters needed as input for reference analyses and soil structure interaction studies as well as testing to determine the dynamic strength characteristics and liquefaction potential of soils. Some laboratory investigations and testing procedures for determining dynamic soil properties and soil behavior are listed, with related references, in Appendix A. The dynamic soils property testing includes cyclic triaxial tests and resonant column tests.

6.2 Cyclic Triaxial Tests Historically, the most common cyclic loading technique for investigating liquefaction resistance involves performance of the cyclic triaxial test, because of such factors as the availability of equipment and the relative ease of preparing undisturbed specimens. This is in spite of wide recognition of the inability of the test to accurately represent field earthquake 8

stresses and boundary conditions (Seed and Idriss, 1982). Other research studies have demonstrated that laboratory-determined cyclic triaxial strengths (in fact, strengths determined from any unidrectional loading test) are higher than those expected to produce equivalent effects in the field (Seed, 1976). Research has also shown that estimation of field cyclic test results may not be possible by universal application of sample factors, e.g., gradation, density, and soil type (Koester, 1992).

As noted above, the cyclic triaxial test does not accurately model the stress conditions in situ. Caution should be exercised when using laboratory-obtained soil cyclic strengths.

There should be appropriate downward adjustments of cyclic stress values obtained from triaxial tests as required. The rationale behind the adjustment and the data supporting its magnitude should be presented and referenced (see also Tatsuoka et al., 1994, on cyclic triaxial tests of sand and gravel, and Vucetic and Dobry, 1991, on cyclic triaxial tests in clays).

Laboratory cyclic tests should be used only to establish parametric effects on cyclic strength behavior.

6.3 Resonant Column Tests ASTM D4015, Modulus and Damping of Soils by the Resonant-Column Method, describes testing procedures to determine the shear modulus, shear damping, rod modulus (Youngs modulus), and rod damping for solid cylindrical specimens of soil in undisturbed and remolded conditions by vibration using the resonant column. Related references for these tests, which discuss their limitations and applicabilities, are included in Appendix A.

7. TESTING PROCEDURES FOR DETERMINING ENGINEERING PROPERTIES OF ROCK Testing procedures and the determination of engineering properties of rock should be performed according to accepted and published methods. Common tests, along with other related references, are outlined in Appendix A. These include:

Porosity Unconfined Compression Permeability Triaxial Compression Seismic Velocity Slate Durability Direct Tensile Strength D. Implementation The purpose of this section is to provide guidance to applicants and licensees regarding the NRC staffs plans for using this regulatory guide.

This proposed revision has been released to encourage public participation in its development. Except in those cases in which the applicant proposes an acceptable alternative method for complying with specified portions of the NRC's regulations, the method to be described in the effective guide reflecting public comments will be used by the NRC staff in evaluating applications for construction permits, operating licenses, early site permits, or combined licenses submitted after January 10, 1997. This guide will not be used in the evaluation of an application for an operating license submitted after January 10, 1997, if the 9

construction permit was issued before that date. This guide reflects current practice accepted by the NRC.

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REFERENCES ASTM D 2487-00, Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System, American Society for Testing and Materials, 2000.

ASTM D 2488-00, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), American Society for Testing and Materials, 2000.

ASTM D 3740-01, Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction, American Society for Testing and Materials, 2001.

ASTM D 4015-92(2000), Standard Test Methods for Modulus and Damping of Soils by the Resonant-Column Method, American Society for Testing and Materials, 2000.

ASTM D 4452-85(1995)e1, Standard Methods for X-Ray Radiography of Soil Samples, American Society for Testing and Materials, 1995.

ASTM D 4753, Standard Specification for Evaluating, Selecting, and Specifying Balances and Scales for Use in Soil, Rock, and Construction Materials Testing, American Society for Testing and Materials, 1995.

ASTM D 5878, Standard Guide for Using Rock Mass Classification Systems for Engineering Purposes, American Society for Testing and Materials, 2000.

Brown, P.T., and Chow, J.C.-P., Prevention of Sample Deterioration, Geotechnical Testing Journal, GTJODJ, Vol. 11, No. 4, pp. 296-300, 1988.

Das, B.M., Soil Mechanics Laboratory Manual, 4th ed., Engineering Press, Inc., San Jose, California, 1992.

EM 1110-2-1906, Laboratory Soils Testing, U.S. Army Corps of Engineers, Washington, DC, 1986.

EM 1110-2-1909, Calibration of Laboratory Soils Testing Equipment, U.S. Army Corps of Engineers, Washington, DC, 1986.

Evans, M. D., and Zhou, S., Liquefaction Behavior of Sand-Gravel Composites, Journal of Geotechnical Engineering, Vol. 121, No. 3, pp. 287-298, 1995.

Germaine, J.T., and Ladd, C.C., Triaxial Testing of Saturated Cohesive Soils, Advanced Triaxial Testing of Soils and Rock, ASTM STP 977, pp. 421-459, ASTM, 1988.

Graham, J., et al., Influence of Storage and Reconsolidation Procedures on Clay Properties, Geotechnical Testing Journal, GTJODJ, Vol. 13, No. 4, pp. 280-290, 1990.

Head, K.H., Manual of Soil Laboratory Testing, Volume 1: Soil Classification and Compaction Tests, Second Ed., Halstead Press: an imprint of John Wiley & Sons Inc., New York-Toronto, 1992.

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Koester, J.P., The Influence of Test Procedures on Correlation of Atterberg Limits with Liquefaction in Fine-Grained Soils, Geotechnical Testing Journal, GTJODJ, Vol. 15, No. 4, pp. 352-361, 1992a.

NUREG/CR-5739, Laboratory Investigations of Soils and Rock for Engineering Analysis and Design of Nuclear Power Plants, T. Holmes, J.P. Koester, Editors, USNRC, January 1999.

Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants (LWR Edition), Revision 3, USNRC, November 1978.

Regulatory Guide 1.132, Site Investigations for Foundations of Nuclear Power Plants, Revision 1, USNRC, March 1979.

Regulatory Guide 4.7, General Site Suitability Criteria for Nuclear Power Stations, Revision 2, USNRC, April 1998.

RTH 102-93, Rock Testing Handbook (RTH), Test Standards 1993, Part I, U.S. Army Engineers, Prepared by Geotechnical Laboratory, Waterways Experiment Station, Vicksburg, MS, 1993.

Sallfors, G., Quality Assurance in Laboratory Testing, Proceedings, Twelfth International Conference on Soil Mechanics and Foundation Engineering, Vol. 1, No. 12, pp. 105-106, 1989.

Scholey, G.K., Frost, J.D., and Jamiolkowski, M., A Review of Instrumentation for Measuring Small Strains During Triaxial Testing of Soil Specimens, Geotechnical Testing Journal, GTJODJ, Vol. 18, No. 2, pp 137, 1995.

Seed, H.B., Evaluation of Soil Liquefaction Effects on Level Ground During Earthquakes, Liquefaction Problems in Geotechnical Engineering, Preprint No. 2752, ASCE National Conven-tion, Philadelphia, pp 1-104, 1976.

Seed, H.B., and Idriss, I.M., Ground Motions and Soil Liquefaction During Earthquakes, Monograph Series, Earthquake Engineering Research Institute, University of California, Berkeley, CA, 1982.

Standard Methods For the Examination of Water and Wastewater, 20th Edition, American Public Health Association, American Water Works Association, Water Environment Federation, 1999.

Tatsuoka, F., et al., Importance of Measuring Local Strains in Cyclic Triaxial Tests on Granular Materials, Dynamic Geotechnical Testing II, ASTM STP 1213, American Society for Testing and Materials, Philadelphia, PA, 1994.

Torrey, V.H. III, and Donaghe. R.T. Compaction Control of Earth-Rock Mixtures, Technical Report GL-91-16, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi, 1991.

Vucetic, M., and Dobry, R., Effect of Soil Plasticity on Cyclic Response, ASCE Journal of Geotechnical Engineering, Vol. 117, No. 1, pp 89-17, 1991.

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APPENDIX A LABORATORY TESTING METHODS FOR SOIL AND ROCK STANDARD OR PROPERTIES OR REMARKS/SPECIAL PREFERRED OTHER PARAMETERS EQUIPMENT Name of Test METHOD REFERENCE DETERMINED REQUIREMENTS S

SOILS --- INDEX AND CLASSIFICATION TESTS Gradation Analysis ASTM D 421 Ref. 1, 2, 3, 4 Particle size distribution Methods are applicable to D 422 some rocks, after D 2217 disaggregation.

D 4221 Percent fines ASTM D 1140 Ref. 1, 4, 5 Percent of weight of material finer than No. 200 sieve.

Atterberg Limits ASTM D 427 Refs. 2, 3, 5, Liquid and plastic limit, D 4318 6, 7, 8 plasticity index, shrinkage D 4943 factor (limit)

Ref. 1 Specific Gravity ASTM D 854 Ref. 1, 2, 4 Specific gravity, apparent Boiling should not be used D 5550 specific gravity, bulk unit for de-airing. Method can be Ref. 1 weight sufficiently fine to used for rock, after grinding.

eliminate internal voids in the intact rock.

Radiography ASTM D 4452 Qualitative test of sample quality Description of Soil and ASTM D 2487 Description of soil from Rock D 2488 visual-manual examination D 4452 Ref. 9 SOILS --- MOISTURE-DENSITY RELATIONS Bulk Unit Weight Ref. 1 Bulk unit weight (bulk Methods are applicable to density) some rocks, with some Obvious modifications.

Water (Moisture) ASTM D 425 Refs. 2, 10, Water content as a percent Method is applicable to rock.

Content D 1558 11, 12 of dry weight D 2216 D 2974 D 4643 D 4959 Ref. 1 Relative Density Ref. 1 Maximum and minimum Requires vibration table. In density of cohesionless vibration table testing, both soils amplitude and frequency should be adjusted to values that yield greatest density.

However, treatment that produces breakage of grains should be avoided and mechanical analyses should be performed as a check on grain breakage.

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STANDARD OR PROPERTIES OR REMARKS/SPECIAL PREFERRED OTHER PARAMETERS EQUIPMENT Name of Test METHOD REFERENCE DETERMINED REQUIREMENTS S

Compaction ASTM D 698 Ref. 2 Maximum dry unit weight of Method for earth-rock D 1557 soil mixtures is given in Ref 6.

D 4253 D 4254 D 5080 Ref. 1 SOILS --- CONSOLIDATION AND PERMEABILITY Consolidation ASTM D 2435 Ref. 2, 4, 5, 14 One-dimensional D 4186 compressibility, Ref. 1 permeability of cohesive soil Permeability ASTM D 2434 Ref. 2 Permeability Suitable for remolded or D 5084 compacted soils. For natural, Ref. 1 In situ soils, field test should be used.

SOILS --- PHYSICAL AND CHEMICAL PROPERTIES Mineralogy Ref. 15 Refs. 16, 17, Identification of minerals Applicable to rock. Requires 18, 19 X-ray diffraction apparatus Differential thermal analysis apparatus may also be used.

Organic Content Ref. 16 ASTM D 2974 Organic and inorganic Dry combustion methods Ref. 20 carbon content as percent (ASTM D 2974) are of dry weight. acceptable, but where organic matter content is critical, data so obtained should be verified by wet combustion tests.

Soluble Salts ASTM D 4542 Ref. 21, 22 Concentration of soluble salts in soil pore water Erodibility Tests Pinhole Test ASTM D 4221 Ref.23 Significant in evaluation D 4647 of potential erosion or Ref. 1 piping.

Crumb Test Ref. 1 SCS Test Ref. 1 Ref. 14 Cylinder Dispersion Ref. 1 SOILS --- SHEAR STRENGTH AND DEFORMABILITY Unconfined ASTM D 2166 Ref. 1 Strength of cohesive soil Compression in uniaxial compression.

Direct Shear, ASTM D 3080 Cohesion and angle of Consolidated-drained Ref. 1 internal friction under drained conditions Triaxial Compression , ASTM D 2850 Ref. 2, 24 Shear strength parameters; Unconsolidated- Ref. 1 Cohesion and angle of Undrained internal friction for soils of low permeability.

Triaxial Compression, Ref. 1 Refs. 2, 24 Shear strength parameters; Circumferential drains, if Consolidated- Cohesion and angle of used, should be slit to avoid Drained internal friction. For long- stiffening test specimen.

term loading conditions.

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STANDARD OR PROPERTIES OR REMARKS/SPECIAL PREFERRED OTHER PARAMETERS EQUIPMENT Name of Test METHOD REFERENCE DETERMINED REQUIREMENTS S

Triaxial Compression, ASTM D 4767 Refs. 2, 24 Shear strength parameters; Circumferential drains, if Consolidated- Ref. 1 Cohesion and angle of used, should be slit to avoid Undrained internal friction for stiffening of test specimen.

consolidated soil. With pressure measurements, cohesion and friction may be obtained.

Cyclic Triaxial ASTM D 3999 Refs. 8, 25, Local strain, modulus and D 5311 26, 27, 28, 29, damping Ref. 1 30, 31, 32, 33 Cyclic Simple Shear Ref. 34 Shear modulus and Tests may be run with either damping values and cyclic- stress control or strain strength of cohesive and control.

cohesionless soils Resonant Column ASTM D 4015 Refs. 35, 36 Shear modulus and Requires resonant column damping in cohesive and device.

cohesionless soils. Some devices can be used with deformations in longitudinal mode to determine Youngs modulus. Some devices can be used to determine cyclic strength.

ROCKS ---- ENGINEERING PROPERTIES Porosity ASTM D 4404 Ref. 13 Bulk unit weight, specific Soil testing methods gravity, and total porosity generally applicable with (Melcher Method) or minor modification.

effective porosity (Simmons or Washburn-Bunting Method)

Permeability ASTM D 4525 Ref. 13 Permeability of intact rock Laboratory permeability values are not normally representative of in situ permeability of shallow jointed rock masses.

Seismic Velocity ASTM D 2845 Compressional and shear Requires signal generator, wave velocities in intact transducers, oscilloscope.

rock Direct Tensile Strength ASTM D 2936 Uniaxial tensile strength of intact rock Brazilian Test ASTM D 3967 Indirect measure of tensile strength of intact rock Unconfined ASTM D 2938 Youngs moduli and Compression unconfined compression strength of intact rock Uniaxial Compression ASTM D 3148 Triaxial Compression ASTM D 2664 Youngs moduli, cohesion Undrained friction parameters of failure envelope Triaxial Compression ASTM D 5407 Without Pore Pressure Measurements 15

STANDARD OR PROPERTIES OR REMARKS/SPECIAL PREFERRED OTHER PARAMETERS EQUIPMENT Name of Test METHOD REFERENCE DETERMINED REQUIREMENTS S

Slake Durability ASTM D 4644 Index of resistance to slaking Direct Shear ASTM D 5607 16

APPENDIX A REFERENCES ASTM STANDARDS ASTM D 421-85(1998), Standard Practice for Dry Preparation of Soil Samples for Particle-Size Analysis and Determination of Soil Constants, American Society for Testing and Materials, 1998.

ASTM D 422-63(1998), Standard Test Method for Particle-Size Analysis of Soils, American Society for Testing and Materials, 1998.

ASTM D 425-88(2001), Standard Test Method for Centrifuge Moisture Equivalent of Soils, American Society for Testing and Materials, 2001, ASTM D 427-98, Test Method for Shrinkage Factors of Soils by the Mercury Method, American Society for Testing and Materials, 1998.

ASTM D 698-00a, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3), American Society for Testing and Materials, 2000.

ASTM D 854-00, Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer, American Society for Testing and Materials, 2000.

ASTM D 1140-00, Standard Test Methods for Amount of Material in Soils Finer Than the No.

200 (75-um) Sieve, American Society for Testing and Materials, 2000.

ASTM D 1557-00, Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700kN-m/m3)), American Society for Testing and Materials, 2000.

ASTM D 1558-99, Standard Test Method for Moisture Content Penetration Resistance Relationships of Fine-Grained Soils, American Society for Testing and Materials, 1999.

ASTM D 2166-00, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil, American Society for Testing and Materials, 2000.

ASTM D 2216-98, Standard Test Method for Laboratory Determination of Water (Moisture)

Content of Soil and Rock by Mass, American Society for Testing and Materials, 1998.

ASTM D 2217-85(1998), Standard Practice for Wet Preparation of Soil Samples for Particle-Size Analysis and Determination of Soil Constants, American Society for Testing and Materials, 1998.

ASTM D 2434-68(2000), Standard Test Method for Permeability of Granular Soils (Constant Head), American Society for Testing and Materials, 2000.

ASTM D 2435-96, Standard Test Method for One-Dimensional Consolidation Properties of Soils, American Society for Testing and Materials, 1996.

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ASTM D 2488-00, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), American Society for Testing and Materials, 2000.

ASTM D 2664-95a, Standard Test Method for Triaxial Compressive Strength of Undrained Rock Core Specimens Without Pore Pressure Measurements, American Society for Testing and Materials, 1995.

ASTM D 2845-00, Standard Test Method for Laboratory Determination of Pulse Velocities and Ultrasonic Elastic Constants of Rock, American Society for Testing and Materials, 2000.

ASTM D 2850-95(1999), Standard Test Method for Unconsolidated-Undrained Triaxial Compression Test on Cohesive Soils, American Society for Testing and Materials, 1999.

ASTM D 2936-95, Standard Test Method for Direct Tensile Strength of Intact Rock Core Specimens, American Society for Testing and Materials, 1995.

ASTM D 2938-95, Standard Test Method for Unconfined Compressive Strength of Intact Rock Core Specimens, American Society for Testing and Materials, 1995.

ASTM D 2974-00, Standard Test Methods for Moisture, Ash, and Organic Matter of Peat and Other Organic Soils, American Society for Testing and Materials, 2000.

ASTM D 3080-98, Standard Test Method for Direct Shear Test of Soils Under Consolidated Drained Conditions, American Society for Testing and Materials, 1998.

ASTM D 3148-96, Standard Test Method for Elastic Moduli of Intact Rock Core Specimens in Uniaxial Compression, American Society for Testing and Materials, 1996.

ASTM D 3967-95a, Standard Test Method for Splitting Tensile Strength of Intact Rock Core Specimens, American Society for Testing and Materials, 1995.

ASTM D 3999-91(1996), Standard Test Methods for the Determination of the Modulus and Damping Properties of Soils Using the Cyclic Triaxial Apparatus, American Society for Testing and Materials, 1996.

ASTM D 4015-92(2000), Standard Test Methods for Modulus and Damping of Soils by the Resonant-Column Method, American Society for Testing and Materials, 2000.

ASTM D 4186-89(1998)e1, Standard Test Method for One-Dimensional Consolidation Properties of Soils Using Controlled-Strain Loading, American Society for Testing and Materials, 1998.

ASTM D 4221-99, Standard Test Method for Dispersive Characteristics of Clay Soil by Double Hydrometer, American Society for Testing and Materials, 1999.

ASTM D 4253-00, Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table, American Society for Testing and Materials, 2000.

ASTM D 4254-00, Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density, American Society for Testing and Materials, 2000.

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ASTM D 4318-00, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils, American Society for Testing and Materials, 2000.

ASTM D 4404-84(1998)e1, Standard Test Methods of Pore Volume and Pore Volume Distribution of Soil and Rock by Mercury Intrusion Porosimetry, American Society for Testing and Materials, 1998.

ASTM D 4452-85(1995)e1, Standard Methods for X-Ray Radiography of Soil Samples, American Society for Testing and Materials, 1995.

ASTM D 4525-90(1995)e1, Standard Test Method for Permeability of Rocks by Flowing Air, American Society for Testing and Materials, 1995.

ASTM D 4542-95, Standard Test Method for Pore Water Extraction and Determination of the Soluble Salt Content of Soils by Refractometer, American Society for Testing and Materials, 1995.

ASTM D 4643-00, Standard Test Method for Determination of Water (Moisture) Content of Soil by the Microwave Oven Method, American Society for Testing and Materials, 2000.

ASTM D 4644-87(1998), Standard Test Method for Slake Durability of Shales and Similar Weak Rocks, American Society for Testing and Materials, 1998.

ASTM D 4647-93(1998)e1, Standard Test Method for Identification and Classification of Dispersive Clay Soils by the Pinhole Test, American Society for Testing and Materials, 1998.

ASTM D 4767-95, Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils, American Society for Testing and Materials, 1995.

ASTM D 4943-95, Standard Test Method for Shrinkage Factors of Soils by the Wax Method, American Society for Testing and Materials, 1995.

ASTM D 4959-00, Standard Test Method for Determination of Water (Moisture) Content of Soil by Direct Heating, American Society for Testing and Materials, 2000.

ASTM D 5080-00, Standard Test Method for Rapid Determination of Percent Compaction, American Society for Testing and Materials, 2000.

ASTM D 5084-00, Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter, American Society for Testing and Materials, 2000.

ASTM D 5311-92(1996), Standard Test Method for Load Controlled Cyclic Triaxial Strength of Soil, American Society for Testing and Materials, 1996.

ASTM D 5407-95(2000), Standard Test Method for Elastic Moduli of Undrained Intact Rock Core Specimens in Triaxial Compression Without Pore Pressure Measurement, American Society for Testing and Materials, 2000.

ASTM D 5550-00, Standard Test Method for Specific Gravity of Soil Solids by Gas Pycnometer, American Society for Testing and Materials, 2000.

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ASTM D 5607-95, Standard Test Method for Performing Laboratory Direct Shear Strength Tests of Rock Specimens Under Constant Normal Force, American Society for Testing and Materials, 1995.

OTHER REFERENCES

1. EM 1110-2-1906, Laboratory Soils Testing, U.S. Army Corps of Engineers, Washington, DC, 1986.

2. EM 1110-2-1909, Calibration of Laboratory Soils Testing Equipment, U.S. Army Corps of Engineers, Washington, DC, 1986.

3. A.K. Howard, and R.C. Horz, Minimum Test Specimen for Gradation Analysis, Geotechnical Testing Journal, GTJODJ, Vol. 11, No. 3, pp. 213-217, 1988.

4. T.W. Lambe, Soil Testing for Engineers, John Wiley & Sons, Inc., New York, 1951.

5. J.P. Koester, The Influence of Test Procedures on Correlation of Atterberg Limits with Liquefaction in Fine-Grained Soils, Geotechnical Testing Journal, GTJODJ, Vol. 15, No. 4, pp. 352-361, 1992a.

6. L.J. Bobrowski, Jr., and D.M. Griekspoor, Determination of the Plastic Limit of a Soil by Means of a Rolling Device, Geotechnical Testing Journal, GTJODJ, Vol. 15, No. 3, pp. 284-287, 1992.

7. B.M. Das, Soil Mechanics Laboratory Manual, 4th ed., Engineering Press, Inc., San Jose, California, 1992.

8. J.P. Koester, Cyclic Strength and Pore Pressure Generation Characteristics of Fine Grained Soils, Ph.D. Thesis, University of Colorado, Boulder, December 1992b.

9. RTH 102-93, Rock Testing Handbook (RTH), Test Standards 1993, Part 1, U.S. Army Engineers, Waterways Experiment Station, Vicksburg, MS, 1993.

10. P.A. Gilbert, Computer Controlled Microwave Oven System for Rapid Water Content Determination, Technical Report GL-88-21, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS, 1988.

11. P.A. Gilbert, Computer-Controlled Microwave Drying of Potentially difficult Organic and Inorganic Soils, Technical Report GL-90-26, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS, 1990.

12. E.L. Krinitzsky, Radiography in the Earth Sciences and Soil Mechanics, Plenum Press, New York, 1970.

13. A.W. Buell, Porosity and Permeability Analysis, Subsurface Geologic Methods (A Sym-posium), 1st ed., Colorado School of Mines, Golden, CO, pp. 168-175, 1950.

14. K.H. Head, Manual of Soil Laboratory Testing, Volume 1: Soil Classification and Compaction Tests, Second Ed., Halstead Press: An imprint of John Wiley & Sons Inc.,

New York - Toronto, 1992.

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15. G.R. Thiers and H.B. Seed, Cyclic Stress-Strain Characteristics of Clay, Journal of the Soil Mechanics and Foundations Division, American Society of Chemical Engineers, Vol. 94, No. SM 2, pp. 555-569, 1968.

16. L.E. Allison, Wet Combustion Apparatus and Procedure for Organic and Inorganic Carbon in Soil, Proceedings, Soil Science Society of America, Vol. 24, pp. 36-40, 1960.

17. American Society of Agronomy and American Society for Testing and Materials, Methods of Soil Analysis, Parts 1 and 2, Americas Society of Agronomy, Inc., Madison, Wisconsin, 1965.

18. G.H. Francher, The Porosity and Permeability of Elastic Sediments and Rocks, Subsurface Geologic Methods (A Symposium), 2nd ed., Colorado School of Mines, Golden, CO, pp. 685-712, 1950.

19. C.M. Warshaw and R. Roy, Classification and a Scheme for the Identification of Layer Silicates, Bulletin of the Geological Society of America, Vol. 72, pp. 1455-1492, 1961.

20. N.O. Schmidt, Suggested Method of Testing for Organic Carbon Content of Soil by Wet Combustion, Special Procedures for Testing Soil and Rock for Engineering Purposes, American Society for Testing and Materials, STP 479, Philadelphia, 1970.

21. M.L. Silver, Laboratory Triaxial Testing Procedures To Determine the Cyclic Strength of Soils, NUREG-0031, U.S. Nuclear Regulatory Commission, 1976.

22. Soil Survey Laboratory Methods and Procedures for Collecting Soil Samples, Soil Survey Investigations Report No. 1, U.S. Soil Conservation Service, Washington, DC, 1967.

23. E.G. Perry, Piping in Earth Dams Constructed of Dispersive Clay, Literature Review and Design of Laboratory Tests, Technical Report S-75-15, U.S. Army Waterways Experiment Station, Vicksburg, MS, 1975.

24. A.W. Bishop, and D.J. Henkel, The Measurement of Soil Properties in the Triaxial Test, 2nd ed., Edward Arnolds, Ltd., London, 1962.

25. M. Evans, Undrained Cyclic Triaxial Testing of GravelsThe Effects of Membrane Compliance, Ph.D. Dissertation, University of California, Berkeley, CA, 1987.

26. M.E. Hynes, Pore Pressure Generation Characteristics of Gravel Under Undrained Cyclic Loading," Ph.D. Dissertation, University of California, Berkeley, CA, 1988.

27. G.K. Scholey, J.D. Frost, and M. Jamiolkowski, A Review of Instrumentation for Measur-ing Small Strains During Triaxial Testing of Soil Specimens, Geotechnical Testing Journal, GTJODJ, Vol. 18, No. 2, pp. 137, 1995.

28. H.B. Seed, Evaluation of Soil Liquefaction Effects on Level Ground During Earthquakes, Liquefaction Problems in Geotechnical Engineering, Preprint No. 2752, ASCE National Convention, Philadelphia, pp. 1-104, 1976.

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29. H.B. Seed, and I.M. Idriss, Ground Motions and Soil Liquefaction During Earthquakes, Monograph Series, Earthquake Engineering Research Institute, University of California, Berkeley, CA, 1982.

30. Shannon & Wilson, Inc., and Agbabian-Jacobsen Associates, Soil Behavior Under Earthquake Loading Conditions; State-of-the-Art Evaluation of Soil Characteristics for Seismic Response Analysis, Report for U.S. Atomic Energy Commission, 1972.

31. F. Tatsuoka et al., Importance of Measuring Local Strains in Cyclic Triaxial Tests on Granular Materials, Dynamic Geotechnical Testing II, ASTM STP 1213, American Society for Testing and Materials, Philadelphia, PA, 1994.

32. M. Vucetic and R. Dobry, Effect of Soil Plasticity on Cyclic Response, ASCE Journal of Geotechnical Engineering, Vol. 117, No. 1, pp 89-17, 1991.

33. M.L. Silver and H.B. Seed, Deformation Characteristics of Sand Under Cyclic Loads, Journal of the Soil Mechanics and Foundations Division, American Society of Chemical Engineers, Vol. 97, No. SM 8, pp. 1081-1098, 1971.

34. M.L. Silver and T.K. Park, Testing Procedure Effects on Dynamic Soil Behavior, Journal of the Geotechnical Engineering Division, American Society of Chemical Engineers, Vol. 101, No. GT 10, pp. 1061-1083, 1975.

35. B.A. Andréasson, Dynamic Deformation Characteristics of Soft Clay, Proceedings, International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, Vol. 1, pp. 65-70, 1981.

36. D.Z. Zavoral and R.G. Campanella, Frequency Effects on Damping Modulus of Cohesive Soils, ASTM STP 1213, American Society for Testing and Materials, 1994.

REGULATORY ANALYSIS

1. STATEMENT OF THE PROBLEM Regulatory Guide 1.138, Laboratory Investigations of Soils for Engineering Analysis and Design of Nuclear Power Plants, was issued in 1978. It describes acceptable laboratory investigations and testing procedures for complying with the NRCs regulations for determining soil and rock properties and characteristics for engineering analysis and design of foundations and earthworks. In the intervening time, both the practice of geotechnical laboratory investigations and NRC regulations for plant siting have changed.

New regulations were issued under Subpart B, Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997, of 10 CFR Part 100. The new regulations have a major impact on seismic siting criteria, which necessitated issuing Regulatory Guide 1.165, Identification and Characterization of Seismic Sources and Determination of Safe Shutdown Earthquake Ground Motion, in March 1997. While the impact on laboratory investigations for soils and rock is much smaller, it is still advisable to revise the related guidance in Regulatory Guide 1.138 because of the changes in practices in 22

laboratory testing as reflected in newer ASTM, Corps of Engineers (COE), and other standards.

In the staffs view, a revision of Regulatory Guide 1.138 would promote the use of newer and more efficient methods of laboratory investigations, providing a better basis for evaluating site safety with respect to foundation design for critical structures.

2. OBJECTIVE The objective of this regulatory action is to update NRC guidance on laboratory investigations for soils and rock for engineering analysis and design of foundations and earthworks to conform with new regulations and practices.

3. ALTERNATIVES 3.1 Alternative 1 - Do Not Revise Regulatory Guide 1.138 With this alternative, new license applications (after January 10, 1997) for nuclear power plants would continue to be based on practices of over 20 years ago, as far as laboratory investigations are concerned. Some future applicants may, on their own initiative, use more modern procedures, but would not be required to do so. This alternative is considered the baseline or no action alternative.

3.2 Alternative 2 - Revise Regulatory Guide 1.138 The staff has identified the following consequences related to Alternative 2:

3.2.1 Benefits Conducting laboratory investigations with newer practices and specifications would be expedient because they represents the present practice in the industry. Other benefits to be derived from the new guidance would include better or less costly design and reduced risk from better designed plants.

3.2.2 Costs Costs are expected to be approximately the same as under the previous version of the guide because no new and different types of laboratory investigations are specified.

Additionally the laboratory investigations presented in an updated version of the guide would represent the present state of practice in that these methods are being used today in virtually any large site investigation of an engineering geological nature.

4. CONCLUSION Based on the regulatory analysis, it is recommended that a proposed revision of Regulatory Guide 1.138 be issued for public comment and then issued as an effective revision. A revision of Regulatory Guide 1.138 would be beneficial because it may lead to safer plant designs, whereas the costs of the investigations should not materially increase.

The staff sees no adverse effects associated with the revision.

BACKFIT ANALYSIS 23

This regulatory guide does not require a backfit analysis as described in 10 CFR 50.109(c) because it does not impose a new or amended provision in the NRCs rules or a regulatory staff position interpreting the NRCs rules that is either new or different from a previous staff position. In addition, this regulatory guide does not require the modification or addition to systems, structures, components, or design of a facility or the procedures or organization required to design, construct, or operate a facility. Rather, a licensee or applicant can select a method for achieving compliance with a license or the rules or the orders of the Commission as described in 10 CFR 50.109(a)(7). This regulatory guide provides an opportunity to use industry-developed standards, if that is a licensees or applicants preferred method.

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