Regulatory Guide 4.19
| ML003739520 | |
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| Issue date: | 08/31/1988 |
| From: | Office of Nuclear Regulatory Research |
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| -nr RG-4.19 | |
| Download: ML003739520 (10) | |
U.S. NUCLEAR REGULATORY COMMISSION August 1988 REGULATORY GUIDE
OFFICE OF NUCLEAR REGULATORY RESEARCH
REGULATORY GUIDE 4.19 (Task WM 408-4)
GUIDANCE FOR SELECTING SITES FOR
NEAR-SURFACE DISPOSAL OF LOW-LEVEL RADIOACTIVE WASTE
A. INTRODUCTION
Waste"; 1 and NUREG-1199, "Standard Format and Content of a License Application for a Low-Level The purpose of this regulatory guide is to provide Radioactive Waste Disposal Facility."'
guidance on screening areas to identify a site or sites for near-surface disposal of low-level radioactive waste Applicants are encouraged to meet informally with the (LLW). Section 61.50, "Disposai Site Suitability Re NRC technical staff at any time during the prelicense quirements for Land Disposal," of 10 CFR Part 61, stage to discuss license application requirements, perform
"Licensing Requirements for Land Disposal of Radioac ance objectives, or technical requirements of 10 CFR
tive Waste," lists technical requirements for the site; Part 61. These informal discussions will streamline the Subpart C of Part 61 lists performance objectives that review process and reduce overall costs to the applicant.
must be met by the disposal facility. The purposes of screening are to identify a site or sites that have a high Any information collection activities mentioned in potential for meeting the site suitability requirements of this regulatory guide are contained as requirements in paragraph 61.50(a) and to help ensure that the perform 10 CFR Part 61, which provides the regulatory basis for ance objectives of Subpart C will be met. this guide. The information collection requirements in
10 CFR Part 61 have been cleared under OMB Clearance This regulatory guide provides guidance for conduct No. 3150-0135.
ing a site screening investigation. It is anticipated that much of the data required for site screening can be
B. DISCUSSION
obtained from published and open file information and aerial photographic interpretation. Only limited onsite The technical site suitability requirements for near studies are anticipated at the screening stage. surface LLW disposal are presented in paragraph
61.50(a) of 10 CFR Part 61. These requirements address This regulatory guide provides guidance on site specific conditions that could affect long-term site selection to be conducted in steps with the goal of stability and waste isolation. The site suitability re finding a site that has a reasonable likelihood of being quirements may eliminate from consideration land that licensed. The site characterization program, on the other has certain unfavorable hydrologic, geologic, land use, hand, is designed to produce all the information neces and demographic conditions that could adversely affect sary to support the license application. Information on the site and its environs.
site characterization requirements for a license applica tion is provided in NUREG-0902, "Site Suitability, In evaluating sites for LLW disposal, it is important Selection and Characterization"; I Regulatory Guide that a reasonable effort be made to select candidate
4.18, "Standard Format and Content of Environmental sites with natural conditions that will maintain radionu Reports for Near-Surface Disposal of Radioactive clide releases to the general environment as low as is reasonably achievable. The NRC staff considers the Copi-esmay be purchased from the Superintendent of Docu long-term contribution of the natural conditions of the ments, U.S. Government Printing Office, 1P.0. Box 37082, Wash site essential in protecting the general population against ington, DC 20013-7082. releases of radioactive material. The effectiveness of USNRC REGULATORY GUIDES The guides are issued in the following ten broad divisions:
Regulatory Guides are issued to describe and make available to the public methods acceptable to the NRC staff of implementing 1. Power Reactors 6. Products specific parts of the Commission's regulations, to delineate tech- 2. Research and Test Reactors 7. Transportation niques used by the staff in evaluating specific problems or postu- 3. Fuels and Materials Facilities 8. Occupational Health lated accidents, or to provide guidance to applicants. Regulatory 4. Environmental and Siting 9. Antitrust and Financial Review Guides are not substitutes for regulations, and compliance with 5. Materials and Plant Protection 10. General them is not required. Methods and solutions different from those set out in the guides will be acceptable if they provide a basis for the findings requisite to the issuance or continuance of a permit or Copies of issued guides may be purchased from the Government license by the Commission. Printing Office at the current GPO price. Information on current GPO prices may be obtained by contacting the Superintendent of This guide was issued after consideration of comments received from Documents, U.S. Government Printing Office, Post Office Box the public. Comments and suggestions for improvements in these 37082, Washington, DC 20013-7082, telephone (202)275-2060 or guides are encouraged at all times, and guides will be revised, as (202)275-2171.
appropriate, to accommodate comments and to reflect new informa tion or experience.
Issued guides may also be purchased from the National Technical Written comments may be submitted to the Rules and Procedures Information Service on a standing order basis. Details on this Branch, DRR, ADM, U.S. Nuclear Regulatory Commission, service may be obtained by writing NTIS, 5285 Port Royal Road, Washington, DC 20555. Springfield, VA 22161.
other measures such as design features, waste form, definable rates are preferred over complex sites. For model waste packaging, and institutional controls is assumed to ing, input assumptions must be valid (representative) for all decrease with time after site closure. site conditions. If a complex site condition is not included in a model, it must be demonstrated that the condition The NRC staff expects that the natural conditions of either has no effect on site performance or can be any proposed near-surface LLW disposal facility will accounted for by using a conservative parameter.
contribute favorably to the isolation of LLW and to the stability of the disposal site after closure. Although it is 1.2 Population Distribution and Land Use (Paragraph unrealistic to expect total isolation or site stability in 61.50(a)(3))
the long term, it is expected that careful selection of a site will limit the potential for radionuclide leaching, The candidate site should be located in an area of low provide long pathways to minimize potential radionu population density where the potential for future popula clide releases, prevent erosion and inundation of the tion growth is estimated to be quite limited. The candidate disposal site to minimize active maintenance, and avoid site should be at least 2 kilometers from the residential areas in which detrimental human activities are occur property limits of the nearest existing urban community ring. It is expected that the concepts in the technical (NUREG-0902, p. 6). However, the exact distance to the requirements in § 61.50 will help the applicant meet the nearest residential property may vary depending on local performance objectives for effluents (§ 61.41 ) and long-term land use and demographic conditions.
stability (§ 61.44). Such careful site selection, along with equally careful consideration of the facility design, opera Applicable State and local land use plans and regula tion, and closure requirements of 10 CFR Part 61, will tions (including zoning ordinances) should be fully ensure that the overall performance objectives of 10 CFR evaluated to be sure that there are no conflicting regula Part 61 will be met and that the health and safety of the tions or conflicting plans for development in the vicinity public will be protected. of the site. Residentially zoned or planned land uses are considered to be conflicting uses and should not exist
C. REGULATORY POSITION
or be planned in the vicinity of the candidate site. In addition, local and State authorities should be consulted The performance objectives of Subpart C of 10 CFR for information on planned highway construction in the Part 61 were established to define a level of safety for vicinity of the site to be sure that no highways are near-surface disposal of LLW. The technical requirements planned that would interfere with the operation of of Subpart D were established to help ensure that the the site. It is also important to determine whether or performance objectives are met. Demonstrating compli not there will be adequate access to the site in terms of ance with the site suitability requirements of paragraph future'highways and land use.
61.50(a) will specifically contribute to achieving the performance objectives of § § 61.41 and 61.44. 1.3 Natural Resources (Paragraph 61.50(a)(4))
1. CONSIDERATION FOR SITE SUITABILITY Published or open file information on natural re sources should be evaluated to determine the potential The following should be considered when screening a impact on the site if natural resources were to be region of interest to identify a site for characterization. exploited. Examples of natural resources to be NUREG-0902 contains information that will assist in demon considered include metallic and nonmetallic minerals and strating compliance with the site suitability requirements. ores; fuels such as peat, lignite, and coal; hydrocarbons including gas, oil, tar sands, and asphalt; geothermal
1.1 Capable of Being Characterized (Paragraph 61.50(a)(2)) resources; industrial mineral deposits such as sand and gravel, clays, aggregate sources, shales, and building The ability of a site to provide long-term isolation of stone; timber; agricultural ground; or surface waters.
waste should be demonstrated by using models and other analyses based on the characteristics of the site. A Areas should be avoided if they contain natural site that is being considered for LLW disposal must be resources in quantities or of such quality that future capable of being analyzed, characterized, and modeled. exploitation could affect waste isolation. Care should be This suggests identifying the individual components of taken not to eliminate areas from consideration by using the site, identifying the physical characteristics that a blanket type of screening criteria, for example, elimi make each individual component unique, and preparing nating all areas with coal deposits. This could eliminate a general representation of each site component to otherwise suitable sites in a broad geographic area even enable predictions of site performance. Although site though many of the coal deposits that exist are insig characterization is not necessary for screening, there are nificant as economically recoverable resources.
some general concepts that should be considered to pro vide reasonable assurance that site characterization can be 1.4 Site Must Be Well Drained (Paragraphs 61.50(a)(5) and fulfilled. 61.50(a)(6))
Sites that are geologically and hydrologically simple A 100-year floodplain, coastal high-hazard areas, and contain processes that occur at consistent and wetlands, or areas where flood velocities could cause
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damage to the disposal facility are not suitable for 1.6 Ground-Water Discharge (Paragraph 61.50(a)(8))
waste disposal. In general, significant flood inundation and high water velocities can be expected in poorly Areas are not suitable for LLW disposal if ground drained areas, the floodplains of major rivers, and areas water discharge features such as springs, seeps, swamps, situated near hydraulically steep streams or arroyos with or bogs are present. The NRC staff prefers long flow large drainage areas. Such areas should be avoided in the paths from the disposal site to the point of ground siting of LLW facilities. water discharge in order to increase the amount of time for decay of the radionuclides, increase the hydrody Additionally, projected land uses (such as urbaniza namic dispersion within the aquifer, and increase the tion or other factors that increase runoff potential) likelihood of retardation of reactive radionuclides in the should be evaluated to determine the effect of such aquifer.
changes on flood levels, flood-water velocities, and the overall impacts of flooding on site stability. Hydrogeologic analyses can be conducted by review ing open file reports, maps, and low-level aerial photo A waste disposal site should not be located in an graphs. In addition, site visits during wet seasons may area where the natural ground slope is steep. Runoff be helpful in identifying ground-water discharges.
from intense local precipitation may cause damage to the waste disposal unit or to diversion channels 1.7 Tectonic and Geomorphic Processes (Paragraphs constructed to divert overland flow around the site. 61.50(a)(9) and 61.50(a)(10))
Intense rainfall could be a determining factor in the stability of the site. Even though the upstream drainage A site in a tectonically active area may have unfavor areas may be minimized, steep slopes could produce able conditions. Volcanism and hydrothermal activity high water velocities that could be difficult to mitigate. may be unfavorable. Potentially unfavorable factors might include active faults as evidenced by earthquake In general, sites should not be located in areas where activity. Correlation of earthquake activity with known extensive hydraulic design features will be needed to faults and tectonic provinces should be considered in provide flood protection or erosion protection for the the evaluation of site suitability. Analysis of known or site. The NRC staff considers that natural conditions of suspected tectonic activity during relatively recent the site, by virtue of typography, elevation, and loca geologic time, especially during the Quaternary, should tion, should provide the principal contribution to site be conducted to evaluate the likelihood that the site stability. While some minor hydraulic engineering designs suitability requirements will be met.
will usually be necessary, extensive hydraulic designs should be avoided because (1) they may lose their Selected sites should not exhibit karst terrain or effectiveness over time without maintenance and (2) other evidence of subsurface settlement and dissolution.
they may not provide an adequate degree of confidence Examples of these features include sink holes, disappear in predicting their long-term performance or in meeting ing streams, and subsurface cavernous weathering in the long-term stability requirements of § 61.44. carbonate and evaporite rocks.
1.5 Depth to Water Table (Paragraph 61.50(a)(7)) Sites should be avoided where eolian, fluvial, or colluvial processes may adversely affect performance of Areas with a known or suspected high water table the disposal facility and its long-term stability. Processes should be avoided. A disposal site should be sufficiently such as dune migration, gullying, river channel migra above the water table so that ground-water intrusion, tion, or landsliding and debris flows on unstable slopes perennial or otherwise, into the waste will not occur. In can impair the operation of the site, affect the long accordance with paragraph 61.50(a)(7), waste disposal term stability and performance of the disposal units, should not be permitted in the zone of fluctuation of and impact design features for hydraulic protection of the water table. the disposal units. The extent and rates of these natural processes are often difficult to predict, and sites where Hydrologic analyses that may be helpful in determining such phenomena are likely should be avoided if possible.
depth to the water table and seasonal fluctuation include surface and subsurface studies. Surface studies may In addition, sites should be located in geologic and include geologic maps and stratigraphic cross sections, topographic settings that are naturally resistant to water aerial photo interpretation, vegetation maps (especially and wind erosion and flooding. For example, a site useful in arid regions), and surface-based geophysical must not be located on a 100-year floodplain, coastal exploration techniques. Subsurface studies may include high-hazard area, or wetland. Ideally, a site should be water-level data from new or existing wells, lithologic located near a drainage divide and must be generally logs, and bore hole geophysical logging. Regional data well drained.
regarding the hydrologic setting can be obtained from a variety of U.S. Geological Survey and State publications, Regional data regarding the tectonic and geomorphic including geologic and topographic maps, professional settings of proposed sites can be obtained from a papers, and bulletins. Other sources include the U.S. variety of U.S. Geological Survey and State publications, Department of Agriculture and U.S. Weather Service. including geologic and topographic maps, professional
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papers, and bulletins. Other sources include the U.S. include proximity to population centers or reserved par Department of Agriculture and U.S. Weather Service. cels of committed lands such as active military land, Indian Site-specific data are likely to require field study. reservations, or parks and monuments. However, other large parcels of public land may be suitable depending
1.8 Adverse Impacts from Nearby Facilities (Paragraph on community impact and environmental considerations.
61.50(a)(1 1))
An example of a candidate area suitable for further A candidate site should not be located near any study would be a sparsely populated area that has no facilities or activities that could adversely affect the apparent geologic limitations, has easy access to an ability of the site to meet the performance objectives of interstate or limited access highway, and is approxi
10 CFR Part 61. In addition, a candidate site should mately in the center of major LLW generators. Trans not be located near facilities that could mask the site portation issues that should be evaluated at this prelimi monitoring program. nary stage include access, distance from waste genera tors, and impacts to residential developments along State and local land use plans should be evaluated to potential transportation routes.
determine the potential for future facilities and activities to adversely impact the proposed disposal facility. 2.2 Step 2
2. SITE SELECTION PROCESS The purpose of Step 2 is to evaluate the candidate areas in order to identify potential candidate sites. Much The generic site selection process outlined below of the local geophysical and land use data can be provides guidance on evaluating a region to identify a obtained through Federal, State, and local agencies.
site that can meet the licensing requirements for near Land use plans, zoning ordinances, U.S. Geological surface LLW disposal. The site selection process may Survey (USGS) and State geological survey reports, and
2 vary from State to State or compact to compact open file data are examples of information sources that depending on a variety of factors, such as the distribu may prove useful in developing a list of candidate sites.
tion of waste generators, population distribution, or For example, local land use documents should indicate geologic conditions. However, the minimum technical whether or not development is planned or permitted in requirements of § 61.50 of 10 CFR Part 61 and the candidate areas. USGS and State geologic survey maps environmental requirements of 10 CFR Part 51 apply and reports often contain detailed information on faults, irrespective of the site selection process employed. flood plains, seismic events, and bedrock and soil com position. Also, the reviewer may wish to examine mid The four-step site selection process presented in this to low-level aerial photographs for recent land use regulatory guide is summarized in Table 1. The site changes. (See NUREG/CR-2861, "Image Analysis for suitability discussion (Section C.1) is fundamental to Facility Siting: A Comparison of Low- and High this site selection process. Altitude Image Interpretability for Land Use/Land Cover Mapping";1 NUREG/CR-3247, "Site Characterization In
2.1 Step 1 formation Using LANDSAT Satellite and Other Remote Sensing Data: Integration of Remote Sensing Data with For the first step, the applicant should define the Geographic Information Systems" ;1 and NUREG/CR
region of interest, such as the compact or State in 3583, "Evaluation of Low-Altitude Remote Sensing which the LLW site will be located. The purpose of this Techniques for Obtaining Site Characteristic Informa first step is to eliminate unfavorable areas and identify tion," 1 for more information concerning remote sensing candidate areas for further consideration. The applicant applications for site selection.)
should conduct a search of all published and open file documents on generalized land use, transportation, and 2.3 Step 3 geophysical information on a regional or State-wide level. Recent high to mid-level aerial photographs should The purpose of this step is to evaluate the candidate be evaluated for recent land use changes. sites in order to identify the proposed site. Since the National Environmental Policy Act of 1969 (NEPA)
Some examples of areas not suitable for LLW dispos requires an analysis of alternatives to the proposed al include areas that contain steep terrain, surface action (site), an environmental report that contains an waters, wetlands, faults or fracture zones, and karst evaluation of the candidate sites must be developed at areas. In addition, there should be no major recharge the site characterization stage. Although a complete areas at the site. Examples of significant land use factors environmental report is not required until a license that should eliminate areas from further consideration application is submitted (§ 61.10), the NRC staff suggests that the applicant consider each category in Chapter 3
2 The Low-Level Radioactive Waste Amendments Act of 1985 of Regulatory Guide 4.18 during the site screening provides the opportunity for States to form compacts to estab process. An early awareness of the environmental re lish and operate regional LLW disposal facilities. Compacts are quirements should provide reasonable assurance that a authorized to restrict the use of their disposal facilities to wastes complete environmental report can be submitted with a generated within the compact region. license application.
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TABLE 1 SITE SELECTION PROCESS
MOST GENERAL MOST DETAILED
Step 1 Step 2 Step 3 Step 4*
Category Region of Interest Candidate Areas Candidate Sites Proposed Sites Study Compact, State, or A homogeneous area. Sites that are potentially The site for which Area geographic region. Sites within an area licensable, the applicant is will contain same seeking a license.
general environmental characteristics.
Criteria General exclusionary General compact or General review of compact Evaluate compact or To Be data pertaining to State criteria, or State criteria, § 61.50, State criteria, Reviewed health and safety, areas general screening and information in § 61.50, Regulatory protected by law. requirements from Regulatory Guide 4.18. Guide 4.18.
§ 61.50, and Regulatory Guide 4.18.
Data To Be USGS and State geologic USGS and State USGS and State geologic Evaluate site Reviewed maps, Federal and State geologic maps, maps, topographic maps, specific data.
regulations, aerial topographic maps, university research, local photographs. university research, government plans and land use plans and ordinances and surveys, and ordinances, and local utility maps. Actual aerial photographs. field observation.
Level of Reconnaissance-level Reconnaissance re Reconnaissance information Demonstrate fulfill Analysis map reviews, literature view of local maps, and site visits (surface ment of site charac and regulation reviews. high-level aerial water samples, low-level terization require photographs, liter aerial photos, onsite ments. Prepare ature, and regula photos, air analysis, environmental report tions. windshield surveys, etc.). as necessary.
Purpose Identify candidate Identify candidate Identify proposed site for Meet site licensing areas. sites. characterization. requirements.
- Step 4 involves site characterization.
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Data collection during this phase of site selection will be easier to acquire for public use. Some states lack the require reconnaissance reviews and site visits. Soil and power of eminent domain; therefore privately owned surface-water sampling may be conducted. Land use, lands may not be available unless the owner is willing transportation, and geophysical data described in the to sell. However, dedicated park land should not be previous steps should be reevaluated. Recent low-level used unless it can be demonstrated that there would be aerial photographs may be useful for further evaluation. no significant environmental or community impacts.
These photographs may show land use and transporta tion changes and geophysical features (faults, mass Meteorological factors that structures may be sub wasting, wetlands) that may not be identified on exist jected to should be considered, such as maximum ice ing maps. The physical inspection may include a low and wind loads. The frequency of extreme meteorolog level aerial or ground survey (windshield survey) of the ical conditions such as hurricanes, tornadoes, water site and the surrounding areas. A suggested technique spouts, and thunderstorms should be considered, as well for conducting a site selection analysis after the data are as extreme precipitation rates and extreme forms of air collected is provided in Appendix A. pollution. Information on these meteorological condi tions may be obtained from the U.S. Department of A substantial amount of information can be obtained Commerce (National Oceanic and Atmospheric Adminis through meetings with local utility officials to determine tration) and other relevant government agencies.
the location of community water distribution systems and other utilities. This information may be important 2.4 Step 4 in candidate areas where the presence of potable wells may require the installation of a new water distribution The purpose of this step is to evaluate the proposed system or an extension from an existing system to site to determine whether it is licensable. A licensable ensure the availability of adequate potable water. In site would fulfill the technical requirements of § 61.50,
addition, information on the location of existing and help ensure that the performance objectives of Subpart planned electrical distribution systems is also important C of 10 CFR Part 61 will be met, and satisfy the require in planning for adequate cost-effective power at the ments of NEPA. A successful screening program will candidate disposal facility. identify a site that can be licensed for near-surface dis posal of LLW.
At this stage of screening, a title search of the candidate sites should be conducted. Land ownership Guidance on implementing Step 4 (site characteriza information is important so that proper authorities tion) can be obtained from NUREG-0902, Regulatory and land owners may be contacted concerning planned Guide 4.18, and NUREG-I199, "Standard Format and onsite visits and surveys. Knowledge of site parcel Content of a License Application for a Low-Level ownership is important because publicly held land may Radioactive Waste Disposal Facility."
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APPENDIX A
GEOGRAPHIC INFORMATION COMPUTER MAPPING
In order to expedite the site selection process, it may A simplified example of the compositing analysis be desirable to conduct a geographic information system process is shown in Figure 1. In this example, tne (GIS) analysis of relevant geophysical and land-use data. system user wants to locate a LLW disposal site in an An effective GIS technique is computer mapping where area free of three factors: shallow bedrock, surface geophysical, land-use, and demographic factors are water, and mature trees (1-A).
encoded to form a data base for analysis. Each factor should be plotted on separate maps that were generated from the same base map. Each map should then be The relative importance of each factor is represented encoded. It is important that the base map (such as by a weight that is a:.signed by the user. In this case, USGS 7.5-minute quadrangle maps) have a coordinate trees have been assigned the greatest importance and grid system (latitude-longitude or UTM grid) so that the shallow bedrock the least (l-C). The seven unique encoded data may be referenced and placed into the combinations of these factors produce scores from one data base format for computer mapping analysis. through seven; each score represents only one combina tion (I-D). For example, a score of three can only Once the relevant data are encoded and geophysically result from the combination of shallow bedrock and referenced according to a set of coordinates, site opti streams. The user could assign the greatest inmportance mization analysis may begin. The primary feature of a to bedrock to determine how areas of relative site computer mapping program is its capability to compos suitability would change based on altering the impor ite several factor maps to produce a single derivative tance of each factor.
map. The compositing is done on a cell-by-cell basis summing the factors within each cell. The user assigns a The result of the analysis is a computer-generated numeric value or "weight" to each of the mapped composite map that indicates areas most suited for factors, and each cell accumulates a "score." The score siting LLW disposal facilities based on given weighted is the result of the sum of the weights in each cell. A factors (l-E). In this case, the user has represented least user-supplied symbol is applied to each score level, and desirable areas by dark symbols and most desirable areas the composite map is produced on a line printer. as white or unpatterned (l-E).
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SHALLOW
BEDROCK STREAMS TREES
SOURCE MAPS A
DIGITIZED MAPS B
oo o oi o o C
WEIGHTS lot* eo 0.. o --22 SCORES D
2~11 COMPUTER
COMPOSITE E
MAP
Figure 1. EXAMPLE OF COMPOSITING ANALYSIS
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VALUE/IMPACT STATEMENT
A draft value/impact statement was published with the draft regulatory guide (Task WM
408-4) when the draft guide was published for public comment in March 1987.
No changes were necessary, so a separate value/impact statement for the final guide has not been pre pared. A copy of the draft value/impact statement is available for inspection and copying for a fee at the Commission's Public Document Room at 1717 H Street NW.,
Washington, DC, under Task WM 408-4.
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