ML20247F290
| ML20247F290 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/1988 |
| From: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| References | |
| TASK-RE, TASK-WM-408-4 REGGD-04.019, REGGD-4.019, NUDOCS 8907270119 | |
| Download: ML20247F290 (9) | |
Text
....
[*%
U.S. NUCLEAR REGULATORY COMMISSION August 1988 o @*%.+ ) REGULATORY GUIDE OFFICE OF NUCLEAR REGULATORY RESEARCH REGULATORY GUIDE 4.19
)
(Task WM 4084) i 1
GUIDANCE FOR SELECTING SITES FOR NEAR SURFACE DISPOSAL OF LOW-LEVEL RADIOACTIVE WASTE I
A. INTRODUCTION Waste";' 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 Factiity."1 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 i
I (LLW). Section 61.50, " Disposal 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 regmrements, 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 at requirements in paragraph 61.50(a) and to help ensure that the perform-10 CFR Part 61, which provides the regulatory basis for i
ance objectives of Subpart C will be met.
Js guide. The information collection requiren ents in 10 CFR Part 61 have been cleared under OMB Clearance This regulatory guide provides guidance for conduct-No. 3150-0135.
(Q) ing a site screening investigation. It is anticipated that O
much of the data required for site screening can be B. DISCUSSION obtained from published and open file information and aerial photographic interpretation. Ordy limited ons:te The technical site suitability requirements for near-studies are anticipated at the screening stage.
surface LLW disposal are presented in paragraph 41.50(a) of 10 CFR Part 61. These requirements address This regulatory guide pravides guidance on site specific conditions that could affect long-term site selection to be unducted in steps with the goal of stability and waste isolation. The site suitabihty 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 N U R EG-0902, " Site Suitability, in evaluating sites for LLW disposal, it is important Selection and Characterization ;8 Regulatory Guide that a reasonabh effort be made to select candidate 4.18, " Standard Format and Content of Environmental sites with natural conditions that will.naintain 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 copies may be purchased fror t the Superintendent of Docu-site essential in protecting the general population against ments, Ll.s. Government Paarin. nrfw en h unnt woh, Tes of radioactive material The effectiveness of ington, DC 200134082.
8907270119 BEiOB31 PDR REGGD 04.019 R PCR USNRC REGULATORY GUIDES The guldet 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 6 implementing
- 1. Power Reactors
- 6. Products specific parts of the Commission's regulations, to delineate tech-
- 2. Research and Test Reactort
- 7. Transportation niques used by the staff in evaluating specific problems or postu.
- 3. F uels and Materials FacPitses
- 8. Occupational HCalth lated accidents or to provide guidance to applicants. Regulatory
- 4. Environmental and Siting
- 9. Antltrust and F6nancial Review Guides are nol substitutes for regulasons, and com,.itace with S. Materials and Plant Protect 6on 10. General
\\ them is not reoutred. Methods and salutions different from thobe set i'j) out in the guides will be acceptable if they provide a basis for the f
fmdings reoutsite to the issuance or continuance of a permit of Copies of issued guidrs may be purchased from the Government i
Printing Office at the current GPO price. Information on current ticense by the Commission.
C PO price
- may be obta6ned by contacting the Superintendent of This guide was issued af ter considerat6on of comments received from Documents.
U.S.
Government Pr6nting Of fice, Post Of fe.e Box the pubHC. Comments and suggestions for improvements in these 3 7082, Washmgtori, 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 accon modate comments and to reflect new in*orma-t6on or expertence, issued guides may also be purchased from the National Technical Written comments may be submitted to the Rules and Procedures infccmation Service on a stand 6ng order basis. Detales on this Branch, DRR
- ADM, U.S.
Nuclear Regulatory Commission, service may be obtained by writing NTIS, %285 Port Royal Road, Wasnington, Dd 20$b5.
Springfield.y A 2 2161.
L
othc; measures such as design features, waste form, definable rates are prefer ed over complex siter. For model-waste packaging, and institutional controls is assumed to ing, input assumptiorts must be valid (representative) for all decrease with time after site closure.
site conditions. If a complex ite 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 uring r. conservative parameter.
contribute favorably to the isolation of LLW and to the stabdity of the disposid site after closure. Although it is 1.2 Population Distribution and Land Use (Paragraph unicalistic to expect total isolation or site stability in 61.50(a)(3))
the lor-g term, it is expected thet careful selectia of a site will limit the potential for radionuclides 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 fi e popula-clide releases, prevent erosion and inundation of the fian growth is estimated to be quite limited. The candidate disposal site to minimize active ma.intenance, and avoid site should be at least 2 kilometers from the residential areas in which detrimental human activities are occur-proper:y limits of the nearest existing urban community ring. It is expected that the concepts in the technical (NUREG-0902, p. 6). liowever, the exact distance to th requirements in g 61.50 wdl help the applicant meet the nearest residential property may vary depen'ing on local d
performance objectives for effluents (5 61.41)andlong-term land use and demographic conditiors.
stability (g 61.44). Such careful site selection, along with egually careful consideration of the facility design, opera-Applicable State and local land use plans and regula-tion, and dosure requirements of 10 CFR Part 61, will tions (including toning ordinances) should be fully ensure that the overall performance objectives of 10 CFR evaluated to te sure that there are no conflicting regula-Part 61 will be met and that the health and safety of the tions or conflicting rians for development in the vicinity public will be protected.
of the sitc. 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 l
l addition, local and State authorities should be consulted l
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 g g 61.41 and 61.44.
1.3 Natural Resources (Paragraph 61.50(a)(4))
- 1. CONSIDERATION FOR SITE SUITABILITY Pu blished or open fde information on natural re-sources should be evaluated to determine the potentia 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 NUR EG-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, tat sands. and asphalt; geothermal 1.1 Capable of Being Characterized (Paragraph 61.50(a)(2))
resources; industrial mineral deposits such as sarid and gravel, clays, aggregate sou rces, shales, and building The ability of a site to provide long-term isolation of stone; timber; agricultural pound; 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 blantet type of screening criteria, for exan?ple, elini-make each individual component unique, and preparing natirg all areas with coal deposits. This could eliminate a general representation of each site component to otherwise suitable s;tes 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 (Paragrsphs 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 4.19-2
damage to the disposal facility are not suitable for 1.G Ground Water Discharge (Pa:& graph 61.50(a)(8))
/
waste disposal. In general, significant flood inundation
.(
and high water velocitia can be expected in poorly Areas are not suitable for 1.1 W divosal if' ground-drained areas, the floodplains of major rivers, and areas water discharge features such as sprmgs, seeps, swamps, j
situated near hydraulically steep streams or arroyos with or bogs ar present. The NRC staff prefers long flor i
large dninage 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 t3 increase the amour.t of time I
for decay of the radionuclides, increase the hydrody-Additiona.Hy,, projected land usos (such as urbaniza-namic dispersion within the aquifer, and lacrease the tion or other factors that increase runoff potential) likelihood of retardathn of reactive radh nuclides in the should be evaluated to determine the effect o" such aquifer.
changes on flood levels, flood-water velocities, and the overall impacts of flooding on site st0bility.
liydrogeclogic analyses can be conducted by review-ing open file reports, maps, and low-level aerial photo-A waste disposal site should rot be located in an graphs. In addition, site visits during wet seasons may area where the natnral ground slope is steep. Runoff be helpful in identifying ground-water discharges.
I from intense local precipitation rnay cause damage to the waste disposal unit or to dieersion channels 1.7 Tectonic and Geomorphie Processes (Paragraphs constructed to divert overland flow around the site.
61.50(a)(9) and 61.50(a)(10))
I 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-i 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 ar evidenced by earthquake in general, sites should not be located in areas where activity Correlation of earthquake activity with known extensive hydraulic design featu res 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, elevadon, and loca-geologic time, especially during the Quaternary, should Lion, should provide the principal contribution to site be conducted to evaluate the likelihood that the site k
stability. While some sninor hydraulic engineering designs
.;uitability requirements will be met.
will usually in 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 I.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 f 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 raspected high water table the disposal facility and its lorg-term stability. Processes should be avoided. A disposal site should be sufficiency such as dune migration, gullying, river channel migra-above the wr.*.cr table so that ground-water intrusion, tion, or landsliding and debris flows on unstable slopes perennial ci scherwise, 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 perfonnance of the disposal units, should not be permitted in the rone of fluctuation of and impact design features for hydraulic protection of t'te water table.
the disposal units. The extent and rates of these natural processes are often difficult to predict, and sites where flydrologic analyses that may be helpful in determining such phenomena are likely should be avoided if poaible, depth to the water table and seasonal fluctuation include surface and subsurface studies. Surface studies may In addition, rites should be located in geologic and l
include geologic maps and stratigraphic cross sections, topographic settings that are naturally resistant to watu I
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-1 azard area, or wetland. Ideally, a site should be water level data from new or existing wells, lithologic located near a drainage divide and rnust be generally q logs, and bore hole geophysical logging. Regional data e ell drained, regarding the hydrologic setting can be obtained from a k
variety of U.S. Geological Survey and State publications, Regional dsta regarding the tectonic and geomorphic includmg geologic and topographic ma ps, professional settings of proposed sites can be obtained from a papers, and buP.etins. Other sources l1clude the U.S.
variety of U.S. Geological Survey and State publications, Departm mt of Agriculture and U.S. Weather Service.
including geologic and topographic maps, professional 4.19-3
parers, and Sulletins. Other sources include the U.S.
include proximity to population centeu or reserved par-Department of Agriculture and U.S. Weather Service.
cels of committed lands such as active mi'itary land,2ndian Site-specific data are likely to require field str Jy.
teservatior:s, or parks and monuments. Ilowever, other targe parecis of pt.blic land may be suitable depending 1.0 Adverse Imp 3 cts fro,n Nearby Facilities (PWagraph on conimunity impact and environmental considerations.
61.50(a)(11))
An exLmple of a candidate area suitable for further A candidate site shoald not be located near any study would be a sparsely populated area that has no facilities or actiTities that could adversely a'fect the apparent geologie limitations, has easy access to an ability of the site ta meet the performance objectives of interstate or limited access highway, and is approxi-l 10 CFR Part 61. In addition, a candidate site shotild mately in the center of major LLW genciators. 'Irans-l not be located near Nilities that could mask the site portation ir;ues that should be evaluated at this prelimi-monitoring program, nary stage include eccess, 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 pror osed disposal facility.
2.2 Step 2
- 2. SITE SELECTION PROCESS The putpose of Step 2 h to evaluate the candidate areas in order to id:nti'y potential candidate sites. Much The generic site f election process ou tlined be!ow of the local geophysical and land use data can be pmvides guidance on evaluatmg a region to identify a obtained through Federal, State, and local agencies.
site that can meet the lice'nsing requirements for near-Land use plans, zoning ordinances, U.S.
Geological rarface LLW disposal The site selection process may Survey (USGS) and State geological survey report;, 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 prave 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. liowever, the ndnimum technical whether or not development is planned or permitted in requiremer.ts of g 61.50 of 10 CFR Part 61 and the candidate areas. USGS and State geologic survey maps environmental requirements 01 10 CFR Part $1 apply and report ot' ten contain det2iled information on faults, irrespective of the site selection process employed.
flood plains, seismic events, and bedrock and sol com-potition. Also, the reviewe: 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 N U R EG/CR-2861, " Image Analysis for suitability discussion (Section C.1) is fundamental to Facility Sitirg: A Comparison of Low-and liigh-this site selection process.
Altitude Image Interpretability for Land Use/ Land Cover Mapping";' NUREG/CR-3247, " Site Characterization in-2.1 step 1 formation Using LANDSAT Satellite and Other Reraote Sensing Data: Integration of Remote Sensing Data with For the first step, the applicant should define the Geographic Information Systems";' and NU R LGlCR-region of interest, such as the compact or State in 3583, " Evaluation of l ow-Altitude Remote Sensing which the LLW site win be located. The purpose of this Techniquer for Obtaining Site Characteristic informa-first step is to climinate unfavorable areas cod identify tion," 8 for more information concerning remote sensim canrlidate areas for further consideration. The applicant applications ior site selection.)
shodd uduct a searcn of all published and open file documents on generalized land use, transportation, and 2.3 Gtep 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 evalurned for recent land use changes.
sites in order to identify the proposed site. Since the National Environmental Policy Act of 1969 (NLPA)
Some examples of areas not suitable for LLW dispos-requires an andysis of alternatives to the proposed al include areas that contain steep tcrrain, surface action isite), an er.J.nr.merdal report that contains an l
waters, wetlands, faults or fracture zones, and kars!
evaluation of the candidate sites must be developed at areas, in addition, there should be no major rechtrge the site characterization stage. Ahhough a comnlete areas at the site. Examples of significa-t land use factors environmental report is not required until a license that should eliminate areas from further consideration application is submitted (s 61.10), the NRC staff suggests that the applicant consider each category in Chapter 3
~
of Regulatory Guide 4.18 during the site screening 2The Low-level Radioactive Waste Amendments Act of 1985 process. An es tly awareness of the environmental re-provides the opportunity for States to form compacts to estab.
( uirements should provide reasonable assurance that a lish and operate regional LLW disposal facilities. Compacts are authorized to testrict the use of their disposal facilities to wastes c mplete environmental report can be submitted with a generated within the compact region, license application.
4.19-4
l l
i TABLE 1 SITE SELECTION PROCESS l
1 l
J MOST GENERAL MOST DETAILED Step 1 Step 2 Step 3 Step 4*
Category Reden of Interest Candidate Areas Candidate Sites Proposed Sites Study e.te, or A homogeneous area.
Sites that are potentially The site for which Area u n.
Sites within an area licensable.
the applicant is will contain same seeking a license.
general environmental characteristics.
Criteria General exclusionary General compact or Generalreview of compact Evaluate compact or ToBe data pertaining to State criteria, or State criteria, { 61.50, State criteria, Reviewed health and safety, areas general screer.ing and information in 61.50, Regulatory protected 1,y 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.
9 Analysis Level of Reconnaissance-level Reconnaissance re-Reconnaissance information Demonstrate fulfill-map reviews, literature view of local maps, and site visits (surface-ment of site charac-and regulation reviews.
high-level serial water samples, low-level terization require-photographs,3ter-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.
characterize tion.
requirernents.
- Step 4 involves site characterization.
O 4.19-5
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. Ilowever, uedicated park land should not be previous steps should be reevaluated. Recent low-level used unless it can be demonstrated that there weald be aerial photographs may be useful for further evaluation.
no significant environmental or community impacts.
These photographs may r,how land use and transporta-tion changes and geophysical features (fau%, 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 pl yhical inspection may include a low-and wind loads. The frequency of extreme nieteorolog-level aenal 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. Inforrnation 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 i
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 g 61.50, addition, information on the location of existing and help ensure that the performanc3 objectives of Subpart l
planned electrical distribution systems is also important C of 10 CFR Part 61 will be met, and satisfy the require-I 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-
'3 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 characterize-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-1199, " 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."
O 4.19-6
l UNITED STATES rinst etass unit l NUCLEAR REGULATORY COMMISSION POSTAGE fr Fff.S PQtD WAS HINGTON, D.C. 20555 PrnurT no. o s7 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE,8303 I
i I
O i
e:
1
r i
APPENDlX A s
GEOGFIAPHIC INFORMATION COMPUTER MAPPING in order to expedite the site selection process, it may A simplified example o t' the compositing analysis be desirable to conduct a geographic information system process is shown in Figure
- 1. In this example, the (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 arca free of three factors: shallow bedrock, surface geophysical, land use, and demographic fac: ors are water, and mature trees (1-A).
encoded to form a data base for analysis. Each factor should be pbited on separate maps that were generated from the same base map. Each map should then be The relative importance of each factor is represented
{
cncoded. It is important that the base map (such as by a weight that is assigned by the user. In tids case,
- l USGS 7.5-minute quadrangle maps) have a coordinate trees have been assigned the greatest importance and grid system (latitude 4ongitude or UTM grid) so that the shallow bedrock.the least (1-C). The seven unique encoded data may be referenced and placed into the combinations of thse factors produce scores from one data base format for computer mapping analysis, through seven; each score represents ordy one cornbina-tion ( 1-D). For example, a score of three can only Once the relevant data are encoded and geophysi: ally result from the combination of shallow bedreck and referenced according to a set of coordinates, site opti-streams The user could assign the greatest importance
,{
mization analysis may t,egin. The primary feature of a to bedrock to determine how areas of relative site cornputer mapping proFram is its capability to compos-suitability would change based on altering the impor-ite several fector 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 mimeric 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 bawed on given weighted is the result of the sum of the weights in each cell. A factors (1-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, ns white or uopstterned (1 E).
I I
O) l
\\.
1 1
4.19 7
SHALLOW h
BEDROCK STREAMS TREES M
\\
MI6N SOURCE MAPS M
/
A l
P/) /
M he144PJ DIGITIZED MAPS fh B
gg 0 $ 0
'O 2_. O
{@@iM WEIGHTS O $j o 0 2 0 O O M C
g, 2
O i O O
O O O
I4 7
4 SCORES O
3 4
D 2
1,1 T
7 COMPUTER 2
)
/
COMPOSITE E
l s
MAP
/l.l.
Figure 1. EXAMPLE OF COMPOSITING ANALYSIS I
4.19-8
- n I, dI' VALUE/ IMPACT STATEMENT
}'
A draft value/ impact statement was published with the draft regulatory guide (Task WM l~
4084) 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 foi a fee at the Commission's Public Document Room at 1717 11 Street NW., Washington,
u i
1 l
.i ' /
.'i.'!
!.N j
1 a
4 i
i l
i
.i:
l f.
i 1
i (a) 4.19-9 4
I
_ __ _ __ _ 3