United States
Environmental Protection
Agency
Office of Radiation and Indoor
Air (6603J)
Office of Solid Waste and
Emergency Response (5101)
9355.0-51 FS
EPA 540-F-94-023
PB 94-963307
January 1996
Fact Sheet: Environmental
Characteristics of EPA, NRC,
and DOE Sites Contaminated
with Radioactive Substances
Quick Reference Fact Sheet
BACKGROUND
Mathematical models that characterize the source,
transport, fate, and effects of hazardous and ra-
dioactive materials are used to help determine
cleanup priorities and select remedial options at
sites contaminated with radioactive materials.
A joint Interagency Environmental Pathway Mod-
eling Working Group has been established by the
EPA Offices of Radiation and Indoor Air (ORIA)
and Solid Waste and Emergency Response
(OSWER), the DOE Office of Environmental Res-
toration and Waste Management (EM), and the
Nuclear Regulatory Commission (NRC) Office of
Nuclear Material Safety and Safeguards (NMSS).
The purpose of the Working Group is to promote
the more appropriate and consistent use of math-
ematical environmental models in the remedia-
tion and restoration of sites contaminated by
radioactive substances.
The Working Group has published reports in-
tended to be used by technical staff responsible
for identifying and implementing flow and trans-
port models to support cleanup decisions at haz-
ardous and radioactive waste sites. This fact
sheet is one of a series of fact sheets that summa-
rize the Working Group's reports.
REPORT
Purpose
This report describes the range of site character-
istics at sites contaminated with radioactive ma-
terials. The report briefly summarizes the overall
waste types, waste forms, and site characteristics
of Superfund sites that are contaminated with
radioactive materials and sites in the NRC's Site
Decommissioning Management Program
(SDMP).
Contents of Report
The report includes an introduction and a brief
overview of the statutory and regulatory programs
administered by EPA and NRC to remediate
abandoned hazardous waste sites. It provides an
overview of site, contaminant, media, and
receptor characteristics, a discussion of the data,
and conclusions.
The full report describes 45 EPA and 38 NRC sites
along with their location, administrative data,
and NPL history. It lists the radioactive isotopes
and the media contaminated at each site, pro-
vides data on the radiochemical and biological
properties of identified isotopes, and summa-
rizes the volume, concentration and physical form
of the wastes. The environmental and geohydro-
logic characteristics of the site and characteristics
surrounding the site are also noted.
Method
Data for this report were compiled from various
federal and non-federal databases and pub-
lications. The emphasis is on the 45 EPA sites
containing radioactive materials. Fourteen of
these are owned or operated by DOE. For com-
pleteness, 38 NRC sites also are reviewed, but the
data for the NRC sites may be sparse in some
cases. A total of 83 sites are included in the sum-
mary of data. For each site, the following informa-
tion is provided:
• List of sites containing radioactive waste
materials.
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• List of sites containing radioactive waste
materials.
• Types of radionuclides found at each site.
• Description of the physical forms of the
waste.
• Description of the physical characteristics of
the site itself.
• Overview of the demographic characteristics
of the region surrounding the site.
Site characteristics were chosen based on useful-
ness in the selection of particular models. The
implications for modeling contaminant mobility
at these sites are discussed.
Findings
Sites are broadly characterized (Figure 1) based on
their historical use into nine general types:
• Scrap Metal Recovery.
• Fuel Fabrication and Processing.
• Commercial Manufacturing.
• Research Facilities.
• Low-Level Waste Disposal.
• Commercial Landfills.
• Radium and Thorium Sites.
• Mill Tailings, Processing, and Disposal Sites.
• Defense Plants (all DOE facilities).
The sites described in this report differ greatly in
the quality and quantity of information available
for characterization. One of the most common
areas where data are scant is in the characteriza-
tion of the source of radiochemical contamina-
tion. The absence of high quality data at a site
may influence the choice and operation of envi-
ronmental pathway models.
A total of 30 radionuclides were identified at the
sites, with uranium, thorium, radium, and pluto-
nium found most frequently (Figure 2). For these
dominant isotopes, radioactive daughters may
be created that have different chemical, physical,
and biological properties from their parents. The
principal health hazards at 25 of the 45 radioac-
tively contaminated NPL sites are related to ra-
dioactive materials; organic chemicals present
the major health hazard at the remaining NPL
sites.
The sites cover all the major geologic terrains of
the U.S. However, many of the NPL sites occur in
either karst or volcanic terrains, where open frac-
ture flow may be important. Although it was
originally believed that ground water would be
the dominant medium of concern, all exposure
pathways are present in roughly equal amounts
(Figure 3).
Sources of radioactive wastes can be classified as
either a point source (a single location that can be
precisely identified) or an area source {occurring
Figure 1. EPA and NRC Radioactively Contaminated Sites
Scrap Metal Recovery
Fuel
Commercial Manufacturing
Research Facilities
Low-Level Waste Disposal
Commercial Landfills
Radium & Thorium Sites
Mill Wastes
Defense Plants
0
D NRC
• EPA
5 10 15
number of sites
20
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Figure 2. Isotope Distribution at EPA and NRC Sites
Other
Technetium
Cobalt
Cesium
Strontium
Tritium
Plutonium
Thorium
Radon
Radium
Uranium
D NRC
• EPA
10
20 30 40
number of sites
50 60
over a measurable area that may be difficult to
identify). Only about 25% of the radioactive ma-
terials at NPL and SDMP sites can be considered
to be point sources. The form of disposal varies
widely and affects the type and rate of release of
radioactive materials to the environment. Disposal
practices included water-based, container-based,
and ground-based disposal (Figure 4).
Simultaneous contamination of multiple media
is the rule rather than the exception. In addition,
Figure 3. Exposure Pathways at
Radioactively Contaminated NPL Sites
Surface Water (26 sites)
Ground Water (37 sites)
Air (29 sites)
Soil (37 sites)
the contaminated media frequently is not homo-
geneous and the contaminants are found in di-
verse forms (gases, solutes, solids).
While the physical and chemical processes that
control the concentration of a given substance
may be complex, it may be possible at some sites
to describe contaminant behavior with relatively
simple approaches, such as using a sorption coef-
ficient. However, this simple approach may not
be valid for radioisotopes, such as uranium, that
exhibit complex geochemical behavior strongly
affecting contaminant mobility.
At present, there are few reliable estimates of the
population potentially impacted now or in the
future from contamination at these sites. Almost
all sites are underlain by both confined and un-
confined aquifers. Ground water at 33 of the sites
is used for drinking water, and four sites are
located above designated sole source aquifers.
Approximately 70 percent of both NPL and SDMP
sites are located in rural or suburban areas. Only
seven NPL sites are in urban areas, and all of
these are radium sites. Even under circumstances
where two sites have the same or very similar
environmental characteristics, there may be a
need to employ different models where receptor
characteristics exert an influence on the approach
taken in modeling a given pathway for a site.
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Figure 4. Source Characterization at EPA and NRC Sites
D NRC
• EPA
5 10 15 20 25 30 35 40
number of sites
The 83 NPL and NRC sites reviewed here pose a
wide range of challenges to the efficient use of
models in environmental and health risk
assessment. The findings imply that a mix of
models capable of addressing the widest possible
range of environmental characteristics may be
needed. In addition, model strengths and weak-
nesses must be carefully examined within the
context of the characteristics at any given site.
CONTACTS
If you have any questions or want a copy of this
or other reports, contact:
Beverly Irla, Project Manager
Office of Radiation and Indoor Air (6603J)
U.S. Environmental Protection Agency
401 M St., S.W.
Washington, DC 20460
(202) 233-9396
Paul Beam
U.S. Department of Energy
Office of Environmental Restoration
EM-451/CLOV BLDG
19901 Germantown Road
Germantown, MD 20874-1290
(301) 903-8133
Sam Nalluswami
U.S. Nuclear Regulatory Commission
Office of Nuclear Material Safety and Safeguards
(T-7F27)
Washington, DC 20555
(301) 415-6694
Superfund Hotline
U.S. Environmental Protection Agency
Office of Solid Waste and Emergency Response
401 M Street, SW (5203G)
Washington, DC 20460
(800) 424-9346
REPORTS
Computer Models Used to Support Cleanup Decision-
Making at Hazardous and Radioactive Waste Sites,
EPA 402-R-93-005, March 1993. Also available
from the National Technical Information Center
(NTIS), (703) 487-4650, PB93-183333/XAB.
Environmental Characteristics of EPA, NRC, and
DOE Sites Contaminated with Radioactive Sub-
stances, EPA 402-R-93-011, March 1993. NTIS,PB93-
185551/XAB.
Environmental Pathway Models — Ground-Water
Modelling in Support of Remedial Decision-Making
at Sites Contaminated with Radioactive Material, EPA
402-R-93-009, March 1993. NTIS,PB93-196657/XAB.
Technical Guide to Ground-Water Model Selection at
Sites Contaminated with Radioactive Substances, EPA
402-R-94-012, September 1994. NTIS, PB94-
205804/XAB.
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