Interim Baseline Radiological Investigation Report in
Support of the Upton Rare Earth Processing Plant
November 15, 2012
1
1.0
INTRODUCTION
Rare Element Resources, Inc. (RER) is proposing the construction of a rare earth element (REE)
mine and hydrometallurgical (beneficiation) processing plant, as part of its Bear Lodge Project.
The mine will be located in Crook County, Wyoming, approximately 16 kilometers (km) north
of Sundance, Wyoming. Mine ore will be physically upgraded into a pre-concentrate and shipped
to RER’s Hydrometallurgical facility near Upton (the Upton Project) in Weston County,
Wyoming. There, the pre-concentrate will be processed through leaching, neutralization and
precipitation to a final REE product. Tailings generated from beneficiation will be placed in the
Tailings Storage Facility (TSF); part of the Upton Project.
Environmental Restoration Group, Inc. (ERG) conducted a baseline radiological investigation of
the Upton Project in support of this proposed development, as requested by RER. The work
described in this report was performed in accordance with applicable requirements in
Bear
Lodge Project Upton Plant/TSF Environmental Sampling and Analysis and Quality Assurance
Plans (Draft)
(SAP [RER, 2011]).
The objective of the radiological investigation —and monitoring program by extension— is to
establish the baseline condition of the Upton Project including 1) concentrations of radionuclides
and lanthanides (cerium and lanthanum) in airborne particulates and gases (i.e. radon-
222[radon]), surface soil, surface water, and groundwater, 2) gamma exposure rates, and 3)
radon flux from soil surface to assess future potential impacts to human health and the
environment during project construction, operation, and closure. Radiological impacts incurred
during the development and operation of the Upton Project, if any, will be evaluated in part by
comparing the data sets of the baseline and operational monitoring. The monitoring of particulate
matter (particles with diameters less than 10 (PM
10
) and (PM
2.5
) 2.5 microns —unrelated to
radiological monitoring but relevant to pre-operational site conditions— is addressed in this
investigation.
It is anticipated that radon, natural uranium and thorium, radium-226, and radium-228 will be the
primary radionuclides of potential concern in assessments of exposure pathways. The
determination of baseline concentrations of radionuclides in vegetation and wildlife species was
not conducted, because RER will be able to more rapidly detect impacts to air, soil and water
resources from mine operations than from vegetation.
Phase 1 of the work, conducted in June 2012, addressed radon concentrations in air and baseline
radionuclide concentrations in soils; and associated radon flux and gamma exposure rates. This
report contains the results of baseline measurements of 1) radioactive and lanthanide (cerium and
lanthanum) particulates and 2) PM
10
and PM
2.5
concentrations in air, all obtained from June to
August 2012. Baseline radionuclide concentrations in groundwater and surface water will be
addressed and reported separately when data become available.
