Interim Baseline Radiological Investigation Report
November 14, 2012
Bear Lodge Project, for Rare Element Resources, Inc.
Rev.1
4
2.0
BASELINE FIELD INVESTIGATION SUMMARY AND SCOPE
2.1 Overall Scope of Project
The baseline radiological field investigation consisted of a:
•
Global Positioning System (GPS)-based gamma survey conducted at 500 meter (m)
transects spanning the Project;
•
co-located exposure and integrated gamma count rate measurements;
•
collection of surface soil samples at 29 randomly selected and three biased location;
and
•
radon flux measurements collocated at five soil sample locations .
Additional work addressed in this version (Revision 1) consists of:
•
Collection of ambient radon concentrations at up to nine locations over four periods,
from November 2011 to October 2012;
•
Collection of airborne radioactive particulate concentrations at four locations, from
November 2011 to July 2012; and.
•
Ambient gamma exposure rate measurements at four locations, from November 2011
to August 2012.
Table 2.1 summarizes the scope of the field program and identifies any deviations from the SAP,
as discussed below.
To assist the reader, it is important to note the following issues that are relevant to the scope of
work:
Differences in scanning and integrated gamma-ray measurements.
Scanning
measurements are those recorded during the walking survey, with the
ratemeter/scaler in ratemeter mode. Count rate measurements are recorded every
second in this method and stored individually, each with its own geoposition.
Integrated measurements, on the other hand, are recorded, in the case of this
investigation, at one location for one minute, with the ratemeter/scaler in scaler
(integrating) mode. In this mode, the detector integrates the number of
interactions (counts) within the one minute counting period. Both types of
measurements are reported as counts per minute (cpm).
Presentation of the scanning data.
Project-wide exposure rates and radium-226
concentrations were predicted from linear correlations between integrated
gamma count rates and co-located exposure rate measurements and soil samples,
respectively. Because the predicted values are multiplicative and additive factors
of gamma count rates, figures depicting Project-wide scanning gamma count
rates; and predicted exposure rates and/or Ra-226 concentrations will appear
