Interim Baseline Radiological Investigation Report in
Support of the Upton Rare Earth Processing Plant
November 15, 2012
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 along transects,
spaced at 100 meter (m), spanning the Upton Project;
•
co-located exposure and integrated gamma count rate measurements;
•
deployment of passive radon track etch detectors at nine biased locations;
•
collection of surface soil samples at 16 randomly selected locations;
•
radon flux measurements co-located at five of the soil sample locations; and
•
collection of particulate concentrations (long-lived radionuclides, stable rare earth
elements, and PM
10
and PM
2.5
fractions of particulate matter) in air at four Upton air
monitoring stations (UAMS).
Table 2.1 summarizes the scope of the field program and the following section identifies
deviations from the SAP.
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 Upton Project-wide scanning gamma
count rates; and predicted exposure rates and/or radium-226 concentrations will
appear similar. Of these, we have chosen to display only the predicted exposure
rates, because they are the most directly meaningful to worker and public safety.
