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POWERTECh IUSA) INC. <br />Addendum 1- Notice of Intent for a Gamma Survey <br />May-2010 <br />1.0 Purpose of Activity <br />The gamma survey data will supplement existing gamma survey data collected in the first phase of the <br />baseline characterization effort (conducted in 2007-2008) regarding radiological parameters required by <br />Federal and State agencies for submittal of a source materials license application. <br />2.0 Description of Gamma-Ray Survey Investigation <br />A GPS-based gamma-ray survey (gamma survey) will be conducted across the site. Currently the site has <br />been divided into three areas: well fields, processing areas (central processing and satellite facility areas) <br />and the remaining permit area. The gamma survey in the well field and processing areas will be <br />conducted along transects spaced at 100 meters. The gamma survey in the remaining permit areas will <br />be conducted along transects spaced at 300 meters. <br />If additional data are needed to delineate the limits of areas with potentially elevated gamma-ray <br />responses, spacing adjustments will be made in the field to provide for delineation of the anomalous <br />area(s). <br />3.0 Description of Methods and Equipment Employed for Gamma-Ray Survey Investigation <br />Instrumentation utilized during the survey include: a Ludlum Model 44-10 (or equivalent) 2-inch by 2- <br />inch sodium iodide high energy gamma-radiation detectors, each coupled to a Ludlum Model 2221 <br />ratemeter/scaler that is, in turn, coupled to a Trimble ProXRS GPS Unit with a TSCe datalogger. The <br />detection systems will be matched and calibrated to National Institute of Standards and Technology- <br />traceable cesium-137 check sources and function-checked daily, prior to and after the work day. <br />All areas will be surveyed at a speed of approximately 0.6 meter/second, with the detectors held at <br />approximately 18 inches above ground surface. Gamma-ray count rates will be recorded every second, <br />with individual count rates tagged with Colorado State Plane location coordinates. Field personnel will <br />drive transects using all terrain vehicles (ATVs) or walk, carrying the instrumentation in backpacks. <br />Exposure Rate Measurements: <br />Direct exposure rate measurements will be made using a High Pressurized Ion Chamber (HPIC) in areas <br />encompassing the expected range of exposure rates at the site. The HPIC data will be correlated to <br />gamma-radiation count rates, using the same geometry and detection systems used in the GPS-based <br />gamma-ray survey. The number and location of the HPIC correlation measurements will be based on <br />the expected range of exposure rates as determined by existing and collected gamma survey data. Using <br />this correlation, the count-rate data from the gamma survey will be converted to predicted exposure <br />rates. <br />Commencement Date: <br />The field work will commence as soon as practicable following appropriate state approvals. The survey <br />is projected to last five days using two field personnel and one Powertech representative. <br />Addendum 1