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Preliminary survey coverage is shown in Plates 1 and 2. Surveys of the parcels was conducted <br />by north-south transects spaced no farther than 0.1 miles apart. Transects were modified as <br />necessitated by topography and field conditions. Higher density measurements were clustered <br />near the planned central processing site, with more dispersed measurements at greater distances <br />from the mill. <br />The equipment used to perform the gamma surveys include a Ludlum Model 2221 portable <br />scaler rate meter, with probe type Ludlum Model 44-10 sodium iodide (NaI) gamma scintillator. <br />This equipment was coupled with GPS equipment: Trimble PRO XRS Receiver and TSC1 Data <br />Logger. The TSC1 Data Logger is connected to the Model 2221 and the GPS receiver. This <br />assembly records two-second integrated count rates and couples with GPS coordinates. For the <br />purpose of covering large outdoor areas, the equipment was mounted to an All-Terrain Vehicle <br />with the 44-10 probe affixed to the front at a height of approximately two feet above the ground. <br />No analysis is performed for the gamma survey. <br />2.8 Thermo-Luminescent Dosimeter Program <br />To supplement the real time gamma survey program, a thermo-luminescent dosimeter (TLD) <br />program was implemented to estimate average direct radiation (gamma) exposure rates over <br />extended time periods. It provides continuous integrated gamma exposure data with statistically <br />valid "average" exposure rates over an extended period of time at locations judged to be <br />"strategically important." It also supports and validates data from the "real time" gamma field <br />survey program. TLDs have been part of background radiometric programs for many uranium <br />mine, mill, and processing sites for over 30 years. The program utilized the InLight® <br />Environmental/Low Level dosimeter manufactured by Landaur, Inc., Glenwood, Illinois <br />(Landaur). The dosimeter fully meets ANSI N545-1977, NRC Regulatory Guide 4.13, and <br />Health Physics Society Draft Standard N 13.29 for environmental dosimetry. <br />The 10 TLD locations are shown in Plates 1 and 2. As shown, five are located at air particulate <br />stations and the remaining five were located in areas where initial gamma readings were either at <br />the high end or low end of the range of site readings. The locations also considered security and <br />preservation - cows are known to be attracted to the TLD sites and the TLD's have been used for <br />unlawful target practice. The TLDs are replaced with new, "unexposed" units after an <br />approximate 90-day exposure period. All TLDs were shipped via the U.S. Postal Service with <br />proper chain of custody. Exposed TLDs were sent to Landaur for analyses for integrated <br />exposure in units of x, gamma, and beta radiation to a sensitivity of 0.1 mrem. <br />April 2009 12 Site Characterization Plan