Environmental Radiation

The ESER and its predecessors have placed an array of thermoluminescent dosimeters (TLDs) distributed throughout the Eastern Snake River Plain (Figure 14) to measure the amount of radiation in the environment.  The TLDs are changed in May and again in November.  The results of the November sampling (the period May 2001 through November 2001) are discussed below.

  Dosimeter locations are divided into Boundary and Distant groupings.  Total exposure for the period for each distant group is listed in Table 4.  The average exposure rate for locations in the Boundary group ranged from a low of 0.32 mR/day at Birch Creek to a high of 0.40 mR/day at Mud Lake.  The overall average was 0.35 mR/day.  The Distant set had a high of 0.43 mR/day at Rexburg and a low of 0.33 mR/day at Jackson, Wyoming.  The overall average Distant value was 0.36 mR/day.  There was no statistical difference between Boundary and Distant locations.  Furthermore, all values are in line with past readings.  Table C-14 shows the results for each location.

TABLE 3.             TLD exposures from May 2001 to November 2001.