Environmental Radiation

An array of thermoluminescent dosimeters (TLDs) is distributed throughout the Eastern Snake River Plain to monitor for environmental radiation (Figure 12). TLDs are changed out in May and again in November after six months in the field. The results of the TLDs exposed from May to November 2009 are discussed below.

Figure 12. TLD Locations.

Similar to the low-volume air results the environmental dosimeter locations are also divided into Boundary and Distant groupings. Boundary average exposure rates ranged from a low of 0.30 mR/day at Blue Dome to a high of 0.38 mR/day at Mud Lake. The overall Boundary average was 0.34 mR/day. The Distant group had a high of 0.40 mR/day at Rexburg and a low of 0.29 mR/day at the Dubois location. The overall average Distant value was 0.35 mR/day. There was no statistical difference between Boundary and Distant locations and all values are consistent with past readings. All results are listed in Appendix C, Table C 12.