An array of optically stimulated luminescent dosimeters (OSLDs) is distributed throughout the Eastern Snake River Plain to monitor for environmental radiation (Figure 14). Two OSLDs are in place at each location. OSLDs are changed out at the beginning of May and again at the beginning of November after six months in the field.
OSLD results from the second quarter are displayed in Appendix C, Table C-11. Results are presented in dose units of millirem (mrem). The Boundary OSLD values ranged from 51.65 mrem at Blue Dome to 64.6 mrem at Mud Lake, with an overall average of 59.04 mrem. This equates to an average dose of 0.32 mrem per day. Distant results varied from 52.7 mrem at Dubois to 74.2 mrem at Sugar City. The Distant average was 59.72 mrem, which also equates to 0.33 mrem per day. Results vary between sampling locations based on the geologic composition of the soils in the vicinity of the OSLD and the elevation of the station.
Radiation has always been a part of the natural environment in the form of cosmic radiation, cosmogenic radionuclides [carbon-14 (14C), Beryllium-7 (7Be), and tritium (3H)], and naturally occurring radionuclides, such as potassium-40 (40K), and the thorium, uranium, and actinium series radionuclides which have very long half lives. Additionally, human-made radionuclides were distributed throughout the world beginning in the early 1940s. Atmospheric testing of nuclear weapons from 1945 through 1980 and nuclear power plant accidents, such as the Chernobyl accident in the former Soviet Union during 1986, have resulted in fallout of detectable radionuclides around the world. This natural and manmade global fallout radioactivity is referred to as background radiation. MORE
The primary concern regarding radioactivity is the amount of energy deposited by particles or gamma radiation to the surrounding environment. It is possible that the energy from radiation may damage living tissue. When radiation interacts with the atoms of a given substance, it can alter the number of electrons associated with those atoms (usually removing orbital electrons). This is called ionization. MORE