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INL Site

Executive Summary

None of the radionuclides detected in samples collected during the fourth quarter of 2017 could be directly linked with INL Site activities.  Levels of detected radionuclides were no different than values measured at other locations across the western United States. All detected radionuclide concentrations were well below standards set by the U.S. Department of Energy (DOE) and regulatory standards established by the U.S. Environmental Protection Agency (EPA) for protection of the public. 

This report for the fourth quarter of 2017 contains results from the Environmental Surveillance, Education, and Research (ESER) Program’s monitoring of the Department of Energy’s Idaho National Laboratory (INL) Site’s offsite environment, October 1 through December 31, 2017. All sample types (media) and the sampling schedule followed during 2017 are listed in Appendix A. This report contains results for the following sample types:

    • Air, including particulate air filters, charcoal cartridges, and atmospheric moisture
    • Precipitation
    • Drinking and surface water
    • Milk
    • Potatoes
    • Large Game Animals
    • Waterfowl
    • Environmental radiation measurements using optically-stimulated luminescence dosimeters

Table E-1 Summary of results for the Fourth Quarter of 2017.


Sample Type





Gross alpha, gross beta

There were some statistically significant differences in monthly and quarterly gross alpha and gross beta concentrations measured at Distant, Boundary, and INL Site sampling locations. Several differences were noted in weekly results but no pattern was discernible. No result exceeded results for the past ten years or the DCS for gross alpha or gross beta activity in air.

Quarterly Composite

Gamma-emitting radionuclides, 90Sr, actinides (americium and plutonium)

No human-made gamma-emitting radionuclides, 90Sr, 238Pu, 239/249Pu or 241Am were detected above 3s uncertainty in any of the fourth quarter composites.

Charcoal Cartridge


Iodine-131 was not detected in any of the 26 batches counted during the quarter.

Atmospheric Moisture



Seven of the 12 sample results showed tritium concentrations greater than the 3s uncertainty during the quarter. No sample result exceeded results for the past ten years or the DCS for tritium in air.




Twenty samples were collected. Eight of the results were greater than the 3s uncertainty. All results were within the range previously measured in the past ten years and were consistent with those reported across the region by the Environmental Protection Agency.

Drinking and Surface Water


Gross alpha, gross beta, tritium

Gross alpha activity was not detected in any drinking or surface water sample. Gross beta activity was detected in five of the eight drinking water and all four surface water samples. Values were consistent with natural levels of gross beta radioactivity in the Snake River Plain Aquifer. Tritium was detected in one drinking water and two surface water samples. Results were similar to previous results and those in precipitation.

Surface Water (Big Lost River)


Gross alpha, gross beta, tritium, gamma-emitting radionuclides

Gross alpha and gross beta activity was detected in some samples similar to previous results. Tritium was also detected in some samples. Concentrations were similar to those found in atmospheric moisture and precipitation samples and were consistent with previous years. No gramma-emitting radionuclides were detected.



Iodine-131, other gamma-emitting radionuclides, 90Sr. tritium

Milk was collected at seven locations. No Iodine-131 or other human-made gamma emitting radionuclides were detected. Strontium-90 was detected in two of six samples analyzed. All were approximately the same concentration (including the offsite control sample from Colorado) indicating the INL Site is not the source. Tritium was detected in one sample at levels similar to previous measurements and to precipitation.



Gamma-emitting radionuclides and 90Sr

No human-made gamma-emitting radionuclides were found. Strontium-90 was detected in one sample just above the detection limit.

Large Game Animals


Gamma-emitting radionuclides

No human-made gamma-emitting radionuclides were found in the muscle tissues of a mule deer sampled in the fourth quarter.



Gamma-emitting radionuclides, 90Sr, actinides (americium and plutonium)

Six human-made radionuclides were detected in some ducks at levels suggesting that they were ingested from ATR effluent ponds. The maximum dose from eating a contaminated duck was estimated to be 0.046 mrem/year.

Environmental Radiation

Optically Stimulated Luminescent Dosimeters (OSLDs)

Ambient Dose

Very similar measurements were observed at Distant locations and Boundary locations. Variation between locations appears to be a function of altitude and geologic composition of soils.

Radiation in Our World

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

Radiation Exposure and Dose

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