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Air Samplers

Atmospheric levels of naturally-occurring radionuclides such as the decay products of uranium and thorium, fallout from nuclear detonations and/or accidents, and radioactivity released from Idaho National Laboratory (INL) Site facilities are monitored with a network of low-volume air samplers. Sampling involves the weekly collection of filters from six locations distant from the INL Site as background, seven locations at or near the INL Site boundary, and three locations on the INL Site. The purposes of the low-volume air samplers are to monitor radioactivity levels on the INL Site and to provide correlation of data provided by the INL contractor Site Environmental Surveillance Program. Two quality assurance (QA) replicate samplers are also maintained and rotated between sampling locations.

Low Volume Air Samplers

Low-volume air sampling locations

The low-volume air samplers consist of a dual membrane filter and cartridge holder, a vacuum gauge, a Gast rotary vacuum pump with a constant air flow regulator that permits regulated air flow to the sampler during long periods of unattended operation, and a Rockwell (Models S‑200 or S‑275) temperature-compensated flowmeter. These samplers maintain an average air flow of approximately 1 to 2 cubic feet per minute (cfm) (28 to 56 liters per minute [Lpm]) through a set of two filters: a non‑woven, nylon-backed polyvinyl acrylonitrile support membrane prefilter (Gelman Versapor‑1200) followed by an activated charcoal cartridge (SAIC/RADeco BG-300). The membrane prefilter has a pore size of 1.2 µm and an efficiency of greater than 99 percent for particles greater than 0.3 µm in diameter. The filter also retains a high percentage of smaller particles. The BG-300 has more than 99 percent retention efficiency for methyl iodide at pump flow rates of 1 cfm and about 95 percent retention efficiency at 2 cfm.

In order to be considered a valid air sample, an air volume of at least 7000 ft3 per week (about 200 m3) must be drawn through the filters. Average weekly air volumes range from about 10,000 ft3 (283 m3) to 18,000 ft3 (510 m3).


43.62000 -113.30000

Atomic City

43.44000 -112.82000


Blackfoot NOAA Air (Mountain View Middle School)
43.112317 -112.195538

Blue Dome

44.07000 -112.84000

Craters of the Moon

3.46000 -113.56000


44.18000 -112.23000

Experimental Field Station (INL)

43.60000 -112.91000

FAA Tower

43.55000 -11254000


43.78000 -112.98000

Idaho Falls

43.510000 -112.060000

Jackson, WY

43.48000 -110.76000

Main Gate INL

43.51000 -112.9000


43.62000 -113.30000

Mud Lake

43.44000 -112.82000

Sugar City


Van Buren Gate INL

43.53000 -11298000
Checking monitors at Sugar City

Checking monitors at Sugar City

©2020 ESER Program.