The U.S. Department of Energy (DOE) supports the development, standardization, and maintenance of calibration facilities for environmental radiation sensors. Radiation standards at the facilities are primarily used to calibrate portable surface gamma-ray survey meters and borehole logging instruments used for uranium and other mineral exploration and remedial action measurements. Standards for calibrating borehole fission neutron devices are also available, but are used infrequently.

Radiation standards are constructed of concrete with elevated, uniform concentrations of naturally occurring potassium, uranium, and/or thorium. Pad standards have large, flat surfaces suitable for calibration measurements with portable surface survey meters. Borehole standards are large concrete cylinders with 4.5-inch-diameter test holes.

Calibration facilities are located at the DOE Site and Grand Junction Regional Airport in Grand Junction, Colorado; Grants, New Mexico; Casper, Wyoming; and George West, Texas; An additional calibration facility located at the DOE Hanford Site near Richland, Washington, is managed by the DOE Office of Environmental Management.

Parties interested in using these facilities may call DOE at (970) 248-6000 for more
information and to request access. Visitors who are foreign nationals must complete and submit the Request for Foreign National Unclassified Visit or Assignment (LMF 142.3) form 30 days before accessing the facilities.