10 CFR 835.401 – General requirements
(a) Monitoring of individuals and areas shall be performed to:
(1) Demonstrate compliance with the regulations in this part;
(2) Document radiological conditions;
(3) Detect changes in radiological conditions;
(4) Detect the gradual buildup of radioactive material;
(5) Verify the effectiveness of engineered and administrative controls in containing radioactive material and reducing radiation exposure; and
(6) Identify and control potential sources of individual exposure to radiation and/or radioactive material.
(b) Instruments and equipment used for monitoring shall be:
(1) Periodically maintained and calibrated on an established frequency;
(2) Appropriate for the type(s), levels, and energies of the radiation(s) encountered;
(3) Appropriate for existing environmental conditions; and
(4) Routinely tested for operability.