Section 39.65 - Personnel monitoring(a) The licensee may not permit an individual to act as a logging supervisor or logging assistant unless that person wears a personnel dosimeter at all times during the handling of licensed radioactive materials. Each personnel dosimeter must be assigned to and worn by only one individual. Film badges must be replaced at least monthly and all other personnel dosimeters that require replacement must be replaced at least quarterly. All personnel dosimeters must be evaluated at least quarterly or promptly after replacement, whichever is more frequent.(b) The licensee shall provide bioassay services to individuals using licensed materials in subsurface tracer studies if required by the license.(c) The licensee shall retain records of personnel dosimeters required by paragraph (a) of this section and bioassay results for inspection until the Commission authorizes disposition of the records.52 FR 8234, Mar. 17, 1987, as amended at 65 FR 63752 , Oct. 24, 2000; 85 FR 15352 , Mar. 18, 2020