Minn. R. agency 144, ch. 4731, WELL LOGGING, pt. 4731.7060

Current through Register Vol. 49, No. 29, 2025

Part 4731.7060 - RADIATION DETECTION INSTRUMENTS

Subpart 1.Required survey instruments.

A licensee must keep a calibrated and operable radiation survey instrument capable of detecting beta and gamma radiation at each field station and temporary job site to make the radiation surveys required under parts 4731.2000 to 4731.2950 and 4731.7000 to 4731.7280. The radiation survey instrument must be capable of measuring 0.1 millirem (0.001 mSv) per hour through at least 50 millirems (0.5 mSv) per hour.

Subp. 2.Availability.

A licensee must have available additional calibrated and operable radiation detection instruments sensitive enough to detect the low radiation and contamination levels that could be encountered if a sealed source ruptured. A licensee may own the instruments or may have a procedure to obtain them quickly from a second party.

Subp. 3.Required calibrations.

A licensee must have each radiation survey instrument required under subpart 1 calibrated:

A. at intervals not to exceed six months and after instrument servicing;

B. for linear scale instruments, at two points located approximately one-third and two-thirds of full-scale on each scale; for logarithmic scale instruments, at midrange of each decade and at two points of at least one decade; and for digital instruments, at appropriate points; and

C. so that an accuracy within plus or minus 20 percent of the calibration standard can be demonstrated on each scale.

Subp. 4.Record retention.

A licensee must retain calibration records for three years after the date of calibration for inspection by the commissioner.

Minn. R. agency 144, ch. 4731, WELL LOGGING, pt. 4731.7060

29 SR 755

Statutory Authority: MS s 144.1202; 144.1203