Minn. R. agency 144, ch. 4731, STANDARDS FOR PROTECTION AGAINST RADIATION, pt. 4731.2520

Current through Register Vol. 49, No. 23, December 2, 2024

Part 4731.2520 - DETERMINATION OF PRIOR OCCUPATIONAL DOSE

Subpart 1.Determining occupational dose.

For each individual who is likely to receive in a year an occupational dose requiring monitoring under part 4731.2210, a licensee must determine the occupational radiation dose received during the current year.

Subp. 2.Planned special exposures.

Before permitting an individual to participate in a planned special exposure, a licensee must determine:

A. the internal and external doses from all previous planned special exposures; and

B. all doses in excess of the limits, including doses received during accidents and emergencies, received during the lifetime of the individual.

Subp. 3.Compliance methods.

In complying with the requirements of subparts 1 and 2, a licensee may:

A. accept, as a record of the occupational dose that the individual received during the current year, a written signed statement from the individual, or from the individual's most recent employer for work involving radiation exposure, that discloses the nature and the amount of any occupational dose that the individual may have received during the current year;

B. accept, as the record of cumulative radiation dose, an up-to-date cumulative occupational exposure form as described under subpart 4, or its equivalent, signed by the individual and countersigned by an appropriate official of the most recent employer for work involving radiation exposure, or the individual's current employer if the individual is not employed by the licensee; and

C. obtain reports of the individual's dose equivalent from the most recent employer for work involving radiation exposure, or the individual's current employer if the individual is not employed by the licensee, by telephone, telegram, electronic media, or letter. The licensee must request a written verification of the dose data if the authenticity of the transmitted report cannot be established.

Subp. 4.Record keeping.

A licensee must record the exposure history of each individual, as required by subpart 1 or 2, on a cumulative occupational exposure record form prescribed by the commissioner, or other clear and legible record including all of the information required by the commissioner's form. The form or record must show each period in which the individual received occupational exposure to radiation or radioactive material and must be signed by the individual who received the exposure. For each period for which the licensee obtains reports, the licensee must use the dose shown in the report in preparing the exposure record. For any period in which the licensee does not obtain a report, the licensee must place a notation on the record indicating the periods and time for which data are not available.

Subp. 5.Assumptions.

If a licensee is unable to obtain a complete record of an individual's current and previously accumulated occupational dose, the licensee must assume:

A. in establishing administrative controls under part 4731.2020, subpart 6, for the current year, that the allowable dose limit for the individual is reduced by 1.25 rems (12.5 mSv) for each quarter for which records are unavailable and the individual was engaged in activities that could have resulted in occupational radiation exposure; and

B. that the individual is not available for planned special exposures.

Subp. 6.Record retention.

A licensee must retain the records under subpart 4 until the commissioner terminates each pertinent license requiring the records. A licensee must retain records used in preparing the cumulative occupational exposure record form, or its equivalent, for three years after the record was made. This includes records required under the standards for protection against radiation in effect prior to January 1, 1994.

Minn. R. agency 144, ch. 4731, STANDARDS FOR PROTECTION AGAINST RADIATION, pt. 4731.2520

29 SR 755; 33 SR 1440; 36 SR 74

Statutory Authority: MS s 144.1202; 144.1203