Occupational Dose Evaluation in Support of the Development of the
October, 2012
Rare Element Resources, Inc. Bear Lodge Project
18
3.4.5
International Guidance
The ICRP recommends in ICRP Report 75
General Principles for the Radiation Protection of
Workers
(ICRP 1997) that the limits of occupational exposures to workers handling TENORM
be consistent with recommendations of ICRP Report 60
Recommendations of the International
Commission on Radiological Protection
(ICRP, 1991). The adult dose limits in ICRP Report 60
are as follows:
An effective dose of 2 rem y
-1
averaged over a 5 y period with a 5 rem maximum in any
single y
An equivalent dose to the lens of the eye of 15 rem y
-1
An equivalent dose to the skin and hands and feet of 50 rem y
-1
The ICRP also incorporates the “optimization” component of radiation protection principles,
which is keeping radiation doses to levels that are ALARA. The ICRP published an update on
radiation protection in 2007, but the recommended limits in ICRP Report 60 did not change.
The IAEA published occupational radiation protection guidelines in Report No GSR Part 3
(Interim)
Radiation Protection and Safety of Radiation Sources: International Basic Safety
Standards, Interim Edition
(IAEA, 2007). The IAEA recommends the following dose limits for
adult workers, for planned exposures to radiation:
An effective dose of 2 rem y
-1
averaged over five consecutive, and of 5 rem in any single
year;
An equivalent dose to the lens of the eye of 2 rem y
-1
averaged over 5 consecutive years
and of 5 rem in any single year;
An equivalent dose to the extremities (hands and feet) or the skin of 50 rem in a year.
These recommended limits are consistent with those in ICRP Report 60, with the exception of
the 2 rem y
-1
equivalent dose limit to the lens of the eye. This is more restrictive than the ICRP
recommendation. The IAEA also incorporates the “optimization” component of radiation
protection principles which is keeping radiation doses to level that are ALARA.
3.5
Regulations on the Transport of Radioactive Material
Transportation of radioactive materials within the U.S. is regulated by the U.S. Department of
Transportation (DOT). These regulations are in 49 CFR 173, Subpart I. The requirements in
Subpart I are specific to radioactive materials as defined therein as follows:
Radioactive material
means any material containing radionuclides where both the
activity concentration and the total activity in the consignment exceed the values
specified in the table in §173.436 or values derived according to the instructions
in §173.433.
