Occupational Dose Evaluation in Support of the Development of the
October, 2012
Rare Element Resources, Inc. Bear Lodge Project
17
TENORM does not include radiation emanating from or radioactivity present in
ores, rocks, soils and materials containing uranium and thorium subject to
regulations under the Atomic energy Act, as amended” (ANSI, 2009).
Given the above definition of TENORM, all material containing thorium or uranium generated at
the BLP would be considered TENORM unless it is regulated by the NRC as source material.
ANSI-N13-53-2009 provides the following recommendations for occupational radiation
protection:
“Occupational doses received from TENORM shall be controlled under normally
encountered conditions such that the following limits shall not be exceeded:
-
annual dose limit of 100 mrem above background
-
annual average radon-222 concentrations in air of 4 pCi/L”
When work conditions are likely to result in doses or exposure to radon in excess of the above
limits under routine conditions, a formal occupational radiation protection and monitoring
program and use of appropriate engineering controls is warranted. In such cases the occupational
dose limits established for radiation workers in state or federal regulations, such as OSHA or
MSHA shall apply.
3.4.2
National Council on Radiation Protection and Measurement (NCRP)
NCRP No. 116
Limitation of Exposure to Ionizing Radiation
provides recommendations for
occupational dose limits that are essentially identical to the limits the NRC currently has in place
(NCRP, 1993). There have been no revisions to these recommendations.
3.4.3
National Academy of Science-National Research Council (NAS-NRC)
At the request of the U.S. Environmental Protection Agency (EPA), the NAS-NRC developed an
evaluation of guidelines for exposure to NORM (NAS-NRC, 1999). It concluded that
occupational exposure to NORM is no different than occupational exposure to other types or
radiation, including material licensed by the NRC, and that differences between agencies in
regulating exposure to NORM have no scientific or technical basis and are largely based on
differences in policies for risk management. It also concludes that ALARA is the most important
concept for occupational exposure to NORM or any radioactive material.
3.4.4
Conference of Radiation Control Program Directors
The CRCPD has developed recommendations regarding the regulation and licensing of
TENORM. These are contained in Subpart N of its
Suggested State Regulations for Control of
Radiation
(CRCPD, 2004). The CRCPD recommends that the standards for protection of
workers from TENORM comply with Subpart D,
Standards for Protection Against Radiation,
which are
consistent with NRC regulations for radiation protection.
