Occupational Dose Evaluation in Support of the Development of the
October, 2012
Rare Element Resources, Inc. Bear Lodge Project
16
are no specific regulations regarding occupational exposure to radiation within the MSHA rules
for metal and non-metal surface mines.
3.4
Guidance on Occupational Exposures to NORM or TENORM
There are several organizations within the U.S. and internationally that provide guidance on
occupational exposures to NORM or Technologically Enhanced Naturally Occurring
Radioactive Material (TENORM), defined according to the standard below). These include but
are not limited to the following organizations:
American National Standards Institute, Inc. (ANSI)
National Council on Radiation Protection and Measurement (NCRP)
National Academy of Sciences-National Research Council (NAS-NRC)
Conference of Radiation Control Program Directors (CRCPD)
International Commission on Radiological Protection (ICRP)
International Atomic Energy Agency (IAEA)
The guidance documents regarding occupational exposure limits for each of these agencies are
described briefly below.
3.4.1
American National Standards Institute, Inc.
ANSI Standard N13.53-2009
Control and Release of Technologically Enhanced Naturally
Occurring Radioactive Material (TENORM)
(ANSI, 2009) provides guidance on occupational
exposure to TENORM. This document defines TENORM as:
“Naturally occurring radioactive material disturbed or altered from natural
settings or present in a technologically enhanced state due to past or present
human activities and practices, which may result in a relative increase in
radionuclide concentrations, radiation exposures and risks to the public and threat
to the accessible environment above background level. Technologically enhanced
means that the radiological, physical, and chemical properties of the radioactive
material have been altered such that there exists a potential for:
a)
redistribution and contamination of environmental media (soil, water, air,
biota),
b)
increased environmental mobility in soils and surface and groundwater,
c)
incorporation of elevated levels of radioactivity or increased accessibility
in products and construction material, or
d)
improper disposal or use of disposal methods that may result in
unnecessary or elevated exposures to individuals and populations via the
accessible environment.
