Occupational Dose Evaluation in Support of the Development of
October, 2012
Rare Element Resources, Inc. Bear Lodge Project
ERG
i
Table of Contents
Section 1
Introduction............................................................................................................... 1
1.1
Project Overview.............................................................................................................. 1
1.2
Report Objective .............................................................................................................. 3
1.3
Naturally Occurring Sources of Radiation and Radioactivity.......................................... 3
1.3.1
Types of Ionizing Radiation...................................................................................... 3
1.3.2
Sources of Naturally Occurring Radiation................................................................ 5
1.3.3
Units of Radioactivity and Dose ............................................................................... 8
1.3.4
Background Radiation Doses in the United States ................................................... 8
1.4
Radiological Issues at Rare Earth Facilities ..................................................................... 9
Section 2
Project Description.................................................................................................... 9
2.1
Bull Hill Mine ................................................................................................................ 10
2.2
Physical Upgrade Plant .................................................................................................. 10
2.3
Hydrometallurgical Plant ............................................................................................... 12
2.3.1
Tailings Storage Facility ......................................................................................... 12
2.4
Radionuclide Content of Ore and Concentrates ............................................................. 12
2.4.1
Bull Hill Ore ........................................................................................................... 12
2.4.2
PUG process............................................................................................................ 13
2.4.3
Hydromet Process ................................................................................................... 13
Section 3
Regulatory Background .......................................................................................... 14
3.1
U.S. Nuclear Regulatory Commission ........................................................................... 14
3.2
Occupational Safety and Health Administration............................................................ 15
3.3
Mine Safety and Health Administration......................................................................... 15
3.4
Guidance on Occupational Exposures to NORM or TENORM .................................... 16
3.4.1
American National Standards Institute, Inc. ........................................................... 16
3.4.2
National Council on Radiation Protection and Measurement (NCRP) .................. 17
3.4.3
National Academy of Science-National Research Council (NAS-NRC) ............... 17
