1. Please read this before using presentation
This presentation is based on content presented at the Exploration Safety Roadshow held in August 2009
It is made available for non-commercial use (e.g. toolbox meetings) subject to the condition that the PowerPoint file is not altered without permission from Resources Safety
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2. Toolbox presentation:
Radiation Safety Part One: Naturally occurring
radioactive material (NORM)

3. Radiation protection – what is it?
Science of protecting people and the environment from the harmful effects of ionizing radiation, which includes both particle radiation and high energy electromagnetic radiation

4. Radiation protection in mining is more commonplace than you may think
40 years of mining, processing and transporting radioactive minerals
AMC
Bemax
BHP
Cable Sands
Doral
Hanwa
Iluka
Isk Minerals
Jennings
Lynas
Rio Tinto
RGC
Rhone Poulenc
Sons of Gwalia
Talison Minerals
Tiwest
Western Mining
Western Titanium
Westralian Sands
Beenup
Bunbury
Capel
Chandala
Cooljarloo
Eneabba
Fremantle
Geraldton
Gingin
Greenbushes
Kalgoorlie
Kintyre
Kwinana
Mt Weld
Mt Walton
Narngulu
Picton
Pinjarra
Yeelirrie

5. NORM – what is it?
Naturally-occurring radioactive material (NORM) — term describing materials containing radionuclides that exist in the natural environment
Parent radionuclides have decay times (half-lives) comparable with or longer than the age of the Earth, so they have always been present in the Earth’s crust and within the tissues of all living species

6. NORM – radionuclides
The radionuclides of interest include long-lived radionuclides such as
uranium-238 (238U)
uranium-235 (235U)
thorium-232 (232Th)
and their radioactive decay products such as isotopes of
radium
radon
polonium
bismuth
lead
and individual long-lived radionuclides such as
potassium-40 (40K)
rubidium-87 (87Rb)
indium-115 (115In)

7. Radiation – what is it?
Radiation — energy travelling through space. Sunlight, radio waves and microwaves are forms of radiation at low-frequency end of energy spectrum
Type of radiation created by uranium is ionizing radiation
Background radiation — everyone exposed to naturally occurring ionizing radiation from space, radioactive atoms in the air, the Earth and even our own bodies
Most atoms stable and will never change, but certain atoms are always changing or decaying in a process by which they eventually become stable as completely different elements (e.g. uranium will naturally turn into lead after billions of years)
As an unstable atom decays, its atomic structure changes, releasing radiation as gamma rays and alpha and beta particles

8. Types of ionizing radiation
Alpha (α) radiation consists of a fast moving Helium-4 (4He) nuclei and is stopped by a sheet of paper.
Beta (β) radiation, consisting of electrons, is halted by an aluminium plate.
Gamma (γ) radiation, consisting of energetic photons, is eventually absorbed as it penetrates a dense material.
Neutron (n) radiation consists of free neutrons, which are blocked using light elements, like hydrogen, which slow or capture them.

9. Exploration radiation levels compared with other NORM exposures
Comparative values using 1 as typical gamma radiation level/hour in WA
1 natural background in Western Australia
3 typical for exploration site with wt % U mineralisation (Lake Maitland)
4 natural background in some areas of Perth Hills
4 some cement
5 typical for exploration site with 0.10 wt % U mineralisation (Lake Way)
5 certain phosphate fertilisers
6 some ceramic tiles
7 typical for exploration site with wt % U mineralisation (Mulga Rock)
7 coal burning slag
10 on board a local WA flight
14 phosphate mine
16 titanium minerals

10. Exploration radiation levels compared with other NORM exposures continued
typical for exploration site with 0.40 wt % U mineralisation (Kintyre)
zirconium minerals
geothermal energy generation waste
heavy mineral sands concentrate
on board an international flight
tin concentrate
uranium mine or processing plant
rare earth processing plant
coal mine (underground water discharge points on the surface)
some areas of titanium dioxide pigment plant
1000 contaminated equipment from oil and gas industry
2500 rare earth mineral (monazite) 10

11. Typical radiation dose a worker could receive
at a uranium mine (5 mSv/year)
**************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** ****************************************
*****
**********
Maximum radiation
exposure limit
in one year (50 mSv)
Amount of radiation
(1000 mSv) that
may cause you
serious harm
Green stars: Typical radiation dose a worker could receive at a uranium mine (5mSv/year)
Blue stars: Maximum radiation exposure limit in one year (50 mSv/year)
Orange stars: Amount of radiation that may cause you serious harm (1000 mSv)

12. What is special about ionizing radiation?
Everyone exposed to radiation, often without knowing it
Human senses cannot detect it
Historical association with nuclear activities
Impossible to determine if there is exposure level below which there is no effect
ARPANSA

13. Radiation exposure in uranium exploration
Typically uranium exploration workers receive less than the annual radiation exposure limit for general public
1 milliSievert (mSv) per year

14. Uranium 238 decay
Main difference between exploration phase and mining phase is the chemical processing used in mining to extract uranium
Processing frees up decay products that remain in waste and can cause health or environmental issues if not managed correctly

15. What are the relative risks of radiation exposure?
Relative risk of 1-in-a-million chances of dying from activities common to our society
Smoking 1.4 cigarettes (lung cancer)
Eating 40 tablespoons of peanut butter
Spending 2 days in Sydney CBD (air pollution)
Driving 65 kilometres in a car (accident)
Flying 4000 kilometres in a jet (accident)
Canoeing for 6 minutes
Receiving 0.1 mSv of radiation (cancer)

16. Units used in radiation protection
Activity measured in Bequerels (Bq)
[Curie or Ci old unit still used in USA]
Uranium ore samples uranium content over 1 Bq/gram are considered radioactive. Equivalent to 0.01% U3O8 or 83 ppm U
Absorbed dose measured in Gray (Gy) [rad – USA]
Technically, survey meters should be in units of µGy/h but most are in µSv/h
Effective dose measured in Sievert (Sv) [rem – USA]
Annual dose usually given in mSv
Many radiation units too large or small, so prefixes are used:
µ = micro
m = milli
M = Mega

17. Radiation Worker's Handbook
More information on radiation protection available in Radiation Workers’ Handbook
Download from Australian Uranium Association