Government of Western Australia Department of Mines and Petroleum 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 Supporting resources, such as brochures and posters, are available from Resources Safety For resources, information or clarification, please contact: or visit 1

Government of Western Australia Department of Mines and Petroleum Toolbox presentation: Radiation Safety Part One: Naturally occurring radioactive material (NORM) 2

Government of Western Australia Department of Mines and Petroleum 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 3

Government of Western Australia Department of Mines and Petroleum 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

Government of Western Australia Department of Mines and Petroleum 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 5

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

Government of Western Australia Department of Mines and Petroleum 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 7

Government of Western Australia Department of Mines and Petroleum Types of ionizing radiation Alpha (α) radiation consists of a fast moving Helium-4 ( 4 He) 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. 8

Government of Western Australia Department of Mines and Petroleum Exploration radiation levels compared with other NORM exposures 9 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

Government of Western Australia Department of Mines and Petroleum Exploration radiation levels compared with other NORM exposures continued typical for exploration site with 0.40 wt % U mineralisation (Kintyre) 22 zirconium minerals 25 geothermal energy generation waste 40 heavy mineral sands concentrate 60 on board an international flight 80 tin concentrate 120 uranium mine or processing plant 250 rare earth processing plant 400 coal mine (underground water discharge points on the surface) 500 some areas of titanium dioxide pigment plant 1000 contaminated equipment from oil and gas industry 2500 rare earth mineral (monazite)

Government of Western Australia Department of Mines and Petroleum 11 **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** **************************************** ********** ***** Amount of radiation (1000 mSv) that may cause you serious harm Maximum radiation exposure limit in one year (50 mSv) Typical radiation dose a worker could receive at a uranium mine (5 mSv/year)

Government of Western Australia Department of Mines and Petroleum 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 12

Government of Western Australia Department of Mines and Petroleum 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 13

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

Government of Western Australia Department of Mines and Petroleum 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) 15

Government of Western Australia Department of Mines and Petroleum 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% U 3 O 8 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 16

Government of Western Australia Department of Mines and Petroleum Radiation Worker's Handbook More information on radiation protection available in Radiation Workers’ Handbook Download from Australian Uranium Association 17