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Radiation Awareness Training

Radiation Awareness Training. Elayna Mellas Radiation Safety Officer Environmental Health & Safety Manager Clarkson University Downtown Snell 155 Tel: 315-268-6640 emellas@clarkson.edu. This training course has been partially adapted from slides provided by Steve Backurz, Radiation

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Radiation Awareness Training

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  1. Radiation Awareness Training Elayna Mellas Radiation Safety Officer Environmental Health & Safety Manager Clarkson University Downtown Snell 155 Tel: 315-268-6640 emellas@clarkson.edu This training course has been partially adapted from slides provided by Steve Backurz, Radiation Safety Officer of The University of New Hampshire

  2. Overview • What is radiation / radioactivity? • What makes radiation harmful? • Radiation dose - how much is too much? • Background radiation – your exposure can never be zero • How are you protected at Clarkson? • Emergencies • Ordering and receiving radioactive material at Clarkson • Questions?

  3. Where Does Radioactivity Come From? • All matter is made up of atoms • Atoms are the smallest component of an element, comprised of three particles • Protons • Neutrons • Electrons • Protons and neutrons are in the central nucleus • Electrons orbit the nucleus

  4. What is Radioactivity? • Definition: a collection of unstable atoms that undergo spontaneous transformation that result in new elements. • An atom with an unstable nucleus will “decay” until it becomes a stable atom, emitting radiation as it decays • The “amount” of radioactivity (called activity) is given by the number of nuclear decays that occur per unit time (decays per minute).

  5. The Curie • A unit of activity defined by the number of radioactive decays from a gram of radium • 1 Curie (Ci) = 2.22 E12 disintegrations/min (dpm) • Sub-multiples of the Curie: millicurie 1 mCi = 2.22 E9 dpm • microcurie 1 uCi = 2.22 E6 dpm • International units: 1 bequerel = 1 disintegration / sec • Typical activities used at Clarkson University are in the Ci to mCi range

  6. Radiation • Definition: energy in the form of particles or waves • Types of radiation • Ionizing: removes electrons from atoms • Particulate (alphas and betas) • Waves (gamma and X-rays) • Non-ionizing (electromagnetic): can't remove electrons from atoms • infrared, visible, microwaves, radar, radio waves, lasers

  7. Radiation wavelength in angstrom units 8 6 4 2 -2 -4 -6 10 10 10 10 1 10 10 10 Radio Infrared V Ultra-Violet X-Rays Cosmic Rays i Light s i b l e Gamma Rays 4 - 10 -8 -6 -4 -2 2 2 2 10 10 10 10 10 1 10 10 Photon energy in million electron volts (MeV) Electromagnetic Spectrum

  8. Ionization Formation of a charged and reactive atom - Ejected electron Beta particle - - - Colliding coulombic fields The neutral absorber atom acquires a positive charge -

  9. Why is Radiation Harmful? • Radiation deposits small amounts of energy, or "heat" in matter • Alters atoms • Damage to cells & DNA causes mutations and cancer • Similar effects may occur from chemicals • Much of the resulting damage is from the production of ions

  10. Radiation Dose • Human dose is measured in rem or millirem • 1000 mrem = 1 rem • 1 rem poses the same risk for any type of ionizing radiation • internal or external • alpha, beta, gamma, x-ray, or neutron • External radiation exposure measured by dosimetry • Internal radiation exposure measured using bioassay sample analysis

  11. Acute Exposure • Large doses received in a short time period • accidents • nuclear war • cancer therapy • Short term effects (acute radiation syndrome 150 to 350 rad whole body) Anorexia Nausea Fatigue Vomiting Epilation Diarrhea Hemorrhage Mortality

  12. Absorbed Effect dose (Rads) 10,000 Death in a few hours 1,200 Death within days 600 Death within weeks 450 LD 50/30 100 Probable recovery 50 No observable effect 25 Blood changes definite 5 1st blood change obs Acute Effects of Whole Body Exposure on Man

  13. Chronic Exposure • Doses received over long periods • Background radiation exposure • Occupational radiation exposure • 50 rem acute vs 50 rem chronic • acute: no time for cell repair • chronic: time for cell repair • Average US will receive 20 - 30 rems lifetime • Long term effects • Increased risk of cancer, genetic defects • 0.07% per rem lifetime exposure • Normal risk: 25% (cancer incidence)

  14. Background Radiation • Your exposure to radiation can never be zero because background radiation is always present • Natural sources – radon gas • Cosmic rays • Terrestrial (uranium-235) • Healing arts: diagnostic X-rays, radiopharmaceuticals • Nuclear weapons tests fallout • Research with radioisotopes • Consumer products • Miscellaneous: air travel, transportation of radioactive material

  15. Total exposure Man-made sources Medical X-Rays Radon 55.0% 11 Other 1% Internal 11% Consumer Products 3% Man-Made 18% Nuclear Medicine 4% Cosmic 8% Terrestrial 6% Total US average dose equivalent = 360 mrem/year Annual Dose from Background Radiation

  16. Consumer Products • Tobacco (Po-210) • Smoke detectors (Am-241) • Welding rods (Th-222) • Television (low levels of X-rays) • watches & other luminescent products (tritium or radium) • Gas lantern mantles • Fiesta ware (Ur-235) • Jewelry

  17. Smoke Detectors Alpha particles from americium-241 (red lines) ionize the air molecules (pink and blue spheres). The ions carry a small current between two electrodes. Smoke particles (brown spheres) attach to ions reducing current and initiate alarm.

  18. Fiesta Ware Glazed with dye containing uranium

  19. Luminous Watches Hands and dials contain H-3 or radium that glows in the dark

  20. Nuclear Medicine X-rays and fluoroscopes are used to look inside the body

  21. Radioactive Material at Clarkson • Activities are licensed by the State of New York • Radiation Safety Committee has responsibility to review, approve, and oversee activities • Radiation Safety Officer (RSO) runs program • Clarkson is required to: • Train individuals that use sources of radiation • Train non-radiation workers that work in the vicinity of radiation sources • Monitor and control radiation exposures • Maintain signs, labels, postings • Manage and properly dispose of radioactive waste

  22. Research at Clarkson Using Radiation Sources • Radioactive materials (both open and sealed sources such as S-35, P-32, C-14, H-3, Ra-226, Am-241) • Gas chromatographs (sealed sources) • Liquid scintillation counters (sealed sources for internal standards) • X-ray diffraction equipment • Electron microscopes

  23. Standards for Protection Against Radiation • Occupational limits • 5,000 mrem / year TEDE • 50,000 mrem / year CDE (any single organ) • 15,000 mrem / year lens of the eye • Members of public • 100 mrem / year • No more than 2 mrem in any one hour in unrestricted areas from external sources • Declared pregnant females (occupational) • 500 mrem / term (evenly distributed)

  24. Anticipated Exposures • Non radioactive workers must receive less than 100 mrems / year • Average annual background exposure for U.S. population = 360 mrem / year • State and federal exposure limits for radiation workers = 5000 mrem / year • Anticipated exposures: Less than the minimum detectable dose for film badges (likely less than 10 mrem / month) - essentially zero

  25. Unrestricted area Controlled area Unrestricted area Unrestricted area Restricted area Access Restriction • Required by license and NY regulations • Security and control of radioactive material

  26. Posting of Radiation Areas All radiation areas are posted with warning signs Use caution when entering and working in a radiation area If any container is labeled “radioactive” do not disturb If you have questions or concerns call: Craig Woodworth, radiation safety officer, 268-2391, Room 147 Science Center

  27. Emergency Response • Fire in radioactive areas: • Notify Fire Department and RSO, clear the area of people. Remove any seriously wounded persons. Keep your distance • Notify RSO if you suspect: • Inhalation, ingestion or other intake of radioactive material • Accidental release of radioactive material into the environment

  28. Radiation Protection Basics • Time: minimize the time that you are in contact with radioactive material to reduce exposure • Distance: keep your distance. If you double the distance the exposure rate drops by factor of 4 • Shielding: • Lead, water, or concrete for gamma & X-ray • Thick plastic (lucite) for betas • Protective clothing: protects against contamination only - keeps radioactive material off skin and clothes

  29. Radiation Exposure Will Not Make You Radioactive • Radiation: energy in the form of particles and waves • Radioactive material: material that is unstable and emits radiation • Contamination: radioactive material where it is not wanted • Campfire example: burning logs (radioactive material), heat (radiation), burning embers that escape the controlled area (contamination)

  30. Shipping Radioactive Materials Since the atomic energy industry began over 50 years ago, there has been an excellent record of safety in transportation of nuclear material Over 4 million packages containing radioactive material are transported annually within the US To date, there have been no deaths or serious injuries

  31. Ordering & Receiptof Radioactive Materials • Only the RSO is authorized to order radioactive material at Clarkson • When packages are received, call the RSO. He will check for contamination, and deliver to the package to the lab on the same day as receipt • All packages containing radioactive materials must be secured to prevent theft or loss • If any package is damaged, do not handle. Call the RSO immediately and ask the carrier to stay to be checked for contamination

  32. Labels on Packages of Radioactive Material Radioactive white I; almost no radiation (0.5 mR/hr or 0.005 mSv/hr) maximum on the surface Radioactive yellow II;low radiation levels (50 mR/hr or 0.05 mSv/hr) maximum at 1 meter

  33. Labels on Packages of Radioactive Material Radioactive yellow III;higher radiation levels (200 mR/hr or 2 mSv/hr) maximum on surface. 10 mR/hr or .1 mSv/hr maximum at 1 meter. The transport index is the maximum radiation level (mR/hr) at 1 meter from the surface of an undamaged package.

  34. Your Role in Radiation Protection • Don’t touch or move anything with radioactive material labels. • Report anything that looks out of the ordinary • If you are uncertain about what to do, where to go, requirements, or exposures: • Call the people on the emergency number list • Call the Radiation Safety Officer (RSO) Elayna Mellas 268-6640 • Call 911

  35. Acknowledgements This training course has been partially adapted from slides provided by Steve Backurz, Radiation Safety Officer of The University of New Hampshire.

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