Principles of Radiation

1. Principles of Radiation Industrial Studies 4020 Topics in Industrial Studies Environmental Safety Management

2. Review • Atomic numberAtomic massNumber of Protons ONLY Number of Protons & Neutrons (weight) Atomic Mass 14 C Chemical Symbol 12 Atomic Number

3. So, what is it ? 3 H Hydrogen – 3 contains one proton + two neutrons. It’s a radioactive isotope of hydrogen also known as tritium

4. Isotopes • Same number of protons; different number of neutrons • Same chemical properties • Different nuclear properties 1 2 3 H H H 1 1 1 Hydrogen 1 Proton * Tritium 1 Proton, 2 Neutrons Deuterium 1 Proton, 1 Neutron * Note: Tritium is Radioactive

5. Atoms with too many neutrons or protons are unstable and emit energy to become more stable. Energy is carried away by a- / b-particle or x- / g-ray. These atoms are called radioactiveand the process is called radioactive decay Radioactivity

6. Natural Uranium Thorium Potassium-40 Carbon-14 (C-14) Hydrogen-3 (H-3) (tritium) Radioactivity • Man made • Phosphorus-32 (P-32) • Sulfur-35 (S-35) • Calcium-45 (Ca-45) • Chromium-51 (Cr-51) • Zinc-65 (Zn-65) • Rubidium-86 (Rb-86) • Iodine-125 (I-125)

7. Background Radiation mrem/yr Cosmic 27 Terrestrial 28 Inhaled 200 Internal 39 Man-made 63 Total:357

8. Microwave light bulb cell phone UV lamp radio / TV laser heat lamp x-rays Radiation Emission / propagation of energy through space or material medium as waves or particles

9. Ionizing Radiation

10. Alpha Particles 2 Protons + 2 NeutronsShort Range in AirNot an External Hazard Internal Hazard

11. Beta Particles Negligible MassLong Range in AirInternal/External Hazard Charged

12. Gamma Rays/Photons Gamma photons & X-Ray both electromagnetic differ only by place of originNo mass or chargeHighly-penetrating

13. Neutrons Very Long RangeVery PenetratingDifficult to detect

14. Other modes of Decay • Positron emission • Electron capture • Fission • Electron

15. Activity • Decay is a statistical process. • Cannot predict when a particular atom will decay. • Canpredict when certain amount (%) will have decayed.

16. Units of Activity Curie(Ci) • 1 Ci = 37,000,000,000 dps (3.7 x 1010 dps) or1 Ci = 2.22 x 1012 dpm Becquerel(Bq) • 1 Bq = 1 dps • 1 Ci = 37,000,000,000 Bq = 37 GBq (Giga Becquerel)

17. Beta and gamma radiation about equally damaging: 1 R = 1 rad = 1 rem Alpha radiation causes greater cellular damage 1 rad of a = 20 rem Quantities & Units

18. Decay Rate Half-life, A= A0 e 0.693t/T½A = A0 (½)# of half-lives

19. Non-Ionizing Radiation

20. Questions?

21. RadiationSafety Industrial Studies 4020 Topics in Industrial Studies Environmental Safety Management

22. Radiation Hazards • External Hazard (exposure from outside the body) • High-energy beta (i.e., energy > 300 keV or > 0.3 MeV) • Gamma and X-rays • Neutrons • Internal Hazard • Radioactive material enters body by eating/drinking in radiation area, by breathing vapors/aerosols, or skin absorption • In body, it is treated like non-radioactive elements • If not incorporated into organ, rapidly excreted and maypose only slight hazard • If stored in organ, slowly excreted (effective half-life)

23. Acute Biological Effects Whole body, external acuteexposure effects • 25 rad some chromosome aberrations • 50 rad minor blood changes • 100 rad 2% radiation sickness • 400 rad 50% die in 60 days (LD50/60) • 700 rad lethal single exposure • 6000 rad cancer therapy (local)

24. Low Dose Biological Effects

25. ALARAAsLow As Reasonably Achievable Benefits outweigh risks? Lower Dose = Lower Risk

26. Monitoring Workers • Whole body badge (TLD) • Collar or Ring TLD • Bioassay -- thyroid (iodine) • urinalysis (tritium)

27. Occupational Exposure Limits Accumulated Dose Equivalent to: Whole Body Lens of the Eye Skin of Whole Body Extremities of Whole Body -- Hands, Feet, etc Not to Exceed mrem/yr rem/yr mSv/yr 5,000 5 50 15,000 15 150 50,000 50 500 50,000 50 500

28. General Safety Measures • DISTANCE • Exposure decreaseswith distance • v • TIME Exposure increases with time • SHIELDING Plastic for beta Lead for gamma

29. Time vs Exposure Increased exposure (risk)over time Linear 3 mR/hr * 4 hr = ???

30. Distance vs Exposure I1d12 = I2d22

31. Exposure & Shielding No shielding needed for alpha or low-energy beta • Thick, dense(i.e., lead) for gamma / x-rays • Plastic beta • Hydrogeneous(or boron + cadmium) for neutrons

32. Detectors/ Monitors

33. Detectors/ Monitors 1) Capable of Detecting 2) Efficiency3) Calibration

34. Industrial Uses of Radiation http://www.epa.gov/rpdweb00/source-reduction-management/applications.html

35. Industrial Uses of Radiation Lasers X-raysGauges Wireless exit signsX-ray Fluorescence(XRF)

36. Industrial Uses of Radiation Moisture/density gauges Radiography Static controlSmoke detectors http://www.epa.gov/rpdweb00/source-reduction-management/applications.html

37. Emergency Response • Lifesaving and serious injury take precedence over radiation exposure and contamination • Control Access to Area • Call for Help

38. RadioactiveWaste Industrial Studies 4020 Topics in Industrial Studies Environmental Safety Management

39. Types of Radioactive Waste Spent Fuel - Withdrawn from a nuclear reactor following irradiationHigh-level waste - Highly radioactive material from reprocessing spent nuclear fuel Transuranic - Man-made elements above atomic number 92

40. Types of Radioactive Waste NORM–Naturally-occurring radioactive material (primarily uranium & thoriumSpecial Nuclear - Pu, U-233, or uranium enriched in the Material isotopes U-233 or U-235Low-level waste - not high-level radioactive waste, spent nuclear fuel, transuranic waste, or certain by-product material

41. Solid Waste • Landfill • Decay • Incinerate • Supercompaction

42. LSC Vial Waste

43. Aqueous Waste • Hold for decay • Sanitary sewer Table II POTW

44. Mixed Waste • RCRA/AEA – Dual regulation • EPA/State Conditional exemption • Department ofEnergy

45. Questions?