1. ANS Congressional Sessions Welcome to Session 1 – What is Radiation? Future Sessions: Session 2 - Reactor/Operators Session 3 - The Fuel-Cycle Session 4 - Nonproliferation Session 5 - Other Uses of Radiation

2. Radiation Basics Mary Lou Dunzik-Gougar, Ph.D. Acting Chair of Nuclear Engineering at Idaho State University with joint appointment at Idaho National Laboratory Candace Davison, M. Engineer Research and Education Specialist Pennsylvania State University Radiation Science and Engineering Center Presented by

3. Radiation in the Media “Iodine 131 was also detected at levels 10,000 times the safety limit in groundwater near Reactor No. 1.” “…our Geiger counter registered a brief spike to 6 microsieverts per hour” “My electronic arming dosimeter registers a.3 millirem, its first detection of radiation.” Inside New York's Indian Point nuclear power plant

4. Radiation: WHY SO SCARY? Invisible, tasteless, odorless, and… Misunderstood.

5. What is radiation? Where does radiation come from? What is radioactivity? What’s the difference between contamination and irradiation? What are some beneficial applications of radiation? How to identify credible information on radiation. Questions we’ll answer...

6. What is Radiation? Transmission of energy via... Particles or Waves

7. Types of Radiation Non-Ionizing Radiowaves Microwaves Infrared Ultraviolet Visible Light and Ionizing

8. Types of Radiation Non-Ionizing Radiowaves Microwaves Infrared Ultraviolet Visible Light Ionizing Alpha Beta Gamma (rays) X-Rays Neutrons

9. Electromagnetic Spectrum What is it? The range of wavelengths or frequencies over which electromagnetic radiation extends.

10. Electromagnetic Spectrum What is it? The range of wavelengths or frequencies over which electromagnetic radiation extends.

11. The Nature of Radiation Alpha (  ) 2 protons, 2 neutrons positively charged particle Beta (  ) like an electron negatively charged particle Gamma (  ) Wave energy (not a particle ) n p+ n _

12. Penetrating Ability n p+ n  _   n n

13. Shielding Paper alpha beta gamma Wood Lead Concrete

14. Where does radiation come from? Atoms... from radioactive or unstable atoms Atoms

15. What part of atoms? The Nucleus! Hence, we have terms such as: nuclear science nuclear medicine nuclear reactors Atoms

16. HELIUM’S subATOMIC COMPOSITION 2 Protons 2 Neutrons 2 Electrons Atomic structure? e-e- n e-e- p+p+ n p+p+ The Helium Atom

17. n Neutrons have large mass, approximately equal to proton mass, but no charge. p+p+ Protons have a large mass and a positive charge. Electrons have a very small mass and a negative charge. Electrons travel outside the nucleus. e-e- More on this helium isotope 4242 MASS NUMBER is total number of protons and neutrons ATOMIC NUMBER is number of protons & identifies the element

18. Why is it called ionizing? Because it creates ions... atoms with a charge. Ionizing Radiation Ejected Electron

19. If radiation comes from atoms and everything is made of atoms, is there radiation around us right now? But, of course! It is called background radiation. Background Radiation

20. Radiation can be read and heard. “Listen” to the background radiation with a Geiger counter. Geiger Counter

21. Is all radiation harmful? Radiation produced by nuclear science provides for a vast range of beneficial applications. CommercialIndustrial Applications ElectricityMedical Uses Food IrradiationReactor Safety Hydrogen GenerationSpace

22. Geiger Demonstration What type of radiation source do you have on your table?

23. Shielding Paper alpha beta gamma Wood Lead Concrete

24. What is radioactivity?

25. The spontaneous emission of “fragments” or “bundles” of energy from energetic nuclei creating more stable nuclei. Radioactive atom Different, more stable atom formed Energy and radiation released What is radioactivity?

26. Radioactive atoms emit radiation. What is radioactivity?

27. “If I’m exposed to radiation, do I become (more) radioactive?” Radioactivity

28. No! You’ve been irradiated, exposed to radiation. Which is not to be confused with... contamination. Radioactivity

29. Radioactive Contamination is radioactive material in an unwanted place. Radioactive Contamination

30. What are some applications of irradiation? Irradiation Alpha radiation is used to - Power space probes - Remove static in copiers

31. Beta radiation is used for gauging – Thickness of aluminum during production – Eggshell thickness before shipping Irradiation

32. Gamma radiation is used for the following: - Sterilizing medical supplies - Preserving food - Inspecting welds and large structures Irradiation

33. Question... How are radioactive atoms formed?

34. Supernova Explosion Answer... Supernovae

35. How do we make a stable atom radioactive? Question...

36. How do we make a stable atom radioactive? – By adding energy to the nucleus – This is done by adding a particle such as a neutron from a reactor or a high energy charged particle such as an electron or proton from a particle accelerator Answer

37. Ok, so I don’t become radioactive from being irradiated, but are there other health effects to radiation exposure? Question...

38. Radiation is part of our natural environment. We are exposed to radiation from materials in the earth itself. Naturally occurring radon in the air, from outer space, and from inside our own bodies (as a result of the food and water we consume). This Radiation is measured in units called millirems (mrems). The average dose per person from all sources is about 620 mrems per year. Answer

39. Provide examples of exaggerated headlines or reports levels of radiation that suggest unsafe levels. How to recognize credible reports on radiation and nuclear in the media

40. Slides 44 to the end are technical, and negative with a lot of information about cancer. Audience take-away is very negative. Can the information regarding dose, half-life, radon, dose vs. risk (risk implies a negative) be reviewed and reworked to present the information in a more relative way? Show DOSE in context and provide examples that are positive. I.e. radiation is part of cancer treatment-show more benefits Slides 44 - end

41. Thank you for your participation in today’s session. We hope you have a better understanding of radiation and nuclear. Please give us your feedback with a brief 5 question survey (provide link): Thank you!

42. ANS Congressional Sessions Join us in April for Session 2 - Reactor/Operators Future Sessions: Session 3 - The Fuel-Cycle Session 4 - Nonproliferation Session 5 - Other Uses of Radiation

43. American Nuclear Society

44. Radon Gas More Deadly Than Carbon Monoxide Poisoning!!!! By Robert Preidt SUNDAY, Jan. 27 (HealthDay News) -- Radon, an invisible radioactive gas that seeps into homes through foundation cracks, causes 100 times more deaths than carbon monoxide poisoning, says the U.S. Environmental Protection Agency. To heighten awareness of that potential danger, the agency has designated January as National Radon Action Month. Radon is the second leading cause of lung cancer behind smoking, and about 20,000 people in the United States will die this year due to breathing too much radon without even knowing it, the EPA said. "It's remarkably easy to protect our loved ones by testing for radon and building new homes with radon-resistant features that allow everyone to breathe freely and safely," EPA Deputy Administrator Marcus Peacock said in a prepared statement. http://abcnews.go.com/Health/Healthday/story?id=4510215

45. Radon Gas – Decay products Image: http://www.sanitred.com/RadonHealth.htm

46. Why are we concerned about Radiation? Ionizing Radiation Human Cells Atoms in Cells Form Ions Change in CellCell Dies No/Neutral Change in Cell Not Replaced ReplacedReproduces Malignant GrowthBenign Growth

47. How much is too much dose? DOSE

48. Dose Radiation is energy – when it interacts with a material, it transfers some or all of that energy to the material The amount of energy transfer is called dose Most international bodies use the GRAY In the US, the common unit is the RAD – 1 Gray = 100 Rad

49. Dose Perspective Dose (mrem)Source 1Dental xray 25Round trip flight to South Africa 40Your body 110Head and body CAT scan 620Average dose in U.S. 5500Average dose in Guarapari, Brazil 10,200Average dose in Ramsar, Iran 0 – 25,000No observable effect

50. Types of Dose and Effects Acute dose vs. Chronic dose Acute is short term Chronic is spread over a long time period Somatic effects vs. Hereditary effects Somatic effects in person exposed Hereditary effects in offspring of exposed person Internal dose vs. External dose Some radiation is not harmful externally, but is internally (e.g. alpha and low energy betas) 50

51. Early Effects of Acute Whole-Body Radiation Doses Dose (rem)Effect 0-25 No observable effect 25-100 Slight blood changes 100-200 Vomiting (5-50%) Moderate blood changes Full recovery within a few weeks 200-600 Vomiting (50-100%) Severe blood changes Hemorrhage, infections, hairloss Death (0-80%) within 2 mos. Survivors recover in 1 mo. to 1 yr. 600-1000 Same as above Death (80-100%) within 2 mos. 51

52. Risk at low doses A lot of people say, ‘Gee, we don't know a lot about the risks of radiation’ … I say: ‘We know a whole lot. We've studied populations all over the world since the turn of the last century. We know what happens at high doses. We know what happens at medical doses. And we know that at low doses the risks are low. The controversy is just how low are they. Are they really low or are they really, really low?’ --- Dr. John Boice, Jr., Founder of the radiation epidemiology section at the National Cancer Institute President, National Council on Radiation Protection and Measurements

53. Risk at low doses Cancer risk can be experimentally proven for doses above about 0.1 Sv (10 rem) It is essentially impossible to design an experiment to directly measure risk at low doses We apply a conservative model to estimate the risks at low dose, assuming that any radiation dose carries some risk (there is no threshold) and that risk at low dose is proportional to risk at higher doses (linear) – Called the Linear, No-Threshold (LNT) model

54. Dose vs. Risk Theory 54 Linear-No-Threshold (LNT)

55. Dose Limits in US Regulations 5000 (radiation workers) & 100 (members of the public) per year in milli-rem (or 50 and 1 in milli-Sievert)

56. How do we protect ourselves? Time – Limit time of the exposure Distance – Increase distance between you and dose Shielding – Between you and the source of radiation

57. ALARA All radiation dose must be made ALARA (As Low As Reasonably Achievable) – Takes into account the effort needed to reduce the dose, how much risk is saved, and what side effects might result. Pushes us to reduced dose where possible, even below the dose limits. Reinforces higher doses is certain situations (medical procedures, emergency conditions, etc.).

58. Important information to remember about radiation and nuclear 1.Radiation and radioactivity are a natural part of our world. 2.Nuclear technology works. 3.Nuclear technology enhances our quality of life.

59. Acute Effects -“Radiation Sickness” Result of a very high one-time or short-term burst of radiation exposure – Nuclear weapons, criticality accidents, etc. Symptoms may be temporary or fatal, depending upon amount of radiation exposure Only occurs above a threshold – A “yes or no” effect Localized radiation exposure may cause acute effects – usually seen as skin burns

60. Delayed Effects -- Cancer Radiation exposure in large enough quantities is known to increase the risk of cancer Cancer in a particular person cannot be tied to a particular cause – roughly 4 in 10 people have cancer at some point in their lives For this, we want some way to quantify the amount of risk associated with radiation exposure

61. Radiation is Radiation (or is it?) Is there a difference between radiation from different sources? – Cosmic rays – Weapons testing fallout – Medical x-ray/CT scan – Radon – Nuclear waste – …

62. Radiation – not created equal Energy alone is not the whole story Different types of radiation can cause different amounts of biological damage for the same amount of energy deposited We multiply the dose by a quality factor to account for this: – Gamma (& x-ray) QF = 1 – Beta QF = 1 – Alpha QF = 20 - + +

63. Radiation – still not created equal Different tissues respond differently to the same radiation dose (or dose equivalent) Particularly important for radioactive material intake, where material may concentrate in particular organs To account for this, we take a weighted average of dose to organs to account for this

64. Radiation – still not created equal We call this Effective Dose Dose to each tissue is multiplied by a tissue weighting factor and summed Effective dose allows us to compare the risk from one kind of radiation dose to another International standard unit is the Sievert US commonly uses the REM – 1 Sievert = 100 rem =

65. Radiation – still not created equal TissueICRP 26 (1977)ICRP 60 (1991)ICRP 103 (2007) Reproductive organs0.250.200.08 RBM0.12 Colon0.12 Lung0.12 Stomach0.12 Bladder0.050.04 Breast0.150.050.12 Liver0.050.04 Esophagus0.050.04 Thyroid0.030.050.04 Skin0.01 Bone Surfaces0.030.01 Brain0.01 Salivary glands0.01 Remainder*0.30.050.12

66. Effective Dose The most important factor in this weighted average is the risk of cancer fatality Cancer incidence (getting cancer, but not necessarily dying from it) is partially included, particularly for cancers with very high treatability and survivability We can estimate the risk of fatal cancer at approximately 4-5% per Sievert (per 100 rem) The total dose, and not the rate it is received, is what matters

67. Dose Limits in US Regulations Dose limits are maximums for normal occupational sources – No authority to limit medical exposures – Very limited authority over dose from natural sources (drinking water is key exception)

68. “Safe Level of Radiation” Dose limits are chosen as a guideline to assure an acceptable margin of safety –Does not mean that 99 millirem is automatically “safe” and 101 millirem is “unsafe” These limits are used to derive “safe levels” of radioactive materials in food/water/air –Assume a consistent intake at normal rates over a whole year