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Radiological Emergencies

Radiological Emergencies. John C. White, CNMT RSO The University of Texas Southwestern Medical Center at Dallas. Course Instructor. John C. White, CNMT, RSO. Certified Nuclear Medicine Technologist Radiation Safety Officer President, Health Physics Society North and South Texas

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Radiological Emergencies

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  1. Radiological Emergencies John C. White, CNMT RSO The University of Texas Southwestern Medical Center at Dallas

  2. Course Instructor John C. White, CNMT, RSO • Certified Nuclear Medicine Technologist • Radiation Safety Officer • President, Health Physics Society North and South Texas • 30 years experience with radioactives and radiation • A/TC WMD Working Group The University of Texas Southwestern Medical Center at Dallas

  3. Introduction This lesson will discuss: • Basic Radiation Principles • Perspectives on Risk • Radiological Incident Sources • Radiological Incident Response The University of Texas Southwestern Medical Center at Dallas

  4. Main Objectives: • To gain a better understanding about radiation and radioactivity • To provide an understanding of the harmful effects of radiation on the human body • How to safely respond to an emergency involving radioactive materials The University of Texas Southwestern Medical Center at Dallas

  5. Radiation and Risks • Radiation exposure • Radiation is everywhere and can be found in many forms • Some are very harmful to the human body • Radiation injuries can take a long time to present. But when they do, it is usually in the form of cancer or birth defects The University of Texas Southwestern Medical Center at Dallas

  6. What Is Radiation ? Energy In the form of: Waves  Particles … • Non-ionizing • Ionizing

  7. Non-ionizing RadiationDoes Not Have Enough Energy to Remove Electrons From Surrounding Atoms

  8. Types of Radiation • Non-ionizing radiation • Waves of energy. Large wavelength • Low frequency Non-ionizing radiation comes from ultraviolet and infrared energy waves • *Note*: • This type of radiation causes “sunburn” and is not a major concern for the hazmat responder

  9. Energy Spectrum The University of Texas Southwestern Medical Center at Dallas

  10. Types of Radiation • Ionizing radiation • Energy emitted in the form of electromagnetic waves or particles from the nucleus or electron cloud of an atom • Energy produced: • Alpha particles • Beta particles • Gamma or X rays • Neutrons • All of these sources may cause damage at the cellular level The University of Texas Southwestern Medical Center at Dallas

  11.  Ionizing RadiationEnergy Can Be Deposited in Neighboring Atoms Resulting in the Removal of Electrons. alpha x-ray neutron • High Frequency • Small Wavelength beta gamma ray

  12. Alpha Radiation • Alpha radiation • Alpha particles will travel 3 - 4 inches in air and cannot penetrate the outer layer of skin • Alpha particles can invade the body by other means, such as: • Injection • Inhalation • Ingestion • Absorption The University of Texas Southwestern Medical Center at Dallas

  13. Alpha Radiation • Not an external risk • Densely ionizing (internal exposure) • Easily shielded by skin, clothing, etc. • Internal risk

  14. Beta Radiation • Beta radiation • Beta particles can travel 3 to 100 feet and may penetrate the skin.* A firefighters gear can deflect beta particles • Personnel can be exposed through: • Inhalation • Ingestion • Injection • Absorption • Penetration The University of Texas Southwestern Medical Center at Dallas

  15. Beta Radiation • Can penetrate thin sheets of aluminum and skin • External skin hazard • Internal hazard, like alpha, through ingestion, inhalation or injection

  16. Gamma Radiation • Gamma radiation. • Gamma radiation is a naturally occurring or man-made high energy electromagnetic wave. • It has a high penetrating power and can travel at the speed of light. • Gamma rays will penetrate the skin and can cause injury to internal organs. The University of Texas Southwestern Medical Center at Dallas

  17. Gamma Radiation • Gamma Radiation Effects • Routes of entry into the body • Ingestion • Inhalation • Injection • Absorption • Penetration The University of Texas Southwestern Medical Center at Dallas

  18. Gamma Radiation • External and internal hazard • Best shielded with dense materials (e.g., lead or concrete) • Will easily penetrate Level A PPE • Easily detected

  19. Neutron Radiation • High Speed Particle – • No electrical charge • Can travel hundreds of feet in air • Can easily penetrate Level A PPE • External hazard • Best shielded w/materials that are hydrogen rich (elastic collisions) The University of Texas Southwestern Medical Center at Dallas

  20. RADIOLOGICAL HAZARD PAPER ALPHA PARTICLE SKIN BETAPARTICLE Penetration capability of types of radiation LEAD GAMMA RAYS Neutron The University of Texas Southwestern Medical Center at Dallas

  21. Common Sources of Radiation Radon - 55% Other < 1% Consumer Products - 3% Nuclear Medicine - 4% Rocks, Soil - 8% Cosmic Rays - 8% X-rays - 11% Water, Food - 11% The University of Texas Southwestern Medical Center at Dallas

  22. Definitions: (For Purposes of Emergencies, R=RAD=REM) • Roentgen (R) (C/Kg) • A unit of exposure: the amount of ionizing radiation (energy) produced in a specific volume of air • Radiation absorbed dose (RAD) (Gy) • A unit of absorbed dose: the amount of energy absorbed in a given volume of material. • Radiation equivalent in man (REM) (Sv) • A unit of dose equivalent: the amount of radiation that has been absorbed times a quality factor (biological effects)

  23. Units of Measurement 2.58 x 10-4 C /kg-1 = 1 R 1 R = 0.97 Rad (tissue) 0.97 Rad x 1 = 0.97 Rem Therefore: 1R ~ 1 Rad ~ 1 Rem 1 R = 1000 mR (milliRem)

  24. Definitions: Activity - the rate at which radioactive materials emit radiation • The number of nuclear disintegrations occurring in a given quantity of material per unit of time – usually referred to as dps or cpm • A curie (Ci) is the number of radioactive atoms that will decay and emit radiation in one second, not a function of weight of volume The University of Texas Southwestern Medical Center at Dallas

  25. International Units • -A Curie (Ci) is 37 billion disintegrations per second • 3.7 x 1010 dps = 1 curie (Ci) or 1000 millicuries • -A Becquerel (Bq) is 1 dps • 1 Bq = 27 pCi = 0.000027 Ci The University of Texas Southwestern Medical Center at Dallas

  26. Definitions • Radioactivity • Ionizing energy spontaneously emitted by a material or combination of materials. • Radioactive material • One that spontaneously emits ionizing radiation • Radioactive contamination • Radioactive material in an unwanted place • Internal / external The University of Texas Southwestern Medical Center at Dallas

  27. Units of Measurement • Curie • A unit of activity: • Milli-curie • One-thousandth of a curie • Micro-curie • One-millionth of a curie . The University of Texas Southwestern Medical Center at Dallas

  28. Definitions: • Half-life- The amount of time a radioactive material takes to decay to 1/2 of its original activity • Each radioactive material (Isotope = Source) has a unique half-life • Sodium 25 60 seconds • Iodine 131 8.04 days • Cobalt 60 5.27 years • Plutonium 239 24,139 years • After 7 half lives < 1% remains The University of Texas Southwestern Medical Center at Dallas

  29. Field Instrumentation • Identify hazards • Types of radiation • External • Magnitude • Identify affected media • Identify nuclide(s) • Offsite analysis (of media samples) • Field spectroscopy May read in mR/hr or microrem/hr – know your meter!

  30. Field Instrumentation • Alpha Detectors • Alpha scintillators (zinc sulfide, ZnS) • Air proportional detector • Pancake G-M (Geiger Mueller) • Beta Detectors • Pancake G-M • Thin Wall G-M • Gamma Detectors • Sodium Iodide (NaI) • Geiger Mueller Tube, Pancake G-M, Thin Wall G-M The University of Texas Southwestern Medical Center at Dallas

  31. Radiation Effects • Acute Exposure - Local or Total Body Exposure occurs in hours or minutes • Repairable damage to cells • Irrepairable damage to cells, but not causing death • Irrepairable damage resulting in death The University of Texas Southwestern Medical Center at Dallas

  32. Radiation Effects • Chronic Exposure Small amounts of exposure over a long period of time • Birth defects of a Teratogenic or Mutagenic nature The University of Texas Southwestern Medical Center at Dallas

  33. Risk Perspective mrem/y Avg. Background 360 Avg. Radiation Worker 400 Regulatory Limit 5,000 (Radiation Workers) The University of Texas Southwestern Medical Center at Dallas

  34. Health Risks • Radiation Risks (bomb survivors)Risk of developing a fatal cancer, non-fatal cancer, genetic effects, and length of life lost 0.0725 %/rem or 0.0000725 %/mrem The University of Texas Southwestern Medical Center at Dallas

  35. EPA Emergency Dose Limit Guidelines The University of Texas Southwestern Medical Center at Dallas

  36. Dose Limit Guidelines • The Maximum Lifetime exposure from a single incident is: • 25 Rem NCRP Report No. 138 • 50 Rem Whole Body , 500 Rem Skin • Justification, understanding risks The University of Texas Southwestern Medical Center at Dallas

  37. Nuclear facility accidents Nuclear weapon and device accidents Nuclear terrorism Satellite re-entry Types of Incidents Los Alamos Wildfires Lost Sources Three Mile Island Space Launches • Contaminated imports • Transportation accidents • Sabotage • Orphan sources* • Foreign incidents*

  38. Potential Terrorist Incidents Involving Radiation • The nature of these attacks (i.e., materials used, facilities involved, method of contamination, destructive intent) can vary greatly • Assault or attack on power plants/nuclear facilities • Improvised Nuclear Weapon/lost or stolen weapon • Radiation Dispersal Device with or without explosives • Radiation Exposure Device • Water system contamination • Purposely contaminated consumer products • Orphan and lost sources The University of Texas Southwestern Medical Center at Dallas

  39. Obtainable Radiological Materials

  40. Radiation Dispersal Device (RDD) • Terrorists pack a conventional explosive around radioactive material • In the U.S., the sources would likely be radiography-type (cesium, cobalt, iridium), which are fairly easy to detect if intelligence gives a general location • Terrorists purposely contaminate an area with radioactive materials through some aerosol spraying method • Lethality is low • Panic is high • Event is intended to panic the public and severely tax the resources of Federal and state government • Many follow-up measurements would have to be made to assess the total contamination picture • Even a small event may take years of study to understand

  41. Source: Knight-Ridder Tribune

  42. Characteristics of Radiation Burn • Thermal Burn as Opposed to Radiation Burn- No sensation or recollection of immediate pain • Delayed Response • RDD as opposed to Atomic Blast- Difference in Debris Field- Flash The University of Texas Southwestern Medical Center at Dallas

  43. Radiation Exposure Device (RED) • Radioactive material that is intended to expose people in the vicinity of the device to emitted radiation • RED could be a sealed source or a material within some type of container (e.g., a shoebox) • The radioactive material could be in the form of a contained powder, a contained liquid, or a solid object • Example: if the radioactive material in an industrial radiography device is left without shielding, a person standing one meter from the source would have to stand at that location for about 5 hours to get a dose that would probably prove lethal (death within 2 months…) The University of Texas Southwestern Medical Center at Dallas

  44. Transportation Accidents • WIPP transports • Industrial Radiography • Passenger / Air Cargo Flights • Rail Transport The University of Texas Southwestern Medical Center at Dallas

  45. Regulatory Agencies • The Department of transportation (DOT) serves as the regulatory agency involving radioactive materials if: • A radioactive material having a specific activity of 70 Bq per gram (0.002 micro-curies per gram) of material • The DOT determines what type of packaging the material shall be encased and shipped in • ICAO/IATA determines types of packages acceptable on passenger/cargo aircraft The University of Texas Southwestern Medical Center at Dallas

  46. Emergency ResponseTransportation Incidents • Radiation presents minimal risk • Undamaged packages are safe. Contents of damaged packages may cause increased exposure or possible internal/external contamination • Type A packages contain non-life endangering amounts • Type B packages, and the rarely occurring Type C packages including [B(U)F, B(M)F, CF] contain the most (potentially) hazardous amounts of material. Life threatening conditions may exist only if contents are released or package shielding fails or in utmost severity. The University of Texas Southwestern Medical Center at Dallas

  47. Emergency ResponseTransportation Incidents FIRE OR EXPLOSION involving Radioactive Material • Some of these materials may burn, but most do not ignite readily. • Radioactivity does not change flammability or other properties of materials. • Type B packages (AF, IF, B(U)F, B(M)F and CF) are designed and evaluated to withstand total engulfment in flames at temperatures of 800°C (1475°F) for a period of 30 minutes. The University of Texas Southwestern Medical Center at Dallas

  48. Trigger Points * Initial Alarm Level – 10 mR/h * Turn Around – 10, 000 mR/h (10 R/h) * Rule of Thumb 3000 - 4000 cpm = 1 mR/h The University of Texas Southwestern Medical Center at Dallas

  49. Radiation ‘Experts’ • Radiation Safety Officer • USNRC • State – TxDSHS • Nuclear Medicine Professionals • FEMA • EPA • USDOE • Several Other Federal Agencies • Health Physics Society The University of Texas Southwestern Medical Center at Dallas

  50. What to Look for in an ‘Expert’ • Familiar with Instruments • Practical Advice • Ability to Calculate • Credential • Familiarity with Contamination The University of Texas Southwestern Medical Center at Dallas

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