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RADIATION ACCIDENTS: TERMINOLOGY, SCOPE OF PROBLEM AND STATISTICS

RADIATION ACCIDENTS: TERMINOLOGY, SCOPE OF PROBLEM AND STATISTICS. Module I. Module I - Radiation accidents. WHAT is an accident?. Accident [BSS, Glossary, p.295, 1996]:

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RADIATION ACCIDENTS: TERMINOLOGY, SCOPE OF PROBLEM AND STATISTICS

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  1. RADIATION ACCIDENTS: TERMINOLOGY, SCOPE OF PROBLEM AND STATISTICS Module I Module I - Radiation accidents

  2. WHAT is an accident? Accident [BSS, Glossary, p.295, 1996]: “Any unintended event including operating errors, equipment failures or other mishaps, the consequences or potential consequences of which are not negligible from the point of view of protection and safety.” Module I. Module Medical I - Radiation accidents

  3. What is a radiation accident? • A situation in which there is an unintentional exposure to ionizing radiation or radioactive contamination • Exposure may be real or suspected Module I. Module Medical I - Radiation accidents

  4. Radiation accidents • Radiation accidents include • radiological and • nuclear accidents • It is more appropriate and practical to use the term “nuclear and radiological emergency” for purposes of planning, preparedness and response Module I. Module Medical I - Radiation accidents

  5. Statistics of radiation accidents, 1944–2001 • Radiation accidents are rare • In 1944-2001420 radiation accidents led to significant overexposure of at least one person • Among 3000 overexposed persons, 133 fatalities are registered • However, loss of control over radiation sources has recently lead to more severe accidents Module I.

  6. Main types of radiation accidents: involved groups • Accidents during work - workers • radiography • irradiators (sealed sources and accelerators) • Accidents due to loss of control over radiation sources - public exposure • radiotherapy • orphan sources • Accidents in medical applications - patients • misadministration of radiopharmaceuticals • miscalculation of the dose for radiotherapy Module I. Module Medical I - Radiation accidents

  7. Where do radiation accidents occur? • Irradiation facilities • Material testing (sealed sources) • Material testing (X-ray devices) • X-ray and radiotherapy devices (medicine, research) • Isotope production facilities • Unsealed radionuclides (medicine, research) • Nuclear reactors • Transportation • ??? Module I. Module Medical I - Radiation accidents

  8. Radiation accidents by facility type, 1945-2000 Module I. Module Medical I - Radiation accidents

  9. Ionizing radiation: medical, industrial and consumer product applications • Radiography techniques • Analytical techniques • Irradiation techniques • Techniques involving unsealed radioactive materials • Miscellaneous techniques Module I. Module Medical I - Radiation accidents

  10. Ionizing radiation: medical, industrial and consumer product applications Radiography techniques (industrial and medical) • Industrial gamma and X-ray radiography (non-destructive testing) • Medical diagnostic radiography • Beta radiography • Neutron radiography Module I. Module Medical I - Radiation accidents

  11. Radiological accidents by source, 1945-2000 Module I. Module Medical I - Radiation accidents

  12. Ionizing radiation: medical, industrial and consumer product applications Analytical techniques • X-ray fluorescence • Electron capture • Neutron capture and activation analysis • Gamma backscatter gauge • X-ray fluorescence gauge • Photon switching (level gauge) • Selective gamma absorption • Gamma scattering • Thermalization of neutrons • Neutron transmission Module I. Module Medical I - Radiation accidents

  13. Ionizing radiation: medical, industrial and consumer product applications Irradiation techniques • Radiation beam therapy (teletherapy) • Brachytherapy • Radiation sterilization and grafting • Food preservation Module I. Module Medical I - Radiation accidents

  14. Ionizing radiation: medical, industrial and consumer product applications Techniques involving unsealed radioactive materials • Radioisotope tracer techniques • Therapeutic uses of radiopharmaceuticals • Self-luminous devices • Enhancement of electrical discharge • Uses of thorium Module I. Module Medical I - Radiation accidents

  15. Ionizing radiation: medical, industrial and consumer product applications Miscellaneous techniques • Static elimination • Smoke detectors • Lightning warning systems • Dewpoint meters • Nuclear batteries Module I. Module Medical I - Radiation accidents

  16. Frequency distribution of major radiation accidents worldwide, 1940-1999 50 Criticalities Radiation devices Radioisotopes 40 30 Number Sum 20 10 0 1940- 1945- 1950- 1955- 1960- 1965- 1970- 1975- 1980- 1985- 1990- 1995- 1944 1949 1954 1959 1964 1969 1974 1979 1984 1989 1994 1999 Module I.

  17. Scale of radiation accidents • Small scale radiation accidents • usually involve a small source term and few people • often come to light from observations by primary care physicians (mainly GPs) • Large scale radiation accidents • usually involve a large source term and many people irradiated/contaminated • require specialist treatment in both primary and secondary medical facilities • can lead to widespread public health action to mitigate the effects of contamination. Module I. Module Medical I - Radiation accidents

  18. MAJOR RADIATION ACCIDENTS WORLDWIDE HUMAN EXPERIENCE 1944 - 1999 Number of Persons Significant Total accidents involved exposures fatalities 417 133 550 3003 127 Source: Radiation Emergency Assistance Center/Training Site Radiation Accident Registries, ORISE-EHSD-REAC/TS, Oak Ridge, 2000 Module I. Module Medical I - Radiation accidents

  19. ‘ORPHAN’ SOURCES • never subject to regulatory control or • initially regulated but then • abandoned • lost or misplaced • stolen or removed without authorization • frequent cause of radiation accidents during the last 15 years Module I.

  20. Terrorist use of radioactive material After September 11th, growing apprehension that by shrouding a core of conventional explosives around a radioactive source…. Module I.

  21. …..contamination could be spread over a wide area… + = …and terror created!! Module I.

  22. Radiation accidents by cause & medical management • Radiation accidents with unknown origin and late recognition: (e.g. Goiania, 1987; Estonia, 1994; Georgia, 1997 & 2001; Turkey, 1998/99; Thailand, 2000; Egypt, 2000 ) • Accidents with initially known radiation origin: (e.g. Iran, 1996; Peru, 1999 ) • Accidental exposure in medical applications: (e.g. Spain, 1990; Costa Rica, 1996, Panama, 2001) • Criticality accidents: (e.g. Sarov, Russia, 1997; Tokaimura, Japan, 1999) • Major nuclear accident: Chernobyl, USSR (1986) Module I. Module Medical I - Radiation accidents

  23. SummaryFrequent causes and application areas of radiological accidents • misuse of gamma sources and X-ray machines in industrial radiography and production control • misuse of gamma sources in sterilization and preservation of foodstuffs or for other purposes • misuse of ionizing radiation or misadministration of radioactive substances for diagnostic radiology, nuclear medicine and radiotherapy (X-ray generating machines and gamma ray sources, particle accelerators, and sealed or unsealed radionuclide sources) • negligent or unregulated disposal of radiation sources or radioactive waste Module I. Module Medical I - Radiation accidents

  24. Lessons identified for prevention of radiation accidents • Registration of all radiation sources and their control (during all phases of application, transport and disposal) • Safety culture • Regular training Module I. Module Medical I - Radiation accidents

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