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Radiation in Your Environment

Radiation in Your Environment. Radiation Around You. Nature Cosmic (direct and cosmic-produced radioactivity Terrestrial (including radon) Medical Consumer Products Transportation Nuclear Power Nuclear Weapons Fallout. Naturally Occurring Radioactive Material.

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Radiation in Your Environment

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  1. Radiation in Your Environment

  2. Radiation Around You • Nature • Cosmic (direct and cosmic-produced radioactivity • Terrestrial (including radon) • Medical • Consumer Products • Transportation • Nuclear Power • Nuclear Weapons Fallout

  3. Naturally Occurring Radioactive Material • Primordial radionuclides- left over from when the earth was created. • Cosmogenic radioactivity - Radionuclides produced when cosmic radiation interacts with the upper atmosphere

  4. Cosmic Radiation • The primary source of cosmic radiation is outside this solar system: sun and stars • The atmosphere and the earth’s magnetic field act as a shield against radiation, reducing the radiation that reaches the earth’s surface. • Higher doses at higher altitudes.

  5. Terrestrial Radiation • Primordial radionuclides in rock and soil • Primarily long lived nuclides • K-40 (also in food) • Body contains about 0.1 µCi which produces 0.2 mSv(20 mrem) per year • U-238 series • Source of radon in buildings • Th-232 series

  6. Environmental Monitoring

  7. Primary Objective of a Nuclear Facility • Keep radioactive effluents at a minimum • Particulate filters to remove particles from air effluents • Charcoal filters to remove iodine • Hold-up tanks or charcoal traps to allow radioactive noble gasses to decay • Filter liquid effluents

  8. Environmental Monitoring • Purpose: • To detect any radioactivity released by a nuclear facility • To look for high activities of natural radioactivity • Verify and validate radioactive effluent monitoring program

  9. Reasons for Environmental Monitoring • External regulators • Nuclear Regulatory Commission • Environmental Protection Agency • Internal motivation • Environmental stewardship • Insurance (American Nuclear Insurers) • Concern for ourselves, families, and neighbors

  10. Nuclear Facilities • Program for nuclear facilities: • Radioactive Environmental Monitoring Program (REMP) • Sampling for a period of three years prior to operation • Assess natural radioactivity • Continual sampling during operation • Look for radionuclides from the plant

  11. Nuclear Facilities REMP • Measure: • Radioactivity • Air • Water • Food • Radiation dose • At site boundary • Public exposures

  12. REMP: Objectives • Protection of environment and people from releases • Documentation of existing and continuing radiological conditions • Compliance with regulations • Documentation of unanticipated environmental effects • Protection from legal liabilities • Research: verification of models

  13. REMP: Design • Facility information • Radioactivity produced • Physical form • Particulates • Gasses • Chemical • Effluent controls • Pathway information

  14. REMP: What to Measure • Direct gamma radiation • Thermoluminescent dosimeters • Ionization meters (real time) • Air pathways (inhalation/ingestion) • Air (particulates/iodine) • Crops • Grass-cow-milk pathway

  15. REMP: How to Measure • Continuous measurements of effluents • Stack monitors to measure airborne effluents • Radiation monitors in liquid streams • Periodic grab samples from environment • Food products (milk, fish, vegetables, etc.) • Plants (pasture grass, broad leaf vegetation)

  16. REMP: MeasurementsDirect Radiation Thermo- Luminescent Dosimeters (TLD) measure radiation from facility

  17. REMP: MeasurementsDirect Radiation

  18. REMP: Water Measurements • Water pathways (ingestion) • Water • Fish • Aquifers • Invertebrates • Field/outfall mixing zones

  19. REMP: Air Measurements • Noble gases: • Not chemically reactive • Readily dispersed • Gases of interest • Xe-133, Xe-135 • Short half-lives (5.2 day, 9.1 hr) • Kr-85 • Long half-life (10.8 yr)

  20. REMP: Air Measurements • Tritium (H-3) • Liquid effluents • Cannot remove from water • Iodine and particulates • I-131, Cs-137, Sr-90,Co-60 • Readily removed from effluent • Very small releases

  21. REMP: Air Measurements Low volume air sampler measures particulate material and iodine

  22. Natural Radioactivity • Cosmic ray produced • H-3, C-14, Na-22, Be-7 • 4 million Curies of H-3 produced each year • Terrestrial • Uranium-238 and Thorium-232 series • Radium and radon • Potassium-40, Rubidium-87

  23. Typical Radioactivity in the Environment • Air particulates • Gross beta: 0.004 - 0.04 pCi/m3 • Be-7: 0.02 - 0.2 pCi/m3 • Air Iodine • Not detectable • Soil • Sr-90: 0.02 - 0.2 pCi/g • Cs-137: 0.1 - 1.0 pCi/g • K-40: 5 - 20 pCi/g • Ra-226: 10 - 50 pCi/g

  24. Typical Radioactivity in the Environment • Precipitation • Gross beta: 1 - 4 pCi/L • H-3: 75 - 200 pCi/L • Be-7: 40 - 100 pCi/L • Water • Gross beta: 0.5 - 5.0 pCi/L • H-3: 75 - 200 pCi/:L • I-131: 0.25 - 1.0 pCi/L (hospital releases) • Sediment • Cs-137: 0.1 - 1.0 pCi/g

  25. Typical Radioactivity in the Environment • Fish • Sr-90: 0.002 - 0.02 pCi/g • Cs-137: 0.01 - 0.02 pCi/g • Milk • I-131: not detectable • Cs-137: 1 - 10 pCi/L • K-40: 1000 - 2300 pCi/L • Sr-90: 0.5 - 5.0 pCi/L • Food products • K-40: 0.5 - 5.0 pCi/g • Sr-90: 0.002 - 0.02 pCi/g

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