Radioactivity and Radiation Flashlight Light Ability to emit light Unit for expressing strength of light [candle (cd)] Unit for expressing brightness [lux (lx)] Radioactive Substance Ability to emit radiation (radioactivity＊) Radiation Unit for expressing strength of radiation Unit for expressing how much impact the radiation exerts [Sievert (Sv)] [Becquerel (Bq)] ＊May also be used to describe a substance (radioactive material) that is radioactive. 6 -1-1 ©JAERO Units Used in Relation to Radioactivity Name Unit (Symbol) Definition Unit of Radioactivity International System of Units (SI) This unit represents the quantity of radioactive mate- Becquerel (Bq) Radioactivity rial in which one nucleus decays per second. Unit of Radiation Dosage International System of Units (SI) This unit represents how much energy is received by an object or person hit by radiation. A dose of 1 Gray Absorbed dose Gray (Gy) corresponds to 1 joule of energy absorbed by 1 kilo- gram of matter. This unit is used for assessing how much risk radia- tion poses to people in terms of inducing cancer or Sievert (Sv) Dose genetic damage. (1 Sievert = 1,000 mSv) Unit of Energy International System of Units (SI) Unit of energy that represents the energy of radiation Joule (J) Energy (1J＝6.2×1018eV) 6 -1-2 ©JAERO Types of Electromagnetic Waves 10-15m 10-14m 10-13m 10-12m 10-11m 10-10m 10-9m 10-8m 10-7m 10-6m 10-5m 10-4m 10-3m 10-2m 10-1m 1m 10m 102m 103m (1Å) (1µm) (1mm) (1cm) (10cm) (1km) Wavelength 0.4µm 0.8µm (VHF) Gamma rays X-rays Ultraviolet Visible (UHF) (Generated from the nucleus) (Generated outside the nucleus) rays rays Within X-rays there are things with rays Infrared wavelengths shorter than gamma rays Far infrared rays infrared Far Millimeter waves Ultrashort waves Short waves (HF) Short waves Centimeter waves Medium waves (MF) Medium waves Sub-millimeter waves Sauna Ultra high-frequency waves Ultra Microwaves X-ray radiography X-ray Electric waves Synchrotron radiation Radar Contact-free thermometer AM radio TV (VHF) TV (UHF) Inhibiting potato germination Suntan and germicidal lamps Computed tomography (CT scan) Computed tomography Shortwave radio Shortwave Specific Examples FM radio, wireless FM radio, Fruit acidity and sugar content gauges Fruit Sterilization of medical equipment via irradiation Cell phones, microwave ranges microwave Cell phones, TV remote control, infrared camera, infrared heaters infrared camera, TV remote control, infrared Fluorescent lamp, incandescent lamp, visible laser light visible incandescent lamp, Fluorescent lamp, 1023Hz 1022Hz 1021Hz 1020Hz 1019Hz 1018Hz 1017Hz 1016Hz 1015Hz 1014Hz 1013Hz 1012Hz 1011Hz 1010Hz 109Hz 108Hz 107Hz 106Hz (1THz) (1GHz) (1MHz) Frequency 6 -1- 3 Source: Japan Atomic Energy Agency, What is Radiation? ©JAERO Properties of Radiation Ionization Effect Fluorescence Effect Permeation Fluorescent substance (inside the glass) Nucleus Atoms of gas (mercury) Electron Pole Pole X-ray Generator Electron Ultraviolet rays Radiation How Fluorescence Works When voltage is applied across the poles of the tube, electrons flow from one pole to the other. When electrons crash into mer- cury enclosed in the tube, it pro- duces ultraviolet light. The ultra- violet rays light up the fluores- cent substance. 6 -1- 4 ©JAERO Types of Radiation 4 Alpha ray ( 2 He nucleus) (Ex.) α Alpha ( ) decay 226 α 222 88Ra 86Rn Beta ray (electron) e (Ex.) Beta (β) decay 24 β 24 11 Na 12 Mg Gamma ray Gamma (γ) ray emission (electromagnetic wave) Proton Neutron X-rays...generated outside the nucleus Electromagnetic wave Gamma rays (γ)...come out of the nucleus Beta rays (β)...electrons that escape the nucleus 4 Radiation Charged particles Alpha rays (α)...Helium- 2 atom nuclei that escape the nucleus Other Uncharged particles Neutrons...generated in the use of nuclear reactors, accelerators and radio isotopes (radionuclide) 6 -1- 5 ©JAERO Permeability of Different Kinds of Radiation Stops alpha rays Stops beta rays Weaken gamma and X-rays Alpha rays (α) Beta rays (β) Gamma rays (γ) X-rays (X) Paper Thin sheet of metal Thick board such as aluminum of lead and iron Weaken Neutrons radiation Neutron radiation Substance containing hydrogen For example water or concrete 6 -1- 6 Source: Ministry of the Environment, Unified Basic Data on Health Effects from Radiation (FY2017) ©JAERO How Radiation Decays Radioactive Substance Emitted Radiation＊ Half-life 1 Initial Level Thorium-232 α・β・γ 14.1 billion years Uranium-238 α・β・γ 4.5 billion years Potassium-40 β・γ 1.3 billion years Plutonium-239 α・γ 24,000 years Carbon-14 β 5,700 years Radium-226 α・γ 1,600 years Cesium-137 β・γ 30 years Strontium-90 β 28.8 years Tritium β 12.3 years 1/2 Cobalt-60 β・γ 5.3 years Cesium-134 β・γ 2.1 years Half-life Level of Radioactivity Iodine-131 β・γ 8 days Radon-222 α・γ 3.8 days 1/4 Sodium-24 β・γ 15 hours Half-life 1/8 Half-life 1/16 Half-life (Time) ＊Includes radiation from products of decay (Nuclides that emit radiation and become a different nuclide.) 6 -1-7 Source: Japan Radioisotope Association, Radioisotope Pocket Data Book (2012) ©JAERO Radiation in our Daily Lives Radiation Exposure (mSv) We receive ＊1 2,500 to 6,000 mGy Infertility (gonads) 10000 doses of radiation in 3,000 to 5,000 mGy Temporary hair loss (skin)＊1 our daily lives from a variety of sources. ｍ From outer space 0.39 100 to 6,200 Gy Cardiac catherization (skin) 100 mSv or less 1000 Amount of radiation (mSv) exposure that bears 500 to 2,000 mGy no statistical difference in terms of the risk of cancer Lens becomes cloudy (eye)＊1 500 mGy Reduced blood-forming function (bone marrow)＊1 From the ground 0.48 Ramsar (Iran), Kerala, Chennai (India), 100 natural radiation from the ground 0.5 to 613.2 250 Limited to emergency workers ＊5 (No adverse impact to the health of residents found.) at power plants, etc. 50 Limit for workers at power plants, etc. (per year)＊4 10 From food 0.29 Natural radiation/person (per year) 2.4 2.4 to 12.9 CT (1 time) (World Average) 2.0 to 10 PET scan (1 time) 1 Natural radiation/person (per year) 2.1 3.0 Stomach X-ray (1 time) (Average in Japan) 1.0 Limit for the general public From radon in the air＊2 1.26 Flight from Tokyo to New York (excluding for medical treatment) (per year) (round trip) 0.08 to 0.11 ＊1：When discussing radiation hazards, it is expressed as 0.1 equivalent to an effective dose of 1 mSv, given that a dose of 1 mSv of gamma radiation is absorbed evenly by each part of the the entire body ＊： 2 Radioactive substances naturally present in the air 0.06 Chest X-ray in annual checkup (1 time) ＊3：Insignificant compared to naturally-occurring radiation levels, and the level does not require handling as 0.01 0.05 Targeted dose around a nuclear plant (per year) ＊ a radioactive substance that presents a safety risk. Clearance level 3 0.01 (year) ＊4：Dose of radiation that must not be exceeded in 1 year is 0.022 Estimated dose at reprocessing plant (Rokkasho) (per year) 50 mSV for workers at places such as power stations, or 100 mSv over 5 years. 0.01 Dental X-ray ＊5：The dose limit was raised to 250 mSv to emergency workers from April 2016 0.001 Less than 0.001 Actual emissions from nuclear power plant due to the revision of the Ionizing Radiation Hazard Prevention Regulations, etc. Sources: United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), 2008 Report, Nuclear Safety Research Association, 6 -2-1 Radiation in the Environment, New Edition, 2011, and ICRP, Publication 103, with others ©JAERO Doses of Radiation from Natural Sources Annual dose/person (average in Japan) Annual dose/person (average worldwide) From breathing From outer space (mainly radon) From outer space 0.3 0.48 0.39 re su e o ur xp s E o l p a x E n r I I l n n e a t t t e n e x r r From the ground r n From breathing E e n t a a x (mainly radon) 0.33 l l E Annual dose of E Annual dose of E x 1.26 x p natural radiation p natural radiation o o From the ground s s (mSv) (mSv) u u r r e 2.1 e 0.48 2.4 From food＊ 0.99 From food＊ 0.29 ＊Compared to Western countries, the Japanese diet of seafood results in a larger effective dose due to Polonium-210. Sources: United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), 2008 Report, 6-2-2 and Nuclear Safety Research Association, Radiation in the Environment, New Edition, 2011 ©JAERO Differences in Natural Radiation Levels Cosmic rays Offshore Gamma rays (γ) Wooden house (Kamakura) 6-story steel-reinforced building (lobby) Underground mall in Ikebukuro Ginza 3-4 Chome Flight from Haneda to Osaka (5,000m) International flight at high altitude 1.61 (11,000m) 0 0.05 0.10 0.15 （µSv/ｈ） ＊1µSv＝1/1000 mSv 1µSv/h=365 days x 24hours x 1,000=8.75mSv/year 6-2-3 Source: High Energy Accelerator Research Organization Radiation Science Center, Trivia about Radiation--Radiation in our Daily Lives, (2005) ©JAERO Naturally Occurring Radiation in the Body & Our Food ●Level of radioactive materials in the body (based on a Japanese person weighing 60kg) Potassium-40 4,000 Becquerel Carbon-14 2,500 Becquerel Rubidium-87 500 Becquerel Lead-210/Polonium-210 20 Becquerel ●Level of the radioactive material Potassium-40 in food (Japan) (Unit: Becquerel/kg) Dried kelp 2,000 Dried shiitake 700 Potato chips 400 Raw seaweed 200 Spinach 200 Fish100 Beef100 Milk 50 Bread 30 Rice 30 Beer 10 6-2-4 Source: Nuclear Safety Research Association, Study on Radiation Data in the Living Environment (1983), New Edition - Radiation in the Living Environment 2011 ©JAERO Various Uses of Radiation Flow rate & velocity exams Non-destructive testing Weld inspection Reinforced plastics Thickness measurement Regulating ripening Gauging Selective breeding New drug development Preventing germination Study of compound structures X-ray exams X-ray CT scans Isotope batteries Cancer treatment Uses of Radiation 6-2-5 ©JAERO Basics of Protection from Radiation 1.