RADIATION SAFETY REFERENCE MANUAL GLOSSARY .............................................................................................................................................................. 1 RADIOACTIVITY AND IONIZING RADIATION ........................................................................................................... 4 THE NATURE OF RADIOACTIVITY ....................................................................................................................................... 4 RADIATION TERMS & UNITS ............................................................................................................................................ 4 THE PROPERTIES OF RADIATION ........................................................................................................................................ 5 Alpha particles (α) ................................................................................................................................................ 5 Beta radiation (ß) ................................................................................................................................................. 5 Gamma radiation (γ) ............................................................................................................................................ 5 BASIC PRINCIPLES OF RADIATION PROTECTION ..................................................................................................... 6 A.L.A.R.A. .................................................................................................................................................................. 6 CONTAINMENT OF RADIOACTIVITY .................................................................................................................................... 6 SHIELDING OF RADIATION SOURCES ...................................................................................................................... 7 Beta Shielding....................................................................................................................................................... 7 Photon (X & γ Ray) Shielding ................................................................................................................................ 7 RADIATION SURVEYS AND DETECTION .................................................................................................................. 9 DETECTION OF SURFACE CONTAMINATION.......................................................................................................................... 9 GUIDLINES FOR SELECTING PORTABLE RADIATION SURVEY METERS ..................................................................... 10 RADIATION SURVEY METER CHARACTERISTICS ....................................................................................................... 11 RADIATION WARNING SIGNS AND LABELS........................................................................................................... 12 GENERAL REQUIREMENTS .............................................................................................................................................. 12 TYPES OF SIGNS AND LABELS .......................................................................................................................................... 12 BIOLOGICAL EFFECTS OF RADIATION ................................................................................................................... 14 ACUTE RADIATION INJURY ............................................................................................................................................. 14 LATENT EFFECTS OF RADIATION EXPOSURE ....................................................................................................................... 15 Stochastic Effects: Cancer .................................................................................................................................. 15 Effects of Fetal Exposure .................................................................................................................................... 15 Other Somatic Effects: Sterility, Cataracts, and Life Shortening ........................................................................ 16 Genetic Effects.................................................................................................................................................... 16 DECONTAMINATION ............................................................................................................................................ 17 PERSONNEL DECONTAMINATION .................................................................................................................................... 17 DECONTAMINATION OF EQUIPMENT AND FACILITIES ........................................................................................................... 17 GUIDELINES FOR DECONTAMINATION OF MATERIALS .......................................................................................................... 18 AVERAGE ANNUAL WHOLE-BODY DOSE RATES IN THE U.S. ................................................................................. 19 REFERENCES ......................................................................................................................................................... 26 GLOSSARY Activity: The number of nuclear disintegrations Committed effective dose equivalent (CEDE): occurring per unit time in a radioactive material. The sum of the products of the weighting factors applicable to each of the body organs or tissues Acute radiation exposure: A large exposure to that are irradiated and the committed dose ionizing radiation within a short period of time. equivalent to these organs or tissues. Acute radiation syndrome: A serious illness, also Carcinogenesis: The development of cancerous known as radiation poisoning, caused by exposure cells from normal ones. to high amounts of ionizing radiation. Onset usually occurs within 24 hours of exposure. Contamination: occurs when radioactive material is deposited on or in an object or a person. Adult: An individual of 18 or more years of age. Cosmic radiation: A source of natural background Agreement State: A State that has signed an radiation, which originates in outer space and is agreement with the NRC authorizing the State to composed of penetrating ionizing radiation (both regulate certain uses of radioactive materials particulate and electromagnetic). within the State. Decay Products (or Daughter products): ALARA (“As Low As Reasonably Achievable): Radionuclides that are formed by the radioactive A radiation safety principle in which practical decay of parent radionuclides. measures are used to minimize exposure to ionizing radiation. Common methods include a Declared Pregnant Woman (DPW): A radiation combination of minimizing exposure time and worker who voluntarily informs her employer, in increasing the distance and appropriate shielding. writing, of her pregnancy. Annual limit on intake (ALI): The derived Disintegration: Any change in a nucleus of an annual limit for the amount of radioactive material atom, whether spontaneous or induced, in which inhaled or ingested into the body of an adult one or more particles, photons, etc. are emitted. radiation worker. See the Table of Radioisotopes in this manual for a list of radionuclides and their Deep Dose Equivalent (DDE): The dose ALIs. equivalent at a tissue depth of 1 cm (1000 mg/cm2). This applies to external whole-body Attenuation: The decrease in exposure rate of exposure. radiation as it passes through matter. This is a result of absorption and scattering. Dose Equivalent: A calculated dose used to characterize the human dose with use of the quality Background radiation: Radiation in the natural factor. environment including cosmic radiation and radiation of naturally radioactive elements. Effective whole body dose equivalent (EDE): The sum of the products of the dose equivalent to Bioassay: The determination of radiation intake the organ or tissue (HT) and the weighting factors due to inhalation, ingestion and uptake. There are (WT) applicable to each of the body organs or two methods of performing the bioassay: tissues that are irradiated (HE=∑WTHT). • In Vivo: direct measurement, or counting, to localize and characterize radiation intake. Electromagnetic radiation: A form of radiant • In Vitro: analysis of human excreta. energy released by certain electromagnetic processes. Familiar forms of electromagnetic Bremsstrahlung radiation: Electromagnetic radiation are: x-rays, gamma rays, ultraviolet, radiation resulting from the interaction and visible, and infrared light. resultant loss of energy by high energy electrons passing through the fields of nuclei. Electron capture: A mode of decay for radioactive nuclei in which an orbital electron is Byproduct material: Radioactive material captured by the nucleus, converting a proton into a produced in nuclear reactors or accelerators. neutron. 1 Electron volt: One eV is equivalent to the energy resulting from an intake of radioactive substances gained by an electron when accelerated by a within the body. potential difference of one volt. Ionization chamber (IC): A portable radiation Epilation: Loss of hair. May occur following detection and measuring instrument used to survey large radiation doses. the external radiation present. The IC will read the exposure rate in units of Rad/hr. This is External radiation: Exposure to