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Glossary
Pages 223-238

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From page 223... ... For purposes of radiation protection and assessing risks to human health, the quantity normally calculated is the average absorbed dose in an organ or tissue, equal to the total energy imparted to that organ or tissue divided by the total mass. The ST unit of absorbed dose is the joule per kilogram () Read the entire page →
From page 224... ... . Background radiation: Ionizing radiation that occurs naturally in the environment including: cosmic -radiation; radiation emitted by naturally occurring radionuclides in air, water, soil, and rock; radiation emitted by naturally occurring radionucTides in tissues of humans and other organisms; and radiation emitted by human-made materials containing incidental amounts of naturally occurring radionuclides (such as building materials) Read the entire page →
From page 225... ... This is a measure of the overall risk associated with internal deposition of radioactive material. Containment: A gas-tight shell or other enclosure around a nuclear reactor to confine radioactive materials that otherwise might be released to the atmosphere in the event of an accident. Read the entire page →
From page 226... ... Dose: A quantification of exposure to ionizing radiation, especially in humans. in this report, the term is used to denote average absorbed dose in an organ or tissue, equivalent dose, effective dose, or effective dose equivalent, and to denote dose received or committed dose. Read the entire page →
From page 227... ... Equivalent (lose: A quantity obtained by multiplying the absorbed dose by a radiation-weighting factor to allow for the different effectiveness of the various types of ionizing radiations in causing late effect harm in tissue. The equivalent dose is theoretical and has replaced the earlier dose equivalent. Read the entire page →
From page 228... ... Half-life, effective: The time required for the activity of a radioactive substance in the body to decrease to I/2 its value due to the combined effects of biological elimination and radioactive decay. The effective half-life facilitates evaluating radiation dose from inhaled and ingested radionuclides and applies when the biological and physical half-lives are constant. Read the entire page →
From page 229... ... accident as well as other accidents involving exposure to ionizing radiation. Incidence: The rate of occurrence of new cases of a specific disease in a specific time period, calculated as the number of new cases during a specified period divided by the number of individuals at risk of the disease during that period. Read the entire page →
From page 230... ... Examples include alpha particles, beta particles, gamma rays or x rays, and cosmic rays. The minimum energy of ionizing radiation is a few electron volts (eV) Read the entire page →
From page 231... ... Leukemia: The term used to descnbe a group of malignant, commonly fatal blood diseases characterized by an uncontrolled increase in the number of white cells (generally their immature forms) in the circulating blood. Read the entire page →
From page 232... ... Nuclear incident: An event or series of events, either deliberate or accidental, leading to the release, or potential release, into the environment of radioactive materials in sufficient quantity to warrant consideration of protective actions. Nuclear power plant: An electrical generating facility using a nuclear reactor as its heat source to provide steam to a turbine generator. Read the entire page →
From page 233... ... In regard to adverse effects of ionizing radiation on humans, the term usually refers to the probability that a given radiation dose to a person will produce a health effect (such as cancer) or the frequency of health effects produced by given radiation doses to a specified population within a specified period. Read the entire page →
From page 234... ... Sheltering: A protective measure that consists of staying indoors, with closed doors and windows, to limit the inhalation of radioactive products that may present following a release of radiation, or to protect against direct gamma radiation from a radioactive cloud, or from radioactive material deposited on the ground. Sievert: The special name for the ST unit of equivalent dose; ~ Sv = ~ kg- = 100 rem. Read the entire page →
From page 235... ... electromagnetic radiation produced in deceleration of energetic charged particles (such as beta radiation) in passing through matter, referred to as continuous x rays or bremsstrahIung; also called x rays. Read the entire page →
From page 236... ... 236 GLOSSARY Conversions between ST units and Traditional Units Exposure roentgen (R) Absorbed red Dose Equivalent rem Dose Activity curie (Ci) Read the entire page →
From page 237... ... Environmental Protection Agency EPZ Emergency Planning Zone FDA Food and Drug Administration FEMA Federal Emergency Management Agency IAEA International Atomic Energy Agency TCRP International Commission on Radiological Protection TCRU International Commission on Radiation Units and Measurements TOM Institute of Medicine K} Potassium iodide KIDS Potassium Todate LET Linear Energy Transfer MTT Monoiodotyrosine NAS National Academy of Sciences NCT National Cancer Institute NCRP National Council on Radiation Protection and Measurements NEA Nuclear Energy Agency NE} Nuclear Energy Institute NEMA National Emergency Management Association NTH National Institutes of Health ,, Read the entire page →
From page 238... ... Nuclear Regulatory Commission OSTP Office of Science and Technology Policy PAG Protective Action Guideline PORV Pilot Operated Relief Valve RATU Radioactive Todine Uptake REP Radiation Effectiveness Factor REAC/TS Radiation Emergency Assistance Center/Training Site REP Radiological Emergency Preparedness SD Standard Deviation S:[ Systeme international (International System) TBG Thyroid-Hormone Binding Globulin T3 Thyroid Hormone Triiodothyronine T4 Thyroid Hormone Thyroxine TEDE Total Effective Dose Equivalent TNT Trinitrotoluene TSH Thyroid-Stimulating Hormone TRH Thyrotropin-Releasing Hormone W-C Effect Wolff-Chaikoff Effect WHO World Health Organization Read the entire page →

From page 223...

... For purposes of radiation protection and assessing risks to human health, the quantity normally calculated is the average absorbed dose in an organ or tissue, equal to the total energy imparted to that organ or tissue divided by the total mass. The ST unit of absorbed dose is the joule per kilogram ()

Glossary Pages 223-238

Glossary
Pages 223-238