| A | B |
|---|
| Absorbed Dose | Category: Nuclear/ Definition: The amount of energy actually deposited in a material or living tissue as a result of exposure to radiation. |
| Accelerometer | Category: Delivery System Terms/ Definition: A device whose output is proportional to the difference between the inertial and gravitational accelerations along its sensitive axis. |
| Accident Response Group (ARG) | Category: Nuclear /Definition: A group of technical and scientific experts composed of U.S. Department of Energy (DOE) and DOS contractor personnel assigned responsibility for providing DOE assistance to peacetime accidents and significant incidents involving nuclear materials anywhere in the world. |
| Acetylcholine | Category: Chemical/Definition: A chemical neurotransmitter produced by nerve cells predominately outside the central nervous system. It is a chemical messenger that stimulates the heart skeletal muscles and numerous secretary glands. Critical for nerve and muscle functions. |
| Acetylcholinesterase | Category: Chemical/Definition: An enzyme that normally hydrolyzes acetylcholine, thereby stopping its activity. Acetylcholinesterase is inhibited by organophosphates, carbamates and glycolates. Many nerve gases and insecticides are potent acteylcholinesterase inhibitors. |
| Acid | Category: Chemical/Definition: A chemical compound having a pH level less than 7. Acids usually have a sour taste and a propensity to react with bases to form salts. |
| Acid Bombs | Category: Conventional Explosives/Definition: Common ingredients are hydrochloric acid and aluminum foil that chemically reacts to give off heat. Ultimately producing hydrogen gas and sufficient pressure to burts the container. Commercial sources for hydrochloric acid are toilet bowl cleaners and etchant solution. |
| Actinides | Category: Nuclear/Definition: The series of heavy radioactive metallic elements of increasing atomic number from Actinium (atomic number Z=89) through Hahnium (atomic number Z-105). Nuclear reactor operations are among the processes which might produce or involve these elements. |
| Activation | Category: Nuclear/Definition: The process by which stable isotopes are converted to radioactive ones, usually by neutron capture. (See transmutation, radioactive decay). |
| Activation Analysis | Category: Nuclear/Definition: A technique for measuring trace quantities of elements in materials by making them radioactive by neutron irradiation. The elements can then be detected by counting the decay radiation. The result is an elemental signature or fingerprint that can be used to trace the source of the material. Activation analysis or neutron activation analysis is often used in forensic investigations. The radioactivity of the activated sample is usually negligible. |
| Active immunity | Category: Biological/Definition: usually long lasting immunity that is acquired through production of antibodies within the organism in response to the presence of antigens. Differs from passive immunity acquired by an individual after the transfer of antibodies through injections. |
| Active Material | Category: Nuclear/Definition: Material, such as plutonium and certain isotopes of uranium, which is capable of supporting a fission chain reaction. |
| Acute | Category: Chemical/Definition: Having a short and relatively severe course; arising quickly, as acute symptoms. |
| Acute Effect | Category: Nuclear/Definition: Symptom of exposure to a hazardous material; normally the result of a short-term exposure which comes quickly to a crisis. For example, one effect of an intense radiation exposure is a rapid browning of the skin, known as a nuclear tan. |
| Acute Exposure | Category: Nuclear/Definition: A single, brief exposure to a toxic substance. |
| Advanced Gas Cooled Reactor (AGCR) | Category: Nuclear/Definition: The AGCR is an advancement of the magnox reactor designed to raise the maximum allowable temperature of the gas coolant in order to improve the steam generation. |
| Advanced Reactors | Category: Nuclear/Definition: There are currently three types of advanced reactor designs: evolutionary light water, Breeder (liquid metal), and PRIME reactors, all with a widespread emphasis on passive and inherent safety. |
| Advanced Thermal Reactor (ATR) | Category: Nuclear/Definition: A new type of nuclear reactor being developed for use in Japan, which can use plutonium mixed with uranium as source fuel. |
| Aerial Measuring System (AMS) | Category: Nuclear/Definition: An aerial radiological detection system utilizing several DOE aircraft equipped for remote sensing. These aircraft systems are continuously maintained in emergency standby at Nellis Air Force Base, Las Vegas, Nevada and at Andrews Air Force Base, Washington, D.C. |
| Aerobic | Category: Biological/Definition: A biological habitat or an organism that requires oxygen to grow |
