01	Fusion Devices (Thermonuclear)	Theory, design, construction, and operation of devices for producing controlled thermonuclear fusion reactions; Development, design, testing, and operation of thermonuclear power plants. See also 20/09, Plasma Physics and Magnetohydrodynamics. For thermonuclear weapons, See 19/11, Nuclear Weapons.
02	Isotopes	Identification, separation, and concentration of isotopes. For isotopic SNAP(Systems for Nuclear Auxiliary Power) applications, See 18/08, SNAP(Systems for Nuclear Auxiliary Power) Technology. For pollution of the environment by radioactive isotopes, See 24/06, Radiation Pollution and Control. For the use of isotopes in a particular application, such as radioactive isotope tracer studies, see the group where the application is treated. See also 07/05, Radiation and Nuclear Chemistry.
03	Nuclear Explosions and Devices (Non-Military)	Design and development of nuclear devices for peaceful purposes, such as Plowshare; Explosion effects such as shock waves and earth movement; Simulation and testing of non-military nuclear devices. Includes the use of nuclear explosions to inject charged particles into the endoatmosphere and exosphere. For the design and applications of military nuclear devices, See 19/11, Nuclear Weapons, and 15/06/04, Nuclear Warfare.
04	Nuclear Instrumentation	Nuclear radiation detection and measurement devices and systems. For nuclear health physics instrumentation, such as dosimeters, See 06/07, Radiobiology.
05	Nuclear Power Plants and Fission Reactor Engineering	Engineering related directly to the design and operation of a fission reactor; Integrated assemblage, including reactor and turbogenerator equipment; Control and regulatory devices. Includes mobile as well as stationary power plants. For critical assemblies, See 18/09, Fission Reactor Physics. See also 18/05/01, Nuclear Fission Reactors (Power), and 18/08, SNAP (Systems for Nuclear Auxiliary Power) Technology. For thermonuclear power plants, See 18/01, Fusion Devices (Thermonuclear). For nuclear propulsion power plants, See 21/06, Nuclear Propulsion.
05/01	Nuclear Fission Reactors (Power)	Design, construction and operation of nuclear fission reactors used for electric power generation. Includes site selection and feasibility studies. See also 18/05, Nuclear Power Plants and Fission Reactor Engineering, and 18/08, SNAP(Systems for Nuclear Auxilary Power) Technology. For disposal of radioactive wastes from nuclear reactors, See 24/06, Radiation Pollution and Control.
05/02	Nuclear Fission Reactors (Non-Power)	Nuclear fission reactors designed and built for purposes other than for electric power or propulsion. Includes production, research and training, test, and process heat reactors.
06	Nuclear Radiation Shielding, Protection and Safety	Shielding design; Nuclear radiation transport properties of materials; Decontamination; Nuclear safety engineering procedures; Container design and transportation requirements for radioactive materials. See also 23/04, Protective Equipment. For civil defense, See 15/02, Civil Defense. For the storage and transport of nuclear weapons, See 15/06/04, Nuclear Warfare. For electromagnetic shielding used to protect electronic equipment, See 09/07, Electromagnetic Shielding.
07	Radioactivity, Radioactive Wastes and Fission Products	Radioactive decay; Natural and induced radioactivity; Interaction of charged particles and radiation with matter; Separation, processing, handling, and storage of radioactive wastes; Fission product utilization; Natural radioactivity. For fission reaction studies, See 18/09, Fission Reactor Physics. For disposal of radioactive wastes and radioactive fallout, See 24/06, Radiation Pollution and Control. See also, 07/05, Radiation and Nuclear Chemistry.
08	SNAP (Systems for Nuclear Auxiliary Power)	Systems for nuclear power, both isotopic and reactor.
09	>Fission Reactor Physics	Fission reactor kinetics and theory; Neutron transport theory; Criticality; Scattering; Slowing down economy. Includes critical assemblies and reactor simulators.
10	Fission Reactor Materials	Production, testing, and reclamation of fuel materials, coolants, moderators, control materials, structural materials, and shielding materials. Includes fabricated elements or assemblies and specific configurations. For disposal of reactor materials, See 24/06, Radiation Pollution and Control.