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Division Spotlight
Aerospace Nuclear Science & Technology
Organized to promote the advancement of knowledge in the use of nuclear science and technologies in the aerospace application. Specialized nuclear-based technologies and applications are needed to advance the state-of-the-art in aerospace design, engineering and operations to explore planetary bodies in our solar system and beyond, plus enhance the safety of air travel, especially high speed air travel. Areas of interest will include but are not limited to the creation of nuclear-based power and propulsion systems, multifunctional materials to protect humans and electronic components from atmospheric, space, and nuclear power system radiation, human factor strategies for the safety and reliable operation of nuclear power and propulsion plants by non-specialized personnel and more.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
ANS designates Armour Research Foundation Reactor as Nuclear Historic Landmark
The American Nuclear Society presented the Illinois Institute of Technology with a plaque last week to officially designate the Armour Research Foundation Reactor a Nuclear Historic Landmark, following the Society’s decision to confer the status onto the reactor in September 2024.
Robert Avery
Nuclear Science and Engineering | Volume 3 | Number 2 | February 1958 | Pages 129-144
Technical Paper | doi.org/10.13182/NSE58-A25455
Articles are hosted by Taylor and Francis Online.
Coupling a fast and thermal assembly in a power breeder reactor affords the possibility of obtaining the relatively long neutron lifetime characteristic of a thermal assembly and the high breeding ratio characteristic of a fast assembly. General properties of such mixed systems are discussed. A suggested design is discussed and compared with a prototype all-fast system. The coupled system considered consists of a 400-liter Pu239 fueled, Na-cooled, fast core surrounded by a 10-cm inner blanket annulus containing natural U, Na coolant, and structural material, but no moderator. Outside the inner blanket is a 30-cm annulus of Be surrounded by an outer blanket consisting primarily of depleted U. The inner blanket serves as core for the thermal system, as barrier for low-energy neutrons between moderator and fast core, and as reflector for the fast core. Its construction is essentially the same as the first part of the blanket in a fast power breeder, so that the transition from an allfast system to the coupled system involves only the replacement of blanket material by moderator and the use of natural rather than depleted uranium in the inner blanket. The properties of the system described are thereby changed: neutron lifetime increases from ∼1.5 × 10-7 sec. to ∼2×10-5 sec; breeding ratio reduced ∼10%; fast core critical mass decreased ∼10%; multiplication constant of the system without the contribution of thermal fissions ∼0.95; thermal fissions generate ∼13% of total power; and the radial power distribution in fast core flattened, maximum to average ratio reduced from ∼1.5 to ∼1.3.
