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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
Sümer Şahin, Elliot B. Kennel
Nuclear Technology | Volume 107 | Number 2 | August 1994 | Pages 155-181
Technical Paper | Fission Reactor | doi.org/10.13182/NT94-A34985
Articles are hosted by Taylor and Francis Online.
A thermo-hydrodynamic-neutronic analysis is performed for a fast, uranium carbide (UC) fueled spacecraft nuclear in-core thermionic reactor. The thermo-hydrodynamic analysis shows that a hybrid thermionic spacecraft nuclear reactor can be designed for both electricity generation and nuclear thermal propulsion purposes. This reactor would deliver a thermal thrust ∼5000 N by a specific impulse of 670 s at a hydrogen exit temperature ∼1900K. During the nuclear thermal thrust phase, the electricity generation will drop, depending on the entry temperature of the hydrogen propellant. Fresh hydrogen can be preheated through nozzle cooling up to 1000 K or more before entering the reactor. The hydrogen pressure and velocity at reactor entry are selected p = 30 atm and ν = 200 m/s, respectively. The pressure drop along the reactor core height (= 35 cm) is calculated Δp = 8.59 atm. The neutronic analysis has been conducted in S8-P3 approximation with the help of one- and two-dimensional neutron transport codes ANISN and DORT, respectively. The calculations have shown that a UC fueled electricity generating single mode thermionic nuclear reactor can be designed to be extremely compact because of the high atomic density of the nuclear fuel (by 95 % sintering density), namely, with a core radius of 8.7 cm and core height of 25 cm, leading to power levels as low as 5 kW(electric) by an electrical output on an emitter surface of 1.243 W/cm2. A reactor control with boronated reflector drums at the outer periphery of the radial reflector of 16-cm thickness would make possible reactivity changes of Δkeff > 10%—amply sufficient for a fast reactor—without a significant distortion of the fission power profile during all phases of the space mission. The hybrid thermionic spacecraft nuclear reactor mode contains cooling channels in the nuclear fuel for the hydrogen propellant. This increases the critical reactor size because of the lower uranium atomic density in this design concept. Calculations have lead to a reactor with a core radius of 22 cm and core height of 35 cm leading to power levels ∼50 kW(electric) under the aforementioned thermionic conversion conditions.
