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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.
Edward T. Dugan, Samer D. Kahook
Nuclear Technology | Volume 103 | Number 2 | August 1993 | Pages 139-156
Technical Paper | Fission Reactor | doi.org/10.13182/NT93-A34839
Articles are hosted by Taylor and Francis Online.
Static and dynamic neutronic analyses have been performed on an innovative burst-mode (hundreds of megawatts output for a few thousand seconds) Ultrahigh-Temperature Vapor Core Reactor (UTVR) space nuclear power system. This novel reactor concept employs multiple neutronically coupled fissioning cores and operates on a direct closed Rankine cycle using a disk magnetohydrodynamic generator for energy conversion. The UTVR includes two types of fissioning core regions: (a) the central Ultrahigh-Temperature Vapor Core (UTVC), which contains a vapor mixture of highly enriched UF4fuel and a metal fluoride working fluid and (b) the UF4 boiler column cores located in the BeO moderator-reflector region. The gaseous nature of the fuel, the fact that the fuel is circulating, the multiple coupled fissioning cores, and the use of a two-phase fissioning fuel lead to unique static and dynamic neutronic characteristics. Static neutronic analysis was conducted using two-dimensional Sn transport theory calculations and three-dimensional Monte Carlo transport theory calculations. Circulating-fuel, coupled-core point reactor kinetics equations were used for analyzing the dynamic behavior of the UTVR. In addition to including reactivity feedback phenomena associated with the individual fissioning cores, the effects of core-to-core neutronic and mass flow coupling between the UTVC and the surrounding boiler cores were also included in the dynamic model. The dynamic analysis of the UTVR reveals the existence of some very effective inherent reactivity feedback effects that are capable of quickly stabilizing this system, within a few seconds, even when large positive reactivity insertions are imposed. If the UTVC vapor-fuel density feedback is suppressed, the UTVR is still inherently stable because of the boiler core liquid-fuel volume feedback; in contrast, suppression of the vapor-fuel density feedback in “conventional” gas core cavity reactors causes them to become inherently unstable. Because of the strength of the negative reactivity feedback in the UTVR, it is found that external reactivity insertions alone are inadequate for bringing about significant power level changes during normal reactor operations. Additional methods of reactivity control, such as variations in the gaseous fuel mass flow rate, are needed to achieve the desired power level control.
