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Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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.
Douglas A. Fynan, Jinhee Park
Nuclear Technology | Volume 207 | Number 3 | March 2021 | Pages 335-351
Technical Paper | doi.org/10.1080/00295450.2020.1760704
Articles are hosted by Taylor and Francis Online.
This study investigates the degradation of the heat transfer performance of a closed-circuit intermediate natural circulation heat transport loop used as a passive safety system in a nuclear power plant (NPP). The degradation arises from the strong thermal-hydraulic (TH) coupling of the loop operating characteristics, saturation temperature and pressure, and natural circulation flow rate, which determine the heat rejection rate to the TH boundary conditions imposed on the hot side of the loop by the transitory state of the primary reactor coolant system (RCS) of the NPP. Several operator actions related to a feed-and-bleed emergency operating procedure (F&B) are postulated, and system TH code simulations are performed to demonstrate how the F&B can induce two-phase flow conditions in the RCS. Natural circulation two-phase flow regimes in the RCS hot leg can significantly reduce the heat transfer to the circulating working fluid of the interfacing heat transport loop over long periods, sometimes lasting over 24 h, of passive system mission time. A transient performance indicator for the passive system mission is introduced for use in the passive reliability assessment and quantitative comparison of transient simulations. The need to consider human factors in the design and operation of NPP passive safety systems is stressed.