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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.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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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Fusion Science and Technology
Latest News
Taking shape: Fusion energy ecosystems built with public-private partnerships
It’s possible to describe fusion in simple terms: heat and squeeze small atoms to get abundant clean energy. But there’s nothing simple about getting fusion ready for the grid.
Private developers, national lab and university researchers, suppliers, and end users working toward that goal are developing a range of complex technologies to reach fusion temperatures and pressures, confounded by science and technology gaps linked to plasma behavior; materials, diagnostics, and electronics for extreme environments; fuel cycle sustainability; and economics.
Sipeng Wang, Bao-Wen Yang, Zhaobo Zhou, Jianping Long
Nuclear Science and Engineering | Volume 193 | Number 1 | January-February 2019 | Pages 14-32
Critical Review – Selected papers from NURETH 2017 | doi.org/10.1080/00295639.2018.1512791
Articles are hosted by Taylor and Francis Online.
The thermal-hydraulic characteristics of nuclear reactors under ocean conditions are significant for reactor safety and reliability. A large number of experiments concerning this issue have been done. However, the focus of these experiments has been mainly on dynamical systems in submarines and aircraft carriers. With the development of floating nuclear power plants (FNPPs)—which are used to provide power for remote areas or ocean platforms—more studies on FNPPs are needed. The differences between FNPPs and dynamical systems bring new challenges to research of thermal-hydraulic characteristics in a nuclear reactor under ocean conditions.
Many experimental studies on natural circulation and forced circulation under ocean conditions are based on tube and rectangular channels. The effects of ocean motions on friction, flow instability, heat transfer, and critical heat flux (CHF) have been investigated. The intensity of ocean motions and their driving head have a huge impact on pressure drop, heat transfer, and flow instability, especially when the driving head is small. Flow oscillations induced by ocean motions can overlap with thermal-induced flow instability. This resonance effect can cause potential harm to systems. CHF under ocean conditions is mainly dependent on motion types and the CHF mechanism.
There are challenges with this research. First, conclusions obtained from a simple channel cannot always extend to rod bundle systems. Second, studies of ocean conditions, which always use one- or two-dimensional movements, are relatively simple and cannot reflect complicated ocean environments. Third, there is a lack of comparison between natural frequency of two-phase flow instability and frequency of ocean waves, and this may cause unwanted problems due to resonance or coupling behaviors. Fourth, CHF experiments that are performed to examine CHF events under ocean conditions are far from real reactor conditions where CHF events occur under high-temperature and high-pressure conditions, with complicated three-dimensional geometry, with open channel environments, and sometimes even under the influence of mixing vane grids [for most small modular reactor designs]. Last, there has been no work on the length effect, nonuniform heating, and mixing effect induced by spacer grids, which differentiate FNPP thermal-hydraulic characteristics from the other applications. A series of suggestions are provided for future work.