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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.
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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
ARPA-E announces $40 million to develop transmutation technologies for UNF
The Department of Energy’s Advanced Research Projects Agency–Energy (ARPA-E) announced $40 million in funding to develop cutting-edge technologies to enable the transmutation of used nuclear fuel into less-radioactive substances. According to ARPA-E, the new initiative addresses one of the agency’s core goals as outlined by Congress: to provide transformative solutions to improve the management, cleanup, and disposal of radioactive waste and spent nuclear fuel.
J. W. Coenen, B. Bazylev, S. Brezinsek, V. Philipps, T. Hirai, A. Kreter, J. Linke, G. Pintsuk, G. Sergienko, A. Pospieszczyk, T. Tanabe, Y. Ueda, U. Samm, The TEXTOR Team
Fusion Science and Technology | Volume 61 | Number 2 | February 2012 | Pages 129-135
Technical Paper | First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies | doi.org/10.13182/FST12-A13378
Articles are hosted by Taylor and Francis Online.
Behavior and characteristics of tungsten materials under impinging high heat fluxes are investigated. Experiments with inertially - not actively - cooled samples have been carried out in the plasma edge of the TEXTOR tokamak to study the changes of material properties such as grain size and abundance of voids or bubbles. In addition, the effects of electron beam impact regarding subsequent W power handling have been studied in view of future devices.The parallel heat flux at the radial position in TEXTOR impinging on the plasma-facing components (PFCs) ranges around q[parallel] [approximately] 45 MW/m2 allowing samples to be exposed at an impact angle of 35 deg to 20 to 30 MW/m2. Melt layer motion perpendicular to the magnetic field is observed following a Lorentz force originating from thermoelectric emission of the hot W sample. Up to 3 g of molten W are redistributed forming hill-like structures at the plasma-connected edge of the sample. The typical melt layer thickness is 1.0 to 1.5 mm. Those hills are, due to the changes in the local geometry, particularly susceptible to even higher heat fluxes of up to the full q[parallel]; hence, locally the temperature of W can reach up to 6000 K, and thus boiling can occur.In terms of material degradation, several aspects are considered: formation of leading edges by redistributed melt, bubble formation, and recrystallization. Bubbles are occurring in sizes between 1 and 200 m while recrystallization increases the grain size up to 1.5 mm. The power-handling capabilities are severely degraded by all those aspects. Melting of tungsten in future devices is highly unfavorable and needs to be avoided especially in light of uncontrolled transients and possible unshaped PFCs.Predamaged samples from the TEXTOR exposures have also been exposed in the JUDITH 1 facility under transient heat loads (up to [approximately]1 GW/m2, energy impact: 36 MWm-2s1/2). The samples show an unfavorable increase in the ductile-to-brittle transition temperature. In addition, surface cracks lose their directionality recrystallizing toward a more isotropic state from the manufactured monodirectional state. The increased grain size leads to a more brittle behavior under transient thermal loads with respect to crack progression.