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Baranwal reviews virtual STEM lessons for U.S. tribal communities
In a blog post to the Department of Energy’s website on November 23, Rita Baranwal, assistant secretary for the Office of Nuclear Energy, commended recent virtual lesson projects from the Office of Nuclear Energy and the Nuclear Energy Tribal Working Group to increase STEM opportunities for Native American tribes.
The spotlighted lesson discussed in the article focused on a 3D-printed clip that turns a smartphone or tablet into a microscope with the ability to magnify items by 100 times. The Office of Nuclear Energy shipped nearly 1,000 of these microscope clips to students across the country, many of them going to U.S. tribal communities.
Kodai Fukuda, Jun Nishiyama, Toru Obara
Nuclear Science and Engineering | Volume 194 | Number 7 | July 2020 | Pages 493-507
Technical Paper | dx.doi.org/10.1080/00295639.2020.1743580
Articles are hosted by Taylor and Francis Online.
Transient analysis for possible prompt supercritical accidents of fuel debris in the Fukushima Daiichi Nuclear Power Station is quite important. However, unlike solution fuel systems, there is little knowledge about supercritical transient analysis in fuel debris systems. In particular, reactivity feedback effects, which may have a significant impact on the results of the analysis, are important and require further study. In particular, the impacts of radiolysis gas void and moderator boiling should be discussed. Thus, the purpose of this study is to clarify whether the reactivity feedback effects of radiolysis gas and boiling of the moderator impact the supercritical transient analysis in fuel debris systems. To accomplish this, we used a power profile obtained by the MIK code with the Doppler reactivity feedback effect; radiolysis gas analysis and heat transfer analysis were performed. For the radiolysis gas analysis, the AGNES2 model was modified to consider the difference between solution fuel and fuel debris systems. The heat transfer analysis used an OpenFOAM solver to perform conjugate heat transfer calculations. We found that the radiolysis gas void was negligible when probable G values, which are the generation number of molecules per absorbed energy, were used. In addition, the results showed that boiling could be also negligible under most conditions. However, we found that the boiling time may be earlier than the peak time of the power when the radius of the fuel debris particle is small. In this case, ignoring the boiling may give conservative results. These considerations should be included in future analyses.