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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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Strong performances across the board
Craig Piercycpiercy@ans.org
Another year, another stellar performance by America’s nuclear plants. We’ve come to expect high capacity factors, and it’s a credit to the men and women of the profession. They’ve made routine something that was unimaginable not so long ago.
The decadal challenge for the nuclear enterprise now is to maintain this high level of operational excellence for the current fleet, while at the same time ushering in a new generation of technologies at scale. It will be a big job—but one that seems more and more likely with each passing day.
Kodai Fukuda, Jun Nishiyama, Toru Obara
Nuclear Science and Engineering | Volume 194 | Number 7 | July 2020 | Pages 493-507
Technical Paper | 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.