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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Latest News
Nano Nuclear wins Air Force contract for Kronos MMR
New York City–based advanced nuclear technology developer Nano Nuclear Energy has been awarded a Direct-to-Phase II Small Business Innovation Research contract for its Kronos micro modular reactor (MMR) by AFWERX, the innovation and venture arm of the U.S. Air Force. The contract calls for AFWERX, with the 11th Civil Engineering Squadron, to explore the feasibility of deploying the Kronos MMR Energy System at Joint Base Anacostia-Bolling (JBAB) in Washington, D.C.
Kodai Fukuda, Delgersaikhan Tuya, Jun Nishiyama, Toru Obara
Nuclear Science and Engineering | Volume 194 | Number 3 | March 2020 | Pages 181-189
Technical Paper | doi.org/10.1080/00295639.2019.1665459
Articles are hosted by Taylor and Francis Online.
Removal of fuel debris is regarded as one of the most important operations in the decommissioning of the Fukushima Daiichi nuclear power station (1F-NPS) to decrease long-term risk. To begin the operation, the consequences of possible criticality accidents must be evaluated in advance. In this work, we evaluated radiation doses during possible criticality accidents at 1F-NPS in assumptive fuel debris systems. In particular, the relationship between the water level surrounding the fuel debris and the radiation dose was investigated. This is because the water level surrounding the fuel debris is thought to have an impact on radiation dose during accidents as it affects both the reactivity and shielding of radiation. A combination of space-dependent kinetic analysis and radiation transport analysis was carried out in order to consider the special characteristics of fuel debris systems in water. Instead of traditional point-kinetics analysis, we used the Multi-region Integral Kinetic (MIK) code, which is a unique method based on Monte Carlo neutron transport calculations. The radiation transport calculation code Particle and Heavy Ion Transport Code System (PHITS) was used as well. The analyses revealed that the dose caused by criticality accidents may be the largest in systems in which part of the fuel debris is exposed to the air.