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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
DOE issues new NEPA rule and procedures—and accelerates DOME reactor testing
Meeting a deadline set in President Trump’s May 23 executive order “Reforming Nuclear Reactor Testing at the Department of Energy,” the DOE on June 30 updated information on its National Environmental Policy Act (NEPA) rulemaking and implementation procedures and published on its website an interim final rule that rescinds existing regulations alongside new implementing procedures.
Rei Kimura, Satoshi Wada
Nuclear Science and Engineering | Volume 193 | Number 9 | September 2019 | Pages 1013-1022
Technical Paper | doi.org/10.1080/00295639.2019.1576454
Articles are hosted by Taylor and Francis Online.
A small modular reactor (SMR) is a promising candidate for future nuclear energy; therefore, many organizations are developing SMRs. Some SMRs have a power output higher than 100 MW(electric). This paper, however, describes a much smaller reactor of less than 10-MW(electric) power output: a microreactor. The microreactor shares the same advantages as SMRs, i.e., passive safety, portability, and maintainability. This paper studies a calcium hydride (CaH2) heat pipe–cooled reactor in which heat pipes and CaH2 accomplish passive removal of generated heat, fuel inventory reduction, high-temperature operation, and prevention of a loss-of-coolant accident. The CaH2 allows operation at a core temperature of 800°C, which improves the efficiency of the reactor system. In the case of moderator function loss, hydrogen dissociation may occur at the higher temperature; however, negative temperature reactivity of the hydride-moderated core prevents reactor runaway. The negative temperature reactivity is realized by the poison nuclides 113Cd and 151Eu, which have a capture resonance peak at thermal energies in high-temperature operation. It was confirmed that the proposed method is capable of controlling the reactor over the whole burnup period.