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Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
S. O. Kucheyev, J. M. Lenhardt
Fusion Science and Technology | Volume 73 | Number 3 | April 2018 | Pages 293-297
Technical Paper | doi.org/10.1080/15361055.2017.1392205
Articles are hosted by Taylor and Francis Online.
Liquid hydrogen confined in pores of nanofoams crystallizes at lower temperatures than in the unconfined, bulk state. Here, we summarize results of our recent systematic relaxation calorimetry studies of the liquid–solid phase transition of hydrogen and deuterium in various materials with open-cell pores. These include spinodal-decomposition-derived silica glasses and nanoporous gold, conventional silica aerogels, and carbon foams with ligaments made from nanotubes and graphene sheets, all of which were studied previously. We present new hydrogen thermoporometry data for polymeric norbornene-based aerogels. Results show that hydrogen freezing temperatures inside all the porous materials studied are depressed. The average depression of the freezing point scales linearly with the ratio of the internal surface area to the pore volume. The average freezing point depression is limited to ≲1.6 K for foams with monolith densities ≲50 mg·cm. Details of the freezing behavior, however, depend nontrivially on the choice of the porous material and on the hydrogen-filling fraction, reflecting phenomena that are beyond the Gibbs-Thomson formalism and pointing to the complexity of pore architectures in the low-density materials of interest to thermonuclear fusion energy applications.