ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
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!
Latest Magazine Issues
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
Fusion Science and Technology
July 2025
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.
M. D. Wittman, M. J. Bonino, D. H. Edgell, C. Fella, D. R. Harding, J. Sanchez
Fusion Science and Technology | Volume 73 | Number 3 | April 2018 | Pages 315-323
Technical Paper | doi.org/10.1080/15361055.2017.1380496
Articles are hosted by Taylor and Francis Online.
Direct-drive inertial fusion experiments conducted at the Laboratory for Laser Energetics implode 860-μm-diameter, 8-μm-thick glow-discharge polymer (GDP) capsules that have a solid, uniform, 60- to 80-μm-thick layer of an equimolar mixture of deuterium and tritium (DT) on their interior. The DT is permeated through the capsule’s wall up to pressures of 1000 atm in small pressure steps to prevent buckling; this occurs over many hours. The capsule is then cooled, the DT is solidified, and the uniform layer is formed using thermal gradients produced by heat deposited from beta decay of the tritium. Thermal contraction of the capsule from cooling is expected to be ~1% of the diameter. Capsules permeated with DT do not exhibit this contraction and retain their room-temperature diameter after cooling. Sources of error in the imaging system were explored, and a systematic 3 μm over measurement of the diameter was revealed and corrected. However, both GDP capsules permeated with only deuterium and polystyrene capsules permeated with DT do exhibit thermal contraction. The highly cross-linked GDP shell is under compressive stress after fabrication and experiences bond breakage when exposed to high-density DT during permeation. It is speculated that some of this compressive stress is relieved during bond cleavage and the capsule’s wall swells, which counteracts contraction during cooling. In addition, mass spectrometry of the DT gas in the permeation system has revealed the presence of hydrocarbons and other carbon-containing species that increase with time, confirming the radio-degradation of the polymer.