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.
Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
August 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Vogtle-3 shuts down for valve issue
One of the new Vogtle units in Georgia was shut down unexpectedly on Monday last week for a valve issue that has since been investigated and repaired. According to multiple local news outlets, Georgia Power reported on July 17 that Unit 3 was back in service.
Southern Company spokesperson Jacob Hawkins confirmed that Vogtle-3 went off line at 9:25 p.m. local time on July 8 “due to lowering water levels in the steam generators caused by a valve issue on one of the three main feedwater pumps.”
Richard V Carlson, Richard Wilhelm, Kenji Okuno
Fusion Science and Technology | Volume 30 | Number 3 | December 1996 | Pages 895-899
Fuel Cycle and Tritium Technology | doi.org/10.13182/FST96-A11963051
Articles are hosted by Taylor and Francis Online.
A systematic program to study the long term generation of gas which results when tritiated water is stored on molecular sieve is ongoing at the Tritium Systems Test Assembly (TSTA). The gas that is generated, as the tritium decays, may result in safety concerns because the pressure generated in the disposal container may lead to a failure of the container.
Tritiated water is generated from processing tritiated effluent waste gases from TSTA process systems and experiments. Tritium contaminated waste gases are generated primarily from glovebox purges and process system evacuation. The various tritium compounds in the waste gas are converted to the oxide form and absorbed on molecular sieve. The tritiated water is collected on a fixed molecular sieve bed and when saturated, the water is regenerated into a 60 liter moisture (MC) filled with molecular sieve (approximately 45 kg of either type 4A or 13X molecular sieves). When the waste container is removed from the waste treatment system the container is evacuated to approximately 200 torr. The 60 liter container contains approximately 11 kg of water with amounts of tritium varying from 200 Ci to 30,000 Ci per container. The tritium content is determined by ion chamber measurement. These containers are eventually packaged and buried in retrievable shafts at the LANL waste facility located on site. Because of difficulty in the disposal of tritiated waste, TSTA currently has 20 waste containers on site that are part of this study. Periodically the gas in the waste container is sampled. The gas composition is measured with a mass spectrometer and an ion chamber. Properties measured are; pressure, gas composition (hydrogen, oxygen, nitrogen, helium-3, …) and tritium content. The waste containers have been stored at TSTA beginning in 1990. Measurements began in 1992.
Gas is generated in the container from the decay of tritium to helium-3 and from the effects of radiolysis. For every mole of tritium that decays two moles of helium-3 are generated. In addition, as the beta particle from the tritium decay loses energy it can cause the decomposition of the water absorbed on the sieve. Previous experiments predict that for every mole of tritium that decays, up to 26 moles of hydrogen and 16 moles of oxygen can result. Measurements to date indicate that significant hydrogen is generated, however it is generated at approximately one half the amount predicted from the previous experiments. Little oxygen has been found. The amount of helium-3 generated does not correlate with the expected amount from the estimated from the tritium loaded on the MC.