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.
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
2021 Student Conference
April 8–10, 2021
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
Latest Journal Issues
Nuclear Science and Engineering
Fusion Science and Technology
Fukiushima Daiichi: 10 years on
The Fukushima Daiichi site before the accident. All images are provided courtesy of TEPCO unless noted otherwise.
It was a rather normal day back on March 11, 2011, at the Fukushima Daiichi nuclear plant before 2:45 p.m. That was the time when the Great Tohoku Earthquake struck, followed by a massive tsunami that caused three reactor meltdowns and forever changed the nuclear power industry in Japan and worldwide. Now, 10 years later, much has been learned and done to improve nuclear safety, and despite many challenges, significant progress is being made to decontaminate and defuel the extensively damaged Fukushima Daiichi reactor site. This is a summary of what happened, progress to date, current situation, and the outlook for the future there.
Masao Matsuyama, Masanori Hara
Fusion Science and Technology | Volume 54 | Number 1 | July 2008 | Pages 182-185
Technical Paper | Tritium Measurement | dx.doi.org/10.13182/FST08-A1791
Articles are hosted by Taylor and Francis Online.
A twin type thermal conduction calorimeter has been specially designed and constructed for absolute measurement of tritium, and then its performance was examined using two kinds of tritium samples, i.e., ZrNi alloy powders loaded with a given amount of tritium. Total amounts of tritium in the ZrNi alloy powders were previously estimated by a small ionization chamber. Changes in radioactivity of two samples were followed for three years, and it was seen that the activity changes obeys the half-life of 4505 days. The initial tritium amounts estimated by the small ionization chamber agreed well with the extrapolated values from the activity changes evaluated by the calorimeter. Namely, it was suggested that the small ionization chamber is able to be used as a secondary standard of the tritium measuring devices. The -ray-induced X-ray counter was also calibrated for non-destructive measurements of high-level tritium by using the present small ionization chamber.