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
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
New coolants, new fuels: A new generation of university reactors
Here’s an easy way to make aging U.S. power reactors look relatively youthful: Compare them (average age: 43) with the nation’s university research reactors. The 25 operating today have been licensed for an average of about 58 years.
V. Spiegel
Nuclear Science and Engineering | Volume 53 | Number 3 | March 1974 | Pages 326-327
Technical Note | doi.org/10.13182/NSE74-A23358
Articles are hosted by Taylor and Francis Online.
The effective half-life of 252Cf has been determined as 2.638 ± 0.007 yr. The method utilized the ratio of the manganese activity induced in a manganous-sulfate bath by a 252Cf spontaneous-fission neutron source and the National Bureau of Standards photo-neutron source to measure the change in emission rate of the 252Cf source over a period of 1.77 half-lives. The data were corrected for the activity of radium (1622-yr half-life) in the photoneutron source (-0.2%) and for the competing neutron production from 250Cf.
