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
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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
Oct 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
November 2025
Nuclear Technology
October 2025
Fusion Science and Technology
Latest News
Russia withdraws from 25-year-old weapons-grade plutonium agreement
Russia’s lower house of Parliament, the State Duma, approved a measure to withdraw from a 25-year-old agreement with the United States to cut back on the leftover plutonium from Cold War–era nuclear weapons.
J. M. Robson, J. Kroon
Fusion Science and Technology | Volume 1 | Number 1 | January 1981 | Pages 160-164
Technical Note | Fusion | doi.org/10.13182/FST81-A19923
Articles are hosted by Taylor and Francis Online.
Measurements have been made of the thermal neutron fluxes at various distances from a point source of 14-MeV neutrons embedded in three large shields. The first shield consisted of a 24-m3 assembly of solid concrete building blocks of density 2.2 g/cm3 and gave an attenuation length of 14.1 ± 0.7 cm at a distance of 150 cm from the source. The second shield was a layered assembly of wood and concrete blocks with a mean density of 1.92 g/cm3 and gave an attenuation length of 15.7 ± 0.7 cm at the same distance. The third assembly consisted of a cube of side 61 cm of steel surrounded by concrete blocks; at a distance of 120 cm from the source it gave an attenuation length of 9.3 ± 0.4 cm.
