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
August 2025
Fusion Science and Technology
Latest News
No impact from Savannah River radioactive wasps
The news is abuzz with recent news stories about four radioactive wasp nests found at the Department of Energy’s Savannah River Site in South Carolina. The site has been undergoing cleanup operations since the 1990s related to the production of plutonium and tritium for defense purposes during the Cold War. Cleanup activities are expected to continue into the 2060s.
A. Radkowsky, M. Segev, A. Galperin
Nuclear Science and Engineering | Volume 94 | Number 1 | September 1986 | Pages 80-86
Technical Note | doi.org/10.13182/NSE86-A17120
Articles are hosted by Taylor and Francis Online.
The “classical” formula for the sharing of power between a seed and blanket was based on the two-group diffusion theory model and gave good agreement with experiments conducted in the original Shippingport program and with transport theory. Recently an extensive series of calculations on seed/blanket assemblies showed that the power sharing deviates widely from the classical formula but paradoxically is in good agreement with the one-group formula, which neglects the back leakage of thermal neutrons from the blanket to the seed. The power-sharing formula has now been rederived, and the paradox is resolved by taking into account epithermal absorptions in the seeds. The diffusion theory model is important as a guide to formulating innovative concepts for improved core designs.