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.
Guillermo Velarde, Carolina Ahnert, José M. Aragonés
Nuclear Science and Engineering | Volume 66 | Number 3 | June 1978 | Pages 284-294
Technical Paper | doi.org/10.13182/NSE78-A27213
Articles are hosted by Taylor and Francis Online.
The time-dependent Boltzmann equation for neutron transport is transformed into eigenvalue equations in k, λ, γ, and α, whose general properties are stated as hypotheses. Numerical solutions are obtained with the discrete-ordinates code DTF, where a direct λ eigenvalue calculation has been added. Eigenvalues and eigenfunctions are analyzed for idealized fast and thermal systems in both bare and reflected configurations. The differences found in these idealized cases provide some useful bases for estimating the behavior of the different eigenvalue solutions in specific applications.