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
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Apr 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
June 2026
Nuclear Technology
March 2026
Fusion Science and Technology
May 2026
Latest News
DOE selects first companies for nuclear launch pad
The Department of Energy’s Office of Nuclear Energy and the National Reactor Innovation Center have announced their first selections for the Nuclear Energy Launch Pad: three companies developing microreactors and one developing fuel supply.
The four companies—Deployable Energy, General Matter, NuCube Energy, and Radiant Industries—were selected from the initial pool of Reactor Pilot Program and Fuel Line Pilot Program applicants, the two precursor programs to the launch pad.
M. Segev
Nuclear Science and Engineering | Volume 77 | Number 2 | February 1981 | Pages 229-235
Technical Note | doi.org/10.13182/NSE81-A21356
Articles are hosted by Taylor and Francis Online.
An equivalence principle is developed for an infinite array of annular rods. The center of a rod is a moderator characterized by the sticking probability γ1. Surrounding the center is an annular absorber characterized by the radii R1 < R2. The rods are uniformly distributed in an outer moderator characterized by the sticking probability γ2. The escape cross section for the lattice is The factor a is an adjustable Bell factor.
