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.
J. E. Morel, T. A. Wareing, R. B. Lowrie, D. K. Parsons
Nuclear Science and Engineering | Volume 144 | Number 1 | May 2003 | Pages 1-22
Technical Paper | doi.org/10.13182/NSE01-48
Articles are hosted by Taylor and Francis Online.
We analyze three ray-effect mitigation techniques in two-dimensional x-y geometry. In particular, two angular finite element methods, and the modulated P1-equivalent S2 method, are analyzed. It is found that these techniques give varying levels of ray-effect mitigation on certain traditional test problems, but all of them yield discrete-ray solutions for a line source in a void. In general, it is shown that any transport angular discretization technique that results in a hyperbolic approximation for the directional gradient operator will yield a discrete-ray solution for a line source in a void. Since the directional gradient operator is in fact hyperbolic, it is not surprising that many discretizations of the operator retain this property. For instance, our results suggest that both continuous and discontinuous angular finite element methods produce hyperbolic approximations. Our main conclusion is that the effectiveness of any hyperbolic ray-effect mitigation technique will necessarily be highly problem dependent. In particular, such techniques must fail in problems that have the most severe ray effects, i.e., those that are "similar" to a line source in a void.