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 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
Latest Magazine Issues
Jul 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
August 2026
Nuclear Technology
July 2026
Fusion Science and Technology
Latest News
The deadline arrives: Checking in on the Reactor Pilot Program
On May 23, 2025, President Trump signed Executive Order 14301, “Reforming Nuclear Reactor Testing at the DOE,” which instructed the Department of Energy to create a Reactor Pilot Program (RPP)—a new system in which companies could pursue DOE authorization to build and test their first-of-a-kind nuclear technologies. EO 14301 set an ambitious goal for that program: three reactors achieving criticality by July 4, 2026.
Warren F. Miller, Jr.
Nuclear Science and Engineering | Volume 108 | Number 3 | July 1991 | Pages 247-266
Technical Paper | doi.org/10.13182/NSE91-A23823
Articles are hosted by Taylor and Francis Online.
Three spatial differencing schemes to be used with the even-parity, discrete ordinates, neutron transport equations are presented for the case of slab geometry and isotropic scattering and sources. These three schemes are analyzed in accordance with several desirable properties for spatial differencing schemes. The analysis indicates that cell-edge differencing of the even-parity equations yields a second-order, positive method that satisfies most diffusion limits and leads to an iteration that can be readily accelerated with an effective diffusion synthetic algorithm. The analyses indicate that this approach is quite promising and should be further developed.