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.
Paul Nelson, Jr.
Nuclear Science and Engineering | Volume 43 | Number 2 | February 1971 | Pages 154-158
Technical Paper | doi.org/10.13182/NSE71-A21263
Articles are hosted by Taylor and Francis Online.
The mean time to destruction of a neutron is shown to be equal to the reciprocal unity-weighted loss rate for a general neutron transport problem. The mean production time and reciprocal importance-weighted loss rate are shown to be similar, but slightly different. The results are illustrated for a simple model problem.
