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.
S. N. Cramer
Nuclear Science and Engineering | Volume 149 | Number 3 | March 2005 | Pages 247-258
Technical Paper | doi.org/10.13182/NSE05-A2491
Articles are hosted by Taylor and Francis Online.
Bounded next-event estimation coupling of forward and adjoint Monte Carlo histories is possible by biasing the track-length selection of either the forward or adjoint calculation such that the 1/r2 term is eliminated from the estimator. This method is analytic, involving only elementary functions and minimal computer resources. A first-adjoint-collision response distribution from the detector can be created from the general forward-adjoint coupling procedure for use with the standard forward next-event point estimator with no 1/r2 term. This estimation is applicable for both a point detector or a point sampled from a finite detector volume. The truncated, first-adjoint-collision version of the general coupling method requires no actual adjoint calculation, but adjoint scattering probabilities must be made available in the forward estimation procedure. Various aspects of the estimator are investigated, and some simple calculational comparisons with standard methods are presented.