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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
Reflections on NOW
Hash Hasemianpresident@ans.org
Last month, I talked about my goal of strengthening ANS’s voice, in part by attending three conferences. I have now checked the first event off that list: the Nuclear Opportunities Workshop.
This year, NOW took another step in outgrowing its “workshop” moniker and transitioning to a full-fledged regional conference and expo. What started only a few years ago as a small gathering in Oak Ridge, Tenn., with roughly 50 attendees has skyrocketed to an event with 1,100 people in attendance in Knoxville.
NOW’s popularity reflected how busy the roughly 350 nuclear companies in Tennessee have been in recent years. There is significant work going on surrounding Gen IV reactor development and deployment, advancements in new nuclear fuels, and defense-related builds like the Uranium Processing Facility.
T. E. Booth, K. C. Kelley, S. S. McCready
Nuclear Technology | Volume 168 | Number 3 | December 2009 | Pages 765-767
MC Calculations | Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (PART 3) / Radiation Protection | doi.org/10.13182/NT09-A9303
Articles are hosted by Taylor and Francis Online.
Dxtran is a deterministic transport method typically used for increasing the sampling in a spherical region that would otherwise not be adequately sampled because the probability of scattering toward the region is often very small. Essentially, the dxtran method splits the particle into two pieces at each source or collision point: a piece that arrives (without further collisions) at the dxtran sphere and a piece that does not. One difficulty with the dxtran method is that it can introduce a large weight fluctuation between particles colliding just before the sphere and particles colliding after crossing the sphere. New work shows that it is possible to mitigate this difficulty by extending the dxtran sphere concept to a set of nested dxtran spheres. Each dxtran sphere then shields its interior from particles whose weights are too large so that weights are more commensurate with their locations. Shielding against the large weights not only increases the efficiency of the calculation but the reliability as well. The effectiveness of the technique in MCNP was demonstrated on a 1-km air transport problem and on a concrete duct problem.