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
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
Remembering ANS member Gil Brown
Brown
The nuclear community is mourning the loss of Gilbert Brown, who passed away on July 11 at the age of 77 following a battle with cancer.
Brown, an American Nuclear Society Fellow and an ANS member for nearly 50 years, joined the faculty at Lowell Technological Institute—now the University of Massachusetts–Lowell—in 1973 and remained there for the rest of his career. He eventually became director of the UMass Lowell nuclear engineering program. After his retirement, he remained an emeritus professor at the university.
Sukesh Aghara, chair of the Nuclear Engineering Department Heads Organization, noted in an email to NEDHO members and others that “Gil was a relentless advocate for nuclear energy and a deeply respected member of our professional community. He was also a kind and generous friend—and one of the reasons I ended up at UMass Lowell. He served the university with great dedication. . . . Within NEDHO, Gil was a steady presence and served for many years as our treasurer. His contributions to nuclear engineering education and to this community will be dearly missed.”
Viktoriya V. Kulik, John C. Lee
Nuclear Science and Engineering | Volume 153 | Number 1 | May 2006 | Pages 69-89
Technical Paper | doi.org/10.13182/NSE06-A2596
Articles are hosted by Taylor and Francis Online.
The presence of a localized spallation source in an accelerator-driven subcritical system leads to significant spatial variations in the power distribution and invalidates the simple point-kinetics approach. To eliminate higher-harmonics contamination in the detector response and to account properly for spatial and spectral effects in reactivity determination, a method directly combining measurements with numerical simulations of the experimental data is developed through a quasi-static formulation. The method provides space-time correction to a variety of traditional point-kinetics techniques and determines the reactivity essentially independent of the detector position, as long as sufficiently accurate information on the reactor configuration is provided. In the current work, the space-time corrections are derived for two well-known point-kinetics methods: area-ratio technique and -method. Numerical simulations performed with the FX2-TH diffusion theory code along with a space-time analysis of MUSE-4 pulsed source experimental data illustrate the applicability of the proposed methods for the determination of significant subcriticality levels in fast and thermal reactor systems.