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
The Frisch-Peierls memorandum: A seminal document of nuclear history
The Manhattan Project is usually considered to have been initiated with Albert Einstein’s letter to President Franklin Roosevelt in October 1939. However, a lesser-known document that was just as impactful on wartime nuclear history was the so-called Frisch-Peierls memorandum. Prepared by two refugee physicists at the University of Birmingham in Britain in early 1940, this manuscript was the first technical description of nuclear weapons and their military, strategic, and ethical implications to reach high-level government officials on either side of the Atlantic. The memorandum triggered the initiation of the British wartime nuclear program, which later merged with the Manhattan Engineer District.
Anselmo T. Cisneros, Dan Ilas
Nuclear Technology | Volume 183 | Number 3 | September 2013 | Pages 331-340
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT13-A19422
Articles are hosted by Taylor and Francis Online.
The Advanced High-Temperature Reactor (AHTR) is a 3400-MW(thermal) fluoride salt-cooled high-temperature reactor that uses coated particle fuel compacted into slabs rather than spherical or cylindrical fuel compacts. Simplified methods are required for parametric design studies to perform burnup analysis on the entire feasible design space. These simplifications include fuel homogenization techniques to increase the speed of neutron transport calculations and equilibrium depletion analysis methods to analyze systems with multibatch fuel management schemes.This paper presents three elements of significant novelty. First, the reactivity-equivalent physical transformation (RPT) methodology usually applied in systems with cylindrical and spherical geometries has been extended to slab geometries. Second, implementing this RPT homogenization, a Monte Carlo-based depletion methodology was developed to search for the maximum discharge burnup in a multibatch system by iteratively estimating the beginning of equilibrium cycle composition and sampling different discharge burnups. This iterative equilibrium depletion search method fully defines an equilibrium fuel cycle (keff, power, flux, and composition evolutions) but is computationally demanding. Therefore, an analytical method, the nonlinear reactivity model, was developed so that single-batch depletion results could be extrapolated to estimate the maximum discharge burnup in systems with multibatch fuel management schemes.
