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.
Division Spotlight
Decommissioning & Environmental Sciences
The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Mar 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
El Salvador: Looking to nuclear
In 2022, El Salvador’s leadership decided to expand its modest, mostly hydro- and geothermal-based electricity system, which is supported by expensive imported natural gas and diesel generation. They chose to use advanced nuclear reactors, preferably fueled by thorium-based fuels, to power their civilian efforts. The choice of thorium was made to inform the world that the reactor program was for civilian purposes only, and so they chose a fuel that was plentiful, easy to source and work with, and not a proliferation risk.
J. Haroon, E. Nichita
Nuclear Technology | Volume 208 | Number 2 | February 2022 | Pages 246-267
Technical Paper | doi.org/10.1080/00295450.2021.1929768
Articles are hosted by Taylor and Francis Online.
A new 37-element PHWR fuel bundle, designed for molybdenum-99 production, has been proposed previously. The new bundle has been shown to have lattice properties and reactivity feedback effects equivalent to the standard PHWR bundle. This study looks at the effect the use of molybdenum-99-producing bundles has on the reactivity worth of reactivity devices, through the prism of reactivity-device macroscopic-cross-section increments. The study utilizes three-dimensional supercell configurations and the neutron transport code DRAGON to calculate and compare the incremental macroscopic cross sections and supercell reactivity for adjuster absorbers, shutoff absorber rods and liquid zone controllers when surrounded by molybdenum-99-producing bundles and by regular bundles. Two geometrical representations of fuel bundles are used: a detailed, cluster, representation, whereby all fuel pins are modeled separately, and an annularized representation, whereby each ring of fuel pins and corresponding coolant is represented as a homogeneous annulus. The latter model is the one customarily used in production calculations for finding cross-section increments of reactivity devices.
The study finds that reactivity-device cross-section and supercell reactivity increments are very similar (< 2% difference in reactivity increments) for the case of the molybdenum-producing bundle and the regular bundle. The study also finds that the use of a detailed, cluster, geometrical representation of the fuel bundle produces slightly different cross-section increments and supercell reactivity increments than the use of an annularized geometrical representation. The supercell reactivity-increment difference between the two representations is found to be ~8.0% for adjuster absorbers and ~11.0% for shutoff absorber rods.