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
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting 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
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
July 2025
Fusion Science and Technology
Latest News
WIPP’s SSCVS: A breath of fresh air
This spring, the Department of Energy’s Office of Environmental Management announced that it had achieved a major milestone by completing commissioning of the Safety Significant Confinement Ventilation System (SSCVS) facility—a new, state-of-the-art, large-scale ventilation system at the Waste Isolation Pilot Plant, the DOE’s geologic repository for defense-related transuranic (TRU) waste in New Mexico.
Toshio Wakabayashi, Isao Minatsuki
Nuclear Science and Engineering | Volume 83 | Number 1 | January 1983 | Pages 50-62
Technical Paper | doi.org/10.13182/NSE83-A17988
Articles are hosted by Taylor and Francis Online.
The physical behavior of burnable poison fuel pins, containing 0.1, 0.5, and 1.0 wt% Gd2O3 in 1.5 wt% UO2 pellets, has been studied through the measurements of reactivity change, coolant void reactivity, local power distribution, and thermal neutron flux distribution including fine structure, using a heavy-water-moderated, cluster-type fuel lattice. A new technique for utilizing a burnable poison has been developed using a gadolinium absorber rod inserted into the center of the cluster-type fuel assembly. Its physical behavior has been studied through the measurements of accompanying reactivity change, coolant void reactivity, local power distribution, and thermal neutron flux distribution. When the Gd2O3 content of the fuel pellets is more than 0.5 wt%, the reactivity effect is reduced largely due to the saturation of the thermal neutron self-shielding effect in the poisoned fuel pin. A gadolinium absorber rod inserted in the center of the fuel assembly, although it causes a small increase in local power peaking, is effective in the control of the initial excess reactivity and favorably affects the coolant void reactivity. An accurate calculation by the WIMS-D code requires division of the fuel pellet region into more than five mesh intervals owing to the enhancement of the thermal neutron self-shielding effect due to absorption by the gadolinium in the poisoned fuel pins.
