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
August 2025
Nuclear Technology
Fusion Science and Technology
July 2025
Latest News
DOE on track to deliver high-burnup SNF to Idaho by 2027
The Department of Energy said it anticipated delivering a research cask of high-burnup spent nuclear fuel from Dominion Energy’s North Anna nuclear power plant in Virginia to Idaho National Laboratory by fall 2027. The planned shipment is part of the High Burnup Dry Storage Research Project being conducted by the DOE with the Electric Power Research Institute.
As preparations continue, the DOE said it is working closely with federal agencies as well as tribal and state governments along potential transportation routes to ensure safety, transparency, and readiness every step of the way.
Watch the DOE’s latest video outlining the project here.
Jae-Joo Ha, Tunc Aldemir
Nuclear Technology | Volume 79 | Number 3 | December 1987 | Pages 297-310
Technical Paper | Fission Reactor | doi.org/10.13182/NT87-A34019
Articles are hosted by Taylor and Francis Online.
An operational concern in natural-convection-cooled research reactors is pool-top 16N activity (PTNA). The conventional technique for reducing PTNA is to disperse the water plume rising above the core by a planar water jet and thus increase the transit time of 16N nuclei to the pool top. The extension in transit time is a function of pool dynamics under dispersion. Ideally, a sufficiently deep stagnant water layer is formed below the pool top to confine 16N activity to lower pool regions. The effects of changes in pool configuration and disperser design parameters on pool dynamics are not well known. These effects are important in determining the feasibility of a power upgrade without major facility modifications. Due to the complexity of pool geometry, pool dynamics under dispersion cannot be described by simple flow models. The COMMIX-1A code is used to simulate the pool dynamics of a typical natural-convection-cooled research reactor with plate-type elements as a function of pool configuration and disperser design parameters. The pool is partly described as continuum and partly as porous medium. All the major pool components are explicitly modeled. The differences between the shapes of some pool structures and computational cells are accounted for using the concept of directional surface permeability. The importance of local turbulence effects and cross-flow friction losses at the guide tubes above the core are also investigated. The results show the following: