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
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
October 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
O. E. Dwyer, H. C. Berry
Nuclear Science and Engineering | Volume 46 | Number 2 | November 1971 | Pages 284-303
Technical Paper | doi.org/10.13182/NSE71-A22362
Articles are hosted by Taylor and Francis Online.
The results of a theoretical study of molecular-conduction heat transfer to liquid metals flowing in-line through unbaffled rod bundles are reported. The flow is turbulent and fully developed, the heat transfer is fully developed, the bundles have equilateral triangular spacing, and there are no effects due to spacing devices. Circumferentially local heat transfer coefficients, rod-average heat transfer coefficients, and circumferential variation of wall temperatures have been obtained and correlated in terms of the various independent variables. The rods represent reactor fuel pins which consist of ceramic cores encased in metallic claddings. The following thermal boundary conditions were treated: (a) uniform wall heat flux in the axial direction and uniform wall temperature in the circumferential direction, on the outside surface of the cladding; (b) uniform wall heat flux in all directions on the outside surface of the cladding; and (c) uniform wall heat flux in all directions on the inside surface of the cladding. For boundary conditions (a) and (b), the independent variables are Reynolds number (Re) and rod spacing (P/D), while for boundary condition (c) there are two additional independent variables, i.e., relative cladding conductivity (kw/kf) and relative cladding thickness [(r2 - r1)/r2]. The results, all expressed in the form of convenient dimensionless groups, are presented in tables and charts and in the form of simple mathematical expressions for ready use by the design engineer.