ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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Division Spotlight
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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!
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Latest News
IEA report: Challenges need to be resolved to support global nuclear energy growth
The International Energy Agency published a new report this month outlining how continued innovation, government support, and new business models can unleash nuclear power expansion worldwide.
The Path to a New Era for Nuclear Energy report “reviews the status of nuclear energy around the world and explores risks related to policies, construction, and financing.”
Find the full report at IEA.org.
R. I. Smith
Nuclear Science and Engineering | Volume 21 | Number 4 | April 1965 | Pages 481-489
Technical Paper | doi.org/10.13182/NSE65-A18792
Articles are hosted by Taylor and Francis Online.
The change in k∞ of a heterogeneous lattice caused by a uniform change in the temperature of the fuel has been measured, using the Physical Constants Testing Reactor (PCTR). The test lattice was moderated with graphite and fueled with concentric-tube elements of slightly enriched uranium metal. The temperature of the fuel was varied from 297 to 1241°K. The change in k∞ with temperature was nonlinear and could be represented by the relation where T is in degrees Kelvin. The experimentally measured values of the constants were α = (−0.308 ± 0.004), β = (−0.120 ± 0.004), γ = (−0.085 ± 0.004). The unit functions, U, represent the changes in k∞ caused by the isothermal volume expansion of the fuel element when the uranium metal undergoes transformations in its crystal structure from alpha to beta and from beta to gamma phases. The term C is a normalization factor related to the lattice under study. The reactivity techniques employed here are shown to be four times more sensitive than activation methods for determining the functional relationship between the effective resonance integral of a fuel element and the temperature of the element. The constant, α, has been experimentally separated into two components: αv = (−0.240 ± 0.04). which is associated with the average interior temperature of the fuel, and αs = (−0.068 ± 0.04), which is associated with the temperature of the surface of the fuel. This separation allows treatment of nonuniform temperature distribution in the fuel.
