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Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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!
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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.
R. J. Tuttle, T. H. Springer
Nuclear Science and Engineering | Volume 49 | Number 4 | December 1972 | Pages 468-481
Technical Paper | doi.org/10.13182/NSE72-A22566
Articles are hosted by Taylor and Francis Online.
Central reactivity worth measurements have been made in a fast reactor spectrum with samples of natural boron, boron-10, europium oxide, and tantalum. Various sized samples were used to investigate self-shielding effects in a fast reactor test region in Assembly 17 of the Epithermal Critical Experiments Laboratory. In addition to single cylinders, clusters of tantalum pins simulating a control rod segment were also used. Compared to an infinitely dilute sample, the most massive tantalum sample showed a reduction of 49 percent in reactivity per unit mass. For comparison with the tantalum measurements, extensive calculations using first-order perturbation theory, exact perturbation theory, and eigenvalue differences show good agreement within appropriate ranges—first-order perturbation for small perturbations, eigenvalue differences for large perturbations, and exact perturbation throughout the range. For europium, first-order perturbation calculations are in excellent agreement with the measurements, while for boron and B, the calculations predict a somewhat greater worth than was measured. By using the calculations to extrapolate the measurements, the following infinitely dilute specific reactivity values are obtained: boron, -55.8 m/g; 10B, −293.8 mg; europium, −20.6 mg; and tantalum, −5.83 m/g.