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
Hash Hashemian: Visionary leadership
As Dr. Hashem M. “Hash” Hashemian prepares to step into his term as President of the American Nuclear Society, he is clear that he wants to make the most of this unique moment.
A groundswell in public approval of nuclear is finding a home in growing governmental support that is backed by a tailwind of technological innovation. “Now is a good time to be in nuclear,” Hashemian said, as he explained the criticality of this moment and what he hoped to accomplish as president.
C. M. Cooling, M. M. R. Williams, E. T. Nygaard, M. D. Eaton
Nuclear Science and Engineering | Volume 177 | Number 3 | July 2014 | Pages 233-259
Technical Paper | doi.org/10.13182/NSE13-55
Articles are hosted by Taylor and Francis Online.
Previously, a point kinetics model of the Medical Isotope Production Reactor has been presented, which included representations of instantaneous power, delayed neutron precursors, fuel solution temperature, radiolytic gas content, and coolant temperature. This model has been extended to include the effects of a vertically discretized temperature profile with a mixing of heat energy by eddies, boiling, and condensation and an extended model of bubble velocity and radius. It is found that the most striking change to the behavior of the system is caused by the effects of steam, which provides a strong negative feedback that tends to depress average powers in cases where the fuel solution temperature rises above the saturation temperature but can also lead to large, sharp power peaks through steam exiting the system (which can remove a large amount of negative reactivity in a short amount of time). The overall effect, however, does not lead to any unbounded power excursions. Possibilities for further extension of the model include the modeling of the composition of the plenum gas and the modeling of global pressure and its effects.