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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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.
R. C. Berkan, B. R. Upadhyaya, L. H. Tsoukalas, R. A. Kisner
Nuclear Science and Engineering | Volume 109 | Number 2 | October 1991 | Pages 188-199
Technical Paper | doi.org/10.13182/NSE91-A28517
Articles are hosted by Taylor and Francis Online.
Axial flux shape control in large pressurized water reactors constitutes one of the most challenging control problems in the nuclear field. In commercial plants, the practical solutions are obtained at the expense of departure from the most economical operational conditions, often due to the difficulties in monitoring xenon-induced oscillations and inadequate control actions. The concept of inverse dynamics in control is introduced as an alternative approach for spatial control. The method is tested through computer simulations using a validated nonlinear model that successfully represents the limit-cycle behavior. Compared with the widely used half-cycling strategy or the proposed optimal control methods in the literature, the use of inverse dynamics for partial-length rod control yields desirable stability characteristics. The return to target axial offset exhibits a smooth transition without any residual flux oscillations between the upper and lower halves of the core. The proposed approach consists of a set of nonlinear algebraic equations for control with single-step solutions. Thus, it is easier to implement compared with iterative or integral techniques.