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Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Osamu Mitarai, Akio Sagara, Nobuyoshi Ohyabu, Ryuichi Sakamoto, Akio Komori, Osamu Motojima
Fusion Science and Technology | Volume 56 | Number 4 | November 2009 | Pages 1495-1511
Technical Paper | doi.org/10.13182/FST09-A9253
Articles are hosted by Taylor and Francis Online.
A new control method for the unstable operating point in the force-free helical reactor (FFHR) is proposed for low-temperature and high-density ignited operation. While in the stable ignition regime, the error of the fusion power of e'DT(Pf) = +(Pf0 - Pf) is used to obtain the desired fusion power with proportional-integral-derivative control of the fueling, we have discovered that in the unstable ignition regime, the error of the fusion power with an opposite sign of e'DT(Pf) = -(Pf0 - Pf) can stabilize the unstable operating point. Here, Pf0 is the fusion power set value, and Pf is the measured fusion power. Around the unstable operating point, excess fusion power (Pf0 < Pf) supplies fueling, increases the density, and then decreases the temperature. Less fusion power (Pf0 > Pf) in the subignited regime reduces the fueling, decreases the density, and then increases the temperature. While the operating point rotates to the clockwise direction in the stable ignition boundary, it rotates to the counterclockwise direction in the unstable ignition regime. Using this control algorithm, it is demonstrated that the operating point can reach the steady-state condition from an initial very low-temperature and low-density regime. The fusion power can also be shut down from the steady-state condition without any problems. Furthermore, characteristics of the stable and unstable ignition regimes are compared for the same fusion power, and control robustness to changes with various parameters has been studied.
