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
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Feb 2026
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
February 2026
Nuclear Technology
January 2026
Fusion Science and Technology
Latest News
DOE announces NEPA exclusion for advanced reactors
The Department of Energy has announced that it is establishing a categorical exclusion for the application of National Environmental Policy Act (NEPA) procedures to the authorization, siting, construction, operation, reauthorization, and decommissioning of advanced nuclear reactors.
According to the DOE, this significant change, which goes into effect today, “is based on the experience of DOE and other federal agencies, current technologies, regulatory requirements, and accepted industry practice.”
D.Q. Hwang, C.M. Fortgang
Fusion Science and Technology | Volume 8 | Number 1 | July 1985 | Pages 759-766
Plasma Heating, Impurity Control, and Fueling | Proceedings of the Sixth Topical Meeting on the Technology of Fusion Energy (San Francisco, California, March 3-7, 1985) | doi.org/10.13182/FST85-A40128
Articles are hosted by Taylor and Francis Online.
With the recent promising results of plasma heating using electromagnetic waves (EM waves) in the ion cyclotron range of frequency (ICRF) on the Princeton Large Torus (PLT) tokamak the feasibility of employing ICRF heating to a reactor-like magnetic confinement device is increasing. The high power ICRF experiments funded on JET (Joint European Torus in England) and JT-60 (in Japan) will have rf source power in the range of 10-30 MW. The time scale for the duration of the rf pulse will range from seconds up to steady-state. The development of new rf components that can transmit and launch such high power, long pulse length, EM waves in a plasma environment is a major technological task. In general, the technology issues may be divided into two categories. The first category concerns the region where the plasma comes in contact with the wave launchers. The problems here are dominated by plasma-material interaction, heat deposition by the plasma onto the wave launcher, and erosion of the launcher material. It is necessary to minimize the heat deposition from the plasma, the losses of the rf wave energy in the structure, and to prevent sputtering of the antenna components. A solution involves a combined design using special materials and optimal shaping of the Faraday shield (the electrostatic shields which can be used both for an EM wave polarization adjustment and as a particle shield for the launcher). Recent studies by PPPL and McDonnell Douglas Corp. on the Faraday shield designs will be discussed.1 The second important area where technology development will be necessary is the transmission of high power rf waves through a gas/vacuum interface region. In the past, the vacuum feedthrough has been the bottle neck which prevented high power operation of the PLT antennae. However, with major improvements of the feedthrough design, the power level attainable has risen from 200 kW per antenna to over 1.25 MW per antenna. In the present experiment, the power limit of the vacuum/gas interface has not been reached. As the pulse length of the rf is increased, modification (or cooling) of the rf components will be essential. According to the recent studies of vacuum feedthroughs2 by PPPL and the Grumman Corp., it is expected that with proper cooling the present components will be able to withstand steady-state operation.