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.”
William L. Barr, B. Grant Logan
Fusion Science and Technology | Volume 18 | Number 2 | September 1990 | Pages 251-256
Technical Paper | Divertor System | doi.org/10.13182/FST90-A29297
Articles are hosted by Taylor and Francis Online.
A new divertor configuration is suggested as a possible solution to the problems of high heat flux and erosion at the divertors in large high-power tokamaks. The proposed configuration is a toroidally symmetrical slot in the divertor that allows part of the edge plasma and most of its power to enter a cavity in a thin annular sheet. The large surface area of the sheet is exposed to interaction with gas in the cavity. This results in radiation and a reflux of fast neutral atoms, both of which transport power to the cavity walls. The heat flux is reduced because the power is spread over a much larger area. Erosion due to sputtering is also reduced because the decreased power flux reduces the sheath potential and, therefore, the average ion impact energy. Sputtering by fast neutrals should not be a serious problem because neutrals are not accelerated by a sheath as are ions. Helium ash and impurity atoms that are ionized within the cavity tend to be trapped there by the electric field that must exist throughout the source region in order to make the removal rates for electrons and ions both equal to the production rate.