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. B. Hayden, D. N. Ruzic
Fusion Science and Technology | Volume 31 | Number 2 | March 1997 | Pages 128-134
Technical Paper | Divertor System | doi.org/10.13182/FST97-A30815
Articles are hosted by Taylor and Francis Online.
The Monte Carlo code DEGAS was used to investigate the neutral atom and molecular interactions for a high-pressure (∼1-Torr) gaseous divertor in the International Thermonuclear Experimental Reactor (ITER). Energy is removed from the plasma by radiation while the plasma pressure is balanced predominantly by a high neutral pressure at the end of the divertor. Plasma parameters were taken from the two-dimensional fluid code PLANET. Neutral sources from both ions recycling off the walls and recombination were included. The neutral density peak calculated with DEGAS of 3.43 ± 0.01 × 1022 m−3 occurred 4.5 cm from the divertor channel end. The ion and neutral atom energy fluxes were calculated to determine the heat load onto the divertor walls. A code was written to calculate the radiation distribution onto the side walls, not including any radiative absorption or reemission. The total energy flux peak (including ions, neutrals, and radiation) was 4.28 ± 0.30 MW/m2. This falls below the design criteria of 5 MW/m2. These results may help determine the wall material, heat removal, and the vacuum pumping requirements for the ITER divertor design and show the importance of a full treatment of neutral atoms and molecules in these regimes.