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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.
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T.W. Petrie, M.E. Fenstermacher, C.J. Lasnier
Fusion Science and Technology | Volume 39 | Number 2 | March 2001 | Pages 916-922
Divertor and Plasma-Facing Components | doi.org/10.13182/FST01-A11963357
Articles are hosted by Taylor and Francis Online.
Advanced tokamaks use D-shaped cross-section plasmas to optimize fusion performance. In turn, the divertor (which handles heat and particles) must operate efficiently in these shaped plasmas. In this paper, we report on recent experiments at the DIII–D National Fusion Facility that compare the advantages/disadvantages of 1) double-null (DN) versus single-null (SN) configurations, 2) particle pumping at low and high density, and 3) open versus tightly baffled divertors. The focus of this paper will be on the important engineering consequences of these physics results for future tokamak designs. Accurate control over the magnetic balance is required by the plasma shaping coils for DN (and near-DN) operation because of the strong sensitivity of the heat flux to small changes in magnetic balance. Alternatively, additional protective armor may be needed for each divertor. We show that precise control over the strike point location by the coil system is important for lower density (attached) plasma operation, but much less so for higher density (detached) operation. We also find that minimizing the angle between the divertor structure and the divertor plasma legs is very useful in reducing the peak divertor heat flux for lower density (attached) plasmas but is of limited benefit for higher density (detached) plasmas. Finally, the physics results imply that significant heating and damage at the divertor “slot” opening may occur, even if several heat flux scrape-off lengths are allowed for clearance.