The ARIES advanced and conservative tokamak power plant study

Tokamak power plants are studied with advanced and conservative design philosophies to identify the impacts on the resulting designs and to provide guidance to critical research needs. Incorporating updated physics understanding and using more sophisticated engineering and physics analysis, the tokamak configurations have developed a more credible basis compared with older studies. The advanced configuration assumes a self-cooled lead lithium blanket concept with SiC composite structural material with 58% thermal conversion efficiency. This plasma has a major radius of 6.25 m, a toroidal field of 6.0 T, a q₉₅ of 4.5, a β_N^total of 5.75, an H₉₈ of 1.65, an n/n_Gr of 1.0, and a peak divertor heat flux of 13.7 MW/m². The conservative configuration assumes a dual-coolant lead lithium blanket concept with reducedactivation ferritic martensitic steel structural material and helium coolant, achieving a thermal conversion efficiency of 45%. The plasma has a major radius of 9.75 m, a toroidal field of 8.75 T, a q₉₅ of 8.0, a β_N^total N of 2.5, an H₉₈ of 1.25, an n/n_Gr of 1.3, and a peak divertor heat flux of 10 MW/m². The divertor heat flux treatment with a narrow power scrapeoff width has driven the plasmas to larger major radius. Edge and divertor plasma simulations are targeting a basis for high radiated power fraction in the divertor, which is necessary for solutions to keep the peak heat flux in the range 10 to 15 MW/m². Combinations of the advanced and conservative approaches show intermediate sizes. A new systems code using a database approach has been used and shows that the operating point is really an operating zonewith some range of plasma and engineering parameters and very similar costs of electricity. Other papers in this issue provide more detailed discussion of the work summarized here.