The primary goal of the Blanket Comparison and Selection Study was the selection of a limited number of fusion power reactor blanket concepts to provide the focus for the U.S. blanket research and development (R&D) program. To facilitate that selection, a comparison methodology and a set of evaluation criteria were developed for four separate areas of evaluation:

  1. engineering feasibility
  2. economics
  3. safety
  4. R&D requirements.
Both the methodology for and the results of the engineering feasibility evaluation are discussed. Seven categories of weighted evaluation criteria were developed. Of these, tritium breeding/inventory and engineering complexity/fabrication were considered the most important with weightings totaling half the possible points. Other categories included maintenance and repair, resource usage, accommodation of power variation, increased capabilities, and startup/shutdown requirements. The 16 top-ranked blanket concepts were evaluated separately for tokamaks (7) and tandem mirror reactors (TMRs) (9). Results indicate distinct differences for most categories among concepts grouped by coolant: liquid metals, pressurized water, helium, and nitrate salt. Overall differences in scores are larger for tokamak concepts than for TMR concepts, reflecting the more difficult design problems due to higher magnetic field strength, higher first-wall surface heating and particle flux, and the more complex geometry of the fusion core. Conclusions for specific evaluation categories and for tokamak and TMR concept groups are presented.