CONF-850310-108 DE85 012890 eunct al ttili •rlicl*. rtw publillw or 7Kipi«nl e>r.knowl«d0ts th« U£. QvJtnmtnt't f iflht to retain • nonaxelutiv*. rav^lty-frM IICOTM [n vid to «ny copyright covtrirtfi trw crtlct*.

•cctotinct Of tftli irtlcfi. th# pubMshvr or r«cipltnt«cknowltdg*t tht US. Qovvrnmtni's rifht to retain • nonaxclutiva, royalty-fr»* lictnM in «nd to any copyright cov«rine th» trtidt.

Lower Hybrid Current Ramp-up Requirements 2.2 Scaling of Poloidal Field Coil Currents With Aspect Ratio 2.3 Effects of Enhanced Elongation and Paramagnetism 2.4 Confinement Scaling Assumptions 3. SYSTEMS CODE TRADE-OFF STUDIES ... 3.1 Benchmark (Reference) Case 3.2 Dependence on Coil Current Density 16 3*3 Dependence on Externally Applied Toroidal Field 3.4 Sensitivity to Uncertainties in Confinement Scaling 4. ENGINEERING ASSESSMENTS 4.

No abstract

Advanced commercial tokamak studies were performed by the Fusion Engineering Design Center (FEDC) as a participant in the Tokamak Power Systems Studies (TPSS) project coordinated by the Office of Fusion Energy. The FEDC studies addressed the issues of tokamak reactor cost, size, and complexity. A scoping 3tudy model was developed to determine the effect of beta on tokamak economics, and it was found that a competitive cost of electricity could be achieved at a beta of 10 to \5%. The implications of operating at a beta of up to 25% were also addressed. It was found that the economics of fusion, like those of fisoion, improve as unit size increases. However, small units were found to be competitive as eleaer.ts of a multiplex plant, provided that unit cost and maintenance time reductions are realized for the small units. The modular tokamak configuration combined several new approaches to develop a less complex and lower cost reactor. The modular design combines the toroidal field coil with the reactor structure, locates the primary vacuum boundary at the reactor cell wall, and uses a vertical assembly and maintenance approach. vii