[en] A reactor based on this concept that produces 1000 MWe consists of a solenoidal magnet about 50 to 100 m long. A cylindrical blanket is used for energy recovery and tritium breeding. Thus the reactor itself is simple and of low technology. The end plugs, however, are of high technology, having the high magnetic fields needed to confine the high-pressure plasma and the high injection energy (0.6 to 1.2 MeV) needed to achieve good magnetic confinement. A low technology, compact, economical hybrid fusion-fission reactor results from injection in the central cell as well as the ends, provided a means can be found to stabilize the end plugs against microinstabilities, particularly in small sizes (plug radius divided by ion gyroradius less than or equal to 10). The Q value is 1.8 and the power is 500 MWe, with 1000 kG of ²³³U produced per year. If, on the other hand, the tandem is operated in the two-component mode (i.e., cold tritium plasma electrostatically contained into which a 100-200 keV D⁰ beam is injected), then the end plugs can be stabilized by the outward flowing tritium plasma. Finally, we show that D-D burning tandem reactors appear feasible in large sizes and at high cost