Nearly all problems encountered in large High-temperature reactor power plants with respect to design and safety are related to the mere physical size of a larger reactor core. Our analyses show that it is feasible to subdivide a larger reactor core into modular units, analogous to the common practice of using several smaller units instead of one large unit. In connecting several modular reactor units in series,a larger power output can be obtained by merely using simple technical designs,in addition to utilizing the favorable safety characteristics of small pebble-bed cores.It can be shown that for these cores such classical safety devices as shutdown systems and decay heat removal systems lose their dominance in respect to risk evaluations.