As one alternative source of energy for the future, fusion power will
be required to demonstrate that it can be a safe, clean and economical
ly attractive option in an increasingly diverse and competitive energy
marketplace. Top-level requirements have been developed and used to g
uide the development of fusion power concepts, most recently, the ARIE
S-RS conceptual power plant design based upon the tokamak operating in
the reversed shear MHD mode. This design is shown to have the potenti
al to meet the necessary requirements. We review the present status of
this and other power plant designs, identify the key fusion R and D i
ssues in a variety of technological areas, and point to the need for a
coordinated, and international, R and D effort to achieve the ultimat
e goal of a commercially desirable fusion system. (C) 1998 Elsevier Sc
ience S.A. All rights reserved.