A spectrum of Encapsulated Nuclear Heat Source (ENHS) reactors have been conceptually designed over the last few years [1-10]; they span a power range from less than 100 MWth to over 200 MWth and consider a number of coolants and fuel types. Common features of all these designs include very long life cores \u2013 approaching or exceeding 20 effective full power years; nearly zero burnup reactivity swing; natural circulation; superb safety; autonomous load following capability; no on-site refueling; simplicity of operation and maintenance. These features make the ENHS and the like reactors of particular interest for developing countries because of the following reasons: they can provide (a) energy to communities not connected to a central electricity grid even in countries having limited technological infrastructure; (b) energy security with minimum risk of proliferation.
Following a brief description of the reference ENHS reactor design (Sec. 2) we\u2019ll elaborate on the unique features of these reactors and discuss how these features could make these reactors of particular interest for developing countries (Sec. 3). A partial summary of different ENHS design options developed so far is provided in Section 4; it considers only Pb-Bi cooled uniform fuel core designs
