The small modular reactor is envisioned to be liquid-metal-cooled and run up to 30 years without requiring fresh fuel. At that point, the fuel would be cut out for burial or for reprocessing. The fuel feedstock could be natural or depleted uranium, or the reactor might run on excess weapons-grade plutonium.

The reactor would have a sealed core -- a feature to make it more proliferation-resistant. It also would have passive safety features, so it would go into a safe shutdown mode without human intervention.

[Source: Jenny Weil (McGraw-Hill), "Small reactors for remote areas get congressional attention", Nucleonics Week, November 28, 2002, p. 9]