Push for Small Nuclear Reactors Runs Into Regulators’ Old Rules

The nuclear power industry is betting its future on a new generation of reactors small enough to fit on a truck—an emerging technology that mostly uses alternatives to water for cooling, runs at lower pressure than traditional units, and costs far less than the behemoth power plants and cooling towers that define the nuclear landscape today.

But advocates of the idea insist that the folks in Washington who police their business have no idea how to assess it. Today’s rules are “really a square peg in a round hole for these advanced reactor designs,” says Amy Roma, a partner ...