In the aftermath of the Fukushima disaster in March, the appetite for new nuclear power plants slipped to post-Chernobyl lows. Regulators from Italy to Switzerland to Texas moved to stop pending nuclear-power projects, and the U.S. Nuclear Regulatory Commission (NRC) began to reevaluate the safety of all domestic plants. Yet nuclear power still provides 20 percent of America’s total electric power and 70 percent of its emissions-free energy, in large part because no alternative energy source can match its efficiency.

One nuclear plant with a footprint of one square mile provides the energy equivalent of 20 square miles of solar panels, 1,200 windmills or the entire Hoover Dam. If the country wants to significantly reduce its dependence on carbon-based energy, it will need to build more nuclear power plants. The question is how to do so safely.

In the 30 years since regulators last approved the construction of a new nuclear plant in the U.S., engineers have improved reactor safety considerably. (You can see some of the older, not-so-safe ones in this sweet gallery.) The newest designs, called Generation III+, are just beginning to come online. (Generation I plants were early prototypes; Generation IIs were built from the 1960s to the 1990s and include the facility at Fukushima; and Generation IIIs began operating in the late 1990s, though primarily in Japan, France and Russia.)

Unlike their predecessors, most Generation III+ reactors have layers of passive safety elements designed to stave off a meltdown, even in the event of power loss. Construction of the first Generation III+ reactors is well under way in Europe. China is also in the midst of building at least 30 new plants. In the U.S., the Southern Company recently broke ground on the nation’s first Generation III+ reactors at the Vogtle nuclear plant near Augusta, Georgia. The first of two reactors is due to come online in 2016.