Advanced Nuclear Fission

Although nuclear power plants account for 20% of U.S. electricity generation, no new reactors have come on line since 1996. In 2007, applications began arriving at the Nuclear Regulatory Commission, with the result that six new plants are currently under construction at existing reactor sites in southern states, with some incorporating various improvements on conventional designs. According to the Nuclear Energy Institute, a trade association, 61 new nuclear plants were being built in 15 countries as of mid-2016.

The future of nuclear power generation in the United States will depend on several factors, including advanced plant design; evolution of new safety and control features, laws, and licensing regulations; finding ways to bring costs down; and public acceptance. The 2011 Fukushima plant nuclear accident in Japan—caused by an earthquake that cut the reactor off from outside electrical power and a tsunami that flooded parts of the facility and eliminated nearly all onsite alternating current and direct current power, thus disabling essential monitoring systems—focused worldwide attention on potential vulnerabilities in the design and operation of existing reactors.

There is growing interest in designs for what are called “small modular reactors”—plants intended to power a specific local facility up to a few hundred megawatts.

In 2014 the National Research Council advised the U.S. nuclear industry to initiate more rigorous identification and assessment of hazards from all sources, including abnormal, “out-of-design” events such as earthquakes and tsunamis; expanded emergency-response planning, operations, and training; improved risk management and analysis; and development of a culture of enhanced vigilance. 

The Fukushima plant, built during the 1970s, is a so-called Generation II design. The next (Generation III) designs generally embody numerous changes, including “passive” systems that allow the nuclear core to be cooled or stabilized without human intervention and/or without electrical power; strong containment facilities that can withstand, for example, the impact of an aircraft; more efficient fuel use; and simpler, standardized designs and components, among other innovations.

Recently, there is also growing interest in designs for what are called “small modular reactors”—plants intended to power a specific local facility up to a few hundred megawatts. They would be made of prefabricated modules that could be trucked in and installed more easily onsite and would be constructed with the reactor and cooling water entirely underground. If approved and built, such reactors would add flexibility to America’s inventory of nuclear power options.

Longer-term advances could broaden the desirability and future use of nuclear energy. The U.S. Department of Energy (DOE) has engaged other governments, international and domestic industry, and the research community to develop Generation IV systems. The goals of these efforts are to improve the economics, safety, fuel-cycle waste management, and proliferation resistance of nuclear reactors, as well as widen their applications. In 2014, the DOE announced $13 million in research and development cost-share agreements “to help address significant technical challenges to the design, construction, and operation of next generation nuclear reactors.”