Shrinking Nuclear

Nuclear power can play a significant role in meeting the world’s environmental and energy challenges if sustainability issues are resolved. China, for example, is constructing more than 20 reactors and plans further growth. There and in other countries, the nuclear industry is being revitalized, along with regulatory development and research on the long-term sustainability of the nuclear fuel cycle.

In the United States, however, the field has been sorely neglected for more than 30 years (see “Giant Holes in the Ground,” p. 60). Construction of new nuclear power plants has ground to a halt, while support for research and for training the next generation of nuclear engineers has suffered.

In recent years, the Obama administration has effectively eliminated the Yucca Mountain repository for spent nuclear fuel, which had been approved by the previous administration. But on the positive side, it has awarded $8.3 billion in loan guarantees for constructing nuclear plants and formed a blue-ribbon commission to find new ways of dealing with spent waste.

Perhaps most important, it has moved to support the development of small modular reactors that generate less than 300 megawatts, around a quarter the output of U.S. plants under construction today. Those reactors could address some of the nuclear industry’s biggest challenges: waste, safety, security and nonproliferation, and the capital cost of construction.

Small modular reactors require less initial capital investment than conventional ones and can have simpler, safer designs. Their modules can be built in factories (unlike the components of a traditional plant, which must be built on site) and can be deployed rapidly. Designs being developed at Berkeley eliminate the need for pumps and pipes. They could run for 20 years on their initial fuel, thus generating minimal waste.

Two U.S. firms, NuScale and Babcock & Wilcox, have already submitted designs to the Nuclear Regulatory Commission. That’s attracted venture capital and opened new financing opportunities that would have been unimaginable 10 years ago. A recent meeting on small modular reactors at Berkeley saw the presentation of designs from the United States, Korea, Japan, France, and Russia.

Those designs are still being refined and are not close to being built. Eventually, however, these reactors could be small enough to be transportable, and they could be installed in isolated locations unsuited to traditional plants or dedicated to specific tasks like water desalination, district heating, or hydrogen production. They have the potential to change the face of nuclear energy.

Jasmina Vujic is a professor at the University of California, Berkeley, and codirector of the Berkeley Nuclear Research Center.