4 May 2015

IEEE‑Spectrum (USA): The Forgotten History of Small Nuclear Reactors

The Forgotten History of Small Nuclear Reactors

IEEE-Spectrum, 27 April 2015

By M.V.Ramana

Economics killed small nuclear power plants in the past—and probably will keep doing so

A tantalizing proposition has taken hold again in the nuclear industry: that small nuclear reactors have economic and other advantages over the standard-size ones being built today. The idea is that by reducing the substantial financial risk of a full-scale nuclear project, small reactors are the best option for kick-starting a much-discussed revival of nuclear power.

Although concerns about climate change have led energy planners to retain nuclear power as an option, the technology remains in stasis or decline throughout the Americas and Europe. Two new nuclear projects now under way in the United States were the first to be awarded construction licenses in the country since the late 1970s. Globally, nuclear power produced about 11 percent [PDF] of all electricity in 2013, down from its high of 17.6 percent in 1996, according to data from the BP Statistical Review of World Energy 2014. In the United States, the number of operating nuclear power plants has slipped below 100, with the recent shutdown of the Vermont Yankee plant.

A fundamental reason for this decline is indeed economic. Compared with other types of electricity generation, nuclear power is expensive. According to a 2014 report by the Wall Street advisory firm Lazard, [PDF] the cost of generating a megawatt-hour of electricity from a new nuclear reactor (without considering government subsidies, including those for liability for severe accidents) is between US $92 and $132. Compare that with $61 to $87 for a natural-gas combined-cycle plant, $37 to $81 for wind turbines, and $72 to $86 for utility-scale solar. Nuclear’s high costs result directly from the very high costs of building a reactor—estimated by Lazard at $5.4 million to $8.3 million for each megawatt. These per-megawatt costs translate into billions of dollars. For example, the latest estimate for one of the two U.S. projects mentioned above—a pair of 1,117-MW reactors being built near Jenkinsville, S.C.—is $11 billion.

These costs were acknowledged in a 2012 brochure for an industry conference devoted to what are called small modular reactors (SMRs). Noting the “huge billion dollar challenges” posed by traditional nuclear plants, the brochure declared that “Small Modular Reactors are the perfect solution to this problem by mitigating billions in financial risk, growing incrementally with power demand and offering shorter and easier construction schedules…. The SMR market is global and extremely vast…. In short the power industry is crying out for commercial SMR projects throughout the world.”

If it is, the power industry is likely to be disappointed. Small reactors, in fact, date back to the earliest days of atomic power, and this long history shouldn’t be overlooked as vendors tout new generations of the technology. As the history makes clear, small nuclear reactors would be neither as cheap nor as easy to build and operate as their modern proponents are claiming they would be.

SMRs have outputs of anywhere from 10 to 300 MW. Compare that with the 860-MW average of the most popular reactor types now operating around the world and the 980-MW average of the reactors under construction. Although some of the dozens of new small reactor designs [PDF] take novel approaches, many of them, especially the ones most likely to be licensed for construction first, are just variations on the familiar light-water reactor. The cost of SMRs can be kept low, proponents say, in part by using factory-fabricated modules, which would require only limited assembly at the site of the power plant itself.

The basic idea actually dates to the 1940s, when the U.S. Air Force, Army, and Navy each initiated R&D on various types of small reactors. From 1946 to 1961, the Air Force spent more than $1 billion trying to build a reactor to power long-range bombers—to no avail. In canceling the program, President John F. Kennedy wrote, “The possibility of achieving a militarily useful aircraft in the foreseeable future is still very remote.”

The Navy had better success with developing nuclear power for its aircraft carriers and submarines. But these have quite different requirements from today’s SMR proposals. A submarine reactor is designed to operate under stressful conditions—to provide a burst of power when the vessel is accelerating, for example. And unlike civilian power plants, naval nuclear reactors don’t have to compete economically with other sources of power production. Their overwhelming advantage is that they enable a submarine to remain at sea for long periods of time without refueling.


About the Author

M.V. Ramana is a researcher with the Nuclear Futures Laboratory and the Program on Science and Global Security at Princeton University. In this article, he writes about small nuclear reactors of the past, many of which suffered from poor economics as well as technical problems. “There was a lot of hope attached to those reactors,” Ramana says. “Given the claims being made about today’s small reactor designs, the history of the earlier ones is worth revisiting.”

To Probe Further

The World Nuclear Industry Status Report 2014 [pdf], by Mycle Schneider and Antony Froggatt, is part of a series published off and on since 1992 that reviews worldwide developments in nuclear energy. This latest report contains surveys of nuclear energy programs by country and region, as well as overviews of the economics of nuclear power, construction periods of reactors, the status of the Fukushima site in the aftermath of the multiple reactor accidents, and a comparison of how renewable energy and nuclear energy are performing.