The nuclear energy industry hopes to secure its future through miniature nuclear reactors. The small underground plants will supposedly be safer than large plants, and would lower the cost of electricity from nuclear power. But critics say that the electricity the plants produce will be too expensive and warn of the risk of proliferation.
By Philip Bethge
In Galena, a town in icy central Alaska, energy is indispensable — but expensive. Although diesel generators provide plenty of electricity, the town’s roughly 600 residents regularly receive monthly electric bills in the hundreds of dollars.
But the future could soon arrive in this tiny town on the Yukon River. “Super-Safe, Small and Simple,” or “4S,” is the name of a machine that could soon be buried 30 meters (98 feet) below the icy soil and placed into service.
The hot core of the device, developed by the Japanese company Toshiba, measures only 2 meters by 0.7 meters (6 feet 7 inches by 2 feet 4 inches). But despite its diminutive size, it is expected to deliver 10 megawatts of electricity. “4S” is a nuclear reactor, and Galena could become a test case for a new kind of electricity generation.
The nuclear power industry hopes to secure its future with miniature reactors for civilian use. The concept of mini nukes that could produce up to 300 megawatts of electricity has been remarkably well received, particularly in the United States. Nine designs are competing for the attention of electric utilities and the US Nuclear Regulatory Commission (NRC), the government agency that regulates nuclear power plants.
The Nuclear PR Machine
Critics, like physicist Edwin Lyman of the Union of Concerned Scientists, are convinced that the projects are all in the “stage of fantasy.” Jim Riccio, a nuclear expert with the environmental organization Greenpeace, blames the “hype” on the “well-oiled PR machine of the nuclear industry.”
But the movement has prominent supporters. Microsoft co-founder Bill Gates, for example, has invested in a company called TerraPower, which plans to build innovative small reactors. US President Barack Obama has pledged to provide $54 billion (€40 billion) in loan guarantees for the nuclear industry.
And for Energy Secretary Steven Chu, who is a winner of the Nobel Prize in Physics, it goes without saying that a portion of these loan guarantees will be available for miniature reactors of what he calls the “plug and play” variety. Small modular reactors are “one of the most promising areas” in the nuclear industry, Chu wrote recently in an enthusiastic opinion piece in the Wall Street Journal.
Proponents of nuclear power present the following arguments in favor of the idea:
- Small reactors could become available in the future at bargain prices of less than $600 million, and they would only take two to three years to build. By comparison, reactors in the gigawatt range cost more than $5 billion, and financing is often a challenge. Some projects, such as the current construction of a new reactor in Olkiluoto, Finland, are years behind schedule and vastly over budget.
- Because they are delivered pre-assembled, mini-reactors could also be used in countries without domestic nuclear experts. The plants produce about as much energy as gas or coal power plants and could therefore simply replace them. Existing power grids and turbines could still be used.
- The miniature reactors unleash their fissile power from locations deep underground, which would make it difficult for terrorists to steal fissile material.
“Small nuclear reactors are cheaper, safer and more flexible,” raves Tom Sanders, president of the American Nuclear Society. Sanders wants to mass-produce nuclear power plants, just as Henry Ford did with cars in his time, and make them available around the world, particularly in developing countries.
“There is certainly a global interest in these kinds of systems,” says Chris Mowry of Babcock & Wilcox, a producer of nuclear power plants based in Lynchburg, Virginia. In the past, the company earned much of its revenue with reactors that power nuclear submarines, but now it has developed one of the most promising mini-reactors for civilian energy use.
The mPower reactor is a conventional, 125-megawatt pressurized water reactor. Once it has been buried underground, it is expected to continue producing electricity for 60 years. One of the device’s most appealing features is that spent fuel assemblies are stored in the reactor shell, making them virtually inaccessible. The steam generator is also integrated into the unit.
“All key components can be manufactured in one single factory,” Mowry says enthusiastically. Three large US electric utilities have shown interest in the technology. The utilities are particularly attracted to the idea of building nuclear power plants in modular fashion in the future. When one reactor has run its course, the next one can be ordered. However, the mPower reactor has yet to obtain NRC approval, which could take years.
A consortium led by US nuclear power producer Westinghouse is pursuing a similar approach. Its Iris reactor would produce 335 megawatts of power and is one of the leading candidates for the Global Nuclear Energy Partnership (GNEP).
Since 2006, the US government has championed the GNEP project, which it hopes could meet the growing energy demands of developing countries. Under GNEP, the nuclear powers would ship complete mini-reactors with sealed reactor cores to developing countries. The plants would be designed to operate without maintenance for close to 30 years. After that, they would simply be returned, like empty deposit bottles, to the country where they were manufactured.
The United Kingdom, France, Canada, China and Japan are among the GNEP donor nations. Countries like Jordan, Kazakhstan and Senegal have shown interest in the small reactors. In return for receiving the plants, they would pledge not to engage in reprocessing or uranium enrichment.
Critics are horrified. They fear that fissile material could end up in the wrong hands all too easily. “Anyone who ships this stuff all over the world shouldn’t be surprised if it comes back in the form of dirty bombs,” says Greenpeace expert Jim Riccio.
Physicist Edwin Lyman agrees, saying that it is preferable to concentrate the technology in only a few places. “I am concerned about exporting these plants to countries that have no experience with nuclear energy and where there are security concerns and corruption.”
Reusing Old Reactors
Critics are also concerned about the plans of Akme, a Russian company. The firm, which was established in December 2009, engages in the typically Russian practice of reusing old equipment: It intends to convert a reactor used in Soviet nuclear submarines into a civilian reactor.
The project is extremely controversial. The reactors operate with relatively highly enriched uranium, which is more easily used to build bombs. In addition, they are cooled in a toxic lead-bismuth alloy.
In addition to safety and security concerns, there are doubts about the mini-reactor’s economic efficiency. In the United States, the costs of licensing a nuclear power plant alone range from $50 million to $100 million. In addition, strict safety requirements make small reactors disproportionately more expensive than larger plants.
This leads physicist Amory Lovins of the Rocky Mountain Institute in Colorado to believe that small reactors will “never be competitive.” Reactor manufacturers expect to see costs of between $3,500 and $5,000 per kilowatt of installed power for the dwarf nuclear power plants. The same value ranges from $900 to $2,800 for coal power plants and $520 to $1,800 for natural gas power plants. Even wind turbines can be built for $1,900 to $3,700 per kilowatt.
‘Not a Sign of Economic Health’
The nuclear industry expects CO2 emissions trading to make nuclear technology, which is largely climate-neutral, more competitive soon. “But the same also applies to hydroelectric power, wind and solar energy,” says Lovins.
“The nuclear industry is desperately trying to make itself look vital,” says the professor. “But government loan guarantees are not a sign of economic health, just as blood transfusions are not a sign for medical health.”
Fans of the new miniature reactor world aren’t allowing the grumblers to spoil their mood. Instead, they are developing bolder and bolder projects for the future. For example, nuclear scientist Tom Sanders and a team at the Sandia National Laboratory are developing a reactor that would cost only about $250 million at a planned production rate of 50 reactors per year. Liquid sodium cools the uranium core of the plant, which resembles a sort of replaceable cartridge.
TerraPower, the company Bill Gates has invested in, is working on a so-called traveling-wave reactor. In this type of reactor, the fission zone travels slowly through an elongated fuel core. Plutonium is bred from depleted uranium and then immediately burned off. The engineers rhapsodize over the system, saying that this “wave of fission” could generate electricity continuously “for 50 to 100 years without refueling or removing any used fuel from the reactor.”
Is it the holy grail of nuclear engineering? The traveling-wave reactor still doesn’t exist outside supercomputers. TerraPower has just entered into a joint venture agreement with Toshiba. The two companies plan to move forward together with the development of a mini-nuke future.
The Japanese might already be finding proof of their capacity for innovation in Galena, the town on Alaska’s Yukon River, if only they hadn’t run into problems with approval for their “4S” reactor.
For now, the residents of Galena have turned to another innovative energy source, paid for with subsidies from Alaska’s renewable energy fund: wood-burning stoves.
Translated from the German by Christopher Sultan