Highly secretive projects have turned the nuclear age upside down. The US government is working on an exotic object that can change its physical form when called for, possibly even superfast and electrically charged.
The nuclear generating breakthroughs could help create a source of clean energy that can provide significant support to the economy and society.
As “internet of things” technology makes computerized controls over factories, homes, factories and vehicles even more important, engineers have expanded the definition of “intelligent” machinery. It is starting to seem that every device on earth is now connected in some way to a network, making it more likely that “smart” objects can be turned to do your bidding. The example of this is the burgeoning commercial drone industry, which may become even more powerful as the explosive growth of “smart” homes allows data to be used to protect property and enforce rules.
This program, which has generated a great deal of interest in several countries, appears to be one of the most important US government initiatives since the Manhattan Project. The National Academy of Sciences in the United States and Europe, the University of York in England, and others have conducted work with the Department of Energy, funding that agency’s Advanced Research Projects Agency-Energy, or ARPA-E. The US Army, the Navy and the Air Force are also involved, according to the latest news report.
The program has a clearly defined goal, the building of “an ultra-compact fusion reactor [that] can be placed in a box no larger than a paperclip.” In terms of power, the apparatus would operate at 1 megawatt, or 10 times the power of conventional nuclear reactors, and produce up to five times the amount of clean energy as is generated by today’s best solar panels.
The US government’s interest in energy sources that depend on nuclear fission rather than fusion have been increasing since the 1970s. The federal government’s interest in this nuclear power project goes back to 1979, when funding was approved for a full-scale “thermonuclear device,” and a prototype was built at Los Alamos National Laboratory in 1986.
Two years later, an advanced nuclear reactor design called NERVA (Neutron Research Engines for Rocket Engine Applications) was begun, and the first full-scale unit completed in 1989. Its budget was almost 10 billion dollars over ten years.
Unfortunately, this program was not very successful. The reactors failed to get off the ground and the company that was responsible for construction went bankrupt, and the machine was scrapped.
The project now taking place in France differs from NERVA in several ways. To make a first breakthrough, the basic “hot-start” nuclear reactor would be developed first, and perhaps the basics of a commercial power plant would be established before the device “doughnut” is built.
The French design is not for a weapon, but the purpose is to produce a compact, fast reactor that can supply reliable, clean power. A similar device has been built in the United States, but the machine was not intended for a bomb. It was a reactor design for a smaller reactor. This prototype, the AP1000, is considered to be the largest reactor in the world, and, as of 2012, it was not available for commercial operation. It is of only minor importance, however, compared to the proposal in France.
The European version of the design has a faster start-up time than the American version and operates at an expected maximum power of 10 to 20 megawatts, producing perhaps 5 megawatts at peak, instead of 1.2 megawatts. This gives it more output for a given amount of input from fuel.
While the European reactor would not be expected to be weaponizable, the American version will be “inherently deployable,” according to Argonne National Laboratory.
The last time any such device was attempted was in the 1960s, when the American-backed NuScale Power company built a working prototype but ran out of money and handed over the machine to the federal government. That reactor, located in Idaho, has been mothballed since then.
Based on the approval to begin work on the new design by the US Department of Energy in 2011, work on the detailed design began in 2015. The prototype unit is now scheduled to be completed and operational in 2020, with the first commercial unit not to come online until about 2022. The units will run on thorium, and thus are more suitable than the older reactors in the US, which run on uranium.
It would be theoretically possible for the French design to be deployed sooner, in about two years. The reactor has been designed to operate on 6 grams of thorium, which is as abundant as uranium, but far more difficult to extract. The major hurdle is in raising the commercial unit’s power output to 5 megawatts from 10 megawatts, which could not be done until the carbon-filtration system, which uses hydrogen for cooling and converts the exhaust gas into electricity, had been installed.
This system, along with the fast breeder reactors, is essential for commercial operation of this reactor design. A uranium-fuelled fast breeder reactor needs very high levels of uranium enrichment for power production. The alternative is to use helium-3 as a fuel source, which is a waste product of nuclear power production.
As far as the French design is concerned, however, the small initial output is not necessarily a problem. Like other French reactors, it has the advantage of being able to burn “standard” fuel, which consists of thorium, uranium and plutonium mixed together, to generate electricity. Such a fuel mix is of less concern than enriched uranium, which would be too expensive to be used in a prototype unit.
The potential dangers of this new reactor design come from its breeder nature. A uranium-fuelled reactor is a natural leader of its generation, because there are only so many of those reactors that can be used in a power station. Breeder reactors have some advantages because they can be run at high power levels and produce large amounts of plutonium. If a breeder reactor is exposed to natural fission products from the normal uranium-fuelled reactor, its potential for creating more plutonium is reduced.
A pressurised-water reactor, the type used in France, is used to breed plutonium for nuclear weapons. A breeder design is better than a standard reactor, as it will usually burn the other fuels produced by the standard reactor.
But a breeder design still runs the risk of a nuclear accident, because it may generate too much plutonium or produce too much U-233, which can be used to make plutonium for weapons. For this reason, the planned two-reactor prototype will have no reprocessing facility. Instead, a study has shown that an operation to burn reprocessed uranium, which may be used to burn the LEU and generate plutonium, would be the most effective way of destroying that material.
As for the fuel used in the French prototype, this too will be localised, because most of the raw materials will come from France. The fuel will be manufactured in situ, on site, by recycling the waste from the earlier nuclear reactors. This technology is used in the APR1400 reactor built by the French company Areva. There are no plans to adopt the United States’ MSR technology, which is based on enriched uranium, because it makes it much easier to steal nuclear materials.
To show that the new French reactor will be safe, a nuclear waste dump is being built on an island near Bugey in the Rhône river, which is operated by the French nuclear industry. The reactor is currently only used to burn down tons of nuclear waste produced by the local nuclear power plants.
Using the fast-breeder design will allow the French nuclear industry to recycle the plutonium produced in its reactors, increasing its amount of supply. This is essential for it to compete with uranium-fuelled reactors for the construction of new nuclear power stations.
There is a risk that the existence of this new reactor, along with a fast-breeder design for its power output, will encourage Western countries to stop seeking more nuclear power plants, because they will then need to breed their own plutonium. This is already happening in the United States. The Department of Energy has begun efforts to develop a breeder reactor in this country. However, its fission gas generator technology is still a few years from completion, and the construction of this reactor will be expensive and will not be profitable in the short term.
Regardless of what happens to fast-breeder reactors, there is no justification for stopping research on breeder reactors. The risks involved in developing a new reactor are greater than the risks involved in exploiting a known one. Despite the new risks, there is no reason why researchers cannot continue their research, and a lot of research is already being conducted at universities. At present, not all nuclear scientists believe that fast breeder reactors are an answer, but they could soon be proved wrong.