(Adapted from Deadly Arsenals) In a nuclear reactor, uranium fuel (either natural uranium or slightly enriched, depending on the reactor design) is used to create a controlled chain reaction. This reaction releases neutrons that are captured by "fertile" nuclear materials, such as Uranium-238, converting it through a series of reactions to Plutonium-239. This is one of the two fissile materials used in nuclear weapons (the other is Uranium-235). However, the fuel rods containing these materials also contain other reaction by-products, many highly radioactive. To extract the plutonium, operators must go through a series of complex steps to reprocess the fuel rods.
To do this, "spent" fuel rods are taken to a reprocessing plant where they are dissolved in nitric acid and the plutonium is separated from the solution in a series of chemical processing steps. Since the spent fuel rods are highly radioactive, heavy lead casks must be used to transport them. In addition, the rooms at the reprocessing plant where the chemical extraction of the plutonium occurs must have thick walls, lead shielding, and special ventilation to contain radiation hazards.
Although detailed information about reprocessing was declassified by the United States and France in the 1950s and is generally available, it is still a complex procedure from an engineering point of view. Indeed, almost every nation that has tried to develop nuclear-weapons via the plutonium route—India, Iraq, Israel, and Pakistan—has sought outside help from the advanced nuclear-supplier countries, although North Korea apparently succeeded in constructing a reprocessing facility at Yongbyon without such foreign assistance.
Breeding Plutonium
Like uranium enrichment facilities, however, reprocessing plants can also be used for legitimate civilian purposes, because plutonium can be used as fuel in nuclear power reactors. Indeed, through the 1970s it was generally assumed that as the use of nuclear power grew and worldwide uranium resources were depleted, plutonium extracted from spent fuel would have to be "recycled" as a substitute fuel in conventional power reactors.
In addition, research and development is under way in a number of nations on a new generation of reactors known as breeder reactors, most notably in France, Japan, Russia and India. Breeder reactors use mixed plutonium-uranium fuel surrounded with a "blanket" of natural uranium; as the reactor operates, slightly more plutonium is created in the core and the blanket together than is consumed in the core, thereby "breeding" new fuel. These programs have encountered complex technical and political challenges, not the least of which relate to the overabundance of plutonium and questions about safety and waste produced from these types of reactors and their spent fuel handling. One growing area of research relates to proliferation-resistant reactors that could be used to consume those large amounts of excess plutonium and whose spent fuel would be less well suited for use in the production of plutonium and nuclear weapons.
The Plutonium Economy
The economic advantages of both breeders and plutonium recycling depends on natural uranium’s becoming scarce and expensive. However, over the past three decades new uranium reserves have been discovered; nuclear power has reached only a fraction of its expected growth levels; and reprocessing spent fuel to extract plutonium (a critical step in the manufacture of plutonium-based fuels) has proven far more expensive and complex than anticipated. Moreover, concern over the proliferation risks of wide scale-use of plutonium as a fuel has grown. These factors led the United States in the late 1970s to abandon its plans to recycle plutonium in light-water reactors and, in the early 1980s, to abandon its breeder reactor development program. The Department of Energy, however, has recently overturned this policy by starting a program to develop a new generation of fast breeder reactors and reprocessing plants. Germany has abandoned its breeder reactor program and is phasing out its recycling of plutonium. Great Britain, too, has frozen its development of breeder reactors, although it is continuing to reprocess spent fuel on a commercial basis for itself and several advanced nations.
The principal proponents of the use of plutonium for civilian purposes are France, Japan, and Russia, which are all continuing to develop the breeder reactor option and are moving forward with sizable plutonium recycling programs. China and India are also developing breeder reactors. The Chinese pilot breeder reactor could begin operation as early as 2005, and the Indians are expecting construction to begin very soon on a 500 MW breeder reactor at Kalpakkam. Belgium and Switzerland, although they do not have breeder reactor programs, are using increasing amounts of recycled plutonium in light-water reactors. Broadly speaking, the proponents of nuclear energy in these countries have maintained support for the civil use of plutonium by arguing that, although it may not be economical, it represents an advanced technology that will pay off in the future and reduce dependence on foreign sources of energy.
What You Will Need to Make Your Plutonium
The production of plutonium entails multiple steps, and many installations and capabilities are needed. The following facilities and resources would be required for an independent plutonium production capability assuming that a research or power reactor, moderated by either heavy-water or graphite, and employing natural uranium fuel, were used:
- uranium deposits;
- a uranium mine;
- a uranium mill (for processing uranium ore containing less than 1 percent uranium into uranium oxide concentrate, or yellowcake);
- a uranium purification plant (to further improve the yellowcake into reactor-grade uranium dioxide);
- a fuel fabrication plant (to manufacture the fuel elements placed in the reactor), including a capability to fabricate zirconium alloy (zircaloy) or aluminum tubing;
- a research or power reactor moderated by heavy-water or graphite;
- a heavy-water production plant or a reactor-grade graphite production plant; and a reprocessing plant.
For Additional Information:
Chapter 3 from Deadly Arsenals on Nuclear Weapons and Materials
"Fissile Material Basics," Union of Concerned Scientists
"The Plutonium Threat," Nuclear Control Institute
