Princeton, N.J., February 17, 2010 — According to a study by the International Panel on Fissile Materials, fast breeder reactors may not the answer to the problem of long term storage for nuclear waste.
The IPFM report concludes that the problems with fast breeder reactors make it hard to dispute that such reactors are expensive to build, complex to operate, susceptible to prolonged shutdown as a result of even minor malfunctions and difficult and time-consuming to repair.
Plagued by high costs, often multi-year downtime for repairs (including a 15-year reactor restart delay in Japan), multiple safety problems (among them often catastrophic sodium fires triggered simply by contact with oxygen) and unresolved proliferation risks, fast breeder reactors already have been the focus of more than $50 billion in development spending, including more than $10 billion each by the U.S., Japan and Russia.
As the IPFM report notes: “Yet none of these efforts has produced a reactor that is anywhere near economically competitive with light-water reactors After six decades and the expenditure of the equivalent of tens of billions of dollars, the promise of breeder reactors remains largely unfulfilled and efforts to commercialize them have been steadily cut back in most countries.”
Today, with increased attention being paid both to so-called “Generation IV” reactors, some of which are based on the fast reactor technology, and a new Obama administration panel focusing on reprocessing and other waste issues, interest in some quarters has shifted back to fast reactors as a possible means by which to bypass concerns about the long-term storage of nuclear waste.
The rationale for pursuing breeder reactors was based on the following key assumptions: 1. Uranium is scarce and high-grade deposits would quickly become depleted if fission power were deployed on a large scale; 2. Breeder reactors would quickly become economically competitive with the light-water reactors that dominate nuclear power today; 3. Breeder reactors could be as safe and reliable as light-water reactors; and, 4. The proliferation risks posed by breeders and their ‘closed’ fuel cycle, in which plutonium would be recycled, could be managed. Each of these assumptions has proven to be wrong.”
Sodium’s major disadvantage is that it reacts violently with water and burns if exposed to air. The steam generators, in which molten-sodium and high-pressure water are separated by thin metal, have proved to be one of the most troublesome features of breeder reactors. Any leak results in a reaction that can rupture the tubes and lead to a major sodium-water fire.
A large fraction of sodium-cooled demonstration reactors have been shut down most of the time that they should have been generating electric power. A significant part of the problem has been the difficulty of maintaining and repairing the reactor hardware that is immersed in sodium.
The requirement to keep air from coming into contact with sodium makes refueling and repairs inside the reactor vessel more complicated and lengthy than for water-cooled reactors. During repairs, the fuel has to be removed, the sodium drained and the entire system flushed carefully to remove residual sodium without causing an explosion. Such preparations can take months or years.
All reactors produce plutonium in their fuel but breeder reactors require plutonium recycle, the separation of plutonium from the ferociously radioactive fission products in the spent fuel. This makes the plutonium more accessible to would-be nuclear-weapon makers.
Breeder reactors —and separation of plutonium from the spent fuel of ordinary reactors to provide startup fuel for breeder reactors — therefore create proliferation problems. This fact became dramatically clear in 1974, when India used the first plutonium separated for its breeder reactor program to make a ‘peaceful nuclear explosion.’
Germany, the United Kingdom and the United States have abandoned their breeder reactor development programs. Despite the arguments by France’s nuclear conglomerate Areva, that fast-neutron reactors will ultimately fission all the plutonium building up in France’s light-water reactor spent fuel, France’s only operating fast-neutron reactor, Phàƒ©nix, was disconnected from the grid in March 2009 and scheduled for permanent shutdown by the end of that year. The Superphàƒ©nix, the world’s first commercial-sized breeder reactor, was abandoned in 1998 and is being decommissioned. There is no follow-on breeder reactor planned in France for at least a decade.
The International Panel on Fissile Materials was founded in January 2006. It is an independent group of arms-control and nonproliferation experts from 17 countries, including both nuclear weapon and non-nuclear weapon states.
The mission of the IPFM is to analyze the technical basis for practical and achievable policy initiatives to secure, consolidate, and reduce stockpiles of highly enriched uranium and plutonium. These fissile materials are the key ingredients in nuclear weapons, and their control is critical to nuclear disarmament, halting the proliferation of nuclear weapons and ensuring that terrorists do not acquire nuclear weapons.