Illustration:"The Mysterious Fast Breeder Reactor and her brood"
This 2,500 word article is an extract from a 5,687 word chapter, “Nuclear Fission power options,” in Sheila Newman, (Ed.) The Final Energy Crisis, (2nd Edition), Pluto Press, UK, 2008
Most reactors round the world use uranium. A breeder reactor must be started with enriched uranium or some fissile substitute.
During the operation of a conventional nuclear power station, some of the neutrons in the atomic pile are captured by its U238, converting it into fissionable material. This includes plutonium and other dangerously radioactive products. These products are increased in a breeder reactor. In conventional reactors, moderators slow the neutrons. By thus reducing each one's likelihood of becoming part of a converted U238 nucleus and increasing its chance of finding one of the already-fissionable U235 nuclei, moderators allow a natural uranium pile to support a slowly increasing chain reaction.[a]
The Fast Breeder reactor (FBR)
Without the moderator, the neutrons slow down less and the reactor becomes a ‘fast neutron reactor', often abbreviated to just ‘fast reactor', with a bias towards the U238 being converted. In a fast breeder the nuclear waste products which present such a problem in conventional reactors become more fuel. The aim is to make this a closed and remote controlled process.[b]
The first Fast Breeder Reactor (FBR) or Fast Neutron Reactor was built in the US in 1951 with a tiny output of 0.2MW (electricity) and operated until 1963, when it was succeeded by a 20MW (electricity) one, a 66 MW one, a 20MW one and “Fast Flux TF” which had a thermal output of 400 MW, from 1980-93. The UK had a 15MW(el) from 1959-1977 and then a 270MW one from 1974-94. France built her first in 1966 with an output of 40 MW (thermal), followed by Phenix in 1973 (250 MWe) (still in operation) and Superphenix 1in 1985-98 with an output of 1240MWe. Germany had one very small one with an output of 21MWe from 77- 91, India has one with an output of 40 MW (thermal), built in 1985; Japan’s Joyu with 140MW (thermal) was built in 1978. Monju (280 MWe) went from 1994-1996 and is currently closed. Kazakstan’s BN350 has been going since 1972 with an output of 135 MWe, half of which desalinates about 80,000 tons of water each year for the city of Aktau. Russia has had 3 FBRs: the first in 1959-1971 reopened in 1973; the second from 1979 produces 12 MWe, and the third, built in 1981, with an output of 600 MWe is the largest still running (with assistance from a US supervisory crew), but it has had a lot of problems with liquid sodium coolant and other leaks, involving long periods out of action. France’s Super Phoenix was the biggest in the world, but it was closed down due to safety problems associated with sodium leaks. Monju Fast Breeder in Japan was also closed due to safety concerns.
Significant commercial success seems to have been elusive so far but there are international ambitious plans for “Generation IV” FBRs of various designs, including thorium based ones. The low cost of uranium is often offered as an explanation for the failure of this technology to find the necessary finance to take it past the experimental stage. Design and research are materially and financially costly. 
Reasons that thorium breeder reactors are not being built:
Potentially thorium breeder-reactors would enable a process of converting all the 98.3 per cent of the natural uranium into radioactive substances which can maintain a sustained fission process in a chain reaction.
No-one is doing this yet.
One experimental thorium breeder reactor  exists in Kalpakkam in India, which is also the only place, where all three fissile types: U235, Pu 239 and Th 233 are burned.
You can read a lot about the bright future of plutonium seeded thorium breeder-reactors on the internet, for instance, Michael Anissimov’s “A Nuclear Reactor in Every Home” . Conventional nuclear power stations now only use about 0.75 per cent of U235 and increase the radioactivity of what is left in the form of terrifyingly lethal contaminants known generally as the actinides. The problem of safe transport of fuels and waste that is presented in conventional nuclear power stations is likely to remain for as long as these power stations are productive. Breeder reactors would generate similar poisonous substances but they would also burn them up in a closed and remotely controlled cycle, in continuous production of lower grade materials which burn usefully for nuclear energy production. The waste problem would be considerably reduced even though some less long-lived wastes would still pose a storage problem.
So why aren’t they being built all over the place?
The potential of thorium breeder reactors is still unproven beyond the small experimental facility in India. There is concern that proving and building them would be very expensive. There are still fears that they may never work properly as units.
There is however growing support for a new paradigm of quasi-continuous self-renewing fission energy which would ‘eliminate’ dangerous wastes. Against this ideal is the contention that breeder reactors could still be used to create weapons grade plutonium. The rebuttal of this is that weapons plutonium requires enormously more expensive Separation Work Hours and is not useful or necessary for generating power and that fast-breeder reactors designed for power production would not lend themselves easily to this use. If weapons plutonium were wanted then weapons plutonium specific reactors much more suited to the task would be built.
Another reason you will read is that there is a looming shortage of plutonium.  Although when Russia and the US agreed to eliminate a lot of their nuclear weapons this made a lot of enriched uranium and plutonium available, much of it was snapped up by conventional reactors and nuclear submarines. Warheads became fuel for US atomic power stations. The weapons-grade plutonium is diluted to become non-explosive. Recycling it saves time and energy normally used for the enrichment process.
Another school says that no-one influential is likely to want to disturb the uranium investment market because it is so profitable, particularly in the light of impending petroleum and other fossil-fuel depletion. This factor, coupled with the legal and other set-up costs of fast breeder-reactors, makes sticking to conventional reactors and mixing weapons plutonium with yellowcake more economically viable in the short to medium term – pending running out of uranium and recycled waste, and possibly pending a perfected thorium breeder reactor.
Importantly, the reliability of conventional reactors with their established safety and legal frameworks and the comparative low cost of building new ones according to ‘tried and true’ models discourages investment in new designs of which the setting up would entail complex and fraught negotiation of new safety and legal frameworks.
The chief beneficiaries have a vested interest in maintaining an industry that reprocesses and sells spent uranium to countries which have conventional reactors but which do not have global approval to reprocess their own waste.
If uranium-fueled nuclear were to expand from the 16 per cent of world electricity  it currently supplies, then diverse projections see uranium failing to meet demand by around 2040. With no nuclear expansion, at current use it might last into the beginning of the 22nd century. 
Still others have argued that there is too much uranium around to worry about thorium or other stuff.
Some more technical problems with thorium and fast breeder reactors:
The costs of developing nuclear power using thorium as fuel are increased by the engineering problems associated with the production, recycling, and containment of extremely radioactive isotopes. Far more shielding would be required than for plants currently operating, including ‘MOX’ plants, which use recycled uranium mixed with plutonium.
The thorium cycle includes the need to come to terms with exotic old and new artificial substances of extreme radioactivity. The substances include U-233, which is chemically separated from the irradiated thorium fuel, and always contains traces of U-232. U-232 itself has a 69 year half life but strong gamma emitting daughter products, including thallium-208 which has a very short half life. Recycled thorium itself contains alpha emitter Th-228, with a 2 year half life.
The weapons proliferation risk associated with thorium FBRs is partly based on fears that U-233 might be separated on its own. The reprocessing of thorium itself is still highly experimental. 
The technical problems associated with the commercial development of thorium breeder-reactors are so formidable, even on the scale of research possible in a country as large as India, that India could just drop its pursuit of thorium FBRs if it could obtain ready access to traded uranium.
Some political and commercial complications: India as the new FBR lab
There are currently delicate international negotiations proceeding with India, which offers a huge commercial market for uranium but has an interest in developing nuclear self-sufficiency based on its huge thorium reserves. India’s nuclear technology has developed independently due to being isolated through India’s having developed nuclear weapons too late (1974) for inclusion as an official Nuclear Weapons State under the Nuclear Non-Proliferation Treaty (NPT).
The NPT of 1970 accorded five countries: France, China, Russia, the United Kingdom and the United States the exclusive official status of Nuclear Weapons States based on their having reached that status prior to 1970. Of those five countries, all but the USA reprocess spent nuclear fuel. As well as having been excluded from this club, India has enduring differences with the NPT’s strategies for lowering risk. Historically it has preferred to support a global policy of universal disarmament initiatives. It claims to be very uneasy about China’s capabilities and not to be reassured by Pakistan’s expressions of potential support for the NPT.
India has thus proceeded in comparative isolation with a civil nuclear power program, planned from the 1950s, receiving little or no fuel or technological assistance from other countries.
Up through the late 1990s India’s nuclear power plants performed poorly with only 60 per cent capacity.
Dot-com revolution and Indian diaspora
The dot-com revolution of the 1990s saw a huge flow of Indian students and scientists into US universities, institutions and firms. With the dot-com crash many of them returned to India, bringing substantial technical knowledge with them. The scientific and technical community in India became very attractive for the global outsourcing of new scientific and technical developments. It is perhaps partly because of these social changes that capacity of its nuclear power plants improved markedly by 2001-02 to 85 per cent. 
As early as the 1950s India planned for a three-stage nuclear development program. Stage One was for U238 to be used in pressurised heavy water reactors (PHWRs). In Stage Two the plutonium generated by these PHWRs was to be deployed to run FBRs. This has so far only been done in a 13 Megawatt experimental small FBR at Kalpakkam. The planned FBRs were to use the plutonium mixed in a 70 per cent oxide (MOX-fuel) in its core within a fertile ‘blanket’  of U233 and thorium232 which would be there to make the fuel in the core sustain fission. In Stage Three it was intended that the FBRs use thorium232 to produce U233 as fuel for the third stage reactors.  India currently has 12 nuclear power plants. The Department of Atomic Energy has government clearance to set up a 500 MW prototype of the ‘next-generation’ FBW at Kalpakkam, with the intention of commercially exploiting thorium for its major fuel supply.
After Australia, India possesses the world’s largest reserves of thorium. Use of Indian thorium would make India independent of imported uranium including reprocessed spent uranium.
Peaceful Atomic Energy Cooperation negotiations
On 9 December 2006 US Congress passed the United States-India Peaceful Atomic Energy Cooperation Act, allowing shipments of nuclear fuel and technology to India for use in its civilian nuclear power program.  India had not yet ratified this agreement. A major point of difference was US insistence that used fuel from any US-supplied reactor must not be reprocessed.”  This would inhibit practices in India’s energy and weapons system, for both kinds of facility were, at the time of writing this article (May 2007), still producing plutonium for reuse. The agreement would require complete separation of power facilities from weapons facilities, which were still exchanging reprocessed materials.
“The opposition to accepting safeguards on the grounds that it is difficult to separate civilian and military facilities, and that it compromises on national security, is, however, ill-founded. Demarcation of facilities as military should not be difficult but a detailed exercise of identifying these has to be carried out. The manner in which the Department of Atomic Energy (DAE) declared the Bhabha Atomic Research Centre (BARC) and a few other facilities out of bounds for AERB inspections with a single bureaucratic order in 2000, would suggest that the process should not pose any administrative problems either. In any case, the agreement is for a phased declaration. But there will be a substantial cost involved and that is the price one has to pay for failing to plan for long-term fuel needs properly.
Since the research reactors Dhruva and Cirus are the chief sources of weapons-grade plutonium, and it makes no sense to use reactor-grade plutonium for weapons, one can easily demarcate all the power plants as civilian. It would seem that the main costs would pertain to replicating reprocessing plants specifically for weapon purposes because one cannot declare the existing plants - which currently reprocess spent fuel from power reactors as well as research reactors to yield plutonium for the breeder programme and weapons respectively - as military.
It is obvious that one-way traffic of nuclear material from military to civilian reactors does not pose any problem; it is only when there is a two-way traffic, as in a reprocessing plant, a dedicated facility for each objective becomes necessary because of safeguards on the material that comes in and goes out. There could be other costs involved in duplicating personnel and equipment required in this as well as other operations where people and equipment double up for the twin objectives at present.” 
Since the UK and France, both countries which reprocess fuel, have also shown interest in the huge commercial market which India could represent, it seems likely that the pressure on the USA to relent on its anti-reprocessing stance will grow. Given the profit issues and that the corporate forces have an interest in this stance changing, resistance will be difficult.
In addition, however, to purchase uranium from the 45 member Nuclear Suppliers Group would require India to sign the NPT, which India does not want to sign. It may be that the very factors which proponents of FBRs cite as discouraging their research and production in countries like the US are positives for FBR research and production in India. In this case, India is probably the place where FBR technology and production may break through first if it is going to.
[a] Many thanks to G.L. Cowan for his rewrite of this paragraph which contained inaccuracies and which originally read: "During the operation of a conventional nuclear power station over the years, via the reactions that occur in the atomic pile, the U238 that is there gets converted into fissionable material which includes plutonium and other dangerously radioactive products. These products are increased in a breeder reactor. In conventional reactors moderators slow the neutron firing down so that the neutrons hit each other more easily and accelerate the natural rate of fission."
[b] Thanks again to G.R.L. Cowan for his changes to this paragraph as well, correcting the error, contained in the original text:
"The Fast Breeder reactor (FBR)
Without the moderator the reactor becomes a ‘fast breeder’ with a bias towards the U238 being converted and producing more fuel than it actually burns. In a fast breeder the nuclear waste products which present such a problem in conventional reactors become more fuel. The aim is to make this a closed and remote controlled process."
It is very hard to find people who will go to the trouble of carefully reviewing the technical detail in such articles, but the authors, who cannot be specialists in every facet they write on, need this kind of feedback. G.R.L. Cowan's feedback makes this article and this site worth visiting for people trying to understand an area where very little is written for the non-specialist in a field where obscurantism compounds rapid change and complex concepts and engineering. Sheila Newman.
 Also known as a Thermal Breeder Reactor and an Advanced Heavy Water Reactor
 Anissimov,M., “A Nuclear Reactor in Every Home”, Oct 16 2006, www.acceleratingfuture.com/michael/blog/?p=212
 The Megatons to Megawatts Program is the name given to the program that implemented the 1993 United States-Russia non-proliferation agreement to convert high-enriched uranium (HEU) taken from dismantled Russian nuclear weapons into low-enriched-uranium (LEU) for nuclear fuel. From 1995 through mid-2005, 250 metric tons of high-enriched uranium (enough for 10,000 warheads) were recycled into low-enriched-uranium. The goal is to recycle 500 metric tons by 2013. Much of this fuel has already been used in many nuclear power plants in the U.S., as it is indistinguishable from normal fuel. http://www.usec.com/v2001_02/HTML/megatons.asp
‘Electricity’ has been substituted for ‘energy’ here as a correction of a mistake in the full chapter version in The Final Energy Crisis.
 Figure 6, “History and forecast of uranium production,” in “Uranium depletion and nuclear power: Are we at peak uranium?” http://www.theoildrum.com/node/2379 Accessed 3-12-07 and “According to the authoritative “Red Book” produced jointly by the OECD’s Nuclear Energy Agency and the UN’s International Atomic Energy Agency, the world’s present known economic resources of uranium, exploitable at below $80 per kilogram of uranium, are some 3.5 million tonnes. This amount is therefore enough to last for 50 years at today’s rate of usage – a figure higher than for many widely used metals.” Source: “Can Uranium supplies sustain the global nuclear renaissance?”, World Nuclear Association Position Statement, http://www.uic.com.au/WNA-UraniumSustainability.pdf and Jan Willem Storm van Leeuwen and Philip Smith Source: http://www.greatchange.org/bb-thermochemical-rebuttal_WNA.html
 Correspondence with Ian Hore-Lacy, Director – Information, Australian Uranium Association, Melbourne, http://www.uic.com.au Mon 4/30/2007 11:58 PM and Tue 5/1/2007 12:34 AM
 REF: http://www.uic.com.au/nip45.htm
 The core is the central part of a nuclear reactor containing the fuel elements and any moderator. A fast neutron reactor is configured to produce more fissile material than it consumes, using fertile material such as depleted uranium in a blanket around the core. Source of definition material: http://www.world-nuclear.org/info/inf51.htm
 Frontline, Volume 22 - Issue 16, Jul 30- Aug 12, 2005, http://www.hinduonnet.com/fline/fl2216/stories/20050812005700700.htm
 Nuclear Technology Milestones 1942 to Present, Nuclear Energy Institute, Washington, http://www.nei.org/index.asp?catnum=3&catid=265
 “Sticking points in US-India talks”, Reuters, 30/03/07, Nucleonics Week 12/4/07, FT 19/4/07.
 R. Ramachandran, “Behind the bargain”, Frontline, Volume 22 - Issue 16, Jul 30- Aug 12, 2005, http://www.hinduonnet.com/fline/fl2216/stories/20050812005700700.htm