It ceased generating power early in but ran until October as a research reactor. Closure of the MWe commercial prototype Superphenix FBR in on political grounds after very little operation over 13 years set back developments.
All the plutonium which was produced was recycled back into the reactor after reprocessing. The plutonium which was recovered was recycled to make new fuel, and sub-assemblies with this being used in the core from Some of these elements have been re-reprocessed at the Marcoule Pilot Plant. This entire experience, involving reprocessing high specific burn-up fuels, waste confinement and closed fuel cycle, is claimed by CEA to be unique, and proving the fast breeder reactor fuel cycle as an industrial reality.
From the start, the reactor core was reloaded the equivalent of 7 times, with more than fissile sub-assemblies, of which nearly were experimental, or , fuel pins. To this must be added the several hundred breeder sub-assemblies where the plutonium forms. A radial breeder blanket of depleted uranium oxide is in about one hundred sub-assemblies, with each assembly containing 61 fuel pins 1.
The structural elements of these sub-assemblies are identical to those used in the fissile assemblies. A breeder assembly contains 2 kg of plutonium after irradiation, has a mass of kg and retains the same overall dimensions of those of a fissile fuel sub-assembly. In mid the French Atomic Energy Commission CEA was commissioned by the government to development two types of fast neutron reactors which are essentially Generation IV designs: an improved version of the sodium-cooled type SFR which already has 45 reactor-years of operational experience in France, and an innovative gas-cooled type — Allegro.
It noted that China and India are aiming for high breeding ratios to produce enough plutonium to crank up a major push into fast reactors. After CEA's Astrid programme was put on hold in August , in January a second five-year agreement on the development of fast neutron reactors took effect. Astrid was initially envisaged as a MWe prototype of a commercial series of MWe SFR reactors which was planned to be deployed from about to utilise the abundant depleted uranium DU available by then France alone will have half a million tonnes and also burn the plutonium in used MOX fuel.
It will use an intermediate sodium coolant loop, and the tertiary coolant in the power conversion system PCS was planned to be nitrogen with Brayton cycle, subject to review. Over experiments with Brayton cycle gas turbine technology driven by nitrogen were carried out with the CEA. Four independent heat exchanger loops are likely, each with two heat exchangers, and it will be designed to reduce the probability and consequences of severe accidents to an extent that is not now done with FNRs.
The reactor core will leak neutrons, which reduces fissile breeding ability but gives it a negative reactivity coefficient to improve safety. Astrid is called a 'self-generating' fast reactor rather than a breeder in order to demonstrate low net plutonium production.
Astrid is designed to meet the criteria of the Generation IV International Forum in terms of safety, economy and proliferation resistance. CEA plans to build it at Marcoule. In December it approved moving to the design phase, with a final decision on construction to be made in The six-year conceptual design was finished in The basic design phase ran to , with 14 industrial partners.
The CEA is responsible for the project and will design the reactor core and fuel, but will collaborate with Areva, which will design the nuclear steam supply system, the nuclear auxiliaries and the instrumentation and control system.
Japanese partners have been playing a major role since The Astrid programme includes development of the reactor itself and associated fuel cycle facilities: a dedicated MOX fuel fabrication line AFC was to be built about and a pilot reprocessing plant for used Astrid fuel ATC about Fuel rods containing actinides for transmutation were scheduled to be produced from , though fuel containing minor actinides would not be loaded for transmutation in Astrid before In June the French government said that Astrid would have its capacity scaled down from the initially planned MWe to between and MWe to reduce construction costs and also due to development of a commercial fast reactor no longer being a high priority.
Following the decision, Toshiba said that the smaller Astrid would be a step back for Japan's fast reactor development process, possibly forcing the country to build its own larger demonstration reactor in Japan rather than rely on Astrid.
In August the CEA said it no longer planned to build the prototype Astrid reactor in the short or medium term. It is now the demonstration project for the reference gas-cooled fast reactor GFR , one of the six or seven designs promoted by the Generation IV International Forum.
Two primary helium circuits connect to secondary circuits with gas or pressurized water. Three decay heat removal loops are integrated in a pressurized guard vessel. In May the Czech nuclear research institute, UJV Rez, announced its project to design by a fourth-generation high-temperature gas-cooled reactor aimed at the heating and industrial sectors. Three versions will be pitched to heating, cogeneration and the chemical industry. The GFR concept avoids the coolant handling issues associated with liquid metal-cooled fast reactors: helium primary coolant is chemically inert and does not become activated, also being transparent it permits simple inspection and repair.
The GFR offers a high temperature heat source for high efficiency electricity generation and high quality process heat. The main technical challenges lie in the development of a high-temperature, high-power density fuel and in the development of a robust decay heat removal system.
Belgium's SCK. As an ADS it will be used to prove that technology and to study transmutation of long-lived radionuclides in nuclear waste. Later on it is intended to be run as a critical fast neutron facility, decoupling the accelerator and removing the spallation loop from the reactor core. Then MYRRHA as a lead-bismuth-cooled fast reactor — LFR will be used for fuel research, for materials research for Generation IV reactors, and for the production of radioisotopes and doped silicon an essential component of high-grade electronic circuits.
The first is with the China Academy of Sciences, since China sees as Myrrha a way forward in treating nuclear wastes. A reduced-power model, Guinevere, became operational at Mol in March First core would be Fission products will be removed at that rate.
It features passive safety systems. The group is to be known as the Fostering Alfred Construction Falcon consortium, which will be expanded through the participation of further European organizations. ELSY is a flexible fast neutron reactor design to use depleted uranium or thorium fuel matrices, and burn actinides from LWR fuel.
Liquid metal Pb or possibly Pb-Bi eutectic cooling is at low pressure. The design was nearly complete in and a small-scale demonstration facility was planned.
This was followed there by the much larger Prototype Fast Reactor which operated for 20 years until the government withdrew funding. Rosatom plans to invest its own funds into FNR development through to BREST appears to be the focus of this. The Russian BN fast breeder reactor — Beloyarsk unit 3 of MWe gross, MWe net — has been supplying electricity to the grid since and is said to have the best operating and production record of all Russia's nuclear power units.
It is a pool-type, with heat exchanger for three secondary coolant loops inside a pool of sodium around the reactor vessel and three steam generators outside the pool, supplying three MWe turbine generators. The BN is reconfigured by replacing the fertile blanket around the core with steel reflector assemblies to burn the plutonium from its military stockpiles.
Its licence has been extended to and a further five-year extension is envisaged. The BN prototype FBR generated power in Kazakhstan for 27 years to and about half of its MW thermal output was used for water desalination. Its design life was 20 years, and after it operated on the basis of annual licence renewal.
Both these are loop-type units with two sets of heat exchangers outside the reactor vessel. BN had five operating primary and secondary sodium coolant loops. There are some significant improvements from BN however. The first and probably only Russian one is Beloyarsk 4, which started up in mid However, during the plutonium disposition campaign it is being operated with a breeding ratio of less than one.
Russia had about 40 tonnes of separated plutonium stockpiled by , which was expected to be burned in the BN by The timing of this has slipped about four years. By the end of it will have a full MOX core. It does not have a breeding blanket, though a version designed for Sanming in China allows for up to DU fuel elements in a blanket.
Service life is 40 years. Net thermal efficiency is It is capable of burning up to 3 tonnes of plutonium per year from dismantled weapons 1. An important feature of BN closed-loop fuel cycle is that actinides both plutonium and minor actinides produced in the reactor are consumed in the same reactor.
The reactor fuel cycle in equilibrium accommodates about 5 t plutonium including 3 t in the core and 2 t in the external fuel cycle , and about kg minor actinides. It is assumed that the reactor core would be recycled 20 times in 40 years of service life, based on equivalent days of a fuel campaign. The main purpose of the BN is to provide operating experience and technological solutions, especially regarding the fuel, that will be applied to the BN In two BN reactors were sold to China.
Construction at Sanming is delayed from intended start in and may happen after Rosenergoatom is ready to involve foreign specialists in its project, with India and China particularly mentioned. Rosatom's Science and Technology Council has approved the BN reactor for Beloyarsk, with plant operation from about A second one will be built at South Urals by Thermal efficiency is Simplified refuelling is on a day cycle cf days for BN The initial loading of fissile plutonium isotopes is 7.
Fuel loading is 47 t of MOX, or 59 t nitride. Core breeding ratio was intended to be 1. Fuel burn-up is designed to progress from It would have fuel assemblies and radial blanket assemblies surrounded by boron shielding assemblies. Spent fuel assemblies would be stored in the reactor for two years. Since about the focus for the BN has been increased safety and reduced capital costs, resulting in reduced power density in the reactor core, reduced core breeding ratio and a focus on nitride fuel.
A lead-cooled version of the BN is under development. To follow the BN series, Rosatom put forward two fast reactor implementation options for government decision in relation to the Advanced Nuclear Technologies Federal Program The second scenario assumed parallel development of fast reactors with lead, sodium and lead-bismuth coolants and their associated fuel cycles, including the multi-purpose small MBIR.
The second option was designed to attract more funds apart from the federal budget allocation, was favoured by Rosatom, and was accepted.
It provides a technological basis of the future innovative nuclear energy system featuring the Generation IV reactors working in closed fuel cycles by Russia has experimented with several lead-cooled reactor designs, and used lead-bismuth cooling for 20 years to the s in reactors for its seven Alfa-class submarines.
It is inherently safe and uses a mixed uranium and plutonium nitride fuel, the fuel load being No weapons-grade plutonium can be produced, since there is no uranium blanket — all the breeding occurs in the core.
The core breeding ratio is 1. Effective enrichment is about Fuel cycle is quoted at years with partial refuelling at about 10 months. The initial cores can comprise plutonium and spent fuel — hence loaded with fission products, and radiologically 'hot'.
Subsequently, any surplus plutonium, which is not in pure form, can be used as the cores of new reactors. Used fuel can be recycled indefinitely, with onsite facilities. The nitride fuel has been successfully tested in the BN reactor to a burn-up of 7. A government decree in August ordered construction by Initial operation will be focused on performance and after ten years or so it will be commercially oriented.
The combination enables a fully closed fuel cycle on one site. The unit would be factory-made and shipped as a 4. A power station with 16 such modules was expected to supply electricity at lower cost than any other new Russian technology as well as achieving inherent safety and high proliferation resistance. Russia built 7 Alfa-class submarines, each powered by a compact MWt Pb-Bi cooled reactor, and 70 reactor-years operational experience was acquired with these.
See also information page on Small Nuclear Power Reactors. This will be a multi-loop research reactor capable of testing lead or lead-bismuth and gas coolants as well as sodium, simultaneously in three parallel outside loops. RIAR intends to set up an on-site closed fuel cycle for it, using pyrochemical reprocessing it has developed at pilot scale.
Rostechnadzor granted a site licence to RIAR in August , a construction licence in May , and completion was expected in Rosatom is inviting international participation. They were 1. They used very highly enriched uranium-beryllium fuel. Three steam loops drove twin turbines delivering 30 MW.
A significant part of Japanese energy policy has been to develop FBRs in order to improve uranium utilisation dramatically.
From to there was a strong commitment to FBRs, but in the FBR commercial timeline was pushed out to , and in commercial FBRs were envisaged by The parameters are: passive safety, economic competitiveness with LWR, efficient utilisation of resources burning transuranics and depleted U , reduced wastes, proliferation resistance and versatility include hydrogen production.
Utilities are also involved. Phase 2 of the study focused on four basic reactor designs: sodium-cooled with MOX and metal fuels, helium-cooled with nitride and MOX fuels, lead-bismuth eutectic-cooled with nitride and metal fuels, and supercritical water-cooled with MOX fuel.
All involve closed fuel cycle, and three reprocessing routes were considered: advanced aqueous, oxide electrowinning and metal pyroprocessing electrorefining. Japan's Joyo experimental reactor which has been operating since with a succession of three cores, was boosted to MWt in , but has been shutdown since due to damage.
After substantial upgrading, JAEA is aiming to restart it in It is a loop-type fast reactor. The MWe Monju demonstration FBR reactor at Tsuruga started up in April , but a sodium leakage in its secondary heat transfer system during performance tests in caused it to be shut down for almost 15 years. About three tonnes of sodium leaked and caught fire. Its oversight passed to JNC, and a Supreme court decision in May cleared the way for restarting it in , but this was delayed and it restarted in May before closing down again due to an ancillary mechanical problem.
The Fukui governor reminded the panel that Monju was positioned in the national Strategic Energy Plan to become an international research base for studies on waste volume reduction, the mitigation of danger, and other improvements to technologies related to nuclear non-proliferation. In December the government confirmed plans to decommission it, despite the Fukui local government being adamantly opposed to this.
This is a large unit which will burn actinides with uranium and plutonium in oxide fuel. It could be of any size from to MWe. Fuelled units would be supplied from a factory and operate for 30 years, then be returned.
Concept intended for developing countries. The reactivity control system is passive, using lithium expansion modules LEM which give burn-up compensation, partial load operation as well as negative reactivity feedback.
As the reactor temperature rises, the lithium expands into the core, displacing an inert gas. Other kinds of lithium modules, also integrated into the fuel cartridge, shut down and start up the reactor. Cooling is by molten sodium, and with the LEM control system, reactor power is proportional to primary coolant flow rate.
Refuelling would be every 10 years in an inert gas environment. Operation would require no skill, due to the inherent safety design features. The whole plant would be about 6. It uses sodium as coolant with electromagnetic pumps and has passive safety features, notably negative temperature and void reactivity.
The whole unit would be factory-built, transported to site, installed below ground level, and would drive a steam cycle. It is capable of three decades of continuous operation without refuelling. Steady power output over the core lifetime is achieved by progressively moving upwards an annular reflector around the slender core 0.
After 14 years a neutron absorber at the centre of the core is removed and the reflector repeats its slow movement up the core for 16 more years. In the event of power loss the reflector falls to the bottom of the reactor vessel, slowing the reaction, and external air circulation gives decay heat removal.
The design has gained considerable support in Alaska and and toward the end of the town of Galena granted initial approval for Toshiba to build a 4S reactor in that remote location. A pre-application NRC review is under way with a view to application for design certification in October delayed from by NRC workload , and construction and operating licence COL application to follow.
They are designed to extend the nuclear fuel supply for the generation of electricity , [1] and have even been mistakenly called a potential renewable energy source. Cohen's main point, see renewable and sustainable energy for a more thorough explanation. Concerns about nuclear weapons proliferation have been one large impediment to creating commercial breeder reactors.
Unlike normal reactors which only use uranium as their fuel, which is only available in scarce concentrations of around 0. They can also use thorium to breed uranium, another fissionable product. The most common breeding is of plutonium , which is bred through the process seen in Figure 1 below. Subsequently Russia, Japan, Great Britain and France all developed experimental breeder reactors, however no nation has developed one suitable for high-capacity commercial use.
There are two categories of breeder reactors, based on the speed of the neutrons. Fast breeder reactors which use uranium as fuel and thermal breeder reactors which use thorium as fuel. Fast breeders do not require moderation since the neutrons need to be moving fast, whereas thermal breeders make us of moderation to achieve slower-moving neutrons. Using water as a coolant would reduce the neutron abundance, since neutrons are absorbed by water.
Therefore liquid sodium is used instead. This immediately raised concerns of safety when initially thought of, since sodium is a highly reactive element. Another is that, to extract the plutonium, the fuel must be reprocessed, creating radioactive waste and potentially high radiation exposures.
For these reasons, in the U. The U. The Enrico Fermi Nuclear Generating Station in Michigan was the first American fast breeder reactor but operated only from until before engineering problems led to a failed license renewal and subsequent decommissioning. Construction of the only other commercial fast breeder reactor in the U.
Elsewhere in the world, only India, Russia, Japan and China currently have operational fast breeder reactor programs; the U. Sign up for our email newsletter. Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Go Paperless with Digital. Read more from this special report: The Future of Nuclear Power.
Andrew Karam, an adjunct professor of physics at the Rochester Institute of Technology, explains. Get smart. Sign Up.
0コメント