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52-686: Experimental Breeder Reactor-II ( EBR-II ) was a sodium-cooled fast reactor designed, built and operated by Argonne National Laboratory at the National Reactor Testing Station in Idaho. It was shut down in 1994. Custody of the reactor was transferred to Idaho National Laboratory after its founding in 2005. Initial operations began in July 1964 and it achieved criticality in 1965 at a total cost of more than US$ 32 million ($ 309 million in 2023 dollars). The original emphasis in

104-460: A "Site-Wide Long-Term Management and Control Program". The use of the site will be industrial in nature for a 100-year period and likely in the indefinite future thereafter. The objective of the EBR-II was to demonstrate the operation of a sodium-cooled fast reactor power plant with on-site reprocessing of metallic fuel. In order to meet this objective of on-site reprocessing, the EBR-II was part of

156-445: A fluid which readily conducts heat from the fuel to the coolant, and which operates at relatively low temperatures, the EBR-II takes maximum advantage of expansion of the coolant, fuel, and structure during off-normal events which increase temperatures. The expansion of the fuel and structure in an off-normal situation causes the system to shut down even without human operator intervention. In April 1986, two special tests were performed on

208-456: A fuel cycle based on pyrometallurgical reprocessing in facilities integrated with the reactor. The second is a medium to large (500–1,500 MWe) sodium-cooled reactor with mixed uranium-plutonium oxide fuel, supported by a fuel cycle based upon advanced aqueous processing at a central location serving multiple reactors. The outlet temperature is approximately 510–550 degrees C for both. Liquid metallic sodium may be used to carry heat from

260-456: A fuel cycle based on pyrometallurgical reprocessing in facilities integrated with the reactor. The second is a medium to large (500–1,500 MWe) sodium-cooled reactor with mixed uranium-plutonium oxide fuel, supported by a fuel cycle based upon advanced aqueous processing at a central location serving multiple reactors. The outlet temperature is approximately 510–550 degrees C for both. Liquid metallic sodium may be used to carry heat from

312-541: A half-life of only 15 hours. Another problem is leaks. Sodium at high temperatures ignites in contact with oxygen. Such sodium fires can be extinguished by powder, or by replacing the air with nitrogen . A Russian breeder reactor, the BN-600, reported 27 sodium leaks in a 17-year period, 14 of which led to sodium fires. No fission products have a half-life in the range of 100 a–210 ka ... ... nor beyond 15.7 Ma The operating temperature must not exceed

364-488: A half-life of only 15 hours. Another problem is leaks. Sodium at high temperatures ignites in contact with oxygen. Such sodium fires can be extinguished by powder, or by replacing the air with nitrogen . A Russian breeder reactor, the BN-600, reported 27 sodium leaks in a 17-year period, 14 of which led to sodium fires. No fission products have a half-life in the range of 100 a–210 ka ... ... nor beyond 15.7 Ma The operating temperature must not exceed

416-655: A large margin to coolant boiling, a primary cooling system that operates near atmospheric pressure, and an intermediate sodium system between the radioactive sodium in the primary system and the water and steam in the power plant. Innovations can reduce capital cost, such as modular designs, removing a primary loop, integrating the pump and intermediate heat exchanger, and better materials. The SFR's fast spectrum makes it possible to use available fissile and fertile materials (including depleted uranium ) considerably more efficiently than thermal spectrum reactors with once-through fuel cycles. In 2020 Natrium received an $ 80M grant from

468-655: A large margin to coolant boiling, a primary cooling system that operates near atmospheric pressure, and an intermediate sodium system between the radioactive sodium in the primary system and the water and steam in the power plant. Innovations can reduce capital cost, such as modular designs, removing a primary loop, integrating the pump and intermediate heat exchanger, and better materials. The SFR's fast spectrum makes it possible to use available fissile and fertile materials (including depleted uranium ) considerably more efficiently than thermal spectrum reactors with once-through fuel cycles. In 2020 Natrium received an $ 80M grant from

520-530: A majority of the electricity and also heat to the facilities of the Argonne National Laboratory-West. The fuel consists of uranium rods 5 millimetres (0.20 in) in diameter and 33 cm (13 in) long. Enriched to 67% uranium-235 when fresh, the concentration dropped to approximately 65% upon removal. The rods also contained 10% zirconium . Each fuel element is placed inside a thin-walled stainless steel tube along with

572-403: A radiological and industrially safe condition". Between 2012 and 2015, some components of the below-ground reactor were removed. The cost for removal actions in the reactor building were about $ 25.7 million. The basement with the reactor was filled with grout. The three-year decontamination and entombment project cost $ 730 million. In a later stage, the large concrete dome that surrounds

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624-467: A small amount of sodium metal. The tube is welded shut at the top to form a unit 73 cm (29 in) long. The purpose of the sodium is to function as a heat-transfer agent. As more and more of the uranium undergoes fission, it develops fissures and the sodium enters the voids. It extracts an important fission product, caesium -137, and hence becomes intensely radioactive . The void above the uranium collects fission gases, mainly krypton -85. Clusters of

676-453: A variety of metallic and ceramic fuels—the oxides , carbides , or nitrides of uranium and plutonium , and metallic fuel alloys such as uranium-plutonium-zirconium fuel. Other sub-assembly positions may contain structural-material experiments. The pool-type reactor design of the EBR-II provides passive safety : the reactor core, its fuel handling equipment, and many other systems of the reactor are submerged under molten sodium. By providing

728-716: A wider complex of facilities, consisting of The EBR-II has served as prototype of the Integral Fast Reactor (IFR), which was the intended successor to the EBR-II. The IFR program was started in 1983, but funding was withdrawn by U.S. Congress in 1994, three years before the intended completion of the program. Sodium-cooled fast reactor A sodium-cooled fast reactor is a fast neutron reactor cooled by liquid sodium . The initials SFR in particular refer to two Generation IV reactor proposals, one based on existing liquid metal cooled reactor (LMFR) technology using mixed oxide fuel (MOX), and one based on

780-423: Is limited by the production of plutonium from uranium. One work-around is to have an inert matrix, using, e.g., magnesium oxide . Magnesium oxide has an order of magnitude lower probability of interacting with neutrons (thermal and fast) than elements such as iron. High-level wastes and, in particular, management of plutonium and other actinides must be handled. Safety features include a long thermal response time,

832-423: Is limited by the production of plutonium from uranium. One work-around is to have an inert matrix, using, e.g., magnesium oxide . Magnesium oxide has an order of magnitude lower probability of interacting with neutrons (thermal and fast) than elements such as iron. High-level wastes and, in particular, management of plutonium and other actinides must be handled. Safety features include a long thermal response time,

884-515: Is that metal atoms are weak neutron moderators. Water is a much stronger neutron moderator because the hydrogen atoms found in water are much lighter than metal atoms, and therefore neutrons lose more energy in collisions with hydrogen atoms. This makes it difficult to use water as a coolant for a fast reactor because the water tends to slow (moderate) the fast neutrons into thermal neutrons (although concepts for reduced moderation water reactors exist). Another advantage of liquid sodium coolant

936-515: Is that metal atoms are weak neutron moderators. Water is a much stronger neutron moderator because the hydrogen atoms found in water are much lighter than metal atoms, and therefore neutrons lose more energy in collisions with hydrogen atoms. This makes it difficult to use water as a coolant for a fast reactor because the water tends to slow (moderate) the fast neutrons into thermal neutrons (although concepts for reduced moderation water reactors exist). Another advantage of liquid sodium coolant

988-403: Is that sodium melts at 371K (98°C) and boils / vaporizes at 1156K (883°C), a difference of 785K (785°C) between solid / frozen and gas / vapor states. By comparison, the liquid temperature range of water (between ice and gas) is just 100K at normal, sea-level atmospheric pressure conditions. Despite sodium's low specific heat (as compared to water), this enables the absorption of significant heat in

1040-403: Is that sodium melts at 371K (98°C) and boils / vaporizes at 1156K (883°C), a difference of 785K (785°C) between solid / frozen and gas / vapor states. By comparison, the liquid temperature range of water (between ice and gas) is just 100K at normal, sea-level atmospheric pressure conditions. Despite sodium's low specific heat (as compared to water), this enables the absorption of significant heat in

1092-614: The Natrium appellation in Kemmerer, Wyoming . Aside from the Russian experience, Japan, India, China, France and the USA are investing in the technology. The nuclear fuel cycle employs a full actinide recycle with two major options: One is an intermediate-size (150–600 MWe) sodium-cooled reactor with uranium - plutonium -minor-actinide- zirconium metal alloy fuel, supported by

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1144-401: The Natrium appellation in Kemmerer, Wyoming . Aside from the Russian experience, Japan, India, China, France and the USA are investing in the technology. The nuclear fuel cycle employs a full actinide recycle with two major options: One is an intermediate-size (150–600 MWe) sodium-cooled reactor with uranium - plutonium -minor-actinide- zirconium metal alloy fuel, supported by

1196-704: The US Department of Energy for development of its SFR. The program plans to use High-Assay, Low Enriched Uranium fuel containing 5-20% uranium. The reactor was expected to be sited underground and have gravity-inserted control rods. Because it operates at atmospheric pressure, a large containment shield is not necessary. Because of its large heat storage capacity, it was expected to be able to produce surge power of 500 MWe for 5+ hours, beyond its continuous power of 345 MWe. Sodium-cooled reactors have included: Most of these were experimental plants that are no longer operational. On November 30, 2019, CTV reported that

1248-642: The US Department of Energy for development of its SFR. The program plans to use High-Assay, Low Enriched Uranium fuel containing 5-20% uranium. The reactor was expected to be sited underground and have gravity-inserted control rods. Because it operates at atmospheric pressure, a large containment shield is not necessary. Because of its large heat storage capacity, it was expected to be able to produce surge power of 500 MWe for 5+ hours, beyond its continuous power of 345 MWe. Sodium-cooled reactors have included: Most of these were experimental plants that are no longer operational. On November 30, 2019, CTV reported that

1300-601: The Canadian provinces of New Brunswick , Ontario and Saskatchewan planned an announcement about a joint plan to cooperate on small sodium fast modular nuclear reactors from New Brunswick-based ARC Nuclear Canada. Sodium-cooled fast reactor A sodium-cooled fast reactor is a fast neutron reactor cooled by liquid sodium . The initials SFR in particular refer to two Generation IV reactor proposals, one based on existing liquid metal cooled reactor (LMFR) technology using mixed oxide fuel (MOX), and one based on

1352-407: The EBR-II reactor would be removed and a concrete cap placed over the remaining structure. In 2018, the plans were changed. The removal of the dome was stopped and in 2019, a new floor was poured and the dome got a fresh paint to prepare the building for industrial use. The building will be used for a research facility on top of the entombed reactor. The dome is an integral part of the tomb along with

1404-412: The EBR-II, in which the main primary cooling pumps were shut off with the reactor at full power (62.5 megawatts, thermal). By not allowing the normal shutdown systems to interfere, the reactor power dropped to near zero within about 300 seconds. No damage to the fuel or the reactor resulted. The same day, this demonstration was followed by another important test. With the reactor again at full power, flow in

1456-458: The coolant (the Phénix reactor outlet temperature was 833K (560°C)) permit a higher thermodynamic efficiency than in water cooled reactors. The electrically conductive molten sodium can be moved by electromagnetic pumps . The fact that the sodium is not pressurized implies that a much thinner reactor vessel can be used (e.g. 2 cm thick). Combined with the much higher temperatures achieved in

1508-405: The coolant (the Phénix reactor outlet temperature was 833K (560°C)) permit a higher thermodynamic efficiency than in water cooled reactors. The electrically conductive molten sodium can be moved by electromagnetic pumps . The fact that the sodium is not pressurized implies that a much thinner reactor vessel can be used (e.g. 2 cm thick). Combined with the much higher temperatures achieved in

1560-423: The core. Sodium has only one stable isotope, sodium-23 , which is a weak neutron absorber. When it does absorb a neutron it produces sodium-24 , which has a half-life of 15 hours and decays to stable isotope magnesium-24 . The two main design approaches to sodium-cooled reactors are pool type and loop type. In the pool type, the primary coolant is contained in the main reactor vessel, which therefore includes

1612-423: The core. Sodium has only one stable isotope, sodium-23 , which is a weak neutron absorber. When it does absorb a neutron it produces sodium-24 , which has a half-life of 15 hours and decays to stable isotope magnesium-24 . The two main design approaches to sodium-cooled reactors are pool type and loop type. In the pool type, the primary coolant is contained in the main reactor vessel, which therefore includes

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1664-579: The deactivated components and structure in a safe condition. The reactor was shut down in September 1994. The initial phase of decommissioning activities, reactor de-fueling, was completed in December 1996. From 2000, the coolants were removed and processed. This was completed in March 2001. The third and final phase of the decommissioning activity was "the placement of the reactor and non-reactor systems in

1716-416: The design and operation of EBR-II was to demonstrate a complete breeder-reactor power plant with on-site reprocessing of solid metallic fuel. Fuel elements enriched to about 67% uranium-235 were sealed in stainless steel tubes and removed when they reached about 65% enrichment. The tubes were unsealed and reprocessed to remove neutron poisons , mixed with fresh U-235 to increase enrichment, and placed back in

1768-431: The fuel's boiling temperature. Fuel-to-cladding chemical interaction (FCCI) has to be accommodated. FCCI is eutectic melting between the fuel and the cladding; uranium, plutonium, and lanthanum (a fission product ) inter-diffuse with the iron of the cladding. The alloy that forms has a low eutectic melting temperature. FCCI causes the cladding to reduce in strength and even rupture. The amount of transuranic transmutation

1820-431: The fuel's boiling temperature. Fuel-to-cladding chemical interaction (FCCI) has to be accommodated. FCCI is eutectic melting between the fuel and the cladding; uranium, plutonium, and lanthanum (a fission product ) inter-diffuse with the iron of the cladding. The alloy that forms has a low eutectic melting temperature. FCCI causes the cladding to reduce in strength and even rupture. The amount of transuranic transmutation

1872-457: The liquid phase, while maintaining large safety margins. Moreover, the high thermal conductivity of sodium effectively creates a reservoir of heat capacity that provides thermal inertia against overheating. Sodium need not be pressurized since its boiling point is much higher than the reactor's operating temperature , and sodium does not corrode steel reactor parts, and in fact, protects metals from corrosion. The high temperatures reached by

1924-457: The liquid phase, while maintaining large safety margins. Moreover, the high thermal conductivity of sodium effectively creates a reservoir of heat capacity that provides thermal inertia against overheating. Sodium need not be pressurized since its boiling point is much higher than the reactor's operating temperature , and sodium does not corrode steel reactor parts, and in fact, protects metals from corrosion. The high temperatures reached by

1976-538: The metal-fueled integral fast reactor . Several sodium-cooled fast reactors have been built and some are in current operation, particularly in Russia. Others are in planning or under construction. For example, in 2022, in the US, TerraPower (using its Traveling Wave technology ) is planning to build its own reactors along with molten salt energy storage in partnership with GEHitachi's PRISM integral fast reactor design, under

2028-437: The metal-fueled integral fast reactor . Several sodium-cooled fast reactors have been built and some are in current operation, particularly in Russia. Others are in planning or under construction. For example, in 2022, in the US, TerraPower (using its Traveling Wave technology ) is planning to build its own reactors along with molten salt energy storage in partnership with GEHitachi's PRISM integral fast reactor design, under

2080-421: The pins inside hexagonal stainless steel jackets 234 cm (92 in) long are assembled honeycomb-like; each unit has about 4.5 kg (9.9 lb) of uranium. Altogether, the core contains about 308 kg (679 lb) of uranium fuel, and this part is called the driver. The EBR-II core can accommodate as many as 65 experimental sub-assemblies for irradiation and operational reliability tests, fueled with

2132-536: The primary cooling system is lost. EBR-II is now defueled. The EBR-II shutdown activity also includes the treatment of its discharged spent fuel using an electrometallurgical fuel treatment process in the Fuel Conditioning Facility located next to the EBR-II. The clean-up process for EBR-II includes the removal and processing of the sodium coolant, cleaning of the EBR-II sodium systems, removal and passivating of other chemical hazards and placing

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2184-495: The reaction. A disadvantage of sodium is its chemical reactivity, which requires special precautions to prevent and suppress fires. If sodium comes into contact with water it reacts to produce sodium hydroxide and hydrogen, and the hydrogen burns in contact with air. This was the case at the Monju Nuclear Power Plant in a 1995 accident. In addition, neutron capture causes it to become radioactive; albeit with

2236-417: The reaction. A disadvantage of sodium is its chemical reactivity, which requires special precautions to prevent and suppress fires. If sodium comes into contact with water it reacts to produce sodium hydroxide and hydrogen, and the hydrogen burns in contact with air. This was the case at the Monju Nuclear Power Plant in a 1995 accident. In addition, neutron capture causes it to become radioactive; albeit with

2288-442: The reactor core and a heat exchanger . The US EBR-2 , French Phénix and others used this approach, and it is used by India's Prototype Fast Breeder Reactor and China's CFR-600 . In the loop type, the heat exchangers are outside the reactor tank. The French Rapsodie , British Prototype Fast Reactor and others used this approach. All fast reactors have several advantages over the current fleet of water based reactors in that

2340-442: The reactor core and a heat exchanger . The US EBR-2 , French Phénix and others used this approach, and it is used by India's Prototype Fast Breeder Reactor and China's CFR-600 . In the loop type, the heat exchangers are outside the reactor tank. The French Rapsodie , British Prototype Fast Reactor and others used this approach. All fast reactors have several advantages over the current fleet of water based reactors in that

2392-419: The reactor, this means that the reactor in shutdown mode can be passively cooled. For example, air ducts can be engineered so that all the decay heat after shutdown is removed by natural convection, and no pumping action is required. Reactors of this type are self-controlling. If the temperature of the core increases, the core will expand slightly, which means that more neutrons will escape the core, slowing down

2444-419: The reactor, this means that the reactor in shutdown mode can be passively cooled. For example, air ducts can be engineered so that all the decay heat after shutdown is removed by natural convection, and no pumping action is required. Reactors of this type are self-controlling. If the temperature of the core increases, the core will expand slightly, which means that more neutrons will escape the core, slowing down

2496-519: The reactor. Testing of the original breeder cycle ran until 1969, after which time the reactor was used to test concepts for the Integral Fast Reactor concept. In this role, the high-energy neutron environment of the EBR-II core was used for testing fuels and materials for future, larger, liquid metal reactors. As part of these experiments, in 1986 EBR-II underwent an experimental shutdown simulating complete cooling pump failure. It demonstrated its ability to self-cool its fuel through natural convection of

2548-402: The secondary cooling system was stopped. This test caused the temperature to increase, since there was nowhere for the reactor heat to go. As the primary (reactor) cooling system became hotter, the fuel, sodium coolant, and structure expanded, and the reactor shut down. This test showed that it will shut down using inherent features such as thermal expansion, even if the ability to remove heat from

2600-565: The sodium coolant during the decay heat period following the shutdown. It was used in the IFR support role, and many other experiments, until it was decommissioned in September 1994. At full power operation, which it reached in September 1969, EBR-II produced about 62.5 megawatts of heat and 20 megawatts of electricity through a conventional three-loop steam turbine system and tertiary forced-air cooling tower . Over its lifetime it has generated over two billion kilowatt-hours of electricity, providing

2652-501: The waste streams are significantly reduced. Crucially, when a reactor runs on fast neutrons, the plutonium isotopes are far more likely to fission upon absorbing a neutron. Thus, fast neutrons have a smaller chance of being captured by the uranium and plutonium, but when they are captured, have a much bigger chance of causing a fission. This means that the inventory of transuranic waste is non existent from fast reactors. The primary advantage of liquid metal coolants, such as liquid sodium,

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2704-501: The waste streams are significantly reduced. Crucially, when a reactor runs on fast neutrons, the plutonium isotopes are far more likely to fission upon absorbing a neutron. Thus, fast neutrons have a smaller chance of being captured by the uranium and plutonium, but when they are captured, have a much bigger chance of causing a fission. This means that the inventory of transuranic waste is non existent from fast reactors. The primary advantage of liquid metal coolants, such as liquid sodium,

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