Integral Fast Reactor

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The Integral Fast Reactor or Advanced Liquid-Metal Reactor is a design for a nuclear fast reactor with a specialized nuclear fuel cycle. A prototype of the reactor was built, but the project was cancelled before it could be copied elsewhere.

Contents 1 Overview 2 Safety 3 Efficiency and Fuel cycle 4 Key benefits 5 Key disadvantages 6 History 7 See also 8 External links

[edit] Overview

This reactor is cooled by liquid sodium and fueled by a metallic alloy of uranium and plutonium. The fuel is contained in steel cladding with liquid sodium filling in the space between the fuel and the cladding.

[edit] Safety

The IFR was designed such that the fuel expanded if the reactor were to overheat and thus the chain reaction would automatically slow down due to the lowered density -- a passive safety feature in the event of certain classes of reactor runaway which could envelope some existing reactor designs.

However it should be noted that the reactor is by no means 'completely safe'. For instance, using liquid sodium as a coolant is not a trivial exercise, sodium reacts chemically in extremely volatile way, for instance exploding on contact with water. A serious accident with respect to the liquid sodium cooling system would be unlikely to leave such a reactor, or its environs, in a "safe" state.

[edit] Efficiency and Fuel cycle

The goals of the IFR project were to increase the efficiency of uranium usage by breeding plutonium and eliminating the need for transuranic isotopes ever to leave the site. The reactor was an unmoderated design running on fast neutrons, designed to allow any transuranic isotope to be consumed (and in some cases used as fuel).

Compared to current light-water reactors with a once-through fuel cycle that uses less than 1% of the energy in the uranium, the IFR has a very efficient (99.5% usage) fuel cycle. The basic scheme used electrolytic separation to remove transuranics and actinides from the wastes and concentrate them. These concentrated fuels were then reformed, on site, into new fuel elements.

The available fuel metals never separated the plutonium, and therefore there was no direct way to use the fuel metals in nuclear weapons. Also, plutonium never had to leave the site, and thus was far less open to unauthorized diversion.

Another important benefit of removing the long half-life transuranics from the waste cycle is that the remaining waste becomes a much shorter-term hazard. After the actinides and transuranics are removed from the spent fuel, the remaining waste elements have half lives of a few decades at most. The result is that within 300 years, such wastes are no more radioactive than the ores of natural radioactive elements.

[edit] Key benefits

• Enhanced safety because of the high thermal conductivity of the fuel.
• Able to withstand both a loss of flow without SCRAM and loss of heat sink without SCRAM.[1][2]
• Ease of fuel fabrication. Because the sodium fills the space between the fuel and cladding, the fuel need not be precisely fabricated. The fuel is simply cast.
• Because casting is simple, the fuel can be fabricated remotely, reducing the hazards of its radioactivity.
• Reprocessing is simplified because there is no need to stringently reduce the radioactivity of the fuel. Actinides can also be incorporated into the fuel.
• Proliferation hazards are reduced by the high radioactivity of the fuel. Because the fuel contains significant levels of transuranics with high spontaneous fission rates, it is not possible to produce nuclear weapons using IFR fuel without extremely difficult centrifugal separation. This is even more difficult than uranium enrichment due to the smaller atomic mass difference between Pu-239 and Pu-240 as compared to U-235 vs U-238, and is rendered even more difficult by the high levels of activity of the fuel.
• Pyroprocessing and electrorefining are feasible with this fuel. This allows on-site reprocessing. Two forms of waste are produced, a noble metal form and a ceramic form. Both are suitable for geological disposal.
• The waste produced contains no plutonium or other actinides. The radioactivity of the waste decays to levels similar to the original ore in about 300 years.

[edit] Key disadvantages

• The flammability of sodium. Sodium burns easily in air, and will ignite spontaneously on contact with water.
• Under neutron bombardment, sodium-24 is produced. This is highly radioactive, emitting an energetic gamma ray of 2.7 MeV followed by a beta decay to form magnesium-24. Half life is only 15 hours, so this isotope is not a long term hazard - indeed it has medical applications.

[edit] History

Research on the reactor began in 1984 at Argonne National Laboratory in Argonne, Illinois. Argonne is a part of the U.S. Department of Energy, and is co-run by the DOE and the University of Chicago.

Argonne also has a branch campus nicknamed "Argonne West" in Idaho Falls, Idaho. At the branch campus, physicists from Argonne had built what was known as the Experimental Breeder Reactor II (EBR II). In the mean time, physicists at Argonne had designed the IFR concept, and it was decided that the EBR II would be converted to an IFR. Charles Till, a Canadian physicist from Argonne, was the head of the IFR project, and Yoon Chang, was the deputy head. Till was positioned in Idaho, while Chang was in Illinois.

With the election of President Bill Clinton in 1992, and the appointment of Hazel O'Leary as the Secretary of Energy, there was pressure from the top to cancel the IFR. Sen. John Kerry (D, MA) and O'Leary led the opposition to the reactor, arguing that it would be a threat to non-proliferation efforts, and that it was a continuation of the Clinch River breeder reactor effort that had been cancelled by Congress. Despite support for the reactor by then-Rep. Richard Durbin (D, IL) and U.S. Senators Carol Mosley Braun (D, IL) and Paul Simon (D, IL), funding for the reactor was slashed, and it was ultimately cancelled in 1994.

[edit] See also

• Experimental Breeder Reactor II
• Fast breeder reactor
• Fast neutron reactor
• Sodium-cooled fast reactor
• Lead-cooled fast reactor
• Gas-cooled fast reactor
• Generation IV reactor

v • d • e Nuclear Technology
Nuclear engineering	Nuclear physics | Nuclear fission | Nuclear fusion | Radiation | Ionizing radiation | Atomic nucleus | Nuclear reactor | Nuclear safety
Nuclear material	Nuclear fuel | Fertile material | Thorium | Uranium | Enriched uranium | Depleted uranium | Plutonium
Nuclear power	Nuclear power plant | Radioactive waste | Fusion power | Future energy development | Inertial fusion power plant | Pressurized water reactor | Boiling water reactor | Generation IV reactor | Fast breeder reactor | Fast neutron reactor | Magnox reactor | Advanced gas-cooled reactor | Gas cooled fast reactor | Molten salt reactor | Liquid metal cooled reactor | Lead cooled fast reactor | Sodium-cooled fast reactor | Supercritical water reactor | Very high temperature reactor | Pebble bed reactor | Integral Fast Reactor | Nuclear propulsion | Nuclear thermal rocket | Radioisotope thermoelectric generator
Nuclear medicine	PET | Radiation therapy | Tomotherapy | Proton therapy | Brachytherapy
Nuclear weapons	History of nuclear weapons | Nuclear warfare | Nuclear arms race | Nuclear weapon design | Effects of nuclear explosions | Nuclear testing | Nuclear delivery | Nuclear proliferation | List of states with nuclear weapons | List of nuclear tests

[edit] External links

• The Unofficial IFR home page and page index
• Integral Fast Reactors: Source of Safe, Abundant, Non-Polluting Power by George S. Stanford, Ph.D.
• The IFR at Argonne National Laboratory
• [3] Frontline interview.