Tag Archives: molten salt reactor

Can Use LFTRs to Consume Nuclear Waste

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A LFTR can use all three of the available nuclear fuels: uranium-235 (what most reactors use, only 0.72% of naturally occurring uranium), uranium-233 (which is bred in the reactor from thorium-232), or plutonium-239 (bred from uranium-238, 99.28% of natural uranium). LFTRs can consume long-term nuclear waste from other reactors, nuclear weapons, or depleted uranium (any isotope of U, Pu or transuranic elements).

Because a LFTR fissions 99%+ of the fuel (whether from Thorium or nuclear waste), it consumes all the uranium and transuranics leaving no long-term radioactive waste. 83% of the waste products are safely stabilized within 10 years. The remaining 17% need to be stored less than 350 years to become completely benign.

“LFTR technology can also be used to reprocess and consume the remaining fissile material in spent nuclear fuel stockpiles around the world and to extract and resell many of the other valuable fission byproducts that are currently deemed hazardous waste in their current spent fuel rod form. The U.S. nuclear industry has already allocated $25 billion for storage or reprocessing of spent nuclear fuel and the world currently has over 340,000 tonnes of spent LWR fuel with enough usable fissile material to start one 100 MWe LFTR per day for 93 years. (A 100 MW LFTR requires 100 kg of fissile material (U-233, U-235, or Pu-239) to start the chain reaction). LFTR can also be used to consume existing U-233 stockpiles at ORNL ($500 million allocated for stockpile destruction) and plutonium from weapons stockpiles.” FLiBe Energy

FS-MSRs essentially avoid the entire fuel qualification issue in that they are tolerant of any fissile material composition, with their inherent strong negative thermal reactivity feedback providing the control necessary to accommodate a shifting fuel feed stream. Fast Spectrum Molten Salt Reactor Options, Oak Ridge National Laboratory

Transuranics (Np, Pu, Am, Cm) are the real reason for “Yucca Mountain” repositories [with PWR/LWR]. All MSR designs can take TRUs from other reactors into the reactor to fission off. TEAC3 Dr. David LeBlanc

A 1GW MSR would consume almost 1 ton of “spent” nuclear fuel/year. 340,000 tons of spent nuclear fuel in the world (and more each year). Although costly to extract from fuel rods, 6600 tons of it in MSRs could replace all the coal, oil, natural gas, and uranium the world used in 2007. Since MSRs can be built on assembly lines, build 6600 x 1GW Molten Salt Reactors, have them operate for 30 years and rebuild once, and we eliminate All current spent nuclear fuel stockpiles. Generates 6600 GW electricity for 60 years, and/or use heat from the reactors, water and CO2, to make carbon-neutral car and truck fuel!

LFTR Can Replace All Fossil Fuels

How does a fluoride reactor use thorium?

from Flibe Energy LCES 2011

LFTR Uses a Liquid fuel, Cooled by Molten Salt

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LFTR fuel is molten; “melt down” is standard operation. Fuel circulates through the reactor, and gets completely fissioned. No expensive fuel rod fabrication. No storing spent fuel rods in cooling ponds. No catastrophic fuel melting out of fuel rods. No risk of spewing radioactive material into the atmosphere if fuel rods overheat (like Three Mile Island, Chernobyl, and Fukushima).

Fission byproducts are continuously and easily removed, for 99+% fuel consumption. (Byproducts trapped in fuel rods in a solid-fuel reactor, stop the nuclear reaction with <2% of the fuel used; the fuel rod then has to be replaced.)

In any emergency, a frozen plug melts and the fuel quickly drains out of the core into tanks where nuclear reaction is physically impossible. Radiation is contained by materials that remain solid at temperatures much higher than inside the reactor, with passive air cooling. This safety feature is only possible with liquid fuel. (In solid-fueled reactors, you have to override everything that normally happens in the core and bring in coolant.)

LFTRs Are Cooled by Stable Salts, Not Water

LFTRs are cooled by salts that remain liquid, even up to ~1400° C, so they operate at atmospheric pressure — no massive containment structures are needed.

Almost all safety problems with current nuclear reactors can be traced to high-pressure water coolant. (Water-cooled reactors have up to 150 atmospheres pressure, to keep water a liquid under high temperatures, so need thick steel walls and massive reinforced-concrete buildings to contain water explosively converting to radioactive steam in an accident.)

LFTRs use No water, so can be built where water is scarce, using passive air cooling.

The salt used is very chemically stable, doesn’t react with materials in the reactor, or with air or water in an accident. The salt is essentially impervious to radiation damage, and doesn’t absorb neutrons (which would affect the rate of fission).

The fluoride salt chemically bonds with most of the more dangerous fission products, trapping them in an accident. For example, radioactive cesium and iodine that were released in Fukushima-Daiichi would not be released in a LFTR accident.

There are a few sodium-cooled reactors. Sodium reacts violently to water. A broken pipe weld in a heat transfer unit heavily damaged the Monju Nuclear Power Plant.