Technology

LFTR Overview

Learn more about the benefits of LFTR Technology

LFTRs have the potential to produce far less waste than LWRs along the entire fuel cycle and process chain, from ore extraction to nuclear waste storage. A LFTR power plant would generate 4,000 times less mining waste (solids and liquids of similar character to those in uranium mining) and would generate 1,000 to 10,000 times less nuclear waste than an LWR. Additionally, because LFTRs can be designed to burn nearly all of their nuclear fuel, the majority of the waste products (83%) are safely stabilized within 10 years, and the remaining waste products (17%) need to be stored in geological isolation for only about 300 years (compared to 10,000 years or more for LWR waste).  Moreover, LFTR’s liquid fuel form allows for extraction of many of these waste products in a commercial useful form, further excluding them from the waste stream.

 

LFTR technology can also be used to consume the remaining fissile material available 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) as an initial fissile charge to begin the thorium-to-uranium breeding cycle).

The properties of fluoride salts used in the LFTR offer many enhanced safety benefits over existing reactor technologies. The first is that the fluid salt in the core is not pressurized, eliminating any potential of explosive failure of the core. The reactivity of the core is also self-controlling due to the density of the salt. Any increase in operating temperature reduces the density of the salt which in turn, causes the reaction to slow and the temperature to fall. LFTR is also designed with a simple frozen salt plug in the bottom of the reactor core vessel. In the event of power loss to the reactor, the frozen salt plug quickly melts and the fuel salt drains down into a storage tank below – causing a termination in the fission process. This simple feature prevents any meltdown scenario from happening and allows for a convenient means to shut down and restart the reactor quickly and easily.

LFTR is an inherently safe, intrinsically stable and self-regulating design that removes the root causes of today’s reactor accidents and the need for complex redundant safety systems.  The core, blanket and primary cooling salt loops are all operated at or near atmospheric pressure and without steam, so a pressurized release, depressurization accident or explosion is impossible. Inherent stability is provided by very negative thermal/reactivity coefficient, i.e., the fuel salt expands as temperature rises, reducing the density and rate of reaction so that a meltdown is impossible.  Thus, when the reactor gets hotter, its ability to generate heat goes down.  Conversely when it gets cooler, its ability to generate heat goes up.  These two effects cause the reactor to be self-stabilizing and to follow the demand for electricity imparted on it by the grid.  Xenon byproduct gas levels are also closely controllable so that a slight increase in xenon gas levels would absorb needed neutrons to terminate the fission reaction in the core.

Thorium is abundant throughout the Earth’s crust. It is the 36th most plentiful element in the crust–four times as common as uranium, 5,000 times as plentiful as gold and generally as abundant as lead. According to the U.S. Geological Survey’s 2006 Mineral Yearbook, the United States is estimated to have 300,000 tons of thorium reserves (about 20% of the world’s supply), more than half of which is readily accessible. Considering only the readily accessible reserves, this national resource translates to nearly 1 trillion barrels of crude oil equivalent–five times the entire oil reserves of Saudi Arabia. In addition to the naturally occurring reserves, the United States currently has a reserve of 3,200 metric tons of processed thorium nitrate buried at a test site in the Nevada desert. This reserve alone is roughly equivalent to 21 billion barrels of crude oil equivalent when used in a LFTR with only minimal processing effort required.  Thorium is so energy dense, a mere 6600 tonnes of thorium could replace the combined 5.3 billion tonnes of coal, 31.1 billion barrels of oil, 2.92 trillion cubic meters of natural gas, and 65,000 tonnes of uranium that the world consumes annually.  What is more, estimated global thorium reserves could supply the world’s energy needs for thousands of years.

Learn more about LFTR

Read the report by EPRI and Southern Company for an independent technological assessment of the Liquid Fluoride Thorium Reactor.

A Better Nuclear Future

LFTR is the ultimate energy source that will propel humanity away from fossil fuels and into a true nuclear era — the thorium age of sustainable development, energy independence, and exploration of new frontiers.