Could Thorium Revive The Nuclear Energy Industry?

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For decades, the nuclear energy sector has been regarded as the black sheep of the alternative energy market thanks to a series of high-profile disasters such as Chernobyl, Fukushima, and Three Mile Island. But recently, the sector has received the backing of the Trump administration, which has sought a $1.5B bailout of America’s flagging uranium industry in a bid to create sufficient federal stockpiles for national security purposes.

Yet, nuclear energy could soon receive yet another shot in the arm that might significantly improve its standing in the eyes of the public: Substituting thorium for dangerous uranium in nuclear reactors.

Thorium is now being billed as the great green hope of clean energy production, producing less waste and more energy than uranium. Thorium is meltdown-proof, has no weapons-grade by-products, and can even consume legacy plutonium stockpiles.

A potential breakthrough

The United States Department of Energy (DOE), Nuclear Engineering & Science Center at Texas A&M, and the Idaho National Laboratory (INL) have partnered with Chicago-based Clean Core Thorium Energy (CCTE) to develop a new thorium-based nuclear fuel they have dubbed ANEEL. ANEEL, which is short for “Advanced Nuclear Energy for Enriched Life” is a proprietary combination of thorium and “High Assay Low Enriched Uranium” (HALEU) that hopes to solve some of nuclear’s knottiest problems, including high costs and toxic wastes.

ANEEL can be used in traditional boiling water and pressurized water reactors but performs best when used in heavy water reactors. More importantly, ANEEL reactors can be deployed much faster than uranium reactors.

A key benefit of ANEEL over uranium is that it can achieve a much higher fuel burn-up rate to the tune of 55,000 MWd/T (megawatt-day per ton of fuel) compared to 7,000 MWd/T for natural uranium fuel used in pressurized water reactors. This allows the fuel to remain

Thor(ium) to You

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Background

Thorium was discovered nearly 200 hundred years ago by the Swedish scientist Jakob Berzelius (1779-1848), who named the new element after Thor, the mythical nordic God of Thunder. Though widespread in nature and more abundant than, for example uranium, thorium does not occur in any deposits at a high concentration. Rather, it is a frequent low-level “contaminant” in some minerals such as monazite, a cerium phosphate.

Since its discovery, thorium has pretty much remained a non-entity in technology and commerce. Except for a few specialty applications, there really was no great use for it – until now. The anticipated change in its importance is due to its existence in many different isotopes (only a few of which are naturally occurring) and ability to deliver power via a nuclear fission process, similar to uranium, in other words, as a different kind of nuclear reactor fuel for electricity generation.

Advantages, Limitations, and Disadvantages of Uranium

Uranium-based reactors are basically straightforward. They require uranium-235 (235U) isotope enriched material (at 3 to 20%, depending on the type of reactor) to work. In natural ores, the 235U isotope is present at only 0.7%. In order to obtain fissionable material, the low-grade uranium needs to be enriched, using thousands of high-speed centrifuges exploiting a minute molecular weight differential of the hexafluorides between the different uranium isotopes. However, this enrichment process requires substantial energy.

Uranium-based nuclear reactors create substantial amounts of “depleted,” but still quite radioactive material. This needs to be stored in a safe facility – for millions of years – to allow the natural decay process to “dispose” of its radioactivity. The problem of long-term and safe disposal of such wastes has been around for decades, both in North America and in Europe, but no acceptable resting place has yet been found.

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