This new nuclear fuel can guarantee India’s green energy transition

This new nuclear fuel can guarantee India’s green energy transition

Subject: Science and Tech

Section: Nuclear technology

ANEEL Fuel:

• The Chicago-based company Clean Core Thorium Energy, founded by Mehul Shah, has developed (and patented) a fuel, which is a mix of Thorium and Uranium of a certain level of enrichment, called HALEU (High Assay Low Enriched Uranium). Clean Core calls this concoction ANEEL (Advanced Nuclear Energy for Enriched Life) — named so to honour one of India’s foremost nuclear scientists, Dr Anil Kakodkar.
• With this India can guarantee green energy security for the subcontinent by fast-tracking the use of Thorium in nuclear reactors.

Use of thorium in ANEEL fuel:

• Thorium is a fertile material and not a fissile material.
• This means it must be paired with Uranium-235 or Plutonium-239 to be used as fuel in a reactor.
• As neutrons from these fissile materials bombard Thorium, it mutates into Uranium-233, which is also a fissile material.
• So, to use the Thorium in India, you need sufficient stocks of Uranium-235 (which India has very little of), or Plutonium-239 (which is produced using Uranium-235).
• So, to use a minimum of uranium and a maximum of thorium fuel, the company has developed the ANEEL fuel.

Uses of ANEEL fuel:

• It can be used in the existing Pressurized Heavy-Water Reactors (PHWRs), an indigenous reactor system that is the workhorse of India’s nuclear fleet.
• India has 18 PHWR reactors with a total capacity of 4,460 MW and is building ten more of 700 MW each.
• India’s approach to Thorium utilisation has been to make a Thorium blanket around uranium or plutonium reactors so that as the reactor produces energy, it also converts thorium into uranium-233. However, ANEEL provides an easier and quicker alternative for the deployment of thorium leveraging imported HALEU.

Advantages:

• The use of thorium in nuclear reactors reduces nuclear waste significantly.
• ANEEL fuel lasts much longer and burns more efficiently.
• The spent ANEEL fuel cannot be used for weapons.

Infrastructural challenges:

• According to the World Nuclear Association, most of the current reactors run on uranium fuel enriched up to 5 percent Uranium-235.
• HALEU is Uranium enriched to more than 5 per cent but less than 20 per cent.
• It is needed for many of the advanced nuclear reactor designs under development.
• HALEU is not yet widely available commercially. At present, only Russia and China have the infrastructure to produce HALEU at scale.

Thorium in India:

• India has the world’s largest reserves of Thorium, estimated at 1.07 million tonnes, enough to last over a century. If India uses this Thorium, it can then produce enough green energy and easily turn net-zero by its target date of 2070.
• Thorium is derived from minerals like monazite (containing 10% thoria and 0.3% urania) and thorianite.
• Monazite sands, found widely on the Kerala coast, serve as the primary source of refined thorium.
• Monazite is a reddish-brown phosphate mineral containing rare earth metals.
• The state-wise resources of in situ monazite established by AMD as of September 2014 are as follows:

Both Uranium and Thorium have got distinctive characteristics governing their utilisation in nuclear reactors. Unlike uranium, thorium alone cannot be directly used as nuclear fuel in a reactor.  Utilisation of Thorium with either uranium or plutonium, without going through the second stage of Fast Breeder Reactors, to build sufficient inventory of plutonium first, will be counter-productive by limiting thorium utilisation to a very small fraction of the total available resources in the country. Utilisation of Thorium in the third stage makes it available as a sustainable energy resource for centuries. With this mode of utilisation, Thorium offers not only a sustainable energy resource, but also excellent fuel performance characteristic in a reactor, better than Uranium with respect to lower inventory of long-lived nuclear waste.

The three stage Indian nuclear programme was formulated at the inception of the DAE and has as its main stay objective of utilisation of large resources of Thorium in a sustainable manner. As explained above, Thorium cannot be used for overcoming power crisis in the short term.