Thorium already powers the Earth, so why not nuclear power plants? The radioactive element is safer, more abundant, and cheaper to extract and handle than the nuclear power fuel of choice uranium. It is so plentiful on Earth and so effective at generating heat that its radiation makes a measurable contribution to our planet’s internal heat.
Three unique properties make thorium superior than uranium in nuclear power plants. First, thorium’s slow decay rate produces alpha radiation which cannot penetrate human skin, making its handling less complex, less costly and less dangerous.
Second, thorium is safer in power plants due to its higher melting point, higher thermal conductivity (gives off heat more easily), and lower coefficient of thermal expansion – all of which mean less risk of a nuclear meltdown.
Third, whereas uranium can be used only once before becoming toxic waste, thorium can be reused up to seven times. Natural uranium from the ground contains 238 neutrons and protons per atom. When used in a power plant, uranium-238 gains 1 neutron to become toxic waste and eventually decays into plutonium-239 which can in turn be used one more time in power plants or in nuclear weapons (after being enriched).
Natural thorium, however, has only 232 protons and neutrons. It can be used seven times in a nuclear reactor, gaining 1 neutron each time until it eventually decays into plutonium-239. However, only about 1 to 2% of thorium ever gets to become plutonium-239, since some 98 to 99% of thorium is spent while it fissions as uranium-233 and uranium-235, long before it becomes plutonium-239.
While the technology required to power electric plants using thorium is still long from being ready, conditions in India are coming together that could make it the world’s first thorium-powered country in the world. India has at least three compelling reasons for harnessing the power of thorium, which would also grant lasting benefits to the rest of the world.
Reason 1: Demand Up, Supply Down
Some 400 million Indian citizens – more than the entire population of the United States – still live without electricity. As India’s expanding industrial production and growing middle class push the nation’s demand for electric power ever higher, the government is on a desperate mission to build more power plants and fast.
But the courts aren’t helping. At present, some 68% of India’s electricity is produced by coal fired plants, with coal being both plentiful and cheap on account of India’s having the world’s fifth largest coal reserves. Yet India’s Supreme Court last week upheld a ruling declaring 218 coal mine licenses issued to private sector companies “illegal” on grounds they were improperly awarded by a process that was arbitrary and corrupt.
Though the closed mines will eventually be reopen once they are handed over to the state-backed mining group Coal India before being re-auctioned back to the private sector, the nation’s over-dependency on coal for its energy needs is increasingly becoming a liability to India’s development with frequent power blackouts an ongoing concern.
“Concerns of power disruptions raised post the Supreme Court judgement on the coal issue show how reliance on a single source of energy is unhealthy,” declared Amit Bhandari, energy and environment fellow at Gateway House, a Mumbai-based consultancy group. “It makes sense investing in nuclear energy, which provides clean power and a hedge against coal supply shocks.”
To this end, newly elected Indian Prime Minister Modi’s government is desirous of expanding the nation’s nuclear power capacity by some 12.5 times its current production. Where the nation currently produces some 2% of its electric power in nuclear plants, the government is aiming to satisfy up to 25% of the nation’s energy needs via nuclear power by 2050. This would require multiplying its current number of 20 nuclear plants to upwards of 250 similar size plants, averaging more than 6.5 new plants annually over the next 35 years.
Reason 2: Material Availability
The obstacle, of course, is that this creates a huge demand for uranium which India cannot supply. With just 2% of global uranium reserves, India is already dependent on outside sources even with just 20 nuclear plants in operation. Imagine the dependency when its uranium demand increased by 12.5 times.
Prime Minister Modi has thus lost no time since taking office this May in attempting to negotiate more uranium imports from Japan, Australia and China.
“India wants to learn from China’s success in achieving self-sufficiency in reactor design and adaptation of technology,” Avinash Godbole, a China expert at the Institute for Defence Studies and Analyses in New Delhi explained the Indian government’s objective. But as forward-thinking as that vision may be, it is not a vision shared by other governments.
Japan, for one, wants assurances that India will stop nuclear weapons testing, which it is unlikely to promise given its ongoing territorial dispute with neighboring Pakistan over the region of Kashmir. China – which is grappling with India over a border dispute of its own – is also apprehensive of supplying India with more uranium which could be used to produce more nuclear weapons.
Even the international community as a whole is reluctant to provide greater access to uranium to India for its continuing refusal to sign a non-proliferation treaty to prevent the spread of atomic warheads.
Yet the whole issue of self-sufficiency could be addressed and resolved simply by switching to thorium, which India already possesses within its borders in the order of 25% of total global reserves.
Reason 3: Research Already Underway
The obstacle here, however, is that the technology required to harness the power of thorium in generating electricity is more complex than even uranium technology. It’s not just nuclear science; it’s the next generation of nuclear science.
Luckily for India, the nation has had a thorium technology program since the 1950’s called the “Three-Stage Nuclear Power Programme”.
• In the first stage, natural uranium-238 is used to produce electricity while generating plutonium-239 as by-product.
• In the second stage, the plutonium-239 recovered from the first stage is mixed with more natural uranium-238. As the plutonium-239 fissions, it gives off neutrons that the fresh batch of uranium-238 captures to produce more electricity and produce more plutonium-239. The old plutonium-239 is thus recycled to produce more electricity, ending up with more plutonium-239 than you had at end of stage one, thanks to the addition of fresh uranium-238.
• In the third and final stage, naturally occurring thorium-232 is added to plutonium-239. As plutonium-239 fissions, it gives off 1 neutron which turns thorium-232 into uranium-233. Uranium-233 then fissions to produce more electricity, and so on down the line until arriving at plutonium-239. The end result is much more power generated from the reuse of these fuels multiple times.
This recycling process allows plutonium to reused again and again with the steady introduction of cheaper more abundant thorium rather than uranium. Not only are costs saved, but you can recycle thorium at least six or seven times, whereas uranium is used only one.
With all the technological advancements that the West has exported to India and the rest of the world, the next generation of nuclear power technology will likely be exported in the other direction as India’s gift to the world.
Joseph Cafariello
