Green Energy from Thorium in South Asia
By Riaz Haq
CA
In addition to green energy from water, wind and sun, is there a source of clean, renewable and plentiful energy that can satisfy the growing needs of humankind without destroying the planet earth? The answer is a qualified yes.
Many scientists believe that the answer lies in developing and exploiting the abundant but mildly-radioactive element thorium in a redesigned nuclear fuel cycle. Large deposits of thorium oxide are found in many countries of the world, including United States, China, India and Pakistan. There are significant concentrations of thorium oxide in Kerala, India and Mardan, Pakistan.
Research conducted by Dr. Muhammad Haleem Khan at Punjab University's Institute of Chemistry found thorium oxide concentrations of 6.5% in Badar near Mardan in Pakistan, and 5.9% in Kerala, India. (Reference: Dr. M.H. Khan, 1992, Chapter 4, Page 114).
Rising concerns about climate change caused by carbon emissions are forcing a second look at nuclear energy. But the uranium-based nuclear power has had a bad name for various reasons, including potential for more disasters like Three-Mile-Island and Chernobyl, as well as genuine worries about nuclear weapons proliferation from uranium/plutonium byproducts, and highly radioactive waste disposal.
Just last week, a fire at an Indian nuclear research facility killed two people, according to the BBC News. And last month, more than 90 Indian workers suffered radiation injuries due to contamination of drinking water at the Kaiga Atomic Power Station in Karnataka, India.
In addition to the high-profile case of nuclear proliferation by Pakistani scientist AQ Khan, there have been other cases posing the nuclear proliferation threat from India, particularly as it dramatically expands its nuclear energy production after the US-India nuclear deal. In July 1998, India’ s Central Bureau of Investigation (CBI) seized eight kg of nuclear material from three engineers in Chennai. It was reported that the uranium was stolen from an atomic research center. The case still remains pending. On November 7, 2000, IAEA disclosed that Indian police had seized 57 pounds of uranium and arrested two men for illicit trafficking of radioactive material. IAEA had said that Indian civil nuclear facilities were vulnerable to thefts.
Thorium-based reactor technology addresses many of the above concerns to a great extent. Dr Hashemi-Nezhad of Australia's Sydney University says thorium has all of the benefits of uranium as a nuclear fuel but none of the drawbacks. Dr Hashemi-Nezhad believes thorium waste would only remain radioactive for 500 years, not the tens of thousands that uranium by-products remain active. The thorium reactor byproducts are not suitable as fissile material for nuclear weapons, reducing concerns about dual-use of peaceful nuclear technology.
"In fact, the green movement must come behind this project because we are moving in a direction to destroy all these existing nuclear wastes, to prevent nuclear weapons production, to [prevent] Chernobyl accident happening again," the Australian ABCOnline quotes Dr Hashemi-Nezhad as saying.
Although thorium itself cannot support a nuclear chain reaction, subjecting thorium to a stream of accelerated neutrons from plutonium inside a nuclear reactor turns this element into uranium-233, which can support fission. For this reason, the designers of nuclear plants have long considered the possibility of combining thorium with a fissionable isotope, which would prime the reaction. Increasing concerns about the diversion of plutonium from spent nuclear fuel to the construction of nuclear weapons has prompted a revival. Thorium-based nuclear fuels would leave far less waste plutonium than conventional fuels. What is more, the plutonium created is of a type that is not weapons-grade. The nuclear power industry is unlikely to adopt thorium for economic reasons alone, but should policymakers mandate its use in an effort to limit the proliferation of weapons and alleviate waste-disposal safety concerns, the technical modifications required of nuclear power plants would be readily achievable.
The idea of thorium reactors for nuclear energy is not new, according to a story published by Wired Magazine. It was first detailed in 1958 in a book titled "Fluid Fuel Reactors" under the auspices of the Atomic Energy Commission as part of its Atoms for Peace program. But it was not pursued at the time because the US was in the midst of a major nuclear arms buildup requiring large amounts of enriched uranium and plutonium for its WMDs. The use of thorium would not help in the weapons production, because the waste from thorium is not suitable for weapons.
The Wired Magazine article features Kirk Sorensen who is championing the revival of research and development into thorium reactors in the United States. Sorenson runs a blog "Energy from Thorium" that is bringing together a community of engineers, researchers, amateurs and enthusiasts talking about thorium.
When Sorensen and his online community of scientists began delving into the history of thorium work done by Alvin Weinberg at Oak Ridge National Lab, they discovered not only an alternative fuel but also the design for the alternative reactor, according to the Wired story. Using that template, the Energy From Thorium team helped produce a design for a new liquid fluoride thorium reactor, or LFTR (pronounced “lifter”), which, according to estimates by Sorensen and others, would be some 50 percent more efficient than today’s light-water uranium reactors. If the US reactor fleet could be converted to LFTRs overnight, existing thorium reserves would power the US for a thousand years.
Currently, there are active research programs in the United States, China and India, the biggest coal users and polluters in the world, to develop thorium fuel cycles. The research teams are exploring various approaches, including Ur+Th oxide rods and Ur and Th fluoride solutions, the latter preferred in the United States for its higher efficiency and safety. While there is promise in the technology, it is far from ready for commercial exploitation. In the mean time, the best way to tackle the climate change menace is to reduce the use of coal and other fossil fuels, and focus on hydro, solar and wind energy development in the foreseeable future.
