As aspiring nuclear countries search for ways to reduce fossil fuel dependence, debate is raging over the use of the lesser-known radioactive element thorium and its application to the nuclear fuel cycle.
Far more abundant than once thought, thorium may well provide a future alternative to the traditional nuclear reactor fuel, uranium. Naturally occurring in quantities comparable to lead and three times that of tin, thorium deposits are not difficult to find. As such, some experts predict that thorium will one day replace uranium as the nuclear reactor fuel of choice. But its application comes not without challenges with experts saying that thorium nuclear reactors are decades away from large scale roll-out. For the moment and for the next generation of reactors, well-trusted uranium will remain the fuel of choice.
Application is decades away
Abundant as it may be the ostensibly conservative nuclear engineering industry does not posses a great deal of hands-on experience with thorium, it also lacks certain technical elements that make it less suitable and less reliable than uranium in the nuclear fuel cycle. For instance, despite the element’s great plus – quantity – it is more challenging to prepare as a nuclear fuel; irradiated thorium is more dangerous in the short-term compared to uranium (something the post-Fukushima world does not want to hear) and it is not easily adaptable in “fast” reactors.
In terms of fuel replacement in the nuclear energy industry, the research and development process can take generations. Thorium is, at least compared to the thorium-plutonium fuels cycle, a relatively new concept, as explained by Mohd Zamzam bin Jafaar, CEO of the Malaysian Nuclear Power Corporation, “We do not think thorium will be a [nuclear fuel] solution until perhaps 2035.” Zamzam does believe that thorium has potential, it may in fact be a long-term solution to uranium use (uranium being only 30% as abundant and in decreasing supply, but this process of replacement will not be for at least two decades. “Furthermore, we need to bear in mind that current nuclear plants and plants in the production pipeline have a very long lifespan. Plants being built today will be operating for the next 60 years or more; so these plants will require uranium for 60 years or longer.”
Apart from the lack of operational experience with the thorium fuel cycle, compared with the decades of uranium experience garnered by the leading technology vendors, there is a concern according to Zam Zam that thorium aids weapons proliferation as it is more adaptable to nefarious uses than uranium – one very strong incentive as to why investment into thorium may not be forthcoming in the near future.
Thorium in India
The rapidly developing nuclear energy industry in India provides a perfect example of one flooded with thorium but cannot transition to a successful commerciality or NPP application. SP Singh, former head of the Nuclear Safety Division of the Atomic Energy Regulatory Board of India, an expert with 50 years experience (including with the IEAE) in nuclear project and plant safety and quality assurance, describes the conundrum. “Thorium is simply not an alternative in the short-term. No power reactors are using thorium on a large scale today, none at all.” Agreeing with Zam Zam, Singh adds, “developing a system for a thorium reactor will take decades.”
India is an example of a nation with a massive disparity in the relative deposits of uranium and thorium. According to experts, the Subcontinent boasts two and a half million tons of thorium against a modest, relatively minute 27,000 to 32,000kg of uranium. Indian uranium supplies are set to last no more than 40 years, a time period shorter than the lifespan of the average reactor. Indian also is a uranium importer, a tag that carries with it geopolitical implications and sensitivities. Thorium is, however for all intents and purposes, unlimited.
As such, with such vast deposits of thorium one would suspect that the development of thorium reactors has come naturally to the Indian nuclear sector. This however, is not the case. “The Indian nuclear sector is trying to develop a thorium reactor. They’ve been trying, polishing it, and improving thorium, et cetera for years but the truth is it’s all on paper and not on the ground. It would take a long time for a thorium demonstration reactor to be established and only then can we take steps toward assessing if thorium is advantageous or not,” says Singh. “We have plenty of thorium, but have no technology available right now to utilise it.”
Thorium in Indonesia
Indonesia is not in a dissimilar position to its more experienced Subcontinental counterpart. Dr Ir Arnold Soetrisnanto, Chairman of Energy Commission, National Research Council of Indonesia offers balanced concluding thoughts on the thorium debate. Although the thorium fuel cycle has several advantages, including the fact that it produces slightly less waste and has the potential to provide supply side diversification in the future, Dr Arnold argues that there is a lack of basic knowledge about the nuclear energy industry in Indonesia that leads to a misleading conclusion that thorium can now become actual new source of energy. “[With respect to] thorium, the situation is clear: today in the world there are no commercially operating thorium cycle reactors [and] no technological breakthrough has been made to replace uranium with thorium. All in all, there is no economic viability and technical maturity of thorium as a fuel source.”
Not implying that Indonesia should cease carrying out R&D in thorium, Dr Arnold suggests that Indonesia could take its lead from current emerging nuclear economies – Vietnam and the UAE, and others – “which are implementing full-scale national nuclear power programmes based on proven NPP technologies based on Uranium-235.”
Undoubtedly the application of thorium has its positives, and dwindling uranium supplies makes thorium a future fuel source saviour. Prudence would dictate that R&D dollars should be invested in the responsible harnessing of thorium’s promising full potential. Nuclear newcomers’ energy agencies must continue to fully explore the wise roll-out of thorium while maintaining traditional uranium cycle NPPs for the foreseeable future.