With a world besieged by global warming and the global population set to hit nine billion by 2050, sustainable energy production has become a major issue for all developing countries. In this, comes the new fangled technology dubbed as “Green Nuclear Energy”.
In a series of TED talks, Kirk Sorensen a former NASA aerospace engineer and former chief nuclear technologist at Teledyne Brown Engineering has been propagating the idea of “Green Nuclear Energy”.
This idea rests upon using thorium based on liquid fluoride thorium reactor.
The liquid fluoride thorium reactor is a thermal breeder reactor that uses the thorium fuel cycle in a fluoride-based molten (liquid) salt fuel to achieve high operating temperatures at atmospheric pressure.
The pro-thorium lobby, led by Kirk Sorensen claim that a single tonne of thorium burned in a liquid fluoride thorium reactor (LFTR) can produce one gigawatt of energy. A traditional pressurized water reactor (PWR) would need to burn 250 tonnes of uranium to produce the same amount of energy. Further claims also include them producing less waste, having no weapons grade by-products, and are meltdown proof.
So, if all these claims are true then why aren’t all countries throughout the world using them ?
The answer is multi-fold and let me tell all the potential disadvantages about it which the TED talks won’t be telling you.
- None have been built- Yes, though the idea exists from several decades, but has never been brought to fruition. Only a few LFTRs have actually been built; those experimental reactors had been constructed more than 40 years ago. So, this technology has is difficult to critically assess.
- Startup fuel– Unlike the uranium based reactors, mined thorium does not have a fission isotope. Thorium reactors breed fissile uranium-233 from thorium, but require a considerable amount of U-233 for the initial start up. Currently there is very little of this material available. This raises the problem of how to start up the reactors in a reasonable time frame. The two alternative options for LFTR startup are enriched uranium and plutonium from reactors or decommissioned bombs. For enriched uranium startup, a quite high enrichment is needed. Decommissioned uranium bombs have a high enough enrichment, and would simultaneously dispose of weapons grade uranium, but not enough is available to start up a large number of LFTRs.
- Waste management – There is still a need to manage the waste, which is still very radioactive, even though it is hazardous for a shorter period.
- De-commissioning costs – The costs for decommissioning a French reactor based on LFTR was $ 130 million. As more reactors have not been constructed or experimented, it is highly unlikely the costs will decrease anytime in future.
- Other toxicity concerns – Other concerns include beryllium toxicity, risk of potential proliferation of radioactive salts, neutron poisoning, corrosion concerns due to tellurium buildup, radiation damage to nickel alloys used in constructing the primary fuel salt loop.
So what now?
Various developing countries, especially India with world’s largest thorium deposit is pushing to get these LFTRs up and running. Development of thorium based reactors is merely a way of deflecting attention and criticism from the dangers of the uranium fuel cycle and excusing the pumping of more money into the nuclear industry.In a post-Fukushima world,the nuclear industry is searching for its own version of radioactive holy grail- safe reactors producing more energy for less and cheaper fuel.
With billions of dollars already spent on nuclear research, reactor construction and decommissioning costs, dwarfing commitments to renewable energy research, the thorium dream is considered by many to be a dangerous diversion.
In the end, despite the hype and pitfalls it represents i ask all of you out there, do you think it is better to spend billions of dollars to commission, research and install these new nuclear power plants or is it high enough time to invest seriously on renewable energy ?
With these thoughts, i leave you folks to read more on this:
- Thorium Fuel – No Panacea for Nuclear Power, Institute for Energy and Environmental Research, 2009.
- Is thorium the answer to our energy crisis?, Independent, 2006
- Liquid Fluoride Thorium Power: Pros and Cons, Triple Pundit, 2012.
- Benefits of Thorium Are ‘Overstated’, UK Report Finds, Clean Technica, 2012