is there one ?
Don’t throw it in your neighbor’s garden?
Most nuclear waste can actually be reprocessed and reused as fuel. However, the government has laws to ensure that this does not happen.
What if we could build a nuclear reactor that offered no possibility of a meltdown, generated its power inexpensively, created no weapons-grade by-products, and burnt up existing high-level waste as well as old nuclear weapon stockpiles? And what if the waste produced by such a reactor was radioactive for a mere few hundred years rather than tens of thousands? It may sound too good to be true, but such a reactor is indeed possible, and a number of teams around the world are now working to make it a reality. What makes this incredible reactor so different is its fuel source: thorium.
Named after Thor, the warlike Norse god of thunder, thorium could ironically prove a potent instrument of peace as well as a tool to soothe the world’s changing climate. With the demand for energy on the increase around the world, and the implications of climate change beginning to strike home, governments are increasingly considering nuclear power as a possible alternative to burning fossil fuels.
But nuclear power comes with its own challenges. Public concerns over the risk of meltdown, disposal of long-lived and highly toxic radioactive waste, the generation of weapons grade by-products, and their corresponding proliferation risks, all can make nuclear power a big vote-loser.
A thorium reactor is different. And, on paper at least, this radical new technology could be the key to unlocking a new generation of clean and safe nuclear power. It could prove the circuit-breaker to the two most intractable problems of the 21st century: our insatiable thirst for energy, and the warming of the world’s climate.
The article says “on paper at least”, but there are several versions of working reactors already.
And this is where it gets interesting: thorium has a very different fuel cycle to uranium. The most significant benefit of thorium’s journey comes from the fact that it is a lighter element than uranium. While it’s fertile, it doesn’t produce as many heavy and as many highly radioactive by-products. The absence of U-238 in the process also means that no plutonium is bred in the reactor.
As a result, the waste produced from burning thorium in a reactor is dramatically less radioactive than conventional nuclear waste. Where a uranium-fuelled reactor like many of those operating today might generate a tonne of high-level waste that stays toxic for tens of thousands of years, a reactor fuelled only by thorium will generate a fraction of this amount. And it would stay radioactive for only 500 years - after which it would be as manageable as coal ash.
So not only would there be less waste, the waste generated would need to be locked up for only five per cent of the time compared to most nuclear waste. Not surprisingly, the technical challenges in storing a smaller amount for 500 years are much lower than engineering something to be solid, secure and discreet for 10,000 years.
But wait, there’s more: thorium has another remarkable property. Add plutonium to the mix - or any other radioactive actinide - and the thorium fuel process will actually incinerate these elements. That’s right: it will chew up old nuclear waste as part of the power-generation process. It could not only generate power, but also act as a waste disposal plant for some of humanity’s most heinous toxic waste.
This is especially significant when it comes to plutonium, which has proven very hard to dispose of using conventional means.
Current programs used for the disposal of plutonium reactor by-products and weapons-grade material using the MOX process are both expensive and complex. Furthermore, thorium proponents say that in conventional reactors, MOX fuel doesn’t use plutonium as efficiently nor in the same volumes as thorium fuel would at lower cost.
So thorium might just be able to kill two birds with one stone. Not only does a thorium-fuelled reactor produce significantly less high-level waste, but it can also dispose of the decommissioned nuclear weapons and highly radioactive waste from nuclear reactors using more conventional fuels. Oh yes, it can also generate electricity.