Dave Elliott: Renewables are doing very well these days, with costs falling, but some say that we will also need other non-fossil options to respond to climate change. Nuclear fission is one, but it is having problems- it’s proving to be expensive and, some say, risky. Some are hopeful that new technology will improve its lot, but for others the big hope is that, at some point in the future, nuclear fusion will be available and will avoid the problems that fission faces. It is usually claimed that fusion will be cleaner and safer, with no fission products to store and no risks of core melt downs. Moreover, since it uses hydrogen isotopes (deuterium and tritium), which are relatively easily obtained (deuterium from sea water, tritium from lithium), fusion can provide energy more or less indefinitely, into the far future. It may not be a renewed resource, but it is large. An exciting high tech solution – that could, some say, be available soon! However, the reality is a bit more complex, with there being issues at each stage of the fuel-to-energy process, and a lot more work to do. In terms of fuel, it takes energy to extract deuterium from water, and lithium reserves, although relatively large, may be increasingly depleted given the growing demand for Lithium Ion batteries for electric vehicles. In terms of fusion plant operation, there will be radiation exposure risks and the potential for accidental release of active materials – tritium has a short half-life, but is still a major health hazard e.g. when dissolved/mixed in water. Depending on the fusion system used, there will also still be some active wastes to deal with- the components and containment structures will be activated by the high radiation fluxes and have to be regularly stripped out. They will be less long-lived than fission wastes, but they are still an issue.
Renew Extra 1st June 2019 read more »