Fission's future: Molten Salt Reactors – can they be the answer?

Paul Littler | 14 Aug 2014 | Comments

The world is looking beyond the current options for nuclear energy and is exploring new ways to exploit the phenomenon of fission. At the same time, energy demand is increasing and we need to reduce CO2 emissions in line with global targets.

It is thirteen years since nine countries formed the Generation IV International Forum to review and sponsor the development of new reactor types which would be a step change from today’s designs. Taking into account issues around sustainability, economics, safety and reliability, and proliferation resistance, scores of concepts were reviewed. Six technologies have been deemed worthy of international support and collaboration. One of the most interesting of these, and probably the most technically challenging, is the Molten Salt Reactor (MSR).

The concept of MSRs is not a new one, having been demonstrated in the 1950s in the USA. The concept has many perceived benefits: chemically inert coolant salts; high power density; fewer long lived waste products; ability to use a variety of fuels including thorium. But there are challenges, particularly around materials and fuel cycle management. However, could this old concept be one of the technology solutions to meet future energy needs?

Government appetite for new nuclear and for the UK to get back as a major player in the design of future reactor technologies means that now is a great time to be looking at options for how this technology could work in the medium to long term.

MSRs could be the technology to fill the gap between the end of current new build programmes and the first commercial operation of a fusion reactor. When this reactor type was initially developed back in the 1950s, and up to the 1980s, the UK was a very different place and we were leaders in reactor technology development; for example the fast reactor programme at Dounreay.

Currently, the biggest push in MSR development is in China. The country has signed a protocol with the US Department of Energy to carry out joint research and are looking to have a 2MW research reactor ready in 2019, with a 1000MWe molten salt cooled demonstrator and a 100MWe molten salt fuelled reactor up and running by 2035.

These advances could demonstrate a practical application for the technology at a time when many countries are looking to what technology will be able to replace existing, ageing or decommissioned plant. India is also looking at the technology through various research programmes.

So where is the UK in this and what can we contribute? We have a rich heritage of nuclear R&D in this country and considerable experience of the whole nuclear fuel cycle, and there is a lot of expertise in the UK that could significantly contribute to the post Gen 3/3+ area to address the long term nuclear future – development of molten salt reactor technology could be a key part of that.

The UK has a long pedigree in nuclear engineering and nuclear R&D as demonstrated, for example, at Sellafield which has given us a wealth of understanding that can be drawn on to support future reactor R&D. There are other examples across the country of industry and academia that are either directly supporting MSR R&D or have capabilities that could contribute to the development of the MSR into a commercially viable option for power generation; the National Nuclear Laboratory molten salt rig in Cumbria, the REFINE project run by Edinburgh University with UCL, Nottingham and Cambridge universities on the use of molten salts in pyro reprocessing; support on material science to the French based EVOL MSR project at Oxford University; and the Accelerator Driven Systems (ADS) Thorium reactor work at Huddersfield University.

International collaboration may be crucial for the development of this exciting technology, but we have a great base in the UK from which we can build on in order to help drive MSR research and development both at home and around the globe. However, whether supporting a UK originated design or looking to credibly support existing international programmes such as those in China, the UK has to act now or else the opportunity will be lost and the UK will again be left as a purchaser of reactor technology, as is the case with the current Gen 3/3+ programme, rather than a seller of reactor technology.