Nuclear powerThorium to play limited role in U.K. future power supply

Published 17 September 2012

Worldwide, there has for a long time been a sustained interest in the thorium fuel cycle and presently there are several major research initiatives which are either focused specifically on the thorium fuel cycle or on systems which use thorium as the fertile seed instead of U-238; the U.K. National Nuclear Laboratory examined the topic and concluded that thorium has theoretical advantages but that these benefits are often overstated; as a result, thorium fuel cycle at best has only limited relevance to the United Kingdom as a possible alternative plutonium disposition strategy and as a possible strategic option

A brief depiction of the thorium cycle // Source: skyscrapercity.com

The U.K. National Nuclear Laboratory was tasked by the U.K. Department for Energy and Climate Change (DECC) to review and assess the relevance to the United Kingdom of the advanced reactor systems, based on the use of thorium, currently being developed internationally. Part of the task was a comparison of the thorium and uranium fuel cycles.

NNL says that worldwide, there has for a long time been a sustained interest in the thorium fuel cycle and presently there are several major research initiatives which are either focused specifically on the thorium fuel cycle or on systems which use thorium as the fertile seed instead of U-238. Currently in the United Kingdom, the thorium fuel cycle is not an option which is being pursued commercially, and DECC wanted to understand why this is the case and whether there is a valid argument for adopting a different position in the future.

NNL has recently published a position paper on thorium which attempts to take a balanced view of the relative advantages and disadvantages of the thorium fuel cycle. Thorium has theoretical advantages regarding sustainability, reducing radiotoxicity, and reducing proliferation risk. NNL’s position paper finds that while there is some justification for these benefits, they are often overstated.

The value of using thorium fuel for plutonium disposition would need to be assessed against high level issues concerning the importance of maintaining high standards of safety, security, and protection against proliferation, as well as meeting other essential strategic goals related to maintaining flexibility in the fuel cycle, optimizing waste arising, and economic competitiveness.

NNL says that it is important that the United Kingdom should be very clear as to what the overall objectives should be and the timescales for achieving these objectives.

Overall, NNL concludes that the thorium fuel cycle at best has only limited relevance to the United Kingdom as a possible alternative plutonium disposition strategy and as a possible strategic option in the very long term for any follow-up reactor construction program after LWR new build.

It is important to recognize, though, that world-wide there remains interest in thorium fuel cycles and that this is not likely to diminish in the near future. It may therefore be judicious for the United Kingdom to maintain a low level of engagement in thorium fuel cycle R&D by involvement in international collaborative research activities. This will enable the United Kingdom to keep up with developments, comment from a position of knowledge, and to some extent influence the direction of research. Participation will also ensure that the United Kingdom is more ready to respond if changes in technology or market forces bring the thorium fuel cycle more to the fore.

— Read more in Comparison of thorium and uranium fuel cycles (National Nuclear Laboratory Ltd., March 2012)