Close the cycle: an alternative approach for used nuclear fuel

The South Australian Nuclear Fuel Cycle Royal Commission identified an economic opportunity in the back end of the nuclear fuel cycle. To reflexive critics, this sounds like weasel words for “dumping waste”. To a certain extent that is reasonable if we get too far ahead of ourselves. If our paradigm is too narrowly focused on deep geological repository, then we are indeed buying into the once-through model of nuclear fuel.

I am entirely at ease with the safety and environmental case for that approach. But it’s not great sustainability thinking and in my opinion would be an error. An intelligent approach to developing a new industry in the 21^st century is to think in terms of providing a service, and remain as open as possible, as long as possible, as to the exact nature of the solution, particularly where new technologies may play a role. Were one to be considering service provision in urban transport it would be unwise to base future expectations on the past dominance of the traditional taxi and lock into that model. The taxi model may survive, but the urban transport need will be met with a blend of taxis, ap-based ride-sharing services, self-driving vehicles and likely a whole lot more.

So in the nuclear discussion it concerns me to see the opportunity to provide service prematurely reduced to a discussion about whether to accept and bury 140,000 t of “nuclear waste”.

Even calling used nuclear fuel “waste” is an appalling misnomer. It is more like an ore that requires processing and conditioning. A small amount of true waste (the fission products, about 3 % of the rod mass) is intermingled with an even smaller amount of long-lived material that can be immediately useful as fuel (plutonium and some other heavy elements in the transuranic group, around 1-2%). The bulk of the rod remains garden-variety, plentiful uranium-238. With the right technologies these materials can be sufficiently separated to provide an excellent new fuel resource, turning troublesome long-lived “waste” into a vast new fuel resource… one that has already been mined.

These are the technological principles behind a new paper published to Asia and the Pacific Policy Studies, in which Barry Brook and I posit an alternate economic pathway for service in used fuel. In common with the detailed study of the Royal Commission we begin with the rapid establishment of an above-ground facility to host used nuclear fuel in dry casks, with payments to Australia based on the transfer of ownership and liability.

Rather than investing an estimated $30 billion plus in a deep underground repository to permanently entomb this material, we explored the pathway of investing around $10 billion in a recycling facility and 622 MWe of fast nuclear reactors as a means of disposing of the plutonium and transuranic elements (half-life of approximately 12,000 years). We reserved actual disposal only for the much shorter lived and far lesser quantity of fission products (principally strontium-90 and caesium-137 with half-lives of approximately 30 years).

Based on a much smaller inventory of 60,000 t of accepted used fuel, we found that after 30 years this pathway delivers a present value of approximately $31 billion as well as new baseload zero-carbon electricity generation to underpin a reliable clean electricity supply in the state.

This pathways offers advantages. We would install reliable clean electricity generation via inherently safe nuclear reactors. These reactors also deliver reliable heat of around 600 ° C, suitable for a range of industrial purposes. We would become an early hub for the late commercialization and early deployment of a new generation of nuclear technology. The proposed recycling facility, at 100 t per year throughput, would gradually condition the inventory of used fuel into new saleable fuel rods for fast reactors elsewhere (or potentially a lesser-fabricated product suitable as fuel input for molten-salt-fueled burner reactors). These highly valuable products were excluded from the benefits in our modelling but could easily have a market value of hundreds of millions of dollars every year.

This pathway circumvents the substantial challenge of social consent for deep geological repositories, facilities that are likely to be best located, on a technical basis, on lands of importance to Aboriginal Australians where native title is present. We can instead offer a completely different question to South Australians: would we like to be involved in high-tech recycling? Would we like to commercialise new clean energy technologies? Would we like to reduce a waste problem from hundreds of thousands of years to mere hundreds? These are attractive lines of enquiry.

At the end of our modelled period of 30 years, Australia would retain a substantial inventory of material in above ground storage as well as the $31 billion present value. The use of fast reactors is so efficient in delivering energy, that we will be only just getting started in working through that inventory based on our first reactor developments. That calls for nothing more than patience. The used fuel we would be holding does not go stale and gets less hazardous with every moment it spends in storage. The expanded use of fast reactors and other advanced reactors will gradually accelerate the disposition of the material just as it accelerates the displacement of fossil fuels from the provision of electricity and high-grade heat in the economy of Australia and the world. We would be placed first to provide the reconditioned fuel and can expand our operations according to the market.

In our paper we present evidence that the experience now gained in dry-cask storage ought to render rolling above ground storage an acceptable management approach…provided it is paired with a demonstrated disposal pathway via fast reactors. Dry storage is low cost, with cask replacement required perhaps every century (but possibly less frequently than that). That’s where we really ask for innovation; not so much the technology, but in our expectations of the way we must manage and regulate the “solution” to used nuclear fuel.

In truth, the correct service in future may well be a blend of many services. As I argued in testimony to the relevant Parliamentary Committee, it is simply too early to know just what the right service(s) will be. We know it will involve accepting material. We know some forms of disposal will eventually be required. A variety of services could happen in between, with a variety of commercial arrangements suiting a variety of client needs. Thus we should position ourselves cleverly to define and then deliver that service through subsequent stages of investigation. What I argue with confidence is that the premature foreclosure of technological and regulatory innovation would certainly be an own-goal, but one we can easily avert as we proceed from here.

The straightforward and crucial next step is to make formal approaches to potential customer nations to shore-up the evidence of the market and the willingness of international partners to engage in developing an Australian-based solution. This is an incredibly low-cost next step for delivering what is mission-critical information. It requires not big dollars, but a firm position from our state government to potential customers that that the conversation, while at the earliest stage, is a real one.

We have an opportunity in Australia to do something quite remarkable: play a leading role in solving what has been an enduring challenge in the international community, and do it in a way that delivers better and more exciting results both for South Australia and the world than anyone expected. It’s definitely worth fighting for, for anyone who wants a cleaner, safer, brighter future.