The nuclear option

A recent opinion poll conducted by the Lowy Institute showed that six in ten Australians agree that global warming is a “serious and pressing problem”. In the same survey, a slight majority of the population supported removing the existing ban on nuclear power.

Yet the whole energy debate in this country seems to come down to people thinking we can replace our coal plants with wind and solar. But there’s a lot more to it than that – there’s distribution and backup and stabilisation, and other services to keep the grid nice and strong.

In fact, the largest source of low-carbon energy in the world is currently hydro-power. Nuclear power is second. In Australia, being a largely flat, dry country, we do have some hydro resources, but not on the scale of other countries. So, if we don’t have access to a lot of hydro, and nuclear is currently in second position, why exclude the second one? Why not make it an option?

There are currently about 55 nuclear reactors under construction in the world. This is a proven low-carbon technology that could do the job for us. But some people can’t see past the issue of the nuclear waste – and radioactive waste is definitely something we need to address.

Some people can’t see past the issue of the nuclear waste – and radioactive waste is definitely something we need to address.

Dr Jo Lackenby

Our radioactive waste is currently stored at over 100 sites around Australia. Most of it is from the generation of life-saving nuclear medicine. The federal government has recently given approval for a centralised site in South Australia for the disposal of low-level waste – items like the contaminated lab coats and gloves used in the making of nuclear medicine. This will be an above-ground facility which will bring it all together in one location, which is international best practice.

Australia doesn’t have any high-level waste. We send the spent nuclear fuel from the operation of our research reactors overseas for reprocessing. The first shipment of spent nuclear fuel from the only operating nuclear reactor in Australia, the Open Pool Australian Lightwater (OPAL) reactor at Lucas Heights, in Sydney’s south, was sent to France a few years ago. In France they will do a partial recycle, and put some of the recycled material into fuel assemblies for nuclear power plants. They will send back what’s called intermediate-level waste.

We’ve had two inward shipments so far, waste products resulting from the operation of Australia’s previous reactor, HIFAR. The responsibility for this material is absolutely with us. The intention is to use the site in South Australia for temporary storage (it’s kept at Lucas Heights at the moment) before final disposal, which will almost certainly be deep underground.

The responsibility for this material is absolutely with us.

Dr Jo Lackenby

Underground is the future for the safe disposal of this waste. In Finland they’re currently constructing the world’s first deep geological repository to dispose of their high-level nuclear waste. This is established practice with some other toxic and hazardous waste around the world. Sweden has also approved a location for placing nuclear waste underground for permanent disposal.

Another option for nuclear waste is to recycle it. About 95% of what we call high-level waste, from spent nuclear fuel, is recyclable. The next generation of nuclear reactors, called fast reactors, could potentially recycle nuclear waste and get about 60 times more energy from uranium compared to today’s nuclear reactors. In this pathway we will still need to responsibly manage radioactive waste, but the volumes are much smaller, and the timeframes for managing the material are much shorter – with half-lives of only around 30 years.

So we can manage waste. What we need to do is build a picture of how we want to power the country and achieve net zero, and that might mean us using different technologies together to be cost-effective. I would like to see us looking forward to 2060, or even 2100. How do we want Australia to look? How many people will live here? How much energy are we going to need? Hopefully we are all going to be driving electric cars – what will our power system look like? What technologies do we have now that can be added to later on?

We can manage waste. What we need to do is build a picture of how we want to power the country and achieve net zero.

Dr Jo Lackenby

Diversity in energy supply is a good idea. Sure, let’s have solar and wind power. But why not use the different low-carbon technologies together to create the best system at the cheapest price, as opposed to pitting renewables against nuclear?

Unfortunately, solar and wind power have limitations. In the US, for example, their nuclear plants deliver on average 93% of their capacity, operating 24/7, accounting for maintenance and refuelling. Yet their wind farms average about 35%, and the solar averages at about 25% – in both cases, sometimes much higher, and sometimes zero. Of course, if you have wind and solar, one might be producing when the other isn’t. But what happens on a still, hot, summer night when everyone wants the aircon on? How do we power that? Nuclear doesn’t need anywhere near as much backup as these other technologies do.

Novel storage technologies, such as batteries, will play a bigger role in the overall system in helping with stabilisation and overcoming brief shortfalls in supply. But we must be realistic about the scale. The biggest battery in Australia, also in South Australia, would run an aluminium smelter in NSW for less than 15 minutes. The smart approach is to treat all storage technologies as optimisation tools for the supply system, and that supply system needs to be 100% decarbonised. There is an optimal mix of steady supply, variable supply and storage which will give Australia the best clean energy system it can have. But at the moment, we are handicapping ourselves by not opening the door to nuclear technologies.

The smart approach is to treat all storage technologies as optimisation tools for the supply system, and that supply system needs to be 100% decarbonised.

Dr Jo Lackenby

Small modular reactors (SMRs) could be a big part of our energy future. A typical nuclear reactor overseas these days is about 1000 megawatts – by comparison, the biggest coal fired generator units in Australia are around 750 megawatts. We could make large nuclear work, but if you’ve got too much capacity coming from one plant it can cause problems for our grids. Small modular reactors that can be built in factories and assembled on site might go up to about 300 megawatts. There are plans to deploy them in Canada, the US and the UK within the next 10 years. There are even plans in the US to directly replace a coal-generated power plant with nuclear, an option that could be very suitable for Australia given our ageing coal-fired infrastructure.

Small modular reactors are also good for remote communities: if you’re running a mine site far from grids, and you are committed to net zero, you could potentially power your mine with an SMR or even a small microreactor. They’re versatile and can be situated in a variety of locations.

Australia would be well served to prepare for the implementation of nuclear energy. There is a well-established process of milestones to set up a nuclear program through the International Atomic Energy Agency, and Australia could begin that process now.

Nuclear energy is currently prohibited in Australia under the Environmental Protection and Biodiversity Conservation Act. But we could start the milestones process now – no change in the law is needed, and no firm commitment to creating the industry is required. We can begin doing the groundwork now so that when we decide to embrace the technology, whether it be bigger reactors or small modular reactors ordered off the shelf, we will be ready to go.

As told to Graem Sims for Cosmos Weekly.