As Australia races towards net-zero emissions, nuclear has re-entered the energy debate. Here, two experts weigh in.
Words Simon Holmes à Court
Every two years since 2018, the Australian Energy Market Operator (AEMO) publishes a 30-year projection of the lowest-cost development pathways of the national grid. Called the Integrated System Plan (ISP), it’s one of the most thorough grid-planning exercises anywhere in the world, with more than $10 million invested and 1000 experts consulted for each update.
Under the scenario considered most likely, all of Australia’s coal-powered generators will be shuttered by 2037. Under the pessimistic scenario, nearly 90 per cent will be gone by 2040.
In all scenarios, the grid stays rock solid, meeting world-leading reliability standards. The energy “hole” left behind by coal is filled by wind and solar, firmed up by batteries, pumped storage and existing hydroelectricity dams, and backed up by gas. Gas usage is small, varying between 1–5 per cent of the grid. While the ISP doesn’t purport to be zero emissions – 3 per cent of emissions remain in 2040 – the final terawatt hours of gas could have zero-net emissions if we chose green hydrogen or biogas over fossil gas.
We’re not at the beginning of this journey. Rather, we’re almost 40 per cent there – the transition started with prime minister John Howard’s announcement of the Renewable Energy Target in 1997. Progress was at the whim of politics until renewables became the cheapest form of new energy about 2017, sidelining political opponents.
AEMO’s modelling does not include nuclear power because it’s currently prohibited by law, but we know from studies by CSIRO and the Net Zero Australia report that including nuclear would drive up costs.
Don’t get me wrong: nuclear power is amazing. Harnessing the power of controlled atomic fission is one of humanity’s greatest technological achievements. Nuclear power promises low emissions and works in places without natural energy resources. The impact is much lower (environment, atmosphere, human health) than fossil fuels and can yield massive quantities of energy from a compact power station.
Unfortunately, there are four barriers that prevent nuclear from helping transform Australia’s grid.
The first is time. Whether we wait for small modular reactors (SMRs) – not yet commercially available – or embark on the mammoth task of building gigawatt-scale reactors, there’s no possibility of nuclear contributing to the mix until the 2040s, years after we must replace our coal power stations. For this reason alone, nuclear has missed the boat for this energy transition.
The second barrier is cost. The cost disparities between nuclear power and renewables are stark. CSIRO research indicates a theoretical SMR starting construction in 2030 could generate power at a cost of $212–$353 per MWh, significantly higher than the $69–$101 per MWh expected from a renewable system. Such high costs, combined with financial risks and long lead times, render a nuclear program uninvestable, except with government investment on a scale of the AUKUS submarine project.
Politics is the third barrier. A 20-year construction program requiring massive and long-term investment from government, planning and environmental consents and removal of bans at federal and state level requires comprehensive and enduring bipartisan support, yet Labor and the Greens remain opposed.
The fourth barrier is technical. Nuclear plants are designed for constant, steady output. Consumer demand has never been steady, but with large volumes of variable renewable resources in the mix, residual demand is becoming more spiky. Nuclear power is becoming increasingly difficult to integrate with modern energy systems that prize flexibility. Batteries and pumped hydro are better suited for managing most of the residual demand.
Eventually, the nuclear industry may address these barriers. Only then could nuclear power become part of the answer – but it is clearly not the answer for Australia any time soon.
Simon Holmes à Court is a clean-tech investor, climate philanthropist and convenor of Climate 200.
Words John Harries
The answer to the challenge of decarbonising the energy system is to use all available technologies – and that includes nuclear energy. Australia cannot afford to ignore nuclear energy if the nation is to meet its commitment to reduce greenhouse gas emissions to zero by 2050, and have a robust economy.
Nuclear energy is a zero-carbon energy technology widely used in 32 countries, where about 440 nuclear reactors provide large-scale, economically competitive electricity and security of supply while producing very low carbon emissions and other air pollution.
Worldwide, 28 new-build nuclear power plants have been added to electricity grids in the past five years and about 60 large nuclear power plants are currently under construction.
Despite widespread acceptance and use of nuclear energy around the world, legislation in Australia bans nuclear energy. This legislation, in place since the late ’90s, will need to be repealed to allow nuclear energy to be considered on its merits. Lifting the ban is not a decision to introduce nuclear energy; rather, it’s a decision to allow rational discussion of the advantages and disadvantages of nuclear energy.
It’s not primarily a question of construction cost. While some expensive nuclear power plants have been built in the US and Finland and are being built in the UK and France, nuclear power plants in China, South Korea and the United Arab Emirates have been built on time and to budget at much lower costs. The UAE decided in 2008 to develop nuclear energy and ordered four large nuclear power reactors from the South Korean company KEPCO, which are now operating and connected to the grid.
It’s important to consider total system costs when assessing the cost of various sources of power. Solar and wind generators have variable outputs, which means they require considerable backup. Their locations also require extra transmission lines, all of which add to the costs.
By contrast, nuclear plants can be built near the existing grid, possibly at sites of retiring coal-fired stations and, like the coal plants they replace, would be available 24/7.
Modern nuclear plants are designed to have a lifespan of 60-plus years, compared with 20-30 years for solar panels and wind turbines. All solar panels and wind turbines currently operating will have to be replaced at least once by 2050.
A fairly recent innovation in nuclear energy is the small modular reactor (SMR), an advanced reactor with about a third or less of the generating capacity of the large reactors now being built around the world. These are expected to be cheaper to build and easier to deploy than large-scale reactors, and able to be constructed in three to five years, compared with, say, five to eight years for large nuclear. It will be a few years before SMRs are commercially available, while larger reactors are commercially available now.
The time it takes to assess, plan and construct nuclear power plants means new-build nuclear plants in Australia might not be productive until the mid-2030s. This means it is a matter of urgency to remove the prohibitions and establish the procedures and regulatory system for assessing proposals for nuclear power plants.
Australia can benefit from overseas experience in licensing, construction and operating nuclear power plants. As well, for more than 65 years, government agencies have successfully operated a small nuclear reactor in the suburbs of Sydney, producing medical and industrial radioisotopes and conducting research in materials science, and we export uranium to fuel nuclear power plants
around the world.
Nuclear energy is a viable option for Australia. Adding nuclear energy to the grid would significantly help decarbonise Australia’s energy system and ensure a reliable and robust power supply into the future.
Dr John Harries is the secretary of the Australian Nuclear Association.
