International 'nuclear tombs' are being built, but how do we warn future generations of what's inside?

Earth is no spring chicken.

In fact, based on scientific dating, it's considered to be 4.5 billion years old.

Coincidentally, that's also how long depleted uranium (a by-product of the process of enriching uranium for use in nuclear power reactors and weapons) remains dangerous.

And so, as the idea of using nuclear energy as an alternative power source dominates headlines, the safe storage of toxic waste produced by nuclear power and how we warn future generations about its dangers is being considered.  

Dr Shastra Deo, a nuclear semiotics expert and author at the University of Queensland, tells ABC Radio National's Future Tense this is a quandary at the centre of nuclear semiotics.

"Nuclear semiotics is obsessed with this idea of creating a sign to warn us about the dangers of nuclear waste into deep time … The main timeline we're working with is 10,000 years, but that's frankly not enough to keep us safe," she says.

Nuclear on the mind

In June 2024, in response to Australia's cost-of-living crisis and an upcoming federal election, Opposition Leader Peter Dutton announced his proposal for nuclear power in Australia.

Promising zero emissions and lower power prices, the announcement named seven locations for the nuclear power plants across Australia, which would be built next to existing infrastructure.

These included Mount Piper Power Station in New South Wales, Loy Yang Power Stations in Victoria and Tarong Power Station in Queensland.

While the announcement didn't include a plan for how the toxic waste produced from nuclear power would be managed, it did state that a community engagement process would occur alongside "a comprehensive site study including detailed technical and economic assessments".

Mr Dutton's announcement added that currently, "32 countries [are] operating zero-emissions nuclear plants. Another 50 countries are looking to do so".

Yet, while nuclear energy is a source of power for many countries, the question of what to do about the highly toxic waste that nuclear energy produces is not settled.

Toxic tension

The rolling hills of France's Champagne region are known for their green landscapes and quaint villages.

But nearly 500 meters beneath the small village of Bure, France, large tomb-like chambers are being constructed by France's national radioactive waste agency, Andra, so that they can demonstrate their suitability for building a geological disposal facility (GDF).

GDFs are built to store intermediate to high-level nuclear waste safely for thousands of years.

Andra's chambers are part of a huge international engineering effort to build giant underground nuclear tombs for waste storage across the United Kingdom (UK) and Europe.

Finland was the first country to build a deep GDF to store spent nuclear fuel for 100,000 years, and initial testing has already begun. 

Mark Piesing, a UK-based freelance journalist, reported on the European and UK GDF plans last year.

He says GDFs take many years to get approved and built, and their long-term success relies on decades of future political stability.

Mr Piesing visited the Andra testing facility in Bure, France, and he describes the scale of the proposed GDF as "quite awe-inspiring".

"The scale of it … you could imagine the pharaohs building something similar, the workers working for years," he says.

While impressive, the construction and plans for GDFs across Europe haven't been without controversy.

The Andra project underneath Bure, France (with a population of only 82 residents) has sparked protests — some violent — from anti-nuclear activists over the company's plans to build a GDF for nuclear storage.

In Sweden, the Swedish Nuclear Fuel and Waste Management Company commenced test drilling across the country in the 1980s to find suitable locations for potential nuclear waste storage, a move that didn't go down well.

"The Swedish authorities perhaps didn't consult the community enough. So this caused protests in a number of locations where they're trying to do their test drilling," Mr Piesing said.

And here in Australia, proposed sites for storage of toxic nuclear waste have also received backlash.

Where would we store nuclear waste in Australia?

The storage of nuclear waste has been a long-held issue of national contention, particularly in South Australia.

In 2023, the Barngarla traditional owners of SA's Eyre Peninsula won a legal challenge to stop the federal government from building a nuclear waste facility near Kimba.

The plans were to store low and intermediate-level radioactive waste at the proposed facility.

Then, in November 2024, Adelaide residents said they were "blindsided" when federal parliament legislation allowed for nuclear waste to be stored and disposed of at a shipping yard in Osborne — 25 kilometres north-west of the CBD and seaside suburbs.

The plans are part of the $368 billion AUKUS project, which will involve building nuclear submarines in South Australia, and include a commitment from the federal government that it would secure storage for nuclear waste produced.

Ted O'Brien, Shadow Minister for Climate Change and Energy, tells the ABC that the Coalition has a long-term plan for nuclear waste storage if it wins the upcoming election.

"Spent fuel from nuclear power plants will be temporarily stored on-site before being transported to a permanent waste repository, where spent fuel from our AUKUS nuclear submarines will also be stored," he says.

Mr O'Brien says the permanent site's location is a matter for the federal government.

The location of the permanent site under the AUKUS deal has not been addressed since late last year by the federal government. 

However in January it was revealed by former senator Rex Patrick that documents obtained via Freedom of Information (FOI) show South Australia's Defence Industries Minister met with a defence company in the UK for the "specific purpose of being briefed" on the dismantling of nuclear reactors and the waste associated with them.

"[The government is] yet to clarify the location … It is now Labor's responsibility for identifying a long-term waste repository," Mr O'Brien says.

"We stand ready to cooperate constructively.".

A warning for generations to come

While the future for Australia's nuclear waste remains unclear, Dr Shastra Deo says we can look back at history to inform the need for warnings surrounding toxic waste storage for future generations.

"You see the [Egyptian] pyramids and they're very intriguing to us … There was a warning message on them from one of the pharaoh's viziers that said, ‘If you intrude on my tomb, I will curse you and you will die,' — and we went in anyway," he explains.

"We're curious people. That's what humanity is … we want to find out what's in these spaces.

In Ms Deo's field of nuclear semiotics, several ideas have been raised to warn future generations of the dangers of toxic waste stored below ground.

These include hostile architecture (an urban design strategy that uses elements of a built environment to purposefully guide behaviour of humans), the use of symbols and an "atomic priesthood" of knowledge keepers.

Rounding out the list is the "black hole" which, as Ms Deo explains, would involve "putting granite over the area and the sun would heat it up to a point where you just couldn't walk across it".

Ms Deo says the ongoing challenge lies in the length of time these warnings are required, which can be hundreds of thousands of years. 

"How can we create a message that will last this long? Already you can kind of see the impossibility in that."

Ms Deo says that regardless of the challenges, we must consider our accountability to those who come after us.

It's a question that we've yet to answer.