"Earthquake Proof" Nuclear Waste will head to Kimba

A monolithic steel cask designed to withstand an earthquake and a jet strike will arrive in Sydney next year, carrying two tonnes of radioactive waste.

Nuclear waste as seen at the Lucas Heights nuclear reactor site, in Sydney. (AAP Image/Supplied by ANSTO)

It will stay at Lucas Heights until Australia's new national nuclear waste storage facility is constructed at Napandee, near Kimba.

For security reasons authorities won't say when the hulking capsule - containing four 500kg canisters of 'intermediate-level material' - will arrive from the UK.

The containers steel walls are 20cm thick, it's 6.5m long and three metres wide. Back in 2015, when the first cask of its type arrived, it was carrying 20 tonnes of Australian nuclear waste that had been reprocessed in France.

About 600 police and security officers were involved in the mission to truck it from Port Kembla, near Wollongong, to Lucas Heights, the southern Sydney suburb that serves as the country's nuclear technology hub.

The waste that's due to arrive in 2022 came originally from ANSTO's High Flux Australian Reactor (HIFAR). ANSTO says the material is being repatriated under the international principle that countries must be responsible for their nuclear leftovers.

However, what's coming won't actually be what is left of the 114 spent fuel rods HIFAR sent to the UK for reprocessing in 1996. The four 500kg canisters inside the cask will be an equivalent amount of reprocessed British waste.

Hefin Griffiths is the chief nuclear officer at ANSTO and says there's no cause for concern about the waste swap deal initiated by the UK. In fact, he says, it's a safer, less costly deal for Australia.

"Originally we were going to get 52 500-litre drums of cemented waste," Griffiths said.

"Specifically it's not the material we sent, it's an equivalent, almost swapping the material that came from reprocessing our waste, for equivalent material that was produced at another UK site."

Mr Griffiths says the UK had to demonstrate that what will be sent to Australia is "within the measurement boundaries" of the accepted definition of intermediate-level waste, which can remain radioactive for thousands of years.

While claiming saving money wasn't the objective, Mr Griffiths says the waste exchange agreement means taxpayer-funded ANSTO will save $12 to $13 million in shipping costs.

The new cask will sit alongside the original one at Lucas Heights until the new national storage facility at Napandee is completed. The facility is up to the design phase but is being contested by Indigenous owners with the casks that are likely to remain at Lucas Heights for a number of years.

Once Napandee is operational, the casks will be moved there and stored, pending a final solution that will involve deep burial.