The government has acquired 211 hectares at Napandee, 24km west of Kimba on the Eyre Peninsula, with its plans subject to heritage, design and technical studies.

"We have reached a major milestone in our work to deliver this national facility, and a solution that has eluded consecutive governments for more than 40 years," Resources Minister Keith Pitt said on Monday.

The site will be used to store nuclear medical waste currently spread across more than 100 facilities including universities and hospital basements.

The Australian Nuclear Science and Technology Organisation says it is "critical infrastructure for Australia".

"Delivery of a national facility will allow ANSTO to focus on our core business of medicine production and science and innovation," a spokesperson said.

But Conservation SA chief executive Craig Wilkins said under existing state laws, any attempt to impose nuclear waste on SA would trigger an investigation by state parliament's Environment, Resources and Development Committee.

He said a wide-ranging inquiry was essential to reveal all the facts.

"This issue has a long way to run. The facility is at least a decade away and faces many opponents and hurdles," Mr Wilkins said.

The Australian Conservation Foundation said the proposal did not have the consent of the Barngarla traditional owners and would be contested both on the streets and in the courts.

"If the minister was convinced of the project's merits he would not be cutting corners with traditional owners and the wider community," spokesman Dave Sweeney said.

"The plan needs formal environmental and regulatory assessment and approval and is a long way from a done deal."

South Australian Greens senator Sarah Hanson-Young described the selection process as "dodgy from the start".

"It's ripped small communities apart and traditional owners have vehemently objected to the proposal," she said.

SA Liberal MP Rowan Ramsey, whose federal seat of Grey covers the site, acknowledged community concern about the facility, which is expected to create 45 jobs.

"The majority of the local community are behind the project that will bring jobs and new economic opportunities for our region and look forward to the facility proceeding," he said.

"This is not to say there are not some people with concerns and I will work with them to resolve those issues wherever possible, as we move into the detailed design, delivery and operational phases."

In June, the federal parliament passed legislation allowing the resources minister to make an "intention to declare" a site for the nuclear waste facility.

Mr Pitt said the vast majority of nuclear waste produced in Australia was associated with the production of nuclear medicine.

"Nuclear medicine is used in the diagnosis of a variety of heart, lung and muscular-skeletal conditions as well as the treatment of specific cancers, and a by-product of its production is low-level radioactive waste," he said.

"Along with the benefits comes a responsibility to manage the by-products. Without a facility like this, we can't enjoy the benefits from vital nuclear medicines on an ongoing basis."

Australian Associated Press