The French nuclear firm EDF Energy is applying for new authorisations to allow radioactive waste to be transported by road between its two nuclear power stations at Hunterston in North Ayrshire and Torness in East Lothian.
Critics say this will mean waste containers will be increasingly moved between the west and east coasts, increasing the risk of accidents.
Two applications for Hunterston and Torness, made by EDF Energy to the Scottish Environment Protection Agency (Sepa), go out for public consultation this month. According to Sepa, they both include "the ability to receive radioactive waste from other EDF Energy power stations for the purposes of interim storage, loading of containers and onward transfer."
Pete Roche, an energy consultant and former government radiation adviser based in Edinburgh, warned: "Transporting nuclear waste is always going to be a risk, so the more you transport it, the greater the danger.
"The Scottish Government should force EDF Energy to operate according to its sensible policy of requiring waste to be treated as near to where it is produced as possible instead of allowing this crazy plan putting the central belt of Scotland at risk."
He described the plan as a "nightmare vision with waste trucks criss-crossing the country".
Rita Holmes, a resident who chairs the official Hunterston Site Stakeholder Group, also feared the risks of road accidents and radiation leaks would rise. "EDF Energy wants to be able to ship dangerous radioactive waste to and fro across Scotland to save money on the way containers are used ... This worries me, and it should worry others too," she said.
The Scottish Government's policy on managing nuclear waste is for it to be stored in near-surface facilities "located as near to the site where the waste is produced as possible".
Councillor Alan Hill, SNP deputy leader of North Ayrshire Council, said: "I am extremely concerned at the possibility of nuclear waste travelling around Scotland. Near-site, near-surface to my mind should prohibit this."
The Office for Nuclear Regulation which oversees nuclear safety in the UK, said it made no objection to the applications because they should help facilitate timely disposal of waste from the sites.
An ONR spokeswoman added: "Any shipments of waste between Torness and Hunterston are required to be carried out in full compliance with the regulations covering the transport of radioactive material."
The Scottish Government pointed out "there would be no long-term storage of waste transferred to Hunterston B power station from another site." Said a spokesman: "Any inter-site transfers that might take place would have to be handled carefully."
EDF Energy confirmed radioactive waste would be transported between Hunterston and Torness by road. "This change is purely a practical one to facilitate more flexible disposals by allowing waste to be collected temporarily at one site before being sent for disposal," said a company spokesman.