A Ministry of Defence (MoD) plan to start dismantling seven defunct nuclear submarines at Rosyth in Fife has led to fears that hundreds of tonnes of radioactive waste will end up being dumped in Scotland.

Babcock, the British multinational engineering group than runs Rosyth Dockyard for the MoD, is to strip down the old reactor-driven submarines that have been berthed near the Firth of Forth since the 1990s. But agreement on where more than 500 tonnes of the most radioactive waste will be stored is years away, prompting accusations that the company has "jumped the gun".

And although UK ministers have said the waste will not remain at Rosyth, one expert has warned that it will have to stay there because of the difficulties of transporting it anywhere else.

The MoD has been trying to decide for more than a decade what to do with the seven submarines tied up at Rosyth, as well as others at Devonport on the south coast of England. Its latest plan is to dismantle them at the two dockyards, and then move waste to stores elsewhere.

But the MoD has yet to announce the shortlist of potential sites for the most radioactive waste. Due later this month, the list will comprise of five sites, expected to include the nuclear complexes at Sellafield in Cumbria, Aldermaston in Berkshire and possibly Hunterston in North Ayrshire.

Despite this, Babcock has launched its bid to start dismantling the submarines by submitting an environmental impact assessment to the UK Government's Office for Nuclear Regulation. It reveals that the reactor compartment of each submarine will produce 520 tonnes of radioactive waste, making a total of 3640 tonnes for all seven boats.

More than 500 tonnes of this total is likely to be defined as "intermediate level" waste, which at the moment has nowhere to go. The rest will be disposed of as low-level waste to a dump at Drigg in Cumbria, or recycled because its contamination is deemed to fall below the regulatory threshold.

This has led independent nuclear consultant John Large to warn that the intermediate waste may never leave Rosyth. "In my opinion the radioactive waste arisings are likely to stay at the site of generation ... that is Rosyth," he told the Sunday Herald.

The packages of waste created were liable to be very large and difficult to transport, he said, while there was a national policy to store waste where it was generated. "This will be a ticklish problem for the Scots alone when independence is delivered," he said.

Previous attempts to agree sites for storing radioactive waste have failed because of public opposition. Large also warned that dismantling the submarines may prove trickier than expected for Babcock because of how badly they are contaminated.

The MoD has promised that dismantling will not commence until a site for the intermediate waste has been identified. It also said the waste would not be stored at Rosyth.

"The submarine dismantling project aims to deliver a safe, secure and cost-effective solution for dismantling the UK's de-fuelled nuclear-powered ­submarines," said an MoD spokesman. "No radioactive waste will be removed from the submarines without a storage or disposal solution being agreed."