Fresh alarms over nuclear dangers on the Clyde have been sounded after the Ministry of Defence revealed that the number of radiation safety incidents had leapt by more than 50 per cent in a year.

There were 105 "nuclear safety events" officially recorded at the Faslane and Coulport submarine and bomb bases in 2013-14, compared to 68 in 2012-13. That's by far the highest for at least the last six years.

Most of the incidents last year - 99 - involved the reactors that power Trident and other Royal Navy submarines. The remaining six involved nuclear weapons, which are carried by Trident submarines and stored at Coulport.

The MoD has not given details of all the incidents, but it stresses that they were minor and did not endanger the health of workers or the public. Forty-five of the events in 2013-14 were categorised as level C, meaning there was "moderate potential for future release or exposure, or localised release within a designated radiological controlled area".

The other 60 incidents were classified as level D. This is defined by the MoD as "low potential for release - but may contribute towards an adverse trend producing latent conditions".

The new figures were disclosed in a parliamentary answer to the SNP's Westminster leader and defence spokesman, Angus Robertson MP. They are "totally shocking", he told the Sunday Herald.

"A near doubling in the number of nuclear safety incidents within a year is totally unacceptable and needs urgent answers from the MoD. It's important to note this doubling has occurred before expansion work at the base for more nuclear submarines is complete."

Robertson called on the MoD to explain what was being done to improve safety procedures. "These figures indicate how widespread nuclear safety breaches are," he said. "We must have an absolute assurance from the MoD that safety concerns are given then highest priority."

John Ainslie, coordinator of the Scottish Campaign for Nuclear Disarmament, argued that the risk of a major accident on the Clyde was increasing. "This could result in lethal radiation spreading across large parts of Scotland," he said.

"The public should be protected by the highest safety standards at Faslane and Coulport. This should be improving each year, not getting worse."

The MoD, however, argued that it was "entirely misleading" to focus only on the number of incidents. "They include very minor issues such as the failure to fill out the correct form before painting works began," said an MoD spokeswoman.

"This rigorous system shows how seriously MoD takes all aspects of nuclear safety, ensuring lessons are learned, and we can be clear that none of the events in the reports posed any risk to the health of our personnel, or to any members of the public."

One of the recorded events was the incorrect labelling of an empty pallet. Minor events were reported and investigated so that performance could be continuously improved.

"This comprehensive, independent recording process allows Clyde to maintain a robust reporting culture, undertake learning from experience and to take early corrective action," the UK Defence Minister, Philip Dunne, told MPs.