There has been a sharp rise in the number of "chilling" safety blunders at the nuclear bomb and submarine bases on the Clyde, according to internal reports from the Ministry of Defence (MoD).

In the last five years there have been 316 "nuclear safety events", 2044 fire alarm incidents and 71 fires at the Royal Navy's controversial facilities at Faslane and Coulport near Helensburgh.

There have also been more than 3000 "near miss" industrial accidents, a positive test for illegal drugs and a series of difficulties with wild animals.

The revelations have been described as "chilling" by Angus Robertson MP, the Scottish National Party's leader at Westminster and its defence spokesman. He is planning to raise them urgently in the House of Commons, and is demanding action from the MoD.

The new figures showed that nuclear safety breaches at the Clyde bases were "widespread", he said.

"Wherever nuclear weapons are concerned, safety must be paramount. We need to know exactly what is being done to address these breaches and tighten procedures."

The panoply of problems at the home of the UK's Trident nuclear weapons system has been disclosed through the MoD's last four annual health and safety reports covering 2009-10 to 2012-13. These reports were requested by the Sunday Herald under freedom of information legislation in January and released last week.

They show that the number of nuclear safety events reported increased 15% from 59 in 2011-12 to 68 in 2012-13. Incidents involving nuclear weapons rose from seven to 11, while those involving submarine reactors rose from 52 to 57.

About half of the incidents were defined by the MoD as "category C", meaning that they had the "potential" to cause radioactive contamination. Most of the rest were defined as "category D", meaning there was "no or little potential" for contamination.

One incident in 2012-13 was rated as "category B" because it exposed workers to radiation.

The "overall increase" in nuclear incidents was highlighted by the MoD in its 2012-13 report.

"This is reflected by a corresponding increase in the number of category D, category C and category B events," it said.

"This is counter to the general falling trend for annual figures that we have previously seen."

The report offered no explanation for the increase.

In total, 316 nuclear safety events were recorded at the Clyde bases for the five years to 2012-13. In the same period there were 2044 fire alarm incidents, the vast majority of which were false alarms, and 71 fires.

Over four years there were also 3243 industrial health and safety incidents reported as "near misses". The number of such reports leapt by more than 50% from 724 in 2011-12 to 1143 in 2012-13, though this is attributed by the MoD to increased awareness.

The MoD reports said that a programme to randomly test 20 workers a month for alcohol and drugs was introduced in October 2011. The report for 2011-12 reveals that one test confirmed the presence of an illegal drug, but no information is given for subsequent years - and the MoD refused to say whether any other staff had tested positive since.

The Clyde bases have also had to endure repeated problems with wildlife, including the build-up of guano from birds in working areas. Seagulls, pigeons, jackdaws, foxes and rats have all been culled, feral cats neutered and a submarine treated for an infestation of red-rust flour beetles.

Independent nuclear expert John Large was scathing about the MoD's safety standards. He said: "From these reports, one gets the distinct impression that health and safety operations at HMNB Clyde are more akin to those practiced in a backstreet car repair shop than a naval base servicing advanced and armed warships, some of which are carrying nuclear weapons and propelled by nuclear reactors."

Safety problems were increasing, the number of false fire alarms was "totally unacceptable" and the MoD reports were "muddled and at times misleading", Large alleged.

He added: "The regulation of health and safety matters at the base should be taken from the military and put squarely under the control of a civilian operated regulatory regime."

The Scottish Campaign for Nuclear Disarmament accused the MoD of failing to gain control of the risks of handling nuclear weapons and submarines.

"The sharp rise in nuclear weapons safety events is particularly worrying," said the campaign's co-ordinator, John Ainslie. "If the safety record continues to decline, then it is only a matter of time before there is a major problem."

The MoD stressed that safety at the Clyde bases was of paramount importance. "That is why our comprehensive reporting system captures even the most minor of incidents and measures are put in place to prevent any repeat," said an MoD spokeswoman.

"It is entirely misleading to focus only on the number of incidents detailed in these reports. Fluctuations in numbers between years are perfectly normal. None of the events in the reports caused any harm to the health of any member of staff on the naval base, or to any member of the public."

The MoD has previously pointed out that the Clyde naval bases are the biggest employment sites in Scotland, with 6700 military and civilian jobs. This is due to rise to 8200 people by 2022, as more nuclear-powered submarines are moved there.