The fleet of nuclear submarines is based at Faslane, on the Clyde
There have been 14 collisions involving British nuclear submarines since 1988 and 237 fires on board the fleet of vessels, the government has revealed.
February's collision between HMS Vanguard and French sub Le Triomphant was the sole recorded collision with another naval vessel, the MoD said.
Of the fires, 213 were classified as small-scale, needing minimal resources to put out, while 21 were more serious.
The SNP, which requested the details, called them "extremely disturbing".
'One too many'
The information was published in a written statement by Armed Forces Minister Bob Ainsworth.
HMS Vanguard's collision with its French counterpart in heavy seas in February was the most serious incident of its kind for two decades.
The two submarines were badly damaged in the collision, which occurred at low speed, but no-one was injured and the Royal Navy insisted that nuclear security was never compromised.
The other incidents consisted of groundings, collisions with fishing vessels and HMS Tireless's coming together with an iceberg while on arctic patrol in 2003.
In 40 years of maintaining the submarine fleet, the MoD said its nuclear security had never been endangered.
"Our submarines are built to be extremely robust and designed to withstand the hazards associated with operating under the oceans," a spokesman said.
"Whilst we would never be complacent about any incident, it should be noted that the vast majority of fires that have occurred were very minor and had no impact on people and submarine operations."
But the SNP said the "catalogue" of incidents raised "serious concerns" about the safety of the fleet.
"Last month's mid-Atlantic collision between HMS Vanguard and Le Triomphant was serious enough," said the SNP's defence spokesman Angus Robertson.
"But this diary of near disasters is extremely disturbing. One collision is too many, especially when it involves a submarine carrying weapons of mass destruction."
The number on-board fires in the past 20 years was "equally grave", he added.
The MoD described the 213 "small-scale" fires as "localised" incidents, such as a minor electrical fault, "dealt with quickly and effectively using minimal onboard resources".
In contrast, the 21 "medium-scale" fires were caused by the failure of mechanical equipment, "requiring use of significant onboard resources".
Three further fires broke out while vessels were docked at a naval base.
The SNP opposes the £20bn replacement of the Trident missile system with a new seaborne nuclear capacity, approved by Labour ministers in 2006.
MPs warned last month the timetable for replacing two submarines, set to be decommissioned, by 2024 was very tight.
Successive governments since 1968 have been committed to a continuous nuclear deterrent at sea, requiring at least one nuclear-armed submarine to be on patrol at any one time.