105 nuclear safety events were recorded during the 2013-14 year at the Faslane submarine base and Coulport nuclear weapons store, which comprise HM Naval Base Clyde – up from 68 in 2012-13.

The majority of the incidents – 99 – related to the nuclear propulsion systems which power the Royal Navy's submarines, with a further six incidents recorded which involved nuclear weapons.

The figures were provided in response to Parliamentary Questions asked by Scottish National Party (SNP) MP Angus Robertson enquiring how many nuclear safety events there were at HMNB Clyde over each of the last six years.

The answer reveals that on two occasions safety arrangements at the Coulport nuclear weapons store were deliberately broken by management.  Twice in 2009 a limit for the total number of annual lifts for a crane at the Coulport Explosives Handling Jetty was exceeded.  The limit, imposed for safety reasons in order to guarantee the structural reliability of the crane, was first breached in February 2009.  Following the breach a concession was granted to allow further lifts to take place – but the new limit was exceeded on 20 March 2009 “for operational support purposes”.

In another incident, which occurred on 17 August 2012, an “inadvertent radiation dose” was received by contractors who were working on a submarine tank.  The incident was classified as a 'category B' incident – one of twelve such incidents that took place at the base over the last six years - meaning that it resulted in “actual or high potential for a contained release within building or submarine or unplanned exposure to radiation”, according to HMNB Clyde's nuclear safety event reporting definitions.  READ MORE