A serious Category A nuclear incident has occurred at Scotland’s Faslane naval base, home to UK Trident submarines. The incident was revealed by Defence Procurement Minister Maria Eagle after she was asked to provide figures regarding Nuclear Site Event Reports (NSERs) at the Faslane and Coulport naval bases. NSERs are given a grade on a scale from Category A down to D to “below scale” that does not meet any of the categories.
The UK Ministry of Defence (MoD) disclosed a Category A event at HM Naval Base (HMNB) Clyde on Gare Loch in Faslane, but refused to provide details, citing “national security”. The event happened between January and April. A Category A event has an “actual or high potential for radioactive release to the environment”. Faslane also recorded two Category B events (involving contained radiation exposure), and multiple lower-tier failures, according to Eagle’s response to a parliamentary inquiry.
The revelation comes amid reports of radioactive water leaking from ageing pipes at the nearby Coulport, where Trident missiles are stored, reported 13 Category C incidents (moderate release potential) and 34 Category D events (minor but revealing systemic flaws). The MoD insists these incidents were of “low safety significance”.
The Ministry of Defence records incidents, inspections as well as regulatory activities. The Nuclear Site Event Reports are then given a grade on a scale from Category A down to D to “below scale” that does not meet any of the categories.
