Overview

• MoD records confirm a Category A nuclear safety event occurred at HMNB Clyde between January and April 2025, the highest-risk NSER rating at the submarine base.
• Category A incidents denote an actual or high potential for radioactive release; MoD asserts no risk to the public or environment yet withholds operational details on security grounds.
• Investigations by The Guardian and The Ferret uncovered leaks of radioactive water from RNAD Coulport into Loch Long linked to ageing pipework; SEPA has deemed the discharges of no regulatory concern.
• SNP leaders have demanded urgent explanations with a full account of safety practices at the UK’s submarine bases, highlighting concerns over environmental safeguards alongside defence transparency.
• Defence analysts warn that these episodes underscore long-standing infrastructure shortfalls at Faslane and Coulport, reigniting debates over maintenance funding and nuclear deterrent oversight.