What environmental and safety incidents have been reported at RNAD Coulport and HMNB Clyde, and how have regulators responded?

1. What was reported: leaks from Coulport’s pipe network

Investigations by The Guardian and The Ferret, amplified by mainstream outlets, found that radioactive water — tritium-bearing effluent used in weapons maintenance — leaked into Loch Long from RNAD Coulport because of poorly maintained pipes, with SEPA files indicating a network of around 1,500 pipes had not been adequately maintained and that many components were beyond design life ^{[1] [4] [5]}.

2. What regulators said about environmental impact

SEPA reviewed monitoring and, while documenting the pipe failures, concluded the discharges were “of no regulatory concern,” a phrase echoed in multiple reports and MoD statements that asserted there had been “no unsafe releases of radioactive material” into the environment and that published monitoring (RIFE reports) showed no significant public-health impact ^{[1] [2] [4]}.

3. Safety incidents logged at HMNB Clyde — scale and categories

Parliamentary responses and NSER summaries show dozens of incidents recorded at Faslane and Coulport in 2025: Faslane reported one Category A, two Category B, several Category C and D events and lower-scale reports between January and April 2025, while Coulport reported multiple Category C and D incidents in the same period ^[3]. Defence statements routinely add that none of these events harmed personnel or caused radiological impacts to the public or environment ^{[3] [6]}.

4. Regulatory oversight and remedial action

SEPA and the Office for Nuclear Regulation (and the MoD’s own Defence Nuclear Safety Regulator) are named regulators for HMNB Clyde and Coulport; SEPA says an “extensive replacement programme for components” had been undertaken and that the sites made “substantial improvements” to asset management and maintenance following the discoveries ^{[1] [7]}. The MoD underscores engagement with regulators and publication of monitoring data in RIFE reports ^[1].

5. Transparency, secrecy and competing public interests

Freedom-of-information appeals and parliamentary questioning reveal tension: requests for correspondence and internal reports have been partially redacted or withheld on security grounds, and ministers have declined to give incident detail citing national security, prompting critics to call for fuller disclosure and asserting a six‑year secrecy battle over the 2019 leak ^{[8] [9] [10]}. Opponents argue public-interest transparency, while the MoD asserts that operational security and the effective functioning of HMNB Clyde justify limits on disclosure ^{[9] [11]}.

6. How to read the official verdicts — cautious reassurance or regulatory capture?

Official narratives from SEPA, the ONR and the MoD emphasize monitoring data, lack of radiological harm, and corrective investment — a regulatory conclusion that the discharges posed no significant environmental risk ^{[1] [3]}. Critics and watchdogs point to systemic maintenance failures and protracted secrecy as indicators that accountability and public confidence need strengthening; several sources explicitly frame the incident history as exposing weaknesses in asset management despite regulators’ eventual endorsement of remedial steps ^{[10] [4]}.

7. Bottom line: incidents occurred, regulators found no significant public-health impact but withheld some detail

Documented maintenance failures and recorded NSERs confirm that leaks and multiple safety events occurred at Coulport and Faslane; regulators have overseen component replacement and published monitoring while concluding there has been no radiological impact of regulatory concern, even as the MoD’s refusal to disclose specific incident details for security reasons fuels calls for greater transparency ^{[1] [3] [2] [9]}.