By stewartb

The public record of incidents at Dounreay from CHATGPT: ‘Here is a chronological timeline of known official / media‑reported pollution, health & safety, and regulatory incidents or concerns at the Dounreay nuclear site, from commissioning to the present, based on the sources I located. Some entries are major events; others are smaller leaks or findings. This is not guaranteed exhaustive, but covers all incidents I could verify. I include dates, description, and sources.’ (Sources have been omitted here for brevity. They could be found readily by asking CHATGPT again – for free. Otherwise what follows is as provided by CHATGPT.)

1963‑1975: Discharges of radioactive waste & fuel swarf / illegal dumping to landfill; release of particles via drains to sea. UKAEA pleaded guilty under the Radioactive Substances Act to allowing release of particles to the environment through drains, and disposing of radioactive waste to a landfill site. Part of the problem: contaminated swarf from fuel elements processed in ponds; swarf entering effluent drainage when ponds were drained; solid particles reaching sea/beaches. These releases occurred over this period.

10 May 1977: Waste shaft explosion involving sodium and potassium (Na/K) reaction. A deep waste shaft (65 m), containing radioactive waste plus several kg of sodium & potassium, flooded with seawater; chemical reaction caused explosion, lifting concrete lid, spreading radioactive particles around. Considered one of the worst in Dounreay history in terms of potential, though much of the danger was mitigated.

Between 1963‑1984 (ongoing through those years and beyond): Radiation particles on beaches and seabed; fuel swarf release. Thousands of radioactive particles found over decades around Dounreay (sea floor, beaches, etc.) from past discharges of solid radioactive fuel fragments / swarf. Fishing bans / seafood restrictions near the site (2 km) in place.

1989, Third Quarter: Leak of ~30 g plutonium from a tank; no external release A small quantity of liquor containing about 30 g of plutonium escaped from a tank inside the facility; contained within the building; no public dose. 

1990, Fourth Quarter: Worker over‑dose & small liquid leak onto road (a) Worker contamination when loading equipment for decontamination, leading to exceeding yearly radiation dose limits; (b) small leak from a drum of low level radioactive waste onto a road — road surface removed; no public exposure. 

1992, Fourth Quarter: Leak of radioactive liquor; operator contamination At Dounreay, small leak of radioactive liquor; two operators had minor contamination to hand/clothing, decontaminated; doses well under legal limits. 

29 June 1993: Intake of radioactive material by an operator in residue recovery plant Drum with centrifuge filter opened, small release of radioactive material; one worker later found to have internal dose exceeding legal limit (plutonium oxide intake). Occurred inside plant, fully contained (no environmental release). 

1995: Worker overexposure; safety breaches; fine UKAEA fined (≈ £101,000) for safety breaches after workers contaminated with excessive radiation doses; also for accidentally damaging main power cable, causing outage. 

7 May 1998: Major power failure in Fuel Cycle Area; safety audit triggered A mechanical digger severed a main 11 kV cable; backup power failed; FCA lost power for ~16 hours. HSE/SEPA raised concerns; safety audit commissioned which identified many weaknesses (management, plant condition, etc.) 

1998: Publication of 1998 safety audit; 143 recommendations HSE/SEPA audit published 1 Sept 1998; many urgent recommendations to fix safety and environmental issues; UKAEA issued “Dounreay — The Way Ahead” response; progress monitored. 

2007‑2016 (approx.): Removal/destruction of NaK coolant from DFR circuits Over a period of years, the large inventory of liquid metal coolant (NaK: sodium‑potassium alloy), which is highly reactive and radioactive, was removed and destroyed. All of the secondary circuit (~100,000 L) and the primary (~57,000 L) were processed. This reduced a major hazard. 

7 October 2014:Fire in the sodium tank farm of Prototype Fast Reactor; unauthorised release of radioactivity** A fire broke out in a PFR sodium tank farm; trace amounts of tritium released; procedural non‑compliances and behavioural failures were cited. ONR issued an improvement notice. 

February (year ≈ 2019‑2020?): Contaminated dust release during ventilation testing Dust disturbed; conditions of radioactive substances authorisation contravened; environmental impact and discharge within authorised limits; very low risk. SEPA investigated. 

April 2022: Chemical incident at sodium storage facility: small radiological release During planned work at storage tank, a chemical reaction; some radioactive material (possibly tritium) may have been released; damage internal; risk to public/environment “extremely low”. Enforcement letter issued. 

1 March 2024: Improvement notice over storage of alkali metals (sodium) in damp conditions Alkali metal storage buildings leaking rainwater; containers of sodium exposed; potential for serious injury though no radiological or environmental release reported. 

26 June 2024: Leak from carbon bed filter, water loss of ~1 litre/day; Cs‑137 activity observed A redundant external carbon bed filter (inactive system) was losing water; prior sampling of water had high activity (~61,000 Bq/L) with Cs‑137 dominant; however, steady loss; incident rated “below scale / no safety significance” under ONR categorisation. 

7 June 2024: Low‑level contamination discovered on worker’s hand/shoe; work halted Employee had minor contamination; area evacuated; no public/environment risk; INES Level 0 (no safety significance) assigned. 

February 2025: Equipment toppled (radiological contamination monitor ~2 tonnes); worker minor injury During moving of heavy monitor, it toppled; worker suffered minor injury; ONR improvement notice issued; risk judged significant. 

May 2025 (25 July 2025 extension): Improvement notice extended re: above heavy equipment movement The improvement notice served in April 2025 for the above incident was extended; compliance deadline moved.

Additional / Long‑Term Concerns: The state of legacy waste storage, particularly in old shafts/drums/storage pits, has been a recurring concern. For instance: the waste shaft used between ~1956‑1977 contains mixed waste (plutonium, fuel fragments, sludge, organic material) with uncertain packaging, risking leakage. 

Safety culture / management and plant condition have been recurring issues: the 1998 audit heavily criticised weaknesses in management, over‑reliance on contractors, ageing plant, lack of integration of decommissioning strategy. 

Environmental contamination monitoring (particles on beaches, foreshore, seabed), with active particle recovery programmes, regulatory monitoring of discharges, etc. ‘