Dounreay placed on ‘special measures’ over wide-ranging safety concerns
Government inspectors have put Dounreay into “special measures” as a result of unresolved safety concerns.
An action plan has been drawn up by operators NRS to address the issues which include ageing, deteriorating plant, radioactive leaks and the storage of chemicals.
Among the problem areas is the condition of buildings in the prototype fast reactor being used to store drums of radioactive sodium.
An inspection by the Office for Nuclear Regulation (ONR), in April made grim reading for site management.
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It found significant corrosion and metal loss of structural steelwork in the turbine hall.
It concluded: “It was judged that alkali metal storage conditions in the turbine hall, steam generator hall and generator transformer house are not adequate, as the licensee has failed to safely protect the drums against uncontrolled degradation via air and moisture ingress.
“It is also judged that the licensee is not recognising when there is degradation in these areas.”
The issue first came to light following a probe into a minute leak of radioactive tritium from a sodium drum in the turbine hall in November 2022. Its exposure to rainwater through a leaky roof was blamed for causing the corrosion.
The inspection was one of a number carried out at Dounreay in the spring and summer to receive an amber rating by ONS.
Others revealed some elderly electrical plant in a “degraded” state while Dounreay was found to have breached the Control of Major Accident Hazards (CoMAH) regulations by its stockpile of chemicals being over its set limit.
A fire safety inspection was generally positive but flagged up a “significant shortfall” in assessment and control of sources of dangerous substances.
The inspector said: “It is my judgement that Dounreay do not currently understand the totality of risk presented by dangerous substances on site and therefore cannot provide adequate assurance as to the safety of personnel on site.”
A final warning letter has been sent to NRS over the detection of radioactive caesium in groundwater being pumped into non-active drains.
The site operators have also been taken to task over leaks of radionuclides and other hazardous substances into groundwater from its cluster of low-level radioactive waste pits.
Regulators have also been pursuing NRS over its response to a leak of radioactive hydrogen in April 2022.
ONR informed NRS on June 26 that Dounreay was being placed in “enhanced regulatory attention for safety.”
NRS set out its action plan to address the concerns in an update to Dounreay Stakeholder Group, dated August 29.
It states urgent repairs are being carried out to make the PFR buildings weathertight by the end of October. The shortcomings identified with the sodium storage are being taken on board in a new strategy being rolled out over the next 18 months.
Steps are being taken to comply with the CoMAH regulations and to address the concern about its approach to hazardous substances.
On the caesium-contaminated groundwater, NRS plans to apply for a new permit which would allow radioactivity to be discharged via sewer outfalls.
NRS admits being unable to stem the pollution from the pits as management continues to deliberate on whether to leave them or empty them.
The site operators add they are now compliant with the conditions breached in the leak from the sodium farm.
NRS notes ONR found security and safeguards at the site “in good health.”
Speaking at DSG’s meeting in Thurso on Tuesday, Dounreay’s interim managing director John Grierson was confident his recently revamped management team would implement the action plan to resolve the issues.
DSG chairman Struan Mackie said: “It’s disappointing that the site is in this position.
“We’ll want to be updated on where they are on these actions.
“There’s not going to be a quick exit from enhanced regulation which covers multiple issues.
“The site will only be removed from it when there’s assurance that everything has been rectified.”
Mr Mackie believed ONS will increasingly seek assurances about the condition of plant and utilities at Dounreay now that its decommissioning is expected to last until the 2070s rather than the early to mid 2030s, as previously scheduled.
He said: “We’re now dealing with deadlines into the 2060s and 2070s so what was appropriate for a site that was closing in the 2030s isn’t so any longer.”
Niall Watson, chairman of the site’s co-ordinating committee, pledged the support of his members in implementing the action plan.
“We’re very much working with the company on this. Both the company and the unions see this as something we need to get after for everybody’s benefit,” he said.
