Safety level at Scotland's largest nuclear site raised to 'enhanced' after leaks found

The Office for Nuclear Regulation (ONR) found leaks from low-level radioactive waste pits in recent site inspections at Dounreay, a nuclear power complex which is currently being decommissioned on the north Caithness coast in the Highlands.

Reports also found wear and tear in a building being used to store drums of radioactive sodium on site.

The findings mean the nuclear watchdog has moved Dounreay up one level in its three-tier regulation chart from “routine” to “enhanced” because of safety concerns.

According to the latest ONR chief nuclear inspectors report, there are only three other licensed nuclear sites in the UK that require “enhanced” regulatory attention. These are Atomic Weapons Establishment in Aldermaston, Devonport in Devonport Royal Dockyard Ltd, and part of the Sellafield (Sellafield Ltd) estate.

Thirty-one sites monitored by ONR are rated as “routine”, while only one site has been rated as “significantly enhanced”, which is the highest regulation level, which is a section of Sellafield with various storage facilities.

Earlier this year, ONR issued an improvement notice to Dounreay for “inadequate” storage of alkali metals which fell below the legal requirements.

Buildings used to store alkali metals, predominantly sodium, were leaking in rainwater - with pools observed where containers of these metals were being kept.

ONR said although nobody was harmed as a result of these shortfalls, and there were no radiological consequences, the watchdog concluded “there was the potential for serious personal injury, if workers had been exposed to these hazardous materials.”

In their latest report, inspectors also found water had built up in a surge tank and samples taken confirmed elevated levels of tritium - a radioactive element.

The report said ONR “does not consider that the levels of tritium detected present a substantive challenge to the site in managing potential exposure to site personnel, and does not consider it presents a concern to persons off the site.”

An ONR spokesperson said: “Based on the scale of the organisational changes, the improvement notice for sodium storage, the degraded asset conditions, and management of non-nuclear high hazard activities, we have moved Dounreay into enhanced regulatory attention from a safety perspective for the 2024/25 financial year.

“It's not uncommon for us to move licensees into enhanced regulatory levels in order to achieve improved performance in specific areas, and this is a key part of our role as an independent regulator.

“The health and safety of workers at the site is of paramount importance to ONR, and if incidents occur, the appropriate action will be taken.

“We will work closely with Dounreay through our proportionate enabling approach to ensure that the required safety improvements are delivered."

A spokesperson for NRS, Dounreay’s operator, said: “NRS Dounreay is working closely with the regulator to implement the agreed action plan.’ 

Campaigners have urged NRS to follow the example of plans being developed to turn the former nuclear reactor site at Chapelcross Power Station in Dumfries and Galloway into a green energy hub.

Scottish finance minister Ivan McKee unveiled the proposal earlier this week during a visit to the plant, near Annan.

The multimillion-pound scheme would create a hydrogen production and storage facility together with manufacturing, energy and enterprise campuses.

This week, ONR granted consent to start decommissioning Hunterston B nuclear power station in West Kilbride, North Ayrshire.

This decision comes after a public consultation and assessment by ONR of the environmental statement from the site’s operator, EDF Energy.