One incident involved an ‘elevated level’ of nitrogen gas, which can cause asphyxiation, at the plant’s Magnox facility. The incident was played down, the source claimed.
Safety at the UK’s biggest nuclear site is under threat due to a culture of secrecy and ‘cover ups’, a whistle blower told the Mirror.
The source described a potentially deadly incident in which nitrogen gas, which can cause asphyxiation, leaked at the Sellafield Magnox storage facility. The incident was covered up, the source claimed, adding that staff are afraid to raise safety issues because they fear they will be “targeted”.
The leak was at the Magnox Swarf Storage Silo – the most hazardous building within Sellafield in Cumbria – where waste products from used nuclear fuel rods are stored.
A fault on indicator readings led to nitrogen contaminating five workers’ shoes, the source said. The noise from the nitrogen leak, 10 times the amount of gas needed for a “routine job”, was so loud that the workers could not hear the alarms on their personal oxygen monitors, the source said.
The whistleblower added: “It was most serious because it could have killed somebody. The whole point of having all these safety procedures is to stop people breathing in inert gas, so we can evacuate before there’s a chance of breathing it in.”
The source said the leak in May 2023 was raised as an incident report and “was of a level that needed to be escalated”. But it was not escalated, according to the whistleblower, who added that “no lessons were learned”.
They said: “There is no confidence or trust in the senior management now. We are dealing with nuclear waste and people are afraid to speak up. The problem is that people are being victimised if they report safety issues.
“Or they are escalated to managers who then try to cover them up or sweep them under the carpet. And that is a really dangerous culture in a place like Sellafield.”
Ex-Sellafield HR consultant Alison McDermott raised safety concerns in an employment tribunal in 2021.
Alison, 60, who lives near Ilkley, West Yorks, said: “In my experience, leaders cover up problems and lash out at people who speak out. That’s a terrifying state of affairs at a nuclear site. In my 30 years in HR it’s the most secretive, punitive toxic culture I’ve ever experienced.”
The Magnox Swarf Storage Silo is said to be the most dangerous building in the UK. It began leaking radioactive water into the ground in the 1970s. A parliamentary report this year found that it still leaks and will pose an “intolerable” risk until the late 2050s.
The whole Sellafield site is being decommissioned at a cost of £136billion – £1.15billion more than expected due to dangerous and costly delays, according to the report.
The report also urged the Nuclear Decommissioning Authority (NDA), which is responsible for cleaning up Sellafield safely and securely, to publish information about “the prevalence and perception of bullying and harassment” at the site. The total decommissioning costs have risen to £136 billion, an 18.8% increase since 2019.
The Nuclear Decommissioning Authority, the body which oversees the work at Sellafield, claimed that they had taken steps to encourage whistleblowers to speak up.
Sellafield said safety was their ‘highest priority’ and staff were encouraged to challenge and report on any safety concerns. They stood by their handling of the Magnox incident.
“This was reported and investigated swiftly and thoroughly. Our regulator was informed in line with established protocols,” they said. “Our Safecall system remains independent providing a safe and confidential reporting system for the whole of the NDA group.
“Whistleblowers are respected, protected, and valued and we actively encourage employees to report matters of concern. Without exception, issues raised are taken seriously, investigated appropriately, and treated confidentially. We strongly advise anyone with a concern about a safety event or investigation to report it so we can act on it.”
They added that during routine testing of a nitrogen delivery system in the Magnox Swarf Storage Silo in 2023, a control valve was opened causing a ‘brief increase in flow and pressure of nitrogen’.
This resulted in an “elevated nitrogen flow and some localised contamination”. Operators had appropriate personal protective equipment with “no safety impacts.” No contamination was detected outside of the controlled area.
Action was taken ‘to avoid a repeat occurrence’. The NDA declined to add to Sellafield’s statement.