A sprawling assembly of cranes, visible from a distance, serves as a marker for the construction of the UK’s first new nuclear plant in a generation, located at Hinkley Point in Somerset.
Once the construction is completed, this facility is expected to provide enough electricity to power approximately six million homes for the next six decades.
However, a short distance away, there are two prominent reminders that the legacy of nuclear power stations persists long after they cease generating power.
The first of these is Hinkley Point B, a massive, angular structure overlooking the Bristol Channel. When it first began operating in 1976, its two advanced gas-cooled reactors (AGRs) represented state-of-the-art technology.
Yet, after nearly fifty years of operation, cracks developed in their graphite cores, posing safety concerns, leading to their permanent shutdown last year.
However, upon entering the vast main hall, it appears that little has changed. Newly painted machinery glistens under bright lights, while teams of workers in blue boiler suits bustle about above the reactors.
Currently, the primary task involves defueling, which entails the removal of hundreds of fuel assemblies from deep within the reactor cores, breaking them down, and transporting the waste to storage facilities in Sellafield.
As we observe, a large steel tower is positioned over the reactor, known as the charging machine. It resembles an old-fashioned helter-skelter but is, in reality, a heavily shielded crane. The fuel assemblies, having spent years in the reactor, are highly radioactive and require extremely careful handling.
Shaheed Mungur, the performance improvement manager at the site owner EDF, explains, “The machine is lifting the fuel assembly, which is highly irradiated and effectively is lethal when it comes to exposure. But that’s the reason why you have all of the shielding around it, and why we have to use this machine to handle the fuel in a safe way.”
After removal from the reactor, the fuel assemblies are placed in a steel-lined cell for disassembly, where the used fuel is extracted from its casings. This work is conducted remotely by operators stationed in a confined control room, peering through a 2-meter thick window filled with radiation-absorbing fluid.
The fuel elements are then left to cool in deep, clear ponds before being transferred to robust 45-tonne containers for their journey to Sellafield, where they will be placed in interim storage.
The removal of all fuel assemblies from the two reactors at Hinkley Point B is expected to take up to four years, with an estimated cost of £1 billion.
Director Mike Davies emphasizes, “End of generation is absolutely not the end of the station’s life. We’ve been trusted for years to operate this plant safely, and during that time, that, of course, included handling the nuclear fuel, and that’s what we’re doing now. We’re taking the nuclear fuel out and just not replacing it with new fuel.”
Upon completion of defueling, EDF will transfer the site to the Nuclear Decommissioning Authority (NDA). To understand what happens next, it’s informative to visit the adjacent Hinkley Point A power station.
Hinkley Point A was one of the UK’s first-generation nuclear sites, with its two reactors becoming operational in 1965 and permanently shutting down in 2000.
Almost a quarter of a century later, its two box-like reactor buildings still stand tall, but other structures, including the massive turbine hall, have been removed, leaving a vacant, overgrown space.
Old fuel storage ponds have been drained, cleaned, and painted to reduce radiation risks, although caution is advised against lingering near them. A water-filled vault elsewhere still contains radioactive scrap, which is being meticulously removed.
A new thick-walled concrete vault has been constructed on the site to store intermediate-level radioactive waste.
One of the major challenges at present involves addressing a completely different industrial hazard. In one of the old boiler houses, teams of laborers, wearing respirators, are meticulously cleaning miles of intricate pipework by hand to eliminate traces of asbestos. Large quantities of asbestos were used as insulation during the plant’s construction, and thousands of tons have already been removed.
According to current plans, most of the decommissioning work will be completed by 2039, but the reactor buildings themselves will remain sealed against the elements for another 20-40 years.
This phase is known as “care and maintenance” since radioactivity decreases over time, and it is considered safer to wait before dismantling the reactor buildings.
The final decommissioning phase is expected to take about a decade, which means that the site may not be fully cleared until at least the 2070s—70 years after power generation ceased.
In the meantime, the most hazardous waste products generated by both Hinkley A and B during their operational lifetimes will require careful handling, potentially for many generations to come.
Despite commercial nuclear plants operating in the UK since 1956, there is still no permanent repository for high or intermediate-level nuclear waste, some of which remains hazardous for thousands of years.
The government’s plan for a geological disposal facility (GDF) deep underground is underway, but it will not be ready for several decades.
Critics of the nuclear industry argue that the challenges of decommissioning old plants and the absence of a permanent waste solution make it inappropriate to construct new ones.
Doug Parr, Chief Scientist at Greenpeace UK, states, “The big lesson that we should take from the difficulty of handling nuclear waste at the moment is that we shouldn’t be creating any more of it.”
Nonetheless, the construction of the new power station at Hinkley Point C is progressing. Generation is expected to commence in four years. When that day arrives, it too will eventually close, and a funded decommissioning plan, now a legal requirement, has already been devised.
If all goes as planned, the decommissioning process will take around 20 years, meaning that the remnants of the plant may not be fully removed until well into the 22nd century.
Last Updated: 27 October 2023