Hinkley Point B: What happens after a nuclear power station stops making electricity?

Station director Nicola Fauvel and project controls manager Karen Lesson are part of a big team defuelling the power station.

What happens after a nuclear power station stops making electricity?

That question is being answered right now at Hinkley Point B in Somerset. After shutting down in 2022, the job now is to carefully remove tonnes of nuclear waste to be transported for storage at Sellafield in Cumbria.

The team is halfway through that task with one reactor empty and one more to go.

I was given exclusive access to the power station, getting the chance to travel deep within the bowels of the building and see something few people outside EDF Energy get to - the cooling ponds, where spent fuel is cooled down before being sealed for transport and storage.

“We are standing on Reactor 4, on top of what would have been 308 fuel stringers, approximately 2,500 fuel elements,” Karen Lesson told me.

She is currently the project controls and improvement manager but was previously the defuelling preparations manager. She is full of knowledge about this mammoth task that the team is undertaking.

The cooling ponds are where the spent fuel cools before being sealed and transported.

It begins in the reactor charge hall - a cavernous room where you can literally stand on top of the nuclear reactors.

They are numbered 3 and 4, following on from reactors 1 and 2 at Hinkley Point A power station, which began decommissioning in 2000.

Standing above reactor 3 is the ‘charge machine’, an enormous device which exists purely to lift and deposit the fuel.

“One stringer is like a string of sausages made up of eight fuel elements", Karen told me.

"The charge machine lifts them out of the reactor, stores it in the machine and then runs across the rails and deposits into the radiated fuel dismantling cell.”

Our journey then takes us down to that stage, into a cramped control room with a window giving just a glimpse of the technology and danger beyond the safety measures.

“The wall is six feet thick,” she said. “As it comes through here as a fuel stringer we use the manipulators to cut the tie bar up and dispose of the elements one at a time down into the fuel ponds.”

Access to the ponds is something few journalists have been given, and for good reason. It is a higher risk zone for contamination and we are required to put extra protective clothing on before entering.

The cooling ponds are, essentially, a large swimming pool where the fuel is left to cool after being used.

The charge machine sits above reactor three in the huge reactor charge hall.

Each ‘sausage’ of fuel is kept in a skip of fifteen compartments. That skip is then lifted into a flask, which is what the fuel is then transported in via road and rail.

The process of disposing of nuclear waste has always been part of the work of Hinkley Point B, but its current operation is entirely focussed on this job now, with multiple flasks of fuel being sent to Sellafield every week.

Karen said: “Previously in generation we would probably send out one flask a week. Now we’re trying to average three and five flasks a week.”

After nearly half a century of power production, Hinkley Point B, and its staff, are well into a new part of its life. For the people, the future might be over at Hinkley Point C, due to start operating later this decade.

For the plant there will be another couple of years to finish defuelling operations, then EDF hands this place over to the Nuclear Decommissioning Authority as the painstaking job of decommissioning will continue for many years.

Nicola Fauvel is Hinkley Point B’s station director. She said: “I’m really struck when I’m on a power station that it’s a human endeavour and the determination that the team brings to what they do here.

"This is really their achievement to be proud of and that’s what I’d like to recognise.”