See the inside of the nuclear reactor at Sizewell B
Few people can get into the Sizewell B nuclear reactor – but today we can give you rare and privileged access to a scientific wonder right here in Suffolk, usually hidden from view.
You will probably be very familiar with the famous White Dome of the Power Station, which can be seen for miles along the Suffolk coast.
But hardly anyone has seen what’s inside the dome – until now.
There are many very good reasons why the interior of the 65-meter-high, 45-meter diameter building is strictly off-limits to everyone except the most qualified nuclear engineers.
The dome houses the beating heart of the 26-year-old plant – the Pressurized Water Reactor (PWR), which splits uranium atoms in a process called fission to create nuclear power.
The energy it creates is intense – enough to power two massive turbines with shafts spinning at 3,000 rpm, which turn it into electricity for 2.5 million homes.
The temperature inside the reactor is 260 ° C and it is highly radioactive, meaning the dome shell is built to withstand the impact of a possible meltdown – although managers say it unlikely such a disaster either.
Obviously, when the station is fully operational and pumping 1,200 MW of electricity, people will only very rarely enter the containment zone – where the reactor is located – to perform the most necessary checks.
At this point, the very few people who enter it must do so through a double hatch airlock to ensure that no radioactive material escapes.
But the EDF Energy plant is currently shut down for a total of six weeks for maintenance work, the most crucial of which is refueling the nuclear reactor, in order to allow it to continue operating for an additional 18 months.
This process takes around a month and requires a high level of skill and expertise that takes years to learn, meaning that around 200 people can be in the containment zone at any one time.
This log made an exclusive tour of the containment area, as workers also take the opportunity to check critical parts and replace or maintain components.
For scientists fascinated by nuclear technology, seeing a reactor up close is a dream – perhaps like seeing your favorite soccer team live.
Even though he has been to the containment area several times, Sizewell B Station Manager Robert Gunn said: “I feel really excited when I walk around the factory and see technology – even after working for the company for 30 years.
“The mere fact that one reactor produces so much electricity for the country is quite astonishing.
“It’s great to see that part of the plant is producing so much energy for the country.”
Yet the protection required to enter a highly radioactive area, even during an outage, is a whole other level than wearing protective masks and washing hands during the Covid pandemic.
Of course, the station also takes all Covid precautions – no one is allowed on site without a negative Covid test, with workers also being tested at least once a week.
Face masks must also be worn at all times when moving around the station.
But in addition to undergoing extensive security checks, those entering the containment zone are required to wear a helmet, goggles, a full yellow coverall, shoe covers, and two sets of gloves – all over a face shield to keep them safe. protect against Covid.
You also wear a handheld radiation monitor at all times and stand in a machine twice to check for signs of radiation on the way out.
Even taking off your suit is a bit of an art form, as you have to remove your gloves from the inside and keep your hands from touching anything that may have been contaminated.
Once you’re inside, it’s hard not to be impressed with the level of technology – whatever your take on nuclear power rights wrongs.
Perhaps the most striking sight inside the dome is the water surrounding the nuclear reactor – which glows bright blue, like something out of a science fiction movie.
This is because when refueling, radiation particles travel faster than light in water.
This causes a shock wave that produces a twinkling glow – or Cherenkov radiation, to give it its technical name.
Yet nuclear scientists are equally fascinated by the complex workings of the equipment inside the reactor – such as a multi-stud tensioner, which lifts the upper and lower covers of the steam generator to allow inspection and maintenance. .
There are also four reactor coolant pumps, which may look like a shiny tube to you and me, but play a vital role – as they transfer heat from the reactor core to the steam generators.
The steam produced in these is what drives the two massive turbines, which are also undergoing maintenance and inspection during shutdown.
Megan Hopkins, 25, is a radiation protection engineer working on the Sizewell C project to build a brand new nuclear power plant next door.
But she gained experience at Sizewell B after graduating from Lancaster University and completing an industrial internship at Heysham Nuclear Power Station in Lancashire.
She recalled how amazed she had been to see the intricate level of engineering detail in the turbine room.
Seeing the nuclear reactor from an observation platform, she said: “It was crazy to think that was something I could do.
“For me, to get an idea of what containment is and to be in there, nothing beats that.
“You can feel like you are in an exclusive club, with access to all areas. You can really look around.”
She added that it also gave her a huge amount of experience in other roles.
On April 16, Sizewell B was completely shut down for a total of six weeks, with over 1,000 workers currently on site at all times.
Even though Sizewell B has reduced the number of subcontractors on site to keep Covid safe, the outage still offers a huge financial boost to neighboring businesses.
This is in addition to the £ 40million that the station, which seeks to extend its lifespan by 20 years, is already contributing to the region’s economy.
Tom Reid, head of strategic shutdowns at Sizewell B, said workers would be refueling for most of the shutdown.
However, he said: “There are a lot of other things that we do when we have the chance.
“There are many inspections of the plant. We also look at the condition of important components and perform maintenance – it’s a bit like servicing your car and changing the oil.
“After we have completed all the maintenance work, we check that everything is working as expected.”
Inspectors from the Bureau of Nuclear Regulation are also observing the outage to ensure the correct standards are being met.