Nuclear decommissioning sector booms as old plants are taken offline
The nuclear decommissioning sector is expected to undergo a boom in the coming years as hundreds of nuclear plants around the world are set to close.
According to the International Energy Agency, about 200 nuclear reactors around the world will be shut down over the next quarter-century, mostly in Europe, which creates a lot of work for the small group of companies that specialise in the complex and dangerous job of dismantling plants.
As head of the Muelheim-Kaerlich nuclear reactor, Thomas Volmar spends his days plotting how to tear down his workplace. The best way to do that, he says, is to cut out humans.
Those firms involved in decommissioning – including Areva, Rosatom’s Nukem Technologies Engineering Services and Toshiba’s Westinghouse – are increasingly turning away from humans to do this work and instead deploying robots and other new technologies.
That is transforming an industry that until now has mainly relied on electric saws, with the most rapid advances being made in the highly technical area of dismantling a reactor’s core – the super-radioactive heart of the plant where the nuclear reactions take place.
The transformation of the sector is an engineering one, but companies are also looking to the new technology to cut time and costs in a competitive sector with slim margins.
Dismantling a nuclear power plant can take decades and cost up to €1bn (£880m), depending on its size and age. The cost of taking apart the plant in Muelheim-Kaerlich will be about €800m, according to sources familiar with the station’s economics.
Some inroads have already been made: a programmable robot arm developed by Areva has reduced the time it takes to dismantle some of the most contaminated components of a plant by 20-30 per cent compared with conventional cutting techniques.
For Areva and rival Westinghouse, reactor dismantling is unlikely to make an impact on the dire financial straits they are mired in at present as it represents just a small part of their businesses, which are dominated by plant-building.
Nonetheless, it represents a rare area of revenue growth: the global market for decommissioning services is expected to nearly double to $8.6bn by 2021, from $4.8bn last year, according to research firm MarketsandMarkets. Such growth could prove important for the two companies should they weather their current difficulties.
“We’re not talking about the kind of margins Apple is making on its iPhone,” said Thomas Eichhorn, head of Areva’s German dismantling activities. “But it’s a business with a long-term perspective.”
When reactors were built in the 1970s, they were designed to keep radiation contained inside at all costs, with little thought given to those who might be tearing them down more than 40 years later.
First, engineers need to remove the spent nuclear fuel rods stored in reactor buildings – but only after they’ve cooled off. At Muelheim-Kaerlich this took about two years in total. Then peripheral equipment such as turbines need to be removed, a stage Muelheim-Kaerlich has begun and which can take several years.
Finally, the reactor itself needs to be taken apart and the buildings demolished, which takes about a decade. Some of the most highly contaminated components are cocooned in concrete and placed in iron containers that will be buried deep underground at some point.
While the more mundane tasks, including bringing down the plants’ outer walls, are left to construction groups such as Hochtief, it’s the dismantling of the reactor’s core where more advanced skills matter – and where the use of technology has advanced most in recent years.
Enter companies such as Areva, Westinghouse, Nukem Technologies, GE Hitachi as well as GNS, owned by Germany’s four nuclear plant operators. They have all begun using robots and software to navigate their way into the reactor core, or pressure vessel.
“The most difficult task is the dismantling of the reactor pressure vessel, where the remaining radioactivity is highest,” said Volmar, who took charge of the RWE-owned Muelheim-Kaerlich plant two years ago. “We leave this to a specialised expert firm.”
The vessel – which can be as high as 13 metres and weigh up to 700 tonnes – is hidden deep inside the containment building that is shaped like a sphere to ensure its 30-centimetre thick steel wall is evenly strained in case of an explosion.
The collapse of the Fukushima power plant in Japan in 2011 is still relatively fresh in the minds of the public.
Decommissioning that facility has proved incredibly difficult and very expensive as it failed during a disaster.
Specialised robots that were created to retrieve radioactive material from the plant have been repeatedly unable to complete their task because the radiation destroys their circuitry when they get close.
Last year, engineers created a giant wall made of ice underneath Fukushima which is used as a frozen barrier to contain contaminated water leaking from the damaged reactor.