A bad year for nuclear power producers has Belgians and Britons shivering more vigorously as summer heat fades into fall. Multiple reactor shutdowns in both countries have heightened concern about the security of power supplies when demand spikes this winter.
In Belgium, rolling blackouts are already part of this winter’s forecast because three of the country’s largest reactors — reactors that normally provide one-quarter of Belgian electricity — are shut down.
Belgium’s troubles started brewing two years ago during inspections at the country’s seven nuclear reactors, all operated by Belgian utility Electrabel. Ultrasound inspection of the reactor pressure vessels at Electrabel’s Doel power station near Antwerp revealed previously unrecognized defects at Doel’s 1,000-megawatt reactor #3.
Prior tests looked only for aging of the welds between a pressure vessels’ steel plates, but this time broader inspections at Doel 3 detected thousands of tiny cracks in the plates created (most likely) when they were originally forged. Electrabel shut down the 1,000-MW reactor #2 at its Tihange power station in eastern Belgium — whose pressure vessel was forged by the same Dutch shipyard as Doel 3’s — and found similar microcracks.
The cracks reduce the vessels’ capacity to withstand spiking pressure and temperature during an accident. Belgium’s Federal Agency for Nuclear Control (FANC) decided that the resulting risk was acceptable and cleared the Doel 3 and Tihange 2 reactors to restart in the summer of 2013. But this March Electrabel shut them down again following tests at Belgium’s national research lab in Mol, where researchers irradiating steel with comparable microcracks observed a greater-than-anticipated reduction in the material’s strength.
It was the shutdown of a third 1,000-MW reactor that threw Belgium into a tizzy this August. This time it was reactor #4 at Doel, where leaking lubricant damaged the plant’s steam turbine. A spokesperson for Electrabel revealed that the leak resulted from “an apparently deliberate manual intervention” of the turbine’s oil drain, according to a Flanders Today report.
Prosecutors and anti-terrorism agents swooped in to investigate the alleged sabotage, while Belgium’s government and power distributors began crafting plans for rolling blackouts this winter. The blackout plans, released in broad form early this month and at the street-by-street level last Friday, lay out how distributors can ration power supplies.
Response to the plans has been explosive. Belgian media reports are replete with recriminations by elected officials questioning the fairness of the plans. Those representing small communities are irked that big cities are to be largely spared, and some Belgians perceive national favoritism at work. Last week leading Flemish politician Koenraad Degroote accused Secretary of State for Energy Catherine Fonck, a francophone, of going easy on Belgium’s French-speaking communities.
Seen through the lens of energy policy, Belgium’s troubles are a classic example of the “brittleness” of large electrical systems — a concept developed by systems analysts Amory Lovins and Hunter Lovins in Brittle Power, their classic 1982 treatise on energy security. The Lovins’ central point is that reliance on a small number of large power stations means that just a few failures — deliberate or otherwise — can have a devastating impact on power supplies.
Sabotage of the sort that may have sidelined Electrabel’s Doel 4 reactor was a key part of the Lovins’ analysis. Despite all of the attention paid to terrorist threats, insider threats remain the “most serious challenge confronting nuclear facilities” according to political scientists Scott Sagan at Stanford University and Matthew Bunn of Harvard. They updated that case in an April 2014 article in the Bulletin of the American Academy of Arts and Sciences.
The U.K., meanwhile, is experience the same sort of “series defect” that started Belgium’s troubles. In August EDF Energy, the U.K. subsidiary of Paris-based EDF, found a crack in a boiler during a routine inspection at a nuclear power plant near Lancaster. EDF immediately shut down three more reactors of the same design. With four reactors suddenly out of service, U.K. grid operator National Grid began seeking emergency power supplies for the winter this month.
Belgium’s microcrack discovery could have had a far greater impact. The discovery sent reactor operators and regulators in several countries scrambling to see if their own vessels forged at the same Dutch shipyard — including 10 reactors examined in the U.S. — harbored hidden flaws. To date no microcracks have been found in reactors outside of Belgium.
But as one Belgian nuclear policy specialist has noted, none of the other reactors have been examined using the wider ultrasound testing performed in Belgium. And the hunt for trouble is widening. At least one regulator, the Swedish Radiation Safety Authority, has ordered ultrasound testing of all vessels forged from steel rings, regardless of their source.
As for Doel 3 and Tihange 2, they remain closed until further testing and analysis by Electrabel can prove they are safe to restart. This will, according to FANC, include a review of Electrabel’s ‘safety case’ by foreign experts.
All this talk of risk and vulnerability might make some people think twice about being dependent on nuclear energy. Ironically, in Belgium, it might have just the opposite effect according to Aviel Verbruggen, an economist and energy policy expert at the University of Antwerp.
Officially Belgium is approaching the first deadline for a nuclear phaseout legislated by Belgium’s parliament in 2003 that would require the shutdown of the three oldest nuclear reactors in 2015 and the remaining four by 2025. But Verbruggen says there has been no coordinated policymaking to create alternative supplies, while the reactors’ French owners — EDF and Electrabel parent company GDF Suez — have been preparing Belgium’s reactors for continued operation.
Verbruggen says the present fear of power shortages may translate into public support for overriding the nuclear phaseout: “Because the strategic behavior of Suez and EDF is strong, and the Belgian political system is weak, the overall result of the black-out campaign could be a 10-year life extension of the three oldest plants. The majority of people will accept the life extension because they place supply reliability at the top of their preferences.”
This post was created for Energywise, IEEE Spectrum’s blog on green power, cars and climate