Japan crisis raises questions about nuclear energy infrastructure, safety
TORONTO―Canada’s nuclear energy industry is eyeing the latest developments in Japan, where last week’s tsunami and earthquake threatens to create a nuclear catastrophe.
The quake knocked out power at Japan’s Fukushima Daiichi nuclear power plant, halting cooling systems that normally keep nuclear fuel from melting down and setting off several hydrogen explosions.
Workers have been using seawater to try to cool the reactor fuel rods, but damage from the blasts has already allowed radiation to escape, Japanese officials confirmed.
Nearby residents are being warned to stay inside and the accident has climbed to a level six out of seven, according to the the France Nuclear Safety Authority’s international scale.
Only the Chernobyl blast of 1986 ―the greatest nuclear disaster in history― has scored a seven.
The unfolding crisis in Japan is raising questions about the design and infrastructure of nuclear power plants across the world, but nuclear experts in Canada say it could take several weeks before those questions are answered.
“Most of the emergency systems there behaved as they were designed to in the initial period after the earthquake,” says David Novog, a professor at McMaster University’s department of engineering physics.
But an ensuing tsunami likely knocked out the plant’s back-up power supply, leaving it without cooling ability.
“I would guess the 10-metre high tsunami was just greater than ever anticipated in the design of the emergency system,” Novog says.
While an earthquake or tsunami of that magnitude is unlikely to ever hit Canada, nuclear reactors here are still prepared for both natural disasters and accidents such as train derailments or airplane crashes, according to Novog.
Canada has 20 CANDU reactors, mostly located in Ontario near Lake Huron and Lake Ontario, as well as one on the St. Lawrence in Quebec and one near St. John’s in New Brunswick.
Canadian reactors are surrounded by a large tank of water that provide cooling for an extended period of time, should all power be lost.
“If we had an earthquake or tsunami here, we would still need to replace the water, but we’d already have a significant amount in there and a slightly longer time frame than what we’re seeing in Japan,” Novog says.
Another important difference is the reactor containment barriers that retain steam and other gases are smaller in Japan, according to Jeremy Whitlock, a physicist at Atomic Energy of Canada Ltd.’s Chalk River Laboratories and a fellow of the Canadian Nuclear Society.
“Every technology has its own drawbacks and benefits and it’s hard to compare the two systems, but it does seem we would have more time available to us in terms of back-up,” Whitlock says.
Canada’s reactors may be able to stand up to force, but the crisis in Japan is stirring new anxieties about nuclear power.
Prices for one of the world’s largest publicly traded uranium companies, Cameco, dropped from C$51.00 to C42.00 this week.
TD Securities released a note on Tuesday saying “the ongoing nuclear emergency in Japan and the attendant uncertainty have prompted us to take a more cautious view towards Cameco…pending greater visibility into theextent and impact of the nuclear crisis in Japan.”
And the Ontario government is getting pressure to hold off on its plans to build two new units at the Darlington facility in Clarington.
Ted Gruetzner, spokesperson for the Ontario Power Generation, says the province’s nuclear reactors have been upgraded in the past decade to withstand potential disasters.
“They’re encased by six feet of concrete and steel lining,” he said.
“Plus there’s individual things like vibration dampers and a number of stand-by generators that would kick in,” he said, noting the Darlington facility has four emergency generators and any one of them could provide enough back-up power.
Still, he acknowledges the Japan disaster could trigger reviews of nuclear emergency systems and designs in Canada.
“Once we see what exactly did happen in Japan, we will take a measured approach for ongoing learning and upgrades to improve technology and safety,” he said.