How Ontario’s Bruce Power applied lessons from 2011 Fukushima nuclear disaster

OTTAWA – The operator of Canada’s largest nuclear power plant has looked “very closely” at the March 2011 disaster at the Fukushima Daiichi nuclear power plant in Japan and has simulated the effect of a tornado hitting the facility, a power plant official said Tuesday at the National Insurance Conference of Canada.

“One of the areas where we hadn’t looked as strongly was external events on reactors and Fukushima focused our attention on that,” said Frank Saunders, vice president of nuclear oversight and regulatory affairs at Bruce Power, which operates the Bruce nuclear power plant on the shore of Lake Huron.

He made his remarks during an NICC session on nuclear risk in Canada.

The Bruce power plant has a total capacity of 6,300 megawatts. Ontario’s other two stations, Pickering and Darlington, have 3,100 and 3,500 megawatts respectively while NB Power’s plant in Point Lepreau produces less than 700 megawatts. Canada’s fifth nuclear power station (Hydro Quebec’s Gentilly plant) was shut down nearly two years ago.

Saunders noted Bruce Power has simulated the effects of flooding, a large wave coming from the lake as well as a tornado similar to the one that hit Goderich — about 50 kilometres south of the Bruce plant — in August 2011.

“We have looked at Fukushima very closely,” Saunders said of the disaster caused when a tsunami hit the Japanese power plant after the March 11, 2011 Tohoku earthquake. “It was what you call a very low probability event. Generally we talk about frequencies that are in the range of one in 100,000 years to one in 10 million years as being the range of likelihood of occurrence of these things.”

The session he spoke at was moderated by Colleen DeMerchant, general manager of the Nuclear Insurance Association of Canada (NIAC), a non-profit association of insurers that form liability and property damage pools for nuclear installations.

“What Fukushima showed us was that nuclear stations, even those built to 1960s earthquake standards, are robust enough to sustain a 9.0 quake,” DeMerchant said. “Had that been the only event, no one in this room would have ever heard the word or the name Fukushima. However, a 15-metre tsunami disabled the power supply and the capability of providing cooling to the reactors.”

The “challenge” for Bruce Power officials “was to go look at our own events and decide whether there was something like that that could happen in Ontario that might cause our systems to fail in a way that we didn’t expect,” Saunders said Tuesday.

Bruce Power aims to protect its plant against “highly unlikely events which have a significant consequence to them,” Saunders added, describing one model they used.

“We assumed two feet of rain in a six-hour period,” Saunders said. “We assumed that all the ditches and all the culverts and everything were plugged, and assumed a huge wash off the lake with something in the order of 10-metre waves coming in off Lake Huron, to do this analysis.”

In Canada, the Nuclear Liability Act stipulates that nuclear operators are, “without proof of fault or negligence, absolutely liable” for breaches of duties imposed by NLA. They are required to have basic liability insurance of at least $75 million for each nuclear installation.

That amount, which has not changed since 1976, will increase to $1 billion if Bill C-22, the Energy Safety and Security Act, is passed into law. Bill C-22 was tabled Sept. 15 for third reading in the House of Commons.

It proposes to create a new law, called the Nuclear Liability and Compensation Act, noted Dave McCauley, director of the uranium and radioactive waste division at Natural Resources Canada, during NICC.

Assuming Bill C-22 is passed by the Senate without amendments, the absolute liability for nuclear operators will increase to $650 million once it gets royal assent. After that, the limit will be increased over a period to three years, to $1 billion, McCauley noted.

“The Minister (of Natural Resources) will be obligated to review that limit at least once every five years to determine whether it should be increased,” McCauley said. “That was a problem with the (current) legislation where you have to open up the whole act to change the liability limit. With this legislation, the minister can change it by regulation.”

In Canada, both the insurers and the insurance policies require approval by the Minister of Natural Resources, McCauley said.

Under Bill C-22, “subject to the Minister’s approval, operators will also be given the flexibility of providing alternative forms of financial security to cover the risks that they are liable for,” McCauley added.

NICC was produced by MSA Research and held in downtown Ottawa.