Good afternoon, Mr. Chairman.
Obviously the presentation on nuclear power would be impacted by the events that have taken place in Japan, so I felt it might be helpful to give the committee an overview of what's here. I've provided a slide deck to try to allow the committee to understand exactly the sequence of events.
Now let me, without actually going through slide by slide, try to give you an overview of the situation. Of course everyone has watched the devastating effect the earthquake and tsunami had on the entire region of Japan that was affected.
With respect to the nuclear plant itself, at the time the earthquake hit there were six units on the site, units one to six. Three were in operation—units one, two, and three—and three were in various stages of shutdown mode. When the earthquake hit, the plant responded as you might have wished it would do. It withstood the earthquake and the automatic cooling systems went into operation, again in a way the design would have wanted to see that happen.
About 30 minutes after the earthquake, the tsunami created massive damage to the facility and in fact swamped much of their shutdown system. Basically, it's easy to see from here that the plant was not capable of withstanding the level of tsunami it was struck by. The height of the wave exceeded the design expectation for the site. It had a devastating effect on all of the shutdown systems.
I've tried to explain this event in many ways to people, and I was just at a meeting in Ontario this morning trying to do the same thing, so if I can explain this in layperson's terms, it might be easier for you.
If you can imagine your own kettle at home that's boiling water, that's actually very much like a boiling water reactor. The water actually boils within the reactor during normal operation, and instead of the water escaping through your spout as it would in your kettle, it actually then is fed to the turbine generator. So if you can imagine a scenario where suddenly you have nowhere to send the steam—because that's what happened when this event occurred, the connection between the reactor and the turbine was broken—you still have a tremendous amount of heat being generated inside your kettle and nowhere for the steam to go.
The obvious concern there is how do you keep it cool? How do you prevent the lid from blowing off? In the early period after this event when they lost cooling, that was exactly the situation they were faced with, the possibility of the water continuing to boil off and structural damage occurring.
Really, from the minute the tsunami hit, they had to consider how to apply cooling to these three powerful reactors that are still generating heat. Having tried a series of things, they then were forced with a situation where they knew that fuel damage was occurring, the water level in the reactor was dropping, and they had to do two things fairly quickly: one, to relieve the pressure by venting, and two, to find some alternate way of adding water to the reactor. They chose to do that by using seawater and using fire pumps, and they progressively worked their way through these three units.
One of the things I think we've all seen pretty dramatic pictures of is where the secondary containment has been affected. Really, the reason for that is that as they're venting, they're also venting hydrogen into that secondary containment. Under normal operation that hydrogen should have been burnt off as it was generated. There would be a lower volume of it, and it would have been dealt with as it came. But their hydrogen ignition equipment was also electrically powered. So without that, they vented hydrogen in a pretty large volume, and then the hydrogen ignited and it blew the secondary containment apart on unit one and then did the same on unit three. Those were the structural impacts we've all watched.
The important thing, however, is despite the obvious visual impact that had, the structure of the primary containment for all of these reactors continues to be sound.
The second stage of the problem, then, is now that they have water in these vessels, they have to deal with the fact that the fuel pools have been sitting with fuel and they'll also need to be cooled. That's compounded by the fact that the secondary containment has been blown off in two of the units. So you have fuel that's overheating in a fuel pool, with no means of cooling it either, and as it steams off it sends contaminants into the atmosphere.
As things stand today, and you'll have seen this in much of the video footage, they've been using extraordinary measures to cool the fuel pool: they've been using fire trucks to hose down the fuel pools and add water; they're using seawater and fire pumps to keep the reactors cool. It really is all a coping strategy.
The situation has gotten better every day, but we'd be wrong to say that they have it stabilized at the moment. They are still doing it in a very non-standard way. Over the course of the last 48 hours they've been able to get electrical power back to these reactors, and that allows them to start recovering instrumentation, controls, and normal cooling systems.
My estimate would be that it will take at least another two weeks to try to get back to normal system operation, in terms of providing cooling by normal means. But these facilities are commercially out of action forever, and it's now about putting them into a safe layup and shutdown state.
At the heart of this, of course, is a question mark over whether or not the design basis for this plant was valid. Everyone I think understands that Japan is a very seismic-reactive area. Their plants are designed to meet earthquake standards that we would never consider applicable to our area. But even there, this quake and the tsunami that was a consequence of it exceeded the design specification.
As Denise said earlier, lessons for us.... We have very sound design-basis arguments here, of course. In Japan, not only is the plant designed differently, but the location of the plant is very different, in terms of the onerous environment.
We are conducting a review of our plants to do three things: firstly, to confirm that the design basis for our plants is sound; secondly, to confirm that the equipment we rely on can be proven to be available in a range of scenarios, such as fire, flood, explosion, and those kinds of things. The third thing we've been asked to do is to liaise with emergency measures organizations so that we can confirm that all of our controls and arrangements for any off-site event are adequate to meet this low-probability outcome.
We've been asked to do that in a matter of months by our regulator. Much of this we consider to be providing reassurance. We have already a pretty advanced situation here in Canada. We have a set of documents called “severe accident management guidelines”. I say that we are, in Canada, ahead of many in the production of those documents, which would obviously provide some reassurance, were we to suffer events that go beyond our design basis.
As an industry, of course, we all believe that there will be lessons to be learnt from the Japanese event. A job we have here in Canada is to reassure people about the safety of our own plants.
I'll finish by saying one thing, which is important: when there were two events that happened in the past that affected our history—Three Mile Island in 1979, 32 years ago last week, and Chernobyl 25 years ago—both of those events originated in the plant and escalated within the plant. We are not that operator today, and we haven't been that operator for a long time. This Fukushima event actually was a natural catastrophe, which affected the plant. We should certainly be prepared to learn lessons from this, but we should not allow it to compromise our view of the 30-plus years of safe operation that we in Canada have seen from our own nuclear plants.
I'll happily answer any questions.