Thank you for the questions.
The reactor has operated safely for more than 50 years now, and in the same geographic area. There are no international standards for fuel failures, so what we were responding to was the reality of the situation that one in a thousand is the calculated probability of an earthquake of sufficient magnitude that is calculated to be around six on the Richter scale, centred on the NRU facility. That is a one-in-a-thousand probability, based on the calculations.
For the onset of fuel failures to occur, the following things have to happen: the earthquake has to be centred on the NRU facility; there has to be total loss of the grid, so the electrical power from the power system; and the diesel generators and the battery backups have to fail.
We don't credit any operator action. There's no intervention on the part of the operating staff, so it's not credited at all. That may sound a bit silly, but that's the way safety and accident analysis goes. You assume that your operators are not capable of responding.
So that assumes you've lost power to the pumps and that you have no forced cooling flow to the reactor. Half an hour later, the reactor water starts to boil. A half hour after that you get the onset of fuel failures. You don't get core damage at that point, but you get the onset of fuel failures.
If it still goes unarrested, you'll ultimately get core damage. If you get the most severe core damage accident, the dose to the workers working right at the facility, at the Chalk River site, is roughly half of what we would get if we were to undergo a CT scan.
The dose, the radiation exposure...or let me correct that. That's lingo from the industry. We're talking about radiation exposure to the workers being roughly half of what you would get if you underwent a CT scan. The radiation exposure to a member of the public would be roughly half of the radiation exposure from a cardiovascular diagnostic treatment.