Yes, in fact most power in Ontario is produced by nuclear fission.
Here is why:
Canada uses Uranium 238, an element that slowly decays over a period of time. U238 is quite stable. So to accelerate the decay of this uranium, heavy water is needed to accelerate the rate of decay, but also to cool down the reaction. It is safer because when you slow down the flow rate of heavy water, the reaction slows down too. A meltdown is possible, but not explosion. For nuclear radiation, the core is protected by several layers of lead. The people working there are equipped with protection and safety devices to prevent exposure.
For poorer countries, they use U235, a purified and volatile isotope. This isotope is able to self ignite. So there is no way to control its reaction. U235 is costly and difficult to purify, but burns with a minimum of equipment. The US used to use U235, but realized that U238 is better. By the way, U235 is found is nuclear warheads in missiles. This is also why Chernobyl exploded, during a drill, cooling water was shut off, producing a meltdown, followed by an explosion.
The major problem is depleted uranium. It is U234 that has a long and strong alfa and gamma radiation. Research should be done to reuse this waste.