Nuclear plants in Canada don’t pose the same risks as Fukushima

In the midst of the crisis in Japan, the Canadian Nuclear Safety Commission is reassuring Canadians that our CANDU generating stations are built to withstand earthquakes.

On March 14, a second explosion occurred at the Fukushima Dai-ichi plant operated by the Tokyo Electric Power Co. The 8.9 magnitude earthquake and tsunami that hit near northwestern Japan on Friday destroyed the main cooling systems and back-up power at the Fukushima plant. The reactors were quickly shut down, but operators still had to flood the reactor cores with seawater and boron in order to cool them down. The explosions at Units 1 and 2 destroyed the containment structures, but the cores themselves are still intact. Fuel rods in another reactor at the Dai-ichi plant, Unit 3, have been temporarily exposed.

Residents in a 10-20 kilometre area around the plant have been evacuated and the government has distributed stable iodine to some centres ready for distribution if necessary. Iodine can help the body’s resistance to radiation. Meanwhile a state of emergency has been declared at another nuclear complex, the Onagawa plant.

The unfolding dramatic events have brought questions about nuclear safety to the forefront in the Canadian and worldwide media.

The Canadian Nuclear Safety Commission responds on its website:  “The CNSC would like to reassure Canadians that nuclear power plants located in Canada are among the most robust designs in the world…. All Canadian NPP have been designed to withstand potential earthquakes. Both the actual structures that form containment and the systems important to safety have been seismically qualified … Similarly, waste management facilities are designed to withstand seismic events (as defined under the National Building Code).”

The CNSC says that nuclear plants in Canada are all located in areas where earthquakes are not expected, and they all have sources of back-up electricity that are different in design and physically separated.

CANDU reactors have two independent shutdown systems and multiple ways of keeping the fuel cool after a shutdown, says CNSC. Compared to the Japanese reactors, the CANDU reactors have “larger inventories of water (such as the primary coolant, emergency coolant, moderator, Steam Generator inventory, and others) that will be available to remove heat from the core.”

The Fukushima reactors are boiling water reactors designed by General Electric. Analysts say there is little chance that the Japan nuclear accidents will be on the scale of Chernobyl, which exploded in 1986 due to a power surge during a systems test.