Our safety philosophy is simple – limit the chances of an accident occurring and limit the effects of an accident in the unlikely case that one should occur.
There are three principles upon which all nuclear reactors are designed – redundancy, diversity and segregation.
We ensure accidents don’t happen by providing high quality design, equipment and operators. As an added layer of safety, there are back-up systems and then back-ups for the back-ups.
We protect the public and our facilities with state-of-the-art technology that layers precaution on top of precaution. That’s why we have four-feet thick steel-lined concrete walls that surround the reactor, as well as back-up systems that function in the event of an emergency.
CANDU reactors, like those operated by Bruce Power, incorporate dozens of safety features to respond to the stringent safety requirements imposed by the Canadian Nuclear Safety Commission. These include:
- Two independent and diverse shutdown systems. Shutdown System No. 1 is the primary means of shutting down a reactor using neutron-absorbing rods that are suspended above the reactor and can be dropped into the core as needed. Shutdown System No. 2 sees a substance called gadolinium nitrate injected into the moderator, which absorbs neutrons to shut the reactor down.
- A vacuum building designed to prevent the release of radioactive material. The building is enclosed in nearly four-foot thick concrete walls. In the event of a large leak in the reactor cooling system, radioactive steam and water would be sucked into the vacuum building and cooled by roughly 12 million litres of water from a dousing tank. High-efficiency filters and charcoal absorbers would then remove 99.9% of the radiation.
- An Emergency Coolant Injection System that ensures water continues to circulate over the fuel if there were a leak in the heat transport system.
- A design that can use passive convection cooling for the primary systems to keep the reactor cool in the absence of power.