Post-Fukushima safety improvements in Canada

More than ten years have passed since a magnitude 9.0 earthquake struck the east coast of Japan and caused a large tsunami, resulting in the tragic loss of thousands of lives and the destruction of more than half a million homes. It was also the cause of the accident at the Fukushima Daiichi nuclear power plant.

While a large-magnitude earthquake is very unlikely around Canadian nuclear power plants, the event has had significant implications.

Here are 10 improvements made in Canada since the accident.

1. Reassessment of hazards

The Fukushima accident has taught the CNSC and nuclear operators to consider and prepare for the most unlikely events.

And it is with this in mind that hazards previously considered implausible in parts of Canada – such as large earthquakes, strong tornadoes and severe floods – were reassessed.

Opportunities to improve the safety of nuclear power plants were identified. For instance, flood barriers and watertight doors were installed and certain structures reinforced inside facilities.

2. Portable emergency equipment

Nuclear power plant operators purchased portable emergency equipment, such as pumps, power generators and hoses.

This equipment would replace disabled equipment in case of a fire or flood inside a nuclear power plant.

It would ensure cooling of the reactors and the used nuclear fuel contained in storage pools onsite.

3. Enhanced control of hydrogen

Hydrogen gas, which can be produced during a severe nuclear accident, caused the explosion that the world saw at Fukushima.

As a result, in Canada, the containment buildings that house nuclear reactors were equipped with passive autocatalytic recombiners to control hydrogen buildup.

These devices work without power and were in addition to existing hydrogen igniters or burners.

4. Emergency filtered venting

The CNSC required that nuclear power plant operators reassess mechanisms in place to prevent uncontrolled releases.

At two facilities, this led to the installation of emergency filtered ventilation (ECFV) systems, which do not require electricity to function and can be activated manually.

These systems provide additional capability to minimize radioactive releases into the environment in case of a severe accident.

5. Pre-distribution of potassium iodide pills

KI pills are used to protect the thyroid gland from radioactive iodine, which could be released into the air during a nuclear radiological emergency.

The CNSC has established new requirements for the pre-distribution of potassium iodide pills (KI pills) in the areas around nuclear power plants.

KI pills are distributed around Canadian nuclear power plants, in zones of up to a 50-km radius around the plants.

6. Real-time radiation monitoring

Radiation levels were a great source of concern and uncertainty during Fukushima.

As part of its action plan, the CNSC asked nuclear power plant operators to add additional radiation monitoring stations around their facilities, to provide real-time data on radiation levels.

7. Exercise-Exercise-Exercise

Since 2011, plant operators have conducted several large-scale exercises, involving severe accident scenarios previously considered implausible.

These exercises have allowed the testing of newly acquired equipment and procedures. They have also helped verify that the different levels of government understand their roles during a nuclear emergency.

8. Stronger regulations

Several Canadian regulations have been modified in order to integrate lessons learned from the Fukushima accident.

For instance, new rules for severe accident management were put into place. These require facilities to have qualified staff, procedures and equipment in place to effectively respond to any potential emergency, no matter how unlikely.

9. Communications and public disclosure

Learning from the communications challenges in Japan, the CNSC has established requirements for licensees to have public information programs.

These programs ensure people have access to information about all Canadian nuclear facilities.

10. International involvement

In addition to reinforcing Canadian safety requirements, the CNSC has also been active internationally, working with regulators from around the world and supporting the International Atomic Energy Agency’s work.

Together, we have been able to better analyze what happened at Fukushima and identify how to further enhance safety at all nuclear facilities.