Safety comes with conditions attached

Most people probably think risk exists when something is not safe. But actually, risk exists because something is safe. People feel they can relax if they think something is safe, whereas in fact there are always conditions attached to safety. A car is only safe on the assumption that its brakes work. The possibility of its brakes ceasing to work is a risk. Risk means the possibility of stopping functioning of the preconditions for safety. A car with damaged brakes is dangerous so we wouldn't drive it in the first place. Risk exists as we act feeling safe.

There have been too many cases of the lack of risk being mistaken for safety. Such a misconception has led to the safety myth that "being safe means having no risk." The result was TEPCO's "nuclear power plant accident beyond assumptions." Rather, it is important to try to secure safety as much as possible by preventing the occurrence of risk (risk management.)

Risk management alone cannot secure safety

If the reception staff at a hotel told you, "This hotel is a fireproofed building. We take all possible fire prevention measures so there are no emergency exits or sprinklers installed. You're in good hands so enjoy your stay," would you feel relaxed about staying there? However fireproofed the building was, wouldn't you worry about there being no emergency exits or sprinklers?

In such a case, the fireproofed building is a fire prevention measure, and therefore a form of risk management. Emergency exits and sprinklers are a form of crisis management, measures for preventing the spread of damage if a fire breaks out. I think you would choose a hotel with emergency exits and sprinklers rather than one that relied solely on fire prevention measures, however thorough such measure were. Fire risk management alone is not enough, and safety measures should also include crisis management in case a fire breaks out.

Safety measures of nuclear power plants

Nuclear power plants implement safety measures based on the concept of multiple safeguards. While Japan works on the principle of three levels of safeguards, international safety standards such as those of the IAEA (International Atomic Energy Agency) incorporate five levels of safeguards.

To prevent severe accidents such as the meltdown of a nuclear reactor, Japanese standards set out risk management to be conducted at different levels: fail safe systems, inter lock systems, and backup systems at level one (preventing an occurrence of a malfunction); reactor trip etc. at level two (preventing the spread of a malfunction); installation of emergency core cooling systems, reactor containment facilities etc. at level three (mitigating the effects in the event of an accident.) However, these standards do not cover crisis management in the event of a severe accident.

In addition to such risk management measures for preventing severe accidents, however, international safety standards such as those of the IAEA also govern crisis management at nuclear reactors in case a severe accident occurs (level four) and crisis management in the areas surrounding a nuclear power station where a severe accident has occurred, such as emergency evacuation (level five).

The debate about safety checks when restarting Oi Nuclear Power Plant seems to rest solely on the effectiveness of measures for preventing a severe accident (risk management), that is, whether an event like the Fukushima nuclear disaster can definitely be prevented. Japan's nuclear safety standards are still nowhere near international safety standards so long as there is insufficient specific verification between our power companies, related local governments, and national government about the effectiveness of the power companies' response measures to a nuclear reactor which is in meltdown (level four) and the effectiveness of securing evacuation means for neighboring residents (level five), as covered by international safety standards.

Safety should be judged by crisis management

As shown in the example of a hotel without emergency exits or sprinklers, the adequacy of safety measures should be judged by whether there is adequate crisis management for when risk becomes a reality.