The probabilities are perhaps easier to understand with the last day of the month as the reference point for the present. If 29 days have passed without a lightning strike, the likelihood of a lightning strike today is 100%.These insights should tell safety engineers that the time to act on mitigating a risk is right now. The greatest error is to kick the can down the road on the assumption that it probably won’t happen anytime soon. Other common mistakes are to think that the risk assessment is flawed and to hope that new research done with favorable methodology will provide a reason for inaction and not spending money on the problem.
Environment News Service 23 Nuclear Power Plants at High Risk of Tsunami. September 24, 2012