Lessons in process safety from Fukushima

The Fukushima nuclear accident continues to unfold. There are lessons to be learnt in process safety from the accident:

1. Were your assumptions for the the worst case scenario correct? (The Fukushima plant suffered from both the earthquake and tsunami). The question I have asked is difficult to answer correctly because during the determination of worst case scenario, nothing bad has happened as yet and this will be weighing heavily on the minds of the decision makers. In other words, they may be wondering, why spend money on something that has never happened? The key word is "Never". How do you decide on probability of an event happening? Is your basis right? Are they supported by data?
2. Are the set points of your automatic shutdown systems correct? (In the Fukushima accident, though some of the operational reactors automatically shutdown once seismic activity was detected,  residual heat continued to be generated) 
3. Are your back up systems truly "back up"? There was no passive cooling water system available at Fukushima that would work even though cooling water pumps failed. It is reported that now in Indian nuclear reactors, authorities are planning to provide automatic shutdown for all reactors for seismic activity at a much lower setpoint than what the reactors are designed for. They are also thinking of providing batteries as power back up and connections for hook up of portable cooling water systems.
4. I am sure that there will be also lessons to be learnt in disaster management once the full details of the accident are out.

But we should not forget one thing - if it could happen in Japan, which is most technologically advanced and disciplined, we in India should be much more careful and conduct a thorough review of disaster preparedness.