Disaster preparedness for government agencies and others is increasingly involving more actual disaster prevention. It falls under "mitigation", which in the past has mostly been picking up the pieces afterwards.
It sometimes involves things as simple as encouraging people not to rebuild their homes where they will be destroyed in predictably repeated disasters. One mitigation technique that I particularly liked was building reinforced safety platforms that allow people who can't run fast enough to avoid flooding to go there. They have more time to be gotten to safety by boats or helicopters once they reach the safety platforms.
It can involve getting uncooperative nuclear power plant operators to build in safety margins that are greater than ten feet higher than maximum historical flooding. This has not been done in some USA nuclear power plants yet. The ten foot safety margin is not going to cut it indefinitely, because climate change guarantees that we can expect more water in floods in areas of the country that contain nuclear power plants.
The Japanese have been making serious changes to protect themselves from more disasters. These changes involve all parts of their society working together. This has not been an easy process for them. Their bureaucracies and traditions have been more "set in concrete" than comparable ones in the USA.
Containment pools in US nuclear power plants typically hold a lot more nuclear waste than the ones that caused the problems in Japan. That means that when we have a disaster with our power plants it will be much worse than the one in Japan.
I would hate for the USA to have a large nuclear disaster before it begins to take commonsense measures to protect itself.