system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the nuclear power plant in Fukushima still not under control?
gpt
You need to define "under control"

Since a few moments after the seismic detectors felt the earthquake and shut down the reactor, the nuclear fission reaction has been completely stopped.

The problem with certain types of nuclear power, is the radioactive waste in the core keeps producing large amounts of heat for a long time and needs cooling.

The cores are cooled down to non-boiling temperatures and are 'under control'. They have been for a couple months and are working to clean up the radioactive contamination and decommission the plants.