As we found with Fukushima, one of the major causes of meltdown is the loss of power.
Loss of power?? In a power plant? Funny, but yes. In the event of a disconnection from the power grid, a nuclear plant automatically shuts down because the massive power being generated has nowhere to go. When the generator shuts down, the only power source to keep the pumps flowing to keep the nuclear fuel rods cool comes from diesel generators. If those generators are not operational or run out of fuel, then a meltdown is eminent.
The obvious solution is to keep the reactor running at lower power levels and send the steam to run a smaller generator. Allow any unused portion of the steam to bypass the generator and be condensed and reused normally. The smaller generator would be able to power all the systems needed to allow the plant to run in a self-sustaining mode until the grid comes back up or indefinitely if necessary. No diesel generators would be necessary. Existing plants can be easily and inexpensively retrofitted.
It pains me to think that engineers haven’t come up with a similar plan that is both simple and elegant.
I give this idea freely to the internet in the spirit of making the world a better place.