I’ve got 42 years in the utility industry including a lead position for the site recovery team at Three Mile Island. One last time as I head out the door. The spent fuel pits are basically swimming pools with casks under water. Most plants have large tanks that will gravity feed into the pits. They will keep the pits cooled for a significant amount of time. Is it infinite no. However, there will be so many more pressing problems during an EMP this is no longer worth discussing.