The unused and spent fuel units were relocated remotely due to high radiation levels in the reactor. Units number 1, 2 and 3 suffered meltdowns following the March 11 earthquake and tsunami in 2011. A hydrogen explosion occurred inside reactor number 4, but not a meltdown. All of the 1,535 fuel assemblies at reactor number 4 were removed in December 2014.

Removal of the fuel rods is an essential part of the decommissioning process, which is said to take 30 to 40 years. 1,700 fuel units remain in the first and second reactor. TEPCO plans to begin transporting the units from the two reactors as early as fiscal 2027 and 2024, respectively.