FILE - Tokyo Electric Power Company Holdings, also known as TEPCO, the operator of Japan's wrecked Fukushima Daiichi nuclear power plant, reveals a robot to be used to retrieve debris at the power plant in Kobe, western Japan, May 28, 2024. (Kyodo News via AP, File)

This photo released by Tokyo Electric Power Company Holdings, shows the melted fuel debris sample collected by a remote-controlled robot and enclosed inside of a primary canister is being placed into another container to be moved to another location of the reactor for additional primary analysis at the Fukushima Daiichi nuclear power plant in Okuma, Fukushima, northern Japan Thursday, Nov. 7, 2024. (Tokyo Electric Power Company Holdings via AP)

This photo released by Tokyo Electric Power Company Holdings, shows a piece of melted fuel debris collected by a remote-controlled robot from inside of No. 2 reactor is being placed inside of a canister before it was closed and taken out of an enclosed compartment for further analysis, at the Fukushima Daiichi nuclear power plant in Okuma, Fukushima, northern Japan Wednesday, Nov. 6, 2024. (Tokyo Electric Power Company Holdings via AP)

A device to remove debris from a reactor at the damaged Fukushima Nuclear power plant demonstrates to pinch a stone, as revealed in Kobe, western Japan, May 28, 2024. (Kyodo News via AP, File)

This photo released by Tokyo Electric Power Company Holdings (TEPCO), shows a robot, top right, clips a tiny gravel of what it believed to be melted fuel debris at the No. 2 reactor of the Fukushima Daiichi nuclear power plant in Okuma, Fukushima, northern Japan, on Oct. 30, 3024. (Tokyo Electric Power Company Holdings via AP)