TOKYO — The utility operating Japan's crippled nuclear power plant said Friday that it would work with the U.S. Department of Energy in the decommissioning of the site and in dealing with contaminated water problems.

Tokyo Electric Power Co. President Naomi Hirose said he made the agreement with U.S. Energy Secretary Ernest Moniz as they visited the Fukushima Dai-ichi nuclear plant Friday to inspect preparations to remove fuel rods from a reactor.

The plant has recently had a series of mishaps, including radioactive water leaks from storage tanks. The incidents, many of them caused by human error, have added to concerns about TEPCO's ability to safely close down the plant, which suffered multiple meltdowns after being hit by the March 2011 earthquake and tsunami.

The plant is currently making final preparations to remove fuel rods from an uncontained cooling pool at Unit 4 — one of four reactor buildings damaged in the crisis, and the one considered the highest risk. Removing the fuel rods from the cooling pool is the first major step in a decommissioning process at the plant that is expected to take decades.

The fuel removal at Unit 4 was approved by Japanese regulators on Wednesday and is to start by mid-November.

Moniz, escorted by Hirose, inspected the Unit 4 pool area, as well as contaminated water storage tanks, radioactive water treatment units and other facilities at the plant.

The reactor building was damaged by hydrogen explosions, and remains a source of international concern about a catastrophic open-air meltdown in case of a pool collapse, despite TEPCO's repeated reassurance that it has reinforced the pool and that the building can withstand another major quake.