The head of a panel of international nuclear experts Friday played down the importance of the decision by Tokyo Electric to not use the term "core meltdown" in describing the situation at the Fukushima No. 1 nuclear complex in the early days of the March 2011 disaster.

"They were trying to bring the reactor into a safe situation," Dale Klein, head of the panel of five experts called the Nuclear Reform Monitoring Committee, which is overseeing Tokyo Electric Power Company Holdings Inc.'s nuclear safety efforts, said at a new conference.

"Their focus was on safety or safe operation, not necessarily a choice of words," he said.

Klein, a former U.S. Nuclear Regulatory Commission chairman, referred to the instruction by then-President Masataka Shimizu to not use the term "core meltdown," which was revealed in June by a third-party commission that had investigated the utility's handling of the nuclear disaster.

Klein said that U.S. nuclear regulators also "typically do not use the word meltdown."

On March 11, 2011, a powerful earthquake and tsunami crippled the seaside power station in Fukushima Prefecture, leading to nuclear meltdowns at three of the six reactors due to a loss of power.