TOKYO (AP) — An outside investigation team appointed by the operator of Japan’s damaged Fukushima nuclear plant said Thursday that an instruction from the company’s then-president to avoid using the term “meltdown” delayed the full disclosure of the status of three reactors.
Tokyo Electric Power Co. described the condition of the three reactors as less serious “core damage” for two months after a March 2011 earthquake and tsunami destroyed the plant.
The panel of three TEPCO-commissioned lawyers said the company used the milder term despite knowing that the damage far exceeded its meaning, because of the instructions by then-President Masataka Shimizu. The report said he was apparently under pressure from the Prime Minister’s Office, but that the panel did not find direct evidence of that.
TEPCO reported to the authorities on March 14, 2011, that the damage, based on a computer simulation, involved 25 to 55 percent of the fuel but did not say it constituted a “meltdown,” the report said. The company’s internal manual defined a “meltdown” as a core condition with damage exceeding 5 percent of the fuel.
In May 2011, TEPCO finally used the description after another computer simulation showed fuel in one reactor had almost entirely melted and fallen to the bottom of the primary containment chamber, and that the two other reactor cores had melted significantly.
TEPCO has been accused of softening its language to cover up the seriousness of the disaster. But the investigation found TEPCO’s delayed acknowledgement did not break any law.
In the 70-page report, the lawyers said Shimizu instructed his deputy not to use the word “meltdown” during news conferences immediately after the crisis when officials were peppered with questions about the reactor conditions. TEPCO’s vice president at the time, Sakae Muto, had used the phrase “possibility of meltdown” until March 14, 2011.
Video of a news conference that day shows a company official rushing over to Muto when he was about to respond to a question about the conditions of the reactors, showing him a memo and hissing into his ear, “The Prime Minister’s Office says never to use this word.”
Yasuhisa Tanaka, the lawyer who headed the investigation, said interviews of 70 former and current TEPCO officials, including Muto and Shimizu, showed that Muto had planned to use the word “meltdown” until he saw the memo, which has since not been found.
“Mr. Shimizu’s understanding was the term ‘meltdown’ could not be used without permission from the Prime Minister’s Office,” Tanaka told a news conference at TEPCO headquarters. “The notion that the word should be avoided was shared company-wide. But we don’t believe it was a cover-up.”
The Nuclear and Industrial Safety Agency, Japan’s nuclear regulatory unit at the time of the accident, was also reluctant to use the word. Two spokesmen were replaced between March 12 and 13, 2011, after suggesting meltdowns had occurred.
Government and parliamentary investigations have suggested officials, seeking to play down the severity of the Fukushima Dai-ichi crisis, resisted using the term. Tanaka said his investigation, which did not interview government officials, could not track down what exactly happened between Shimizu and the Prime Minister’s Office.
The Prime Minister’s Office has denied putting any pressure on TEPCO and the safety agency over language. But previous investigations of the accident show it demanded they coordinate with the office and unify approaches before making any announcement.
TEPCO has said the delay in confirming the meltdown didn’t affect the company’s emergency response at the plant. Although the reactors have been stabilized significantly, the company is still struggling with the plant’s decades-long decommissioning.
Delays in the announcement of meltdowns surfaced earlier this year in a separate investigation in which TEPCO acknowledged that a company manual had been overlooked, reversing its earlier position that it had no internal criteria for a meltdown. TEPCO has eliminated the definition of a meltdown from the manual that was revised after the Fukushima accident.
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