TOKYO (AP) - An independent panel said the operator of Japan's tsunami-crippled nuclear plant misinformed investigators and blocked an inspection of key equipment last year, but that it was not part of a cover-up.
The case involves a parliamentary probe of equipment at the Fukushima No. 1 nuclear plant's Unit 1 reactor. An investigator said he and his fellow team members had to scrap an inspection of the reactor's emergency cooling equipment, accusing plant operator Tokyo Electric Power Co., or Tepco, of falsely stating that the building was dark and too dangerous.
The equipment - called an isolation condenser, which can function without electricity - is at the centre of a major controversy, with some experts suspecting that its failure might have been caused by the magnitude-9.0 earthquake on March 11, 2011, and not by the subsequent tsunami, as has been widely thought. The disasters destroyed power and cooling systems at the plant, causing multiple meltdowns, including at Unit 1.
The parliamentary investigators eventually released a report on Unit 1 that refers to possible earthquake damage to the equipment, and if proved would shake the current anti-quake measures at nuclear facilities nationwide, experts say.
After the scandal caused an outcry from lawmakers and the public, Tepco commissioned a panel last month to look into the matter. Tepco, which had quickly ruled out quake damage to the plant's key safety equipment, was accused of blocking the investigation to hide unfavorable evidence.
On Wednesday, the panel said it attributed the problem to a Tepco official's misunderstanding of the situation at Unit 1, and said the company was not trying to hide the equipment from the inspectors. The panel also said top Tepco officials were not involved.
"The explanation he provided did include false information. That, as a result, caused the parliamentary investigation team to give up part of its inspection, and we find it unforgivable," said Yasuhisa Tanaka, a lawyer who headed the Tepco-commissioned panel. "The company also should have made better preparations and explanations to accommodate the investigation team."