The Tokyo Electric Power Company Holdings said it will need 12 to 15 years of preparation – or until 2037 or later – before starting the full-scale removal of melted fuel debris.

No abnormalities in plant parameters or equipment have been noted thus far, according to Tokyo Electric Power Company.

Workers at Japan's embattled Fukushima nuclear plant were evacuated earlier on Wednesday after tsunami warnings were issued across the country. The plant's operator said all 4,000 of its workers had been evacuated, adding that there were no "abnormalities" detected.