"Clearly they were not taking responsibility for the accident initially, and that has now changed," he said. He added, however, that he still thinks TEPCO is underestimating how difficult it would be to transform.
The reform plans apparently aim to use Fukushima's lessons at TEPCO's Kashiwazaki-Kariwa plant in northern Japan. The cash-strapped utility wants to restart that plant.
TEPCO was bitterly criticized for allegedly covering up or holding key information about meltdowns and radiation data.
Various investigative reports, including one commissioned by Parliament, blamed collusion between the regulators and the operator for a lack of safety culture, as well as for the lax supervision that allowed TEPCO to continue lagging behind in safety steps. The Parliament investigation called the accident "man-made."
U.S. nuclear regulatory chief Allison Macfarlane told the Associated Press on Friday that Fukushima's disaster highlighted the importance of a strong nuclear watchdog.
"In general, one of the important takeaways from the Fukushima accident is the importance of a strong, independent regulator that operates transparently and is well-funded and has the backing of the government," said Macfarlane, who is in Japan to attend this weekend's international conference on nuclear safety in Fukushima.
Until recently, Japan lacked an independent regulatory system. The regulator at the time of the accident was part of the industry ministry that promotes nuclear energy.
A more powerful and independent unit, the Nuclear Regulation Authority, launched in September. It is currently upgrading safety standards and evacuation guidelines.