NIIGATA ( Kyodo) The head of a local advisory panel of experts on safety at a quake-hit nuclear power station in Niigata Prefecture resigned Friday after saying a day earlier that quake-caused damage at the plant was "an irreplaceable, invaluable experiment."

Kenzo Miya, visiting professor at the graduate school of Hosei University, made the remark at a press conference Thursday after conducting an inspection of the power plant in Kashiwazaki, Niigata Prefecture, that was hit by the magnitude-6.8 quake on July 16.

Miya offered his resignation Thursday night as the panel's chair for "personal reasons" and the prefecture accepted it, the local government said.

He had chaired the technology committee concerning safety management of Tokyo Electric Power Co.'s nuclear power station since the panel was started in February 2003. Miya specializes in reactor device engineering.

The earthquake has forced the nuclear plant, the world's biggest in terms of power generation capacity, to shut down indefinitely until the safety of its seven reactors is fully ensured.