Japan on Monday ushered in what regulators call the world's toughest safety standards for atomic power plants, determined to prevent another disaster like the March 2011 meltdowns at Tokyo Electric Power Co.'s Fukushima No. 1 complex.

But the Nuclear Regulation Authority, power utilities and the government still have much to do to reassure the public that the country is now ready to shift back into high gear and bring its idled reactors back online.

Under the new standards, reactors will be equipped with dozens of additional functions that hadn't been required in the past to deal with various situations, including reactor core meltdowns, tsunami hazards and acts of terrorism.