The announcement came after a magnitude-5.9 earthquake jolted Japan on Saturday morning, hours after the country’s nuclear safety agency ordered plant operators to beef up their quake preparedness systems to prevent a recurrence of the nuclear crisis.
There were no reports of damage from the earthquake, and there was no risk of a tsunami similar to the one that struck the Fukushima Dai-ichi plant March 11 after a magnitude-9.0 earthquake, causing Japan’s worst-ever nuclear plant disaster.
Since the tsunami knocked out the plant’s cooling systems, workers have been spraying massive amounts of water on the overheated reactors. Some of that water, contaminated with radiation, leaked into the Pacific. Plant officials said they plugged that leak on April 5 and radiation levels in the sea dropped.
But the government said Saturday that radioactivity in the seawater has risen again in recent days. The level of





