Shores are submerged in Natori city, Miyagi prefecture (state), Japan, after a ferocious tsunami spawned by one of the largest earthquakes ever recorded, slammed Japan's eastern coasts Friday, March 11, 2011. (AP Photo/Kyodo News) JAPAN OUT, MANDATORY CREDIT, FOR COMMERCIAL USE ONLY IN NORTH AMERICA
Authorities say the pressure is rising at a nuclear power plant in northeastern Japan after its cooling system failed.
Japan's nuclear safety agency says pressure inside the reactor at the Fukushima No. 1 power plant has risen to 1.5 times the level considered normal. To reduce the pressure, slightly radioactive vapor may be released.
The agency said the radioactive element in the vapor would not affect the environment or human health.
Japan has issued an evacuation order to about 3,000 residents living near the plant. The government also issued a state of emergency at the power plant.
The agency says plant workers are scrambling to restore cooling water supply at the plant but there is no prospect for an immediate success.