the helicopter of the self-defense forces in rikuzentakata in iwata prefecture. the massive earthquake has also damaged two nuclear power plants in fukushima prefecture. air has been released from the plants to ease the mounting pressure, but high levels of radioactivity have forced the fukushima number one plant to suspend the release. radiation at the fukushima number one plant rose tie level 1,000 times higher than unusual the central control room at one point. the rising pressure poses a threat to the containment vessel. japan's nuclear and industrial safety agency says the operation to release air from the react boers gan before 9:00 a.m. local time on saturday. the valves to release the air have to be operated by hand but the radioactivity at one valve was too high to ensure the safety of workers. the agency is now considering other options, including rotating the workers frequently to limit their exposure and operating the valve by remote control. the agency says the release air -- the released air poses no risk to people outside the ten-kilometer evacuatio