NEW : Commander : ` ` We are being very conservative in our recommendations '' The Navy is limiting outdoor activities and installing ventilation systems . The Navy says the radioactivity detected comes from the nearby Daiichi plant . Workers at the plant are scrambling to avoid a full meltdown .
NEW : Commander : `` We are being very conservative in our recommendations '' The Navy is limiting outdoor activities and securing ventilation systems . The Navy says the radioactivity detected comes from the Fukushima Daiichi plant . Workers at the plant are scrambling to prevent a full meltdown .