The Nos . 1 and 3 reactors are prime concerns at the northeastern Japan plant . Like with No . 1 , there has been evidence of high radiation levels in spots in and around the No . 2 reactor -- though not as high as that of the No . 3 unit . Authorities are trying to determine the source of an apparent leak in reactor No . 3 . A man walks past a sign for Tokyo Electric Power Co.'s tsunami-crippled Fukushima Daiichi nuclear power plant, March 11, 2011 in Okuma, Japan.
The Nos . 1 and 3 reactors are prime concerns at the northeastern Japan plant . Authorities are trying to determine the source of an apparent leak in reactor No . 3 . A man walks past a sign for Tokyo Electric Power Co.'s tsunami-crippled Fukushima Daiichi nuclear power plant, March 11, 2011 in Okuma, Japan.