UPDATE AS OF 1:30 P.M. EDT, MARCH 27:
U.S. Navy barges carrying 500,000 gallons of fresh water were nearing the Fukushima Daiichi nuclear power plant Sunday as workers continued to pump cooling water into reactors and spent fuel pools.
Beginning Friday, workers began to switch from sea water to fresh water to cool reactors 1, 2 and 3. The arrival of the barges will maintain the fresh water supply. Engineers are concerned that continued use of sea water will cause corrosion inside the reactors and hinder the cooling process.
Dose rates at the site boundary continued to range from 1 to 3 millirem per hour (10-30 microSieverts per hour).