Note the reference to NEI’s Understanding Radiation booklet below. You can get a pdf of it here.
UPDATE AS OF 1:30 P.M. EDT, MARCH 24
In a sign of progress, Tokyo Electric Power is working to switch from sea water to borated fresh water to cool uranium fuel at three reactors at the Fukushima Daiichi nuclear power plant.
All reactors now have access to offsite power, and work is under way to inspect, repair and connect equipment needed to cool the reactors. Testing by Tokyo Electric Power Co. indicates that many pumps are inoperable because of flood damage.
Restoring regular cooling to the used fuel pools at Fukushima Daiichi remains a high priority. The used fuel pools at reactors 5 and 6 are being cooled using heat removal systems with electric power. Workers continue to spray seawater on the reactor buildings and spent fuel pools at reactors 1, 3 and 4. Additional cooling water to the spent fuel pool is being supplied by a fire hose connection.
Overnight, steam was rising from the secondary containment buildings that house reactors 1 through 4.
Radiation dose rates at the site boundary range from 1 to 3 millirem per hour.
NEI has updated the brochure “Understanding Radiation: Its Effects and Benefits,” which includes facts about monitoring and protection against radiation.