Updated

The Fukushima plant is located 150 miles away from Tokyo, 40 miles from the earthquake's epicenter.

- About 30% of electricity in Japan is produced by 55 nuclear power units in 17 plants
Japan is the world's third largest producer of nuclear power.

- The earthquake has led to the shutdown of 11 of the Japan's 55 nuclear power plants, representing nearly 20% of the country's capacity.

- The Fukushima Daiichi unit is just one of five reactors severely imperiled by the earthquake.

- The Fukushima plant covers about 865 acres and it is built on solid bedrock.

- Opened in 1971 -- the Fukushima Daiichi Nuclear Power Station (No.1) would be marking its 40th anniversary on March 26.

- Some 40,000 people had evacuated from the areas around two Fukushima plants as of Saturday afternoon, according to reports.

- Authorities evacuated a 12.5 mile radius around the reactor, and told residents within 16.5 miles to remain indoors.

- Virtually any increase in ambient radiation can raise long-term cancer rates.

- A partial meltdown in one of the light water reactors at Three Mile Island in 1979 resulted in the release of radioactive gases in the most serious incident in the history of the U.S. nuclear power industry.

(Source: "Japan Officials Probe Nuclear Plant Collapse," The Wall Street Journal: 12 March 2011)
(Source: "Damage to cooling system had sparked warning of meltdown," MarketWatch: 12 March 2011)
(Source: "Japan Officials Probe Nuclear Plant Collapse," The Wall Street Journal: 12 March 2011)
(Source: IAEA, http://www.iaea.org/cgi-bin/db.page.pl/pris.powrea.htm?country=JP&sort=&sortlong=Alphabetic)
(Source: "Explosion at Japan nuke plant, disaster toll rises," Associated Press: 12 Mar 2011)
(Source: "Explosion rocks Japanese power plant," The Washington Post: 12 Mar 2011. http://www.washingtonpost.com/wp-dyn/content/article/2011/03/11/AR2011031103673_4.html?hpid=topnews&sid=ST2011031100651)
(Source: "Fukushima nuclear plant blast puts Japan on high alert," Guardian Unlimited: 13 March 2011)