SNIP

>keep it in perpective. At Chernobyl the actual reactor was running at full power during a poorly planned test and exploded. The graphite in the reactor then caught fire . Nothing approaching that is happening in Japan.

I haven't heard any news reports from state departments telling citizens to evacuate Tokyo. Only those within the 50 mile radius of the site. This is an interesting article on the overall situation over time:

Special report - Mistakes, misfortune, meltdown: Japan's quake:
http://uk.reuters.com/article/2011/03/17/uk-japan-quake-meltdown-idUKTRE72G66420110317?pageNumber=1

Statements by the U.S. Department of State:
http://www.state.gov/r/pa/prs/ps/2011/03/158459.htm

Snippet:

Despite the best efforts of responders, the situation remains very serious. Given the situation, we recommended the evacuation of American citizens to at least 50 miles, in keeping with the guidelines applied in the United States. Since the continued or increased release of windborne radioactive material cannot be ruled out, American citizens in Japan are advised to take prudent precautions against potentially dangerous exposure. As a general matter, residents in areas further from Fukushima Prefecture face less risk of significant exposure, but changing weather conditions and wind direction means that radiation levels in the future might become elevated.

The Department of State urges American residents in Japan to take prudent precautions against the risk of sustained exposure, including relocating for potentially affected areas in northeastern Japan. The Department of State has authorized the voluntary departure, including relocation to safe areas within Japan, for family members and dependents of U.S. Government officials who wish to leave northeast Japan. The U.S. Government is also working to facilitate the departure of private American citizens from the affected areas – that is a 50-mile radius of the reactor – and a Travel Warning containing detailed information has been issued at www.travel.state.gov.

Interestingly, radiation detectors were triggered at airports in the U.S. by luggage of passengers arriving from Japan:
http://www.bloomberg.com/news/2011-03-17/tokyo-passengers-trigger-u-s-airport-detectors-n-y-post-says.html