The area within the 8-kilometer radius from Fukushima II (Daini) Nuclear Power Plant has been designated as "evacuation" zone following March 11 earthquake/tsunami and the residents have been evacuated. The Japanese government has decided to abolish that zone by the year-end, paving the way for the residents of Okuma-machi, Naraha-machi, Tomioka-machi, and Hirono-machi to return.
Never mind that Okuma, Naraha, Tomioka also happen to fall within the 20 kilometer-radius "no entry" zone for Fukushima I (Daiichi) Nuclear Power Plant.
From Fukushima Minyu, a local newspaper in Fukushima (12/14/2011):
The Nuclear and Industrial Safety Agency under the Ministry of Economy, Trade and Industry told the municipalities within the 8-kilometer radius "evacuation" zone around Fukushima II (Daini) Nuclear Power Plant on December 13 that the evacuation order would be lifted shortly.
According to the people involved, the national government is to indicate its thinking about how to redesign the "no-entry" zone within the 20-kilometer radius from Fukushima I Nuke Plant and the "planned evacuation" zone [between 20 and 30-kilometer radius] before the year-end. The "no-entry" zone for Fukushima I includes the evacuation zone for Fukushima II. By lifting the evacuation order for Fukushima II first, the government may be trying to create a favorable environment in which to revise the "no entry" zone for Fukushima I.
Revision of the evacuation zones is to be carried out by the national government on the completion of the "step 2" of the roadmap to recovery of the Fukushima I Nuclear Power Plant. The plan seems to be that the no-entry zone will be reorganized into three different zones depending on the cumulative [external] radiation exposure levels per year. If the annual cumulative radiation exposure is to be 50 millisieverts and above, the areas will be designated as "difficult to return for a long time"; the areas between 20 and 50 millisieverts as "restricted residence", and the areas below 20 millisieverts as "preparing for return". The national government is said to have been discussing with the municipalities affected, and to disclose its thinking before the year-end.
To be more precise, in practical terms, on the "declaration" of the completion of the step 2, whether the so-called "step 2" has been achieved or not. As long as you declare.
According to Yomiuri Shinbun (12/15/2011) on the subject, a NISA official told the mayor of Tomioka-machi the reason for lifting the evacuation order as Fukushima II fully prepared for disaster with "external power source secured and emergency generators equipped".
The mayor of Naraha-machi has been itching to restart Fukushima II Nuclear Power Plant and get "genpatsu (nuke plant)" money flowing again. He may get his wish soon.
When the national government talks about "radiation" in these areas, it is talking about external radiation only, and at 1 meter off the ground. The latest survey result (12/13/2011) by the Ministry of Education and Science is here.