A few examples of contamination that I have come across:
Chernobyl evacuation zone (over 1480 kBq/m2);
Sept 27 MEXT map from wide-area aerial surveys. Notable Cesium contamination 160km to southwest of the plant.
Sept 1 METI map, detailed groundlevel sampling of 2500 locations in the evac zone, with Okuma town having highest rate – over 700 mSv per year.
California + Pacific fallout modelling from CEREA… there is a groovy flash animation of the plume crossing the Pacific half-way down their page. Click thumbnails below to compare, roughly, plumes from Chernobyl and Fukushima, according to CEREA.
Some radiation details round Fukushima province, including the Cesium map from aerial surveys (below) and more distant places.
Radioactive cesium levels within 60km of Fukushima 1. From a US/Japanese aerial survey in May 2001. Note that after Chernobyl, the Soviets evacuated people from areas over 550 Bq/m2. The original US govt map was here .
Land-sea comparison: Organ dose to infants from ministry of education, March 25 Note this is a SPEEDI model based on known weather data and unknown total radiation release from the plant. The proportions of land/sea contamination are probably valid, the numbers may not be. Note that SPEEDI’s plume did not really match reality.
Plants with cesium levels over allowed limits, up to 350km from the Fukushima 1 This is by no means a complete list