He said 'is probably going to be' not 'has already been'.
There is plenty of suggestive evidence, like the nytimes article EScott11 referenced, showing cesium 137 contamination 200% of Chernobyl levels 25 miles from the plant, or the recent Greenpeace video where they max out their Geiger handhelds 35km from the plant, that there are going to be some fairly widespread consequences to the contamination of soil by radioactive material.
Maxing out a handheld geiger counter is misleading because they've got a sesitivity knob. A friend brought one to a party recently and showed everyone that their soda cans would max out the counter (at full sensitivity). Believe it or not, some people then refused to drink more soda because they thought it was contaminated. Better not bring them into a brick building!
There is plenty of suggestive evidence, like the nytimes article EScott11 referenced, showing cesium 137 contamination 200% of Chernobyl levels 25 miles from the plant, or the recent Greenpeace video where they max out their Geiger handhelds 35km from the plant, that there are going to be some fairly widespread consequences to the contamination of soil by radioactive material.