Is a school trip to japan safe?

Question:

in april i have been invited to join my high school japanese class in a 9 day trip to japan. i know this sounds ignorant, but, is it safe to go to japan (radiation wise)?
radiation is one of my biggest fears, any where, even X-rays scare the daylights out of me.
(mainly because you cant see, feel, or know you have been affected until you get like cancer in the future...)
but i really want to know for sure that i will be completely safe, i will be visiting tokyo, kyoto, and Nara.
i need to know for sure it is safe. thank-you.

Answer:

Safe as a trip to Hawaii ! There are no, and never has been a radiation problem in Tokyo. The only problem area is within a 20 km radius of the Fukushima nuke plant.
Tokyo, Kyoto & Nara are perfectly safe. Don't you think it would be in the news if they weren't safe ?
Go ! It's a once in a life time opportunity !