Will be going to Japan on April 10?

Question:

Before the earthquake, tsunami and the whole nuclear crisis even came about, I had my itinerary confirmed already; Incheon (South Korea) to Los Angeles (USA), with a 24-hour stopover in Narita (Japan).

With all of these things going on, especially the radioactive exposures in some parts of Japan, what should I do? To reroute my stopover (if I do, I have to pay $1500 more just to reroute the stopover to Hong Kong), cancel my flight (all refunded but the $300 penalty fee) or just let it be?

Should I go out of Narita Airport (considering I will be in Japan for 24 hours, therefore I need to get myself a hotel/some place to stay in overnight)?

Also, I am holding an American passport. Will my passport be stamped for transit purposes?

Answer:

I'm staying in Japan for 2 months this summer leaving in April an the exchange program said that I will still be going at that date, so I think its fine if you stay in Japan I day.