The BBC had a "live feed" of a huge blazing fire, and the caption was "Government declares Nuclear Emergency".
The fire was at a natural gas storage tank...
I don't know if these news agencies like stoking mass panic, but you need to be a little sceptical about reporting in the media about "contentious" issues like nuclear power.
It's standard procedure in these situations to evacuate a 3km radius from the plant, just in case. If the situation gets slightly more... interesting (as in, they need to vent some steam), they evacuate 10km.
TL;DR: Let's wait and see what happens before declaring that Japan is about to be annihilated by nuclear fallout.