accident. three mile was very difficult. it was caused by operation error. this was following by a devastating earthquake and tsunami. nonetheless the nature of cooling the reactor was the same. three mile island was the expense x tense sieve meltings of the core. what we have to hope is there's a similar outcome on this occasion. any time you have a core melting there's a substantial increase for radio activity but there's no guarantee. >> you can find out more about the impact the earthquake has had on our website. i know you've got a lot of questions about that as have the rest of us. got in touch with a number of agencies to try to answer those queries. all of that is at cnn.com/international. we've been seeing images