What is a reactor meltdown?

Related questions

1. Why is Fukushima radioactive?
2. What caused Fukushima?
3. Could Chernobyl have been prevented?
4. How long will Fukushima radiation last?
5. Are the reactors in Chernobyl still active?
6. Is it safe to go to Fukushima?
7. What happened Trinoble?
8. Is Fukushima still evacuated?
9. Why is heavy water used as moderator?
10. How did they put out the fire in Chernobyl?

Tags

1. #overheating
2. #defined
3. #severe
4. #partial
5. #results
6. #nuclear
7. #agency
8. #regulatory
9. #atomic
10. #meltdown
11. #officially
12. #energy
13. #damage
14. #reactor
15. #commission
16. #accident
17. #international