1.   Radioactivity is induced in the metallic containment vessel that surrounds a reactor core by neutrons that escape from the core.

2.   The reactor core erupted in a gigantic explosion, spewing enormous amounts of heat and disintegrated radioactive fuel into the atmosphere.

3.   To protect power station workers from this invisible threat the reactor core has to be encased behind many metres of thick concrete.

4.   Leaks in primary circuits distributing heat from the reactor core would be uncontrollable, leading to a core meltdown.

5.   After numerous operator mistakes and miscommunications, coolant water was restored to the reactor core, bringing it under control.

6.   After that, there are the small matters of the overheating reactor core and malfunctioning central computer to deal with.

7.   By early evening, Nuclear Regulatory Commission officials received the results of an analysis that showed damage to the reactor core was more substantial than anticipated.

8.   He watched intently as a huge crane gradually lowered a four-ton steel cover into the containment pool and atop the gaping hole of the reactor core.

9.   In fact it was open, dumping coolant and causing a partial meltdown of the reactor core.