change protactinium-234 to: protactinium-234mchange 77,000 years to: 75,000 years

change lead or iron to: lead or thallium-205

change The Japan Academy of Science to: the Science Council of Japan

change The Japan Academy of Science to: the Science Council of Japan

change Sea of Japan to: Pacific Ocean

Delete two sentences: The chain reaction in the reactor core continued to generate heat, albeit it less…nuclear fuel began to melt. Replace with: Although the chain reaction had terminated, the radiation from the fission products in the core continued to release enough energy to act as if the reactor was still operating at about 7 percent of full power. As there was no circulating water to remove this heatthe reactors overheated and there was an explosion.

in dates for Morgan change 1886 to: 1866

change a RNA to: an RNA
change radiation forces to: radiation levels

The number after Denver in the chart should be 4, not 7.

change cumulative effective dose to: collective effective dose