A few questions

Submitted by Anonymous on Mon, 2011-03-28 20:13

1) Are any of the radioactive isotopes released from nuclear plants naturally found in air, water and/or food?

2) When you say that we would have to drink many 100's of liters of water to receive the same amount of radioactive exposure as flying once across the US, does this also mean that we would be exposed to the same radioactive isotopes whilst flying as we are from a nuclear power plant meltdown? If not, why do you say it is the same? Is the amount of exposure more important than the type of exposure?

3) Are TEPCO trying to salvage their reactors or is what they are doing, the first steps to permanently decommissioning the reactors?

Also, I would like to thank you for providing this service to the community. It is extremely difficult to find such useful information anywhere else.

‹ Radioactive rainwater recorded on east coast and level is "comparable to findings in California"? Produce testing ›

1) None of these radioactive

Submitted by bandstra on Mon, 2011-03-28 23:17.

1) None of these radioactive isotopes we are measuring are found naturally. They are products of nuclear fission. Naturally-occurring radioactive isotopes like K-40 and U-238, the signatures of which we see in our detectors all the time, were generally formed during supernovae explosions long before the solar system itself was formed. They only persist because their radioactive half-lives are very long (~billions of years). As a comparison, the longest half-life of any of the isotopes from Japan is 30 years (Cs-137). If these isotopes are ever detected, it is an unequivocal sign of very recent nuclear fission (e.g., release from a nuclear reactor).

2) As you can guess from the answer to #1, you are never exposed to these isotopes unless there is a release of radioactive material from a nuclear power plant. However, you are constantly exposed to natural background radiation that is similar but not exactly the same in energy. The dose you get from a particular radioactive isotope depends on the type of radiation and the energy of the radiation, but these different properties are normalized for each isotope into an "equivalent dose" so that the dose can be compared with doses from other sources (e.g., a plane flight). Please see our FAQ on dose comparisons for more information on this.

3) TEPCO gave up any plans to ever use those reactors again when they pumped in seawater to cool them.

It is our pleasure to provide this information. Thank you for your comments.