Japan’s Radiation Scare: The Good News and the Bad
Japan’s Radiation Scare: The Good News and the Bad (NYRB blog).
What accounts, then, for the appearance of iodine-131 but not large quantities of cesium-137? The waste in these pools is stored for long periods of time. This means that the shorter lived isotopes such as iodine 131 decay away but the cesium-137 remains. Indeed there is about as much cesium-137 stored in the pools as there is in the core of the reactor. Now you see why this news about the iodine was good. It means that the radioactive emission from the reactors was coming from the reactors themselves and not the pools. (A small amount of cesium was released from the core of the reactor, but it has not been found in any quantity far from the plant and is negligible compared to the amount that could be emitted from the pools.) It is clear that putting water into these pools to cool them after the accident was touch and go. If that had failed it would have been a calamity. If this situation persists we may be looking at an accident less from the point of view of seriousness like Chernobyl and more like Three Mile Island. These two accidents were produced by human failures and not an act of God like an earthquake. (underlined by myself)
So, actually Defence Minister Kitazawa was right.