Regarding Michael Radcliffe's Sept. 20 letter, "Fear-mongering over fuel rods": It is refreshing in a sense to have someone say that spent nuclear fuel rods from a cooling pool that had collapsed or had become dry could "just lie in a pile" until someone came around to pick them up. Is Radcliffe ready to do so?

There are reasons that assemblies with their spent nuclear rods have to be kept two to six years under several meters of water; that, once their temperature cools to 200 degrees Celsius and they become less radioactive, they are usually kept for 10 to 20 years in another pool of water before reprocessing or dry-cask storage; that the rods have to be covered with water all of the time; that the water and the pool are treated and strictly controlled nonstop; and that, inside the pool, metal racks keep the assemblies carefully apart to avoid a nuclear chain reaction. Yes, if the rods are exposed, they may reach criticality, starting a chain reaction.

Inside a rod, which is the size of a pencil, you have small fuel pellets containing either uranium oxide or MOX (blend of uranium and plutonium oxides). And here's a new challenge: The rods are made of zircaloy, a highly flammable material whose combustion cannot be stopped with water. If an accident occurs and the rods lie around, say, the fourth reactor (of the Fukushima No. 1 nuclear plant), the heat will grow fast, the zircaloy will melt, then tons of uranium pellets will start to react. Nobody will dare go near, nobody will be able stay there, and the tragedy will soon extend to all the reactors and their pools. The plant will be out of control.

Radcliffe does not seem to like engineer Arnie Gundersen, although Gundersen merits respect as a whistle-blower who has given clear explanations on issues where the nuclear village had tried hard to keep things secret and confused.

Perhaps Radcliffe would prefer the opinion of professor Hiroaki Koide, one of the leading nuclear specialists in Japan. Well, Koide does not say anything different from Gundersen.

The opinions expressed in this letter to the editor are the writer's own and do not necessarily reflect the policies of The Japan Times.

janick magne