Workers in Japan are still struggling to limit environmental contamination at the Fukushima plant. The latest problem has been a break that is allowing heavily contaminated water flow directly into the ocean, a leak that has continued despite two attempts to plug it. Meanwhile, worries persist about the state of the reactor cores on the site.We'll start with the ocean. As we said in our previous coverage, all indications are that the cooling system for at least some of the reactors is no longer a closed loop. In order to keep the reactors cool, workers at the site are pumping prodigious amounts of water into the cooling system of some of the reactors, where it's either being vaporized into steam, or leaking back out; in either case, chances are good that it's coming in contact with the reactor core first, and will pick up radioactive isotopes then. (CNN indicates that reactor 2 has been receiving 200 tons of water a day.)
Currently, it seems that a lot of it is leaking out, creating highly radioactive pools of water on-site and making its way into the ocean through a damaged area of concrete. The high levels of radioactivity mean that humans can't work directly on the crack, making what would otherwise be a routine repair about as difficult as fixing an oil well on the bottom of the Gulf of Mexico. Workers have tried to patch the concrete twice but, so far, have only managed to reduce the flow of water slightly. The continued leakage means that, in the area around the damage, radiation levels have reached the point where exposure would be fatal in less than a day, and are millions of times the legal limit.
Leaks send radioactivity into ocean at Fukushima, cleanup to take years
