In an acknowledgment of the seriousness of the crisis at the Fukusihima Daiichi nuclear plant, Japan has raised the alert level at its overheating nuclear reactors to five on a seven-point scale, placing it two rungs below Chernobyl and equal with Three Mile Island. Attempts to cool the Fukushima Daiichi nuclear reactors by throwing water at them from helicopters and fire hoses seems to be having little immediate effect. For the past two days, Japanese officials have focused on cooling the spent-fuel pool at the No. 3 reactor, but on Friday steam was seen rising form Reactor No. 2, and a senior nuclear industry executive said there appears to be damage and a possible leak at the spent-fuel pool at the No. 4 reactor. Meanwhile, the operator of the Fukushima plant said the utility was not ruling out burying the plant in concrete, a last-ditch effort that was used after the Chernobyl nuclear disaster. The good news is that the World Health Organization believes radiation from the plant has yet to spread far from the plant and remains too low to pose a health risk.