The crisis at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant does not warrant optimism. Nuclear fuel in the cores of the No. 1, No. 2 and No. 3 reactors is believed to have been severely damaged. In the No. 4 reactor's storage, where spent nuclear fuel is kept, water evaporated at one point, and a hydrogen explosion released radioactive substances into the environment.

The government should pay close attention to proposals made by 16 Japanese experts on nuclear power engineering, nuclear physics and radiology on April 1. It should mobilize all available means to mitigate the crisis.

Tepco is cooling the reactors by pumping water into them by using pumps connected with external power sources. But it cannot stop highly radioactive water from flowing out of the reactors. The more water it pumps into the reactors, the more contaminated water flows outside. Apparently, components for containing radioactive water have been damaged. The No. 2 reactor's suppression pool is feared to have cracked.