that s been seeping out. also the cold weather. it s starting to snow there. we want to just hunker down inside and make sure they re safe. again, broken dishes she was saying, the tv toppled over, going outside of their house for the first time, seeing the devastation. their neighborhood just demolished. some of the homes around them just leveled. and your grandmother had seen and also some fatalities. right. your grandmother saw bodies in the neighborhood. right. when they went outside initially after the quake, my cousin who works in the fukushima pref prefectu prefecture, they witnessed some bodies. it s a tight-knit community. as luck would have it, they installed a new water pumen on their property so they ve been able to get water. they ve been an oasis for that community. people coming by trying to get water. they ve been bringing by what food they could find. right now it s a big scramble. they did tell us that the power just came back on. the gas is on now.
need to stay inside, close the doors and windows and stay out of any potential harmful contact with the hazardous materials. all the while the fight continues to bring the situation under control, to cool the reactors. now the authorities are saying they will use helicopters to fly over reactor number four and try to dump water into that pool and solve the problem of the spent fuel rods. this is a situation that really is minute by minute. it is hour by hour. and watching on the people of japan who have been through so much since that earthquake really hit here and tore through the country, creating so much damage, loss of life and also this nuclear emergency. stan grant, cnn, tokyo. stan continues to report for us. chad is here to give us some explanation. we ll have to hear this and see this many times to understand. a lot of us in this country benefit from nuclear energy in the united states, about one-fifth of all of our electricity in the uts u.s. is generated by nuclear power.
have to make to go back into the reactor to make the steam go. they lost that water supply because the pumps that were pushing it in stopped because the reactor stopped. and then the backup generator stopped because the tsunami swum spaum ped them. that stopped the water from coming in, stopped the cooling. the water boiled out. all of a sudden the rods are sitting there. it s like draining ault the water out of your radiator in the car. take the car on the road. eventually your engine is going to melt down. that s what happened here. we didn t get a meltdown. we got escape of steam. we got something close. to get hydrogen and oxygen to separate, to see the explosion, you almost have to be 2,200 degrees in there. that s close to a meltdown. but thouey got water back in to stop the meltdown. by the way, they used sea water because that s what they
pure, pure water. that pure water boils off. it steams, causes huge amounts of pressure and the pressure goes out through that pipe. so these rods come in, they hit the water, they steam. yep. you have to be careful how much steam you make. they become up and down here with these control rods controlling how many neutrons are flying around in there, the control rods slow down the reaction. you take the control rods out, you get a lot of reaction and you have to it comes through here. now you have the turbines moving. do you need more or less power? is it day, night, more power or less power? you can do that by those rods. you spin it through here and you spin it through eventually it s still steaming here, goes into a condenser that is cooled by outside forces. opposite, it makes the steam back into water. it condenses it just like you put a glass of ice water on the bar. eventually you ll get a puddle of water. that s the puddle of water you
prospect of a hydrogen explosion. what s also worrying is that that contained a pool and in that pool was spent fuel rods. what they re concerned about is that the water may have evaporated and those spent fuel rods may have caught on fire. now, that also led to a spike in radiation around about the same time within the plant. it went to level that we haven t seen before throughout the crisis, levels that the authorities said posed a risk to humans. that was contained within the plant. in the hours since then, the levels have come down when measured just outside the perimeter of the plant. the prime minister naoto kan is warning we could see the radiation levels rise again in the coming days, now there is an exclusion zone of 20 kill meters, 200,000 people have been moved away from there. the prime minister saying people within a 30-kilometer radius