WEBVTT 00:00.000 --> 00:04.160 JUDY WOODRUFF: Ukraine gets much of its electricity from nuclear power. 00:04.160 --> 00:09.160 And a series of Russian attacks near nuclear plants over the last two weeks 00:09.200 --> 00:13.520 are elevating fears of potential accidents and what they could trigger. 00:13.520 --> 00:14.897 John Yang has the latest. 00:14.897 --> 00:17.920 JOHN YANG: Judy, the latest warnings come from Ukrainian authorities, 00:17.920 --> 00:22.800 who say Russian attacks have left Chernobyl disconnected the power grid. 00:22.800 --> 00:27.800 Chernobyl, as many know, is the site of the world's worst nuclear accident in 1986. 00:28.480 --> 00:33.480 And while it's no longer generating electricity, it still stores spent nuclear fuel, which must be 00:34.640 --> 00:39.640 cooled. There are emergency generators providing power to do that, but they run on diesel fuel 00:40.720 --> 00:45.720 and only had a 48-hour supply. And, last week, a training area near another nuclear 00:46.800 --> 00:51.800 plant in Ukraine, the largest one in Europe, briefly caught fire during a Russian assault. 00:52.480 --> 00:54.560 Science correspondent Miles O'Brien, 00:54.560 --> 00:58.560 who covered the aftermath of Chernobyl and other nuclear accidents, joins us now. 00:58.560 --> 01:03.560 Miles, the name Chernobyl, of course, haunts any discussion of nuclear power. 01:03.920 --> 01:06.320 What's the real threat of what's happening there now? 01:06.320 --> 01:09.360 MILES O'BRIEN: John, I think we have to put it in perspective. 01:10.000 --> 01:15.000 The nuclear fuel we're talking about there is old and cold. The last operative reactor 01:16.000 --> 01:21.000 at Chernobyl closed down in 2000. Yes, there are 20,000 spent fuel rods in a pool 01:23.280 --> 01:28.280 there slowly cooling down, but each of them has about the equivalent of 35 watts, 01:29.760 --> 01:34.720 or a night-light, to them. And so, if you left them in that pool of water for a week, 01:35.280 --> 01:40.280 it might -- without doing anything to it, it might get to the temperature of a warm bath. 01:40.560 --> 01:45.560 Now, as for the actual melted-down portion of Chernobyl, where the real trouble occurred 36 01:46.000 --> 01:51.000 years ago, there's no power or water required to keep it safe. It's inside a shelter. 01:51.600 --> 01:55.360 JOHN YANG: But there are operations still going on, decommissioning operations. 01:55.360 --> 02:00.360 What are the options of restoring power to Chernobyl? And why would the Russians want to 02:00.400 --> 02:05.400 be in that area, which is uninhabitable because of contamination from radioactive materials? 02:06.480 --> 02:07.840 MILES O'BRIEN: It's a good question. 02:07.840 --> 02:12.000 There are a couple of other connections to the grid which could be reactivated, one inside 02:12.000 --> 02:17.000 Ukraine, one which comes from Belarus, which was turned off right before the invasion. So, 02:19.120 --> 02:23.600 you could get the power on there fairly quickly, in theory, and there are a few 02:23.600 --> 02:27.440 hundred people who work there. And, on a good day, it's a dark and dank place to work. 02:28.080 --> 02:31.280 Strategically, it makes good sense for the Russians to be there. 02:31.280 --> 02:34.240 It's north of Kyiv, straight shot into the capital, 02:34.880 --> 02:39.360 and there is a sophisticated electrical switching station there which they may want to control. 02:39.360 --> 02:42.480 JOHN YANG: Miles, you have been to that area. What's it like? 02:42.480 --> 02:46.480 MILES O'BRIEN: Well, it's 1,000 square miles of mostly nothing, 02:47.040 --> 02:51.760 and then this plant, this surreal abandoned plant in the middle of it. 02:52.560 --> 02:56.960 Some old people have held on and are still living there. I remember talking to an elderly 02:56.960 --> 03:01.440 woman living in her house, asking her why she didn't move. She said she was more worried about 03:01.440 --> 03:06.440 the roof falling on her head than the possibility of radiation exposure. 03:07.040 --> 03:12.040 What has happened, interestingly, is, it's become, some would suggest, sort of an ironic 03:12.160 --> 03:16.560 Garden of Eden, a lot of wildlife there. But a lot of scientists would tell you 03:16.560 --> 03:21.360 there's been all kinds of genetic mutations making the wildfire there not so healthy. 03:21.360 --> 03:26.360 JOHN YANG: Ukraine does rely heavily on nuclear power for its electricity. 03:26.720 --> 03:30.240 A number of nuclear power plants across the country. 03:30.240 --> 03:35.240 What is the danger or how dangerous is it to have a battlefield like this? 03:35.360 --> 03:38.240 MILES O'BRIEN: Yes, this is where you get into the nightmare scenario. 03:38.240 --> 03:42.640 There are 15 operative reactors there. And if you cut off power to one of them, 03:42.640 --> 03:47.640 you could march down the road to a Fukushima scenario. You need water flowing over the hot core 03:50.400 --> 03:55.400 of these operating plants in order to keep them from melting down. Since Fukushima, 03:55.680 --> 04:00.680 plants all over the world have bolstered their defense in depth to try to insure against this. 04:01.520 --> 04:05.920 But we're not exactly certain how well-defended these plants are. 04:05.920 --> 04:09.200 John, this is unprecedented. We cannot think of another time 04:09.200 --> 04:13.840 in history when nuclear power plants have been caught in the crossfire of war. 04:13.840 --> 04:18.240 JOHN YANG: Earlier in the program, we heard the Ukrainian ambassador to the 04:18.240 --> 04:22.960 United States tell Judy that monitors have been disabled at Chernobyl and some other plants. 04:22.960 --> 04:25.200 What are the dangers? What's the threat of that? 04:25.200 --> 04:29.520 MILES O'BRIEN: Well, it's always good to have visibility of what's going on at Chernobyl, 04:29.520 --> 04:34.400 in case things don't become stable. Right now, it is relatively stable. 04:35.040 --> 04:39.440 But the sensors that are there from the International Atomic Energy Agency 04:40.080 --> 04:42.800 are -- many of them are remote. They're solar-operated. 04:42.800 --> 04:47.680 And the data comes back on cellular networks. And, of course, if the power grid is down, 04:47.680 --> 04:52.680 there's no cellular transmission. So, right now, we're a little bit blind about Chernobyl. 04:53.200 --> 04:57.760 And that's kind of a scary thing to say on the face of it. But the experts tell me, 04:57.760 --> 05:02.640 because it hasn't been operating for 22 years, we need to temper our concern. 05:02.640 --> 05:05.760 JOHN YANG: Science correspondent Miles O'Brien, thank you very much. 05:05.760 --> 05:09.840 MILES O'BRIEN: You're welcome, John.