1 00:00:00,120 --> 00:00:01,920 Speaker 1: This Day in History Class is a production of I 2 00:00:02,040 --> 00:00:06,440 Speaker 1: Heart Radio. Hey everyone, it's Eaves again and welcome to 3 00:00:06,480 --> 00:00:09,600 Speaker 1: another episode of This Day in History Class, a podcast 4 00:00:09,640 --> 00:00:11,920 Speaker 1: that brings you a little bit of history every day. 5 00:00:14,120 --> 00:00:28,200 Speaker 1: Today is March. The day was March nineteen seventy nine. 6 00:00:29,120 --> 00:00:31,760 Speaker 1: A failure in a reactor at the Three Mile Island 7 00:00:31,880 --> 00:00:36,879 Speaker 1: Nuclear Generating Station lead to a partial meltdown. It was 8 00:00:36,920 --> 00:00:41,360 Speaker 1: the worst nuclear disaster in US history. Three Mile Island 9 00:00:41,440 --> 00:00:44,800 Speaker 1: was a nuclear power plant in London Dairy Township, Pennsylvania. 10 00:00:45,400 --> 00:00:50,360 Speaker 1: The plant had two pressurized water reactors. Unit one went 11 00:00:50,360 --> 00:00:53,760 Speaker 1: into service in nineteen seventy four and Unit two began 12 00:00:53,840 --> 00:00:57,800 Speaker 1: operation at the end of nineteen seventy eight. On March 13 00:00:58,480 --> 00:01:01,760 Speaker 1: nineteen seventy nine, the Unit one reactor was shut down 14 00:01:01,840 --> 00:01:05,600 Speaker 1: from a refueling outage. Wild Unit two was operating at 15 00:01:05,680 --> 00:01:10,319 Speaker 1: nine power. A failure caused the feet water pumps to 16 00:01:10,440 --> 00:01:14,080 Speaker 1: stop sending water to the steam generators that removed heat 17 00:01:14,120 --> 00:01:17,800 Speaker 1: from the reactor core. This triggered the shutdown of the 18 00:01:17,840 --> 00:01:21,760 Speaker 1: turbine generator, and because the steam generators weren't getting fee water, 19 00:01:22,120 --> 00:01:25,720 Speaker 1: the temperature in the primary coolant rows. This caused the 20 00:01:25,720 --> 00:01:29,959 Speaker 1: reactor to go into an emergency shut down. Also, the 21 00:01:30,000 --> 00:01:33,400 Speaker 1: pressure was rising in the primary loop. To control the pressure, 22 00:01:33,560 --> 00:01:36,520 Speaker 1: the pilot operated relief of valve on the reactor cooling 23 00:01:36,560 --> 00:01:40,199 Speaker 1: system opened as it was supposed to, but it stayed 24 00:01:40,240 --> 00:01:43,440 Speaker 1: open after it should have closed, and coolant water continued 25 00:01:43,480 --> 00:01:47,360 Speaker 1: to escape from the relief of valve. Because instruments in 26 00:01:47,360 --> 00:01:51,080 Speaker 1: the control room indicated that the valve was closed, operators 27 00:01:51,120 --> 00:01:54,240 Speaker 1: did not realize that coolant water was still being released. 28 00:01:55,320 --> 00:01:58,520 Speaker 1: Due to the loss of coolant water, high pressure injection 29 00:01:58,560 --> 00:02:02,120 Speaker 1: pumps sent replacement water water into the reactor system. As 30 00:02:02,160 --> 00:02:05,800 Speaker 1: the water level rose in the pressurizer, operators decided to 31 00:02:05,840 --> 00:02:09,040 Speaker 1: reduce the flow of replacement water because they thought the 32 00:02:09,080 --> 00:02:13,240 Speaker 1: reactor system was too full of water. The reactor coolant 33 00:02:13,240 --> 00:02:16,400 Speaker 1: pumps began to vibrate, so the operators shut them down. 34 00:02:17,000 --> 00:02:20,639 Speaker 1: This stopped forced cooling of the reactor core. The core 35 00:02:20,760 --> 00:02:24,880 Speaker 1: in turn overheated as reactor coolant water boiled away. The 36 00:02:24,919 --> 00:02:28,520 Speaker 1: fuel rods were damaged, and they released radioactive material into 37 00:02:28,560 --> 00:02:32,720 Speaker 1: the coolant water. Operators continued to attempt fixes based on 38 00:02:32,760 --> 00:02:36,320 Speaker 1: their training, but hundreds of thousands of gallons of radioactive 39 00:02:36,360 --> 00:02:40,480 Speaker 1: coolant water had been released. Radioactive gases were sent into 40 00:02:40,520 --> 00:02:44,720 Speaker 1: the atmosphere from the ventilation stack of an auxiliary building. Initially, 41 00:02:44,800 --> 00:02:48,160 Speaker 1: officials believed that there may be a big hydrogen explosion 42 00:02:48,600 --> 00:02:52,519 Speaker 1: and that a meltdown was possible. The governor of Pennsylvania 43 00:02:52,560 --> 00:02:56,440 Speaker 1: recommended pregnant women and young children evacuate the area within 44 00:02:56,480 --> 00:03:00,400 Speaker 1: a five mile radius of the plant. People panic, and 45 00:03:00,440 --> 00:03:04,239 Speaker 1: within days tens of thousands of people had fled the area. 46 00:03:04,840 --> 00:03:09,160 Speaker 1: Schools and businesses closed, but officials said that the small 47 00:03:09,200 --> 00:03:13,079 Speaker 1: amount of radiation that was released had no measurable adverse 48 00:03:13,120 --> 00:03:15,520 Speaker 1: health effects on people who lived near the three Mile 49 00:03:15,560 --> 00:03:21,240 Speaker 1: Island facility. Still, the accident energized anti nuclear sentiment and 50 00:03:21,360 --> 00:03:26,079 Speaker 1: lead to new regulations in the nuclear power industry. For instance, 51 00:03:26,200 --> 00:03:30,119 Speaker 1: there were changes to standards for nuclear plant design, inspections 52 00:03:30,120 --> 00:03:35,840 Speaker 1: were expanded, and emergency preparedness requirements were strengthened. Many people 53 00:03:35,880 --> 00:03:39,880 Speaker 1: have claimed over the years that nuclear radiation contamination did 54 00:03:39,960 --> 00:03:42,680 Speaker 1: have an effect on the physical health of local residents. 55 00:03:43,640 --> 00:03:47,000 Speaker 1: Unit two was too damaged to continue operating. Clean up 56 00:03:47,040 --> 00:03:51,040 Speaker 1: officially ended in nineteen. Unit one went back online in nine, 57 00:03:52,040 --> 00:03:54,320 Speaker 1: but it was shut down for a good in twenty nineteen. 58 00:03:55,640 --> 00:03:58,200 Speaker 1: I'm each Jeffcote and hopefully you know a little more 59 00:03:58,200 --> 00:04:01,880 Speaker 1: about history today than you did yesterday. 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