April 26 1986 – Chernobyl Nuclear Power Plant Experiences a Meltdown

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*Image Credit: Wikimedia Commons In the western Soviet Union, 60 miles north of the Ukrainian capital Kiev, darkness exploded at 1:23am on April 26, 1986. During a routine test, an error by the technical team led reactor Unit 4 at the Chernobyl Nuclear Power Plant to experience a horrifying accident. Less than a decade after the less-serious incident at the Three Mile Island facility in Pennsylvania, the safety of nuclear power was once again called into question — and, thanks to dangerous levels of secrecy, the Soviet Union was soon facing condemnation from every corner of the globe. The third RBMK-1000 nuclear reactor commissioned by the Soviet government, construction on the V.I. Lenin Nuclear Power Station at Chernobyl began in 1970. The six-reactor design — a rather basic layout created for the sake of saving money just as much as producing power — represented a leap forward from the plants built only 15 years before. Focused on pinching pennies, officials in Moscow came up with a cookie-cutter structure with a minimum of moving parts to make maintenance as simple as possible. In addition, the design allowed the plants to use natural uranium to generate power instead of the more expensive enriched version, resulting in an overall cost savings of some 75 percent when compared to heavy water reactors built elsewhere in the world. When the new station at Chernobyl came online, it eventually provided almost one-tenth of the electricity for the entire Soviet Union, all without taking any of the enriched uranium necessary for nuclear weapons away from the military. Situated just a few miles from the border with Belarus along the Dnieper River, everything about Chernobyl would be built from the ground up, effectively in the middle of nowhere. In order to staff the facility, Soviet administrators ordered the construction of Prypiat, a “nuclear city” to house workers and their families in ready-made apartment buildings a short drive away. Much like any frontier town, the region developed quickly around its main industry before gaining access to others. By the mid-1980s, less than a decade after officially opening, Prypiat was a bustling rail and river trade center of almost 50,000 people. In 1983, the fourth reactor core was completed and quickly joined the three running units as a source of nuclear power. A more refined design than Units 1 and 2, the reactor could produce a thousand megawatts of electricity when operational with the added benefit of additional safeguards to seal off malfunctioning areas in the case of an accident. (Just the year before, Unit 1 experienced a partial core meltdown — a state secret not revealed until 1985, three years after the fact.) According to Soviet safety procedures, reactor cores were to be run through tests during the late evening and early morning hours to minimize the impact on electricity recipients. And, due to the heavy emphasis on seniority throughout the nuclear power apparatus — it was overseen by the military, after all — many times the crews in charge of performing these exercises were among the least experienced members of the powerplant staff. The situation was ripe for a disaster. Shortly after midnight on Saturday, April 26, 1986, night shift engineers began the final stages of a planned drawdown on Chernobyl Unit 4. Out of nowhere, a burst of energy loaded the system. The crew initiated an emergency shutdown in response and were shocked to see it create the opposite effect: the amount of power generated actually rocketed up and blew the seals on the reactor vessel. Unit 4 was now undergoing an uncontrolled chain reaction, causing components of the reactor to explode under unintended levels of pressure which, in turn, exposed the superheated graphite moderators to the outside air. Flames shot into the sky, lifting a thick cloud of radioactive smoke into the atmosphere. Chernobyl was in the midst of the worst nuclear disaster in history, with much of the Soviet Union and eastern Europe under threat of radiation poisoning. The fallout produced was 400 times greater than the atomic bomb dropped on Hiroshima, Japan at the end of World War II and spread across more than 62,000 square miles. Firefighters were on the scene within minutes to contain the blaze, with additional ground teams and helicopters arriving from as far away as Kiev in two hours. By 6:35am, the external fires were extinguished and only the inferno inside Unit 4 continued to burn, as it would for another two weeks. Hoping to avoid embarrassment, the Soviet government moved to evacuate Prypiat with as little media attention as possible. Many citizens reported feeling ill by morning, coughing and vomiting involuntarily. Dosimeters on site at Chernobyl had malfunctioned, leaving crews unsure how bad exposure had been. (Later estimates suggested the Unit 4 meltdown produced enough radiation every 1.5 seconds to kill a person.) It would not be until 2:00pm the following day — nearly 37 hours after the explosion — that officials began moving citizens out of the area. In a matter of hours, the town was empty. Meanwhile, in Moscow, Communist Party leaders were working frantically to keep the situation quiet. The morning of April 28th, workers nearly 700 miles away at the Forsmark Nuclear Power Plant in Sweden were stopped when trace amounts of radioactive material were found on their clothes. Swedish administrators rapidly began testing the facility for evidence of a leak, ultimately discovering by midday that the isotopes were from another location . In time, the fallout would reach as far away as the mountainous regions of Scotland, exposing Europeans to harmful radiation largely without their knowledge — and, until the Swedes brought their information onto the national stage, without a Soviet admission of guilt. Only the Fukushima Daiichi event after the Japanese earthquake and tsunami in March 2011 joins the meltdown of Unit 4 as being designated an International Nuclear Event Scale level 7. More than half a million people were required to counteract the spread of contamination, making the incident at Chernobyl cost as much as 18 billion rubles. Though 31 acknowledged deaths occurred, the long-term results of the accident will likely not be seen for generations. Fueled by the lack of Soviet communication and tendency toward secrecy, many are left wondering if the number of people killed was not significantly higher. In the days after the explosion, a debate over the safety of such a volatile and potentially dangerous source of power erupted on a global scale. Further, considering initial reporting came from outside the Soviet Union, international officials exerted tremendous pressure on the Communist government to open its nuclear activities to further scrutiny. Eager to heal a broken Soviet reputation, General Secretary Mikhail Gorbachev was inspired to install the glasnost reforms on official transparency, a major factor in the eventual weakening of the Communist bloc in Eastern Europe. Remarkably, the Chernobyl Nuclear Power Plant continued operation for almost 15 years. With Unit 4 contained in 200 cubic meters of concrete and lead, Soviet officials deemed the site capable of continuing to provide power to the region, only deciding to decommission it after a fire in Unit 2 in 1991. Crews continue to work in the Exclusion Zone to create a safer seal around the former power station. According to scientists, it will be another 20,000 years before humans will be able to inhabit the area. Also On This Day: 570 – Muslim prophet and founder Muhammad is born in Mecca. 1721 – The city of Tabriz in northwestern Iran is leveled by an earthquake, killing an estimated 80,000 people. 1865 – John Wilkes Booth, assassin of President of the United States Abraham Lincoln, is cornered and killed. 1933 – Nazi Germany’s secret police force, the Gestapo, is established. 1981 – The world’s first human open fetal surgery is performed at the University of California, San Francisco.