Environmental Problems, Their Causes, and Sustainability 1

17 NonrenewableEnergy ResourcesEnergyCASE STUDYBitter Lessons from ChernobylChernobyl is known around the globe as the site ofthe world’s most serious nuclear power plant accident(Figure 17-1). On April 26, 1986, a series of explosionsin one of the reactors in a nuclear powerplant in Ukraine—then part of the Soviet Union—blew the massive roof off a reactor building andflung radioactive debris and dust high into the atmosphere.A huge radioactive cloud spread overmuch of Belarus, Russia, Ukraine, and other parts ofEurope and eventually encircled the planet. Cloudsof radioactive material escaped into the atmospherefor 10 days. The surrounding environment and peoplewere exposed to radiation levels about 100 timeshigher than those caused by the atomic bomb theUnited States dropped on Hiroshima, Japan, near theend of World War II.According to various UN studies, the disaster wascaused by poor reactor design and human error.Around 30 people near the accident site died from radiationexposure and nearly 2,000 children developedthyroid cancer. Thousands of others may have also developedvarious cancers and died. But because of poorrecordkeeping no one knows the exact death toll, withthe estimated number of premature deaths rangingfrom 8,000 to 15,000. Regardless of numbers, this was amajor human-caused tragedy.More than 100,000 people had to leave theirhomes. Most were not evacuated until at least 10 daysafter the accident. These environmental refugees hadto leave their possessions behind. They also had to saygoodbye to lush green wheat fields and blossomingapple trees, land their families had farmed for generations,cows and goats that would be shot because thegrass they ate was radioactive, and their cats and dogspoisoned with radioactivity.In 2003, Ukraine officials downgraded the area ina 27-square kilometer (17-square mile) radius from thereactor to a “zone with high risk” to allow those willingto accept the health risk to return home.The accident exposed more than half a million peopleto dangerous levels of radioactivity and has causedseveral thousand cases of thyroid cancer. The total costof the accident is at least $140 billion according to theU.S. Department of Energy and could eventually reachat least $358 billion according to Ukrainian officials—many times more than the value of all nuclear electricityever generated in the former Soviet Union.Chernobyl taught us that a major nuclear accidentanywhere has effects that reverberate throughout much ofthe world.Figure 17-1 Major events leading tothe Chernobyl nuclear power plantaccident on April 26, 1986, in the formerSoviet Union. The accident happenedbecause engineers turned offmost of the reactor’s automatic safetyand warning systems to keep themfrom interfering with an unauthorizedsafety experiment. Also, the safetydesign of the reactor was inadequate(there was no secondary containmentshell, as in Western-style reactors),and a design flaw led to unstable operationat low power. After the reactorexploded, crews exposed themselvesto lethal levels of radiation to put outfires and encase the shattered reactorin a hastily constructed concretetomb. This 19-story tomb is crumblingand leaking radioactive materials intothe surrounding area. In 2003, theEuropean Bank of Reconstruction andDevelopment provided $85 million tomake emergency repairs to the tomband will provide an additional $750million to build a new protective shieldaround the damaged reactor.2 Almost all control rodswere removed from thecore during experiment.1 Emergency coolingsystem was turnedoff to conduct anexperiment.Radiation shieldsCoolingpondCrane formoving fuel rodsReactor5 Reactor power output was lowered toomuch, making it too difficult to control.Steamgenerator3 Automatic safety devicesthat shut down the reactorwhen water and steam levelsfall below normal and turbinestops were shut off becauseengineers didn’t want systemsto “spoil” experiment.TurbinesWaterpumps4 Additional water pump to cool reactorwas turned on. But with low power outputand extra drain on system, water didn’tactually reach reactor.