![]() ![]() ![]() Nuclear Regulatory Commission (NRC), an organization whose official responsibilities include screaming ‘Yes!’ to anyone who broaches this question. In his day job, Wellock is the official historian of the U.S. The quotes are from the book Safe Enough? A History of Nuclear Power and Accident Risk, by Thomas Wellock. Once they removed the padlock, they had to descend a ladder, remove more chained locks, reset the pump's trip valve, and reposition other valves. One operator was fleeter than the other, and the lagging operator threw him the key ring as he sprinted ahead. Despite a "no running" policy, a pair of men bounded down the stairs. Two plant operators would have to improvise and run down several levels to the locked basement auxiliary feedwater rooms to reset the trip valves and start the pumps. The next failure at Davis Besse exactly followed that script: “the pilot-operated relief valve cycled open and closed three times to relieve primary coolant pressure before it stuck open, just like at Three Mile Island.” If you, like me, grew up in the 1970s and 1980s you might have heard of Three Mile Island, as in 1979 it made some news. The Davis-Besse reactor was a near-twin of reactors at the Three Mile Island nuclear plant. ![]() The reactor operators had their hands full as the primary system temperature rose four degrees per minute and pressure soon exceeded 2400 psi. Over the next twenty minutes there were twelve separate equipment malfunctions, including several common-mode failures, and operator errors… steam-driven main and auxiliary feedwater systems tripped offline and could not be restarted from the control room…. It is just after 1:35 am, and the plant has a small malfunction: "As the assistant supervisor entered the control room, he saw that one of the main feedwater pumps had tripped offline." But instead of stabilizing, one safety system after another failed to engage. The place is the Davis-Besse nuclear plant near Toledo, Ohio. ![]()
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