Incidents and Accidents
- In 1978, fuel rods fell in reactor No. 3, causing a nuclear reaction. It took about seven and a half hours to place the rods back into proper positions.
- On February 25, 2009 a manual shutdown was initiated during the middle of a startup operation. The cause was a high pressure alarm that was caused by the shutting of a turbine bypass valve. The reactor was at 12% of full power when the alarm occurred at 4:03 am due to a pressure increase to 1,029.8 psi (7,100 kPa), exceeding the regulatory limit of 1,002.2 psi (6,910 kPa) The reactor was reduced to 0% power, which exceeded the 5% threshold that requires event reporting, and pressure dropped back under the regulatory limit at 4:25 am. Later, at 8:49 am the control blades were completely inserted, constituting a manual reactor shutdown. An inspection then confirmed that one of the 8 bypass valves had closed and that the valve had a bad driving fluid connection. The reactor had been starting up following its 25th regular inspection which began on October 18, 2008.
- On March 26, 2009 unit 3 had problems with over-insertion of control blades during outage. Repair work was being done on equipment that regulates the driving pressure for the control blades, and when a valve was opened at 2:23 pm a control blade drift alarm went off. On later inspection it was found that several of the rods had been unintentionally inserted.
- On November 2, 2010 unit 5 had an automatic SCRAM while an operator was conducting an adjustment to the control blade insertion pattern. The SCRAM was caused by a reactor low water level alarm. The turbine tripped along with the reactor and there was no radiation injury to workers.
Read more about this topic: Fukushima Daiichi Nuclear Power Plant
Famous quotes containing the words incidents and/or accidents:
“An element of exaggeration clings to the popular judgment: great vices are made greater, great virtues greater also; interesting incidents are made more interesting, softer legends more soft.”
—Walter Bagehot (1826–1877)
“Depression moods lead, almost invariably, to accidents. But, when they occur, our mood changes again, since the accident shows we can draw the world in our wake, and that we still retain some degree of power even when our spirits are low. A series of accidents creates a positively light-hearted state, out of consideration for this strange power.”
—Jean Baudrillard (b. 1929)