November 23, 2010 8:02 AM EDT
#21a: Nuclear Power’s Dirty Little Secret
One June 17, 1970, an operator at the LaCrosse nuclear plant near Genoa, Wisconsin, used a dust cloth to clean a console in the control room. The cloth snagged the identification tag attached to one of the key switches and caused it to move around to the OFF position. The repositioning of this single switch caused the reactor to automatically shut down.
To prevent this unfortunate event from happening again, the plant’s owner directed control room operators to use a feather duster when cleaning control room consoles.
The training program for operators consists of more than a year’s worth of classroom instruction and simulator exercises. Proper dusting techniques–whether dust cloth or feather duster–are not covered during this otherwise comprehensive training.
#21b: Safety SWISHed at Waterford
An operator at the Waterford nuclear plant near New Orleans, Louisiana used a commercial cleanser called SWISH to clean a control room panel on October 25, 1992. In less than two hours, “the cleaner solvent caused the plastic parts of 16 safety-related control switches to bond together, making the switches inoperable” according to the NRC. The broken switches included those for valves on both the high-pressure and low-pressure systems needed to supply makeup water to the reactor core in case of an accident.
Had an accident occurred with these switches cleaned but busted, things in Louisiana may have gotten dirty and stayed dirty a long time.
Fission Stories #20 described the importance of asking all the right questions to ensure safe outcomes. These events further illustrate the necessity of asking all the right questions. The seemingly innocuous task of cleaning a control room panel undermined safety levels. Such events are as important tribal knowledge as the lessons from the Three Mile Island accident because they help calibrate questioning attitudes to the level of detail needed to flush out subtle but significant issues.
“Fission Stories” is a weekly feature by Dave Lochbaum. For more information on nuclear power safety, see the nuclear safety section of UCS’s website and our interactive map, the Nuclear Power Information Tracker.