Emergency Diesel Generator Defects
at US Nuclear Plants
as reported by the US Nuclear Regulatory Commission
This database includes incidents and reports from
January 1, 1999 to the present. It shows that defects
and problems occur on a weekly basis. There are 28
reports affecting 40% of all US commercial nuclear
plants so far this year.
There is currently a petition for rulemaking before the
Nuclear Regulatory Commission regarding backup
power supplies. The NRC is now three months late
on making its decision.
Cook, Michigan: July 27, 1999
All four diesel generators are declared inoperable but still functional.
Discovery of condition which could leave EGDs inoperable following a
tornado.
Beaver Valley, Pennsylvania: July 16 - 17, 1999
Diesel Generator fails during test due to voltage and current problems.
Battery chargers become inoperable. Generator restart faulty. Batteries are
inoperable. Plant shutting down. Pumps inoperable briefly.
Pilgrim, Massachusetts: July 16, 1999
An existing modification of the circuit logic would prevent bus from
energizing properly from diesel generators.
Idaho National Engineering and Environmental Laboratory,
Idaho: July 12, 1999
(not a commercial power reactor) Two diesel generators fails following a
fire at substation. No fuel from Three Mile Island remains onsite.
Pilgrim, Massachusetts: July 5, 1999
Both diesel generators for Unit 1 outside design basis due to high room
temperature..
Cook, Michigan: June 25, 1999
Diesel generator oil lubrication valve installed backwards. Uncertainty
about the ability to operate for 7 days has caused the EDG to be declared
inoperable
Kewaunee Wisconsin: June 14, 1999
Diesel generator declared inoperable due to misadjusted speed sensor.
Ginna, New York: June 10, 1999
Both diesel generators inoperable. There would have been an inability to
automatically respond to an event coincident with a loss of offsite power.
Summer, South Carolina: May 5, 1999
Faulty circuit breaker identified as substantial safety hazard used with diesel
generators.
Six Nuclear Plants: April 28, 1999
Manufacturer reports a potential defect in connecting rod assemblies,
which are components of diesel generator systems.
Nine Mile Point, New York: April 24, 1999
Reactor scram. Diesel Generator starts but fails to load. Partial loss of
lighting in the control room. Loss of lighting in turbine building. Loss of site
perimeter lighting. Natural circulation of coolant.
Arkansas Nuclear, Arkansas: April 23, 1999
During Y2K testing, would not properly load. Only 500 Kw, instead of its
expected load of 4400 Kw.
Point Beach, Michigan: April 20, 1999
Design defect could have disabled diesel generators.
Susquehanna, Pennsylvania: April 17, 1999
Operator switching error causes diesel generator to be inoperable.
Beaver Valley, Pennsylvania: April 9, 1999
Following instructions in operator's manual could have caused diesel
generators to fail.
Ginna, New York: April 9, 1999
Missing oil drain port could have caused serious diesel generator damage.
Cook, Michigan: April 7, 1999
Design defect could cause long-term operational failure of diesel generator
following a seismic event.
Seabrook, New Hampshire: March 31, 1999
Defective relay might not have allowed bus to load to diesel generator.
Grand Gulf, Mississippi: March 25, 1999
Diesel Generator declared inoperable due to leaking oil.
South Texas, Texas: March 12, 1999
Diesel Generator output circuit breaker failed to close.
Pilgrim, Massachusetts: February 25, 1999
Temperature of diesel generator building fell below design due to winter
storm.
Wolf Creek, Kansas: February 18,1999
Improper switching could have caused fire and loss of diesel generators altogether.
River Bend, Louisiana: February 2, 1999
The NRC proposes a $55,000 fine for the company's failure to correct
deficiencies in the compressed air system that controls the emergency
diesel generators.
San Onofre, California: February 1, 1999
Diesel generator started but did not complete circuit due to relay lockout
Fitzpatrick, New York: January 21,1999
Emergency diesel generators may have failed to energize emergency busses.
Hope Creek, New Jersey: January 20, 1999
Incorrect resistor could effect speed switch on diesel generators. This
manufacturer defects also could effect 8 other US nuclear plants at Hatch,
Fermi, Millstone, Beaver Valley, Limerick, Callaway and Wolf Creek
which might have the same defect because of same manufacturer.
Duane Arnold, Iowa: January, 20 1999
Forced reactor shutdown after both standby diesel generators failed test to
reach required voltage and frequency within the required time.
Grand Gulf, Mississippi: January 13, 1999
Diesel generator degraded due to output transformer leaking.
North Anna, Virginia: January 5,1999
Spillway emergency diesel generator declared inoperable during test.
*******
Jim may not want to 'go there' regarding nuclear safety issues. i just did with the above report copied from NRC records.
These Generators mentioned above deal with the backup system for raising and lowering the rods as Jim's textbook pointed out.
Remember, there is not a SINGLE EMERGENCY DIESEL GENERATOR attached to or assigned to the cooling pool to prevent meltdown in the event offsite power requires EDGs assigned to above lifting and lowering rods functions fail to either engage, engage but don't come to required power output in Kw's or refuse to stay on line and operable due to operator error, design defect, or longterm load stress on EDGs designed to only work for short durations, approximately 8 hours so i have read. |
