Emergency Diesel Generator Defects
at US Nuclear Plants

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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 27 reports affecting 41 plants; or 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.

Link

The Weakest Link -- -- Emergency
Diesel Generators
by Scott D. Portzline - Three Mile Island Alert

The most worrisome defect is the emergency diesel generators(EDGs). During a "station blackout" (loss of offsite power) these generators supply the electricity needed to bring the plant to a safe shutdown. If they fail, the chance of an accident approaches certainty. Former NRC Chairman Dr. Shirley Jackson said, "NRC reviews in recent years have left no doubt that a station blackout at a nuclear power station is a major contributor to reactor core damage frequency." The NRC claims a 97.5 reliability rate but watchdogs say it is lower. Nearly every month, the EDGs fail at a nuclear plant; fortunately not during a station blackout.

When a tornado struck the Davis Besse plant (same design as TMI) in Ohio in June 1998, for 41 nervous hours an array of equipment problems complicated efforts to keep the reactor under control. One of the two EDGs overheated and the other failed briefly due to a faulty relay switch. It was a close call which caused the plant's emergency director to say, "For a few minutes your heart goes up into your throat.''

This station blackout also caused the temperature of the spent fuel pool to increase to the point where water would be lost. Nuclear plants currently don't have an emergency power supply for these pools. A petition has been filed by the Nuclear Information and Resource Services (NIRS) to add this safety feature.

Fires have temporarily knocked out the EDGs at the Limerick and Crystal River nuclear plants in recent years. Six years ago, TMI's EDGs were inoperable for one month before the problem was discovered. Last year, TMI's EDGs were labeled a "fire hazard" by an NRC administrator who said they were as "ugly as I have ever seen" because of leaking oil. TMI has since "cleaned up" that situation.

At a June 15, 1999 Y2K meeting between the NRC and the Nuclear Energy Institute (NEI), I recounted what the administrator said about TMI. The vice-president of NEI answered, "So what? As long as they are up to regulations." This is the same kind of arrogance that led to the TMI accident.

The NRC does not draw a clear line for Y2K safety. The General Accounting Office (GAO) stated that despite six major reviews over two decades of NRC regulatory oversight, the NRC still does not adequately define safety. For example: the very same valve which caused the loss-of-coolant accident at TMI 20 years ago is still not rated as a safety component.

The NRC's assurances that all safety systems are Y2K ready does not rest well with TMIA. When Peach Bottom lost its safety parameter display for seven hours during a Y2K test, the NRC claimed that safety wasn't compromised. This system was added to every plant as a result of the TMI accident. Sometimes the NRC's judgment defies common sense. The GAO is now recommending that state public utility commissions publicize descriptions of the probable and worst case Y2K scenarios.

The NRC will permit plants to violate their licenses to keep them online come January 1, 2000. This situation is reminiscent of the Challenger explosion where rocket engineers were literally told to "remove your engineering hats and put on your management hats" to get the "green light" for the mission.

Resident inspectors at each plant will grant safety exemptions to plants in an effort to protect grid stability rather than public health and safety from radioactivity which is the NRC's statutory mandate. With millions of lives at stake, the NRC would do well to strengthen the emergency diesel generators by thorough testing and requiring an additional backup power source as petitioned by NIRS. The NRC is now three months late for its own deadline for responding to the NIRS petitions.

-- flb (fben4077@yahoo.com), July 27, 1999

Answers

center off

-- flb (fben4077@yahoo.com), July 27, 1999.

Hhmm, kept seeing reports of back-up generators failing in tests, in many industries. Hope Robert Cook sees this; he's noticed the trend too!

-- Ashton & Leska in Cascadia (allaha@earthlink.net), July 27, 1999.

hmmmmmmmmmmmmmmmmmm Don't need power to cool the reactors.... They have backup gens that will keep the water flowing.... hmmmmmmmmmmmm Looks like they will be forced to shut them down. hmmmmmmmmmmmm Got Iodine?

-- FLAME AWAY (BLehman202@aol.com), July 27, 1999.

AND a dustbin

-- a night janitor (r@r.r), July 27, 1999.

Same old tired anti-nuclear diatribe masquerading as Y2K. Got an agenda?

-- cd (artful@dodger.com), July 28, 1999.