Peach Bottom takes 15 years to identify transformer problem

Franklin Delano Roosevelt, before he died, said that December 7th would live in infamy.
 
He certainly won't say the same about December 15th, since he's dead, but if he weren't he might.
 
Attached are two licensee event reports both dated December 15, 2011.
 
One is for Peach Bottom in Pennsylvania and the other is for Perry in Ohio. Both involve violations of federal safety regulations (Criterion 17 in Appendix A to 10 CFR Part 50) requiring two or more connections between a nuclear power plant and its offsite electrical grid. Both times, there were one or fewer connections.
 
On October 18, 2011, Perry was preparing to restart from an outage. At 12:12 am (way early in the morning), workers performed a surveillance test to verify that two or more connections to the offsite power grid were available and operable. At 4:19 pm that afternoon with the reactor being started up, workers found that one of the required offsite power connections had been disconnected and Danger tags hung. Workers fixed that illegal configuration within an hour or so.
 
On November 16, 2011, workers at Peach Bottom belatedly figured out that a modification installed at the plant in the mid-1990s to "upgrade the reliability of the offsite sources" actually failed to do so due to "an inadequate design of the auxiliary power" to the new transformer. Basically, that new transformer used the same auxiliary power source as another transformer, such that failure of that auxiliary power source disabled both transformers. [The transformers in questions were connections between the offsite electrical grid and the plant --- they increased the voltage of outgoing electricity to that of the grid and decreased the voltage of incoming voltage to that of the plant.] The LER was submitted because Peach Bottom had counted operability of these two transformers as satisfying the federal safety regulation for two or more offsite power sources, when in fact they were but a single source due to their lack of separation/independence.
 
Where's the beef?
 
Safety studies generally rely on the backup power supply from onsite emergency diesel generators and take little credit for the normal power provided by the electrical grid. But there's a caveat --- the reliability of the offsite electrical grid is a factor in the safety studies. The less reliable the offsite grid, the more reliability the emergency diesel generators must be. Also, the now well-known station blackout event (e.g., the Fukushima script) ends when either an onsite emergency diesel generator is recovered or offsite electrical power is restored. Having two or more connections to the offsite power grid BEFORE the station blackout event is considered in determining how long it'll take to restore one of them.
 
Once again, U.S. federal safety regulations protect Americans from disasters such as that occurring at Fukushima last March.
 
Or rather, these regulations would provide that protection if only they were met.
 
Thanks,
Dave Lochbaum
UCS

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