Where the reactors are - U.S., Midwest
About the Prairie Island reactors
How a pressurized water nuclear reactor works - part I
How a pressurized water nuclear reactor works - part II
Northern States Power sues Westinghouse over faulty tubes
Problems with Steam Generator Tubes (Part I)
Problems with Steam Generator Tubes (Part II)
A nightmare confirmed: steam tube degradation is increasingly likely to cause a nuclear meltdown (Part I)
A nightmare confirmed: steam tube degradation is increasingly likely to cause a nuclear meltdown (Part II)
Chernobyl to Prairie Island - We are all in the zone (Part I)
Chernobyl to Prairie Island - We are all in the zone (Part II)
Prairie Island routinely emits radioactivity into the environment
A little lesson on radioactivity: how it affects the human body
The difference between high-level and low-level radiation exposure
The effects of low-level radiation exposure
The waste fuel pools are filling up
Dry cask storage: problems guaranteed, and problems unknown
Yucca Mountain, Nevada: not a good place for nuclear waste
Transporting the waste: how safe can 45,000 shipments be?
Most mining and milling of uranium occurs on Indian lands
People of color are also targeted for other uranium processing facilities
Nuclear waste dumps - guess where they want to put them
Anything is cheap if you don't pay the cost
Nuclear power can be phased out
An interview with two of the neighbors
REFERENCES
Broken Reactor Components
Problems with Steam Generator Tubes (Part I)
Tube degradation
tends to concentrate
in the following areas:
1) where tubes are welded to the tubesheet at the bottom of the steam generator;
2) where tubes pass through support plates;
3) where interior tubes are bent tightly near the top of the steam generatator;
4) where sludge piles accumulate around the tubes.
Stress and corrosion cause pits, pinholes, and two types of tube cracks:
axial cracks run the tube length; circumferential cracks run around the tube.
New cracks are occurring in ways the nuclear industry doesn't understand and can't predict. For example, cracks are appearing in mid-span regions, in between support plates, where there is no ready explanation for their presence.
We now know that steam generators were poorly designed and made out of the wrong metal. Crevices, where corrosion readily occurs, are inherent in vertical steam generator designs. And Inconel, the nickel/chromium alloy used to make the tubes, is more susceptible to crevice-corrosion cracking than stainless steel. To quote the senior NSP nuclear engineer who inspired our title: