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 II)
The nuclear industry does not know how to stop the global epidemic of tube cracking. Steam generator leakage can't be prevented.
Tube defects cause all steam generators to leak all the time.  Even when reactors first come back on-line after being down for repairs, tubes still leak. There have been 14 tube ruptures in the U.S., including a rupture at Prairie Island in October, 1979.
At first, leaking tubes were plugged and taken out of service. But there is a limit to how many tubes can be plugged before performance suffers. So, many plugs have been removed and a smaller tube, or sleeve, gets welded inside the original tube. Unfortunately, sleeves and plugs soon leak as well.
The trend of steam generator tube defects at Prairie Island is consistent with the national pattern. As of October, 1996, the four Prairie Island steam generators had almost 600 tubes plugged. Without plugging, each of these tubes could have ruptured.