About the series
On Sept. 9, 1997, both reactors at Donald C. Cook Nuclear Plant are taken offline in a controlled, but unexpected, shutdown after their emergency core cooling systems are declared inoperable. The shock is slow to register.
After all, the plant shouldered about 9 percent of American Electric Power's electrical output, keeping AEP's rates to more than 500,000 customers in northern Indiana and southwestern Michigan among the nation's lowest.
But the worst is to come. In succeeding days, many of the safety systems designed to control and remove radioactive emissions come under scrutiny. New problems are discovered daily.
What had always been considered an "infinitesimal" risk -- an uncontrolled release of radioactivity into the atmosphere, blown by the prevailing winds over Michiana, causing a range of maladies from minor skin irritations to death -- crept ever so slightly into public earshot.
Senior Cook officials, many of whom have since been replaced, act to dispel any doubts. They dash through a self-generated safety-systems checklist, pronounce the plant ready to resume full power and prepare for restart in early 1998.
It never happens. A last-minute inspection of Cook's ice condenser system is ordered by the Nuclear Regulatory Commission. As the story is related in various documents, inspectors find enough problems in a single walkthrough to continue the plant shutdown.
A Tribune investigation into events before and after the 1997 outage showed that Cook officials failed to address safety concerns for years, and the NRC had to be prodded to enforce its own rules.
For the record, Cook voluntarily shut down both reactors, and the NRC kept them down while the company retooled internally and embarked on a $574 million project to identify and fix problems.
Yet it took a nuclear watchdog group and a pair of whistleblowers from distant plants to make the case that Cook was unfit, by NRC standards, to sustain a large-break, loss-of-coolant accident in either of its oval containment structures next to Lake Michigan.
As Cook heads toward restart, possibly early next month, the question remains: What has changed to make sure it doesn't happen again?