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Executive Summary

n March 28, 1979, the Unit 2 reac- tor at the Three Mile Island (TMI) nuclear power plant in Pennsylvania suffered a partial core meltdown. It was the worst accident—so far—in the history of commercial nuclear power in the United States. The fact that this event occurred more than a quarter-century ago is often cited as evidence that nuclear power is safer today. O

But is it safe enough? A car speeding through a school zone at 90 miles per hour (mph) is safer if it slows to “only” 75 mph, but it isn’t safe enough. Children in the school zone are at just as great a risk.

Is nuclear power in the United States safe enough today just because a reactor has not expe- rienced a meltdown since 1979? The answer is a resounding no. In the 27 years since the TMI meltdown, 38 U.S. nuclear power reactors had to be shut down for at least one year while safety margins were restored to minimally acceptable levels. Seven of these reactors experienced two year-plus outages.

Though these reactors were shut down before they experienced a major accident, we cannot assume we will continue to be so lucky. The number and length of these shutdowns testifies to how serious and widespread the problem is.

A History of Neglect

The vast majority of these extended outages were caused not by broken parts but a general degrading of components to the point that safe operation of the plant required a shutdown for broad, system-wide maintenance. Federal regulations require plant owners to maintain corrective action programs (CAPs, often referred to as quality assurance progams) that find and fix problems,

Rev. 1 09/25/06

Walking a Nuclear Tightrope

but a review of year-plus outages demonstrates that existing CAPs are inadequate. In each case, it took considerable time and cost to find and fix the many problems these inadequate CAPs had either overlooked or improperly “corrected,” and to address the flaws in the programs themselves. In other words, it took longer than one year for plant owners to get back on the right side of the law and make the reactor safe enough to operate.

Nuclear power is clearly not safe enough when so many reactors have to be shut down for a year or more before they can be restarted under the minimum conditions considered acceptable by federal safety regulations. Extended outages are prima facie evidence of how far safety margins have been allowed to erode, making nuclear power more dangerous and costly than necessary. Furthermore, extended outages caused by inad- equate CAPs also indicate that plant owners have violated federal regulations many times and in many places.

Waking Up the Watchdog

The Nuclear Regulatory Commission (NRC), which oversees safety at U.S. nuclear power reac- tors, simply must do a better job of monitoring reactor safety levels so it can intercede before safety margins erode to the point that it takes a year or more to restore them to acceptable levels. Specifically, the NRC must improve its perfor- mance in terms of:

  • assessing the adequacy of CAPs;

  • communicating with plant owners about CAP failures identified at other reactors;

  • integrating all available reactor data so NRC staff around the country can “connect the dots” about potential problems at similar reactors; and

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