What Happened at Three Mile Island?

On March 28, 1979, the worst accident in the history of Nuclear Power Generation in the United States occurred at Unit 2 of the Three Mile Island Nuclear Plant in Pennsylvania. There was no loss of life, but the multi-billion dollar reactor was rendered unusable, and the hoopla surrounding the event prevented the restart of Unit 1, which was down for maintenance and refueling at the time, until 1985. Conflicting reports concerning how much radiation was released and health effects of the accident abound. This accident will no doubt be used again and again to argue against nuclear power, so obviously we need to learn what really happened, just how much danger the public was actually in, and if it can happen again. The problem is so much of the information will have passed through the "spin doctors" on both sides that how do we know what to believe?

For now we are working from "A Short History of Nuclear Regulation, 1946, 1999", apparently no longer available from the Nuclear Regulatory Commission web site. From that document:

"As a result of a series of mechanical failures and human errors, the accident (researchers later determined) uncovered the reactor's core and melted about half of it. The immediate cause of the accident was a pressure relief valve that stuck open and allowed large volumes of reactor coolant to escape. The reactor operators misread the signs of a loss-of-coolant accident and, for several hours, failed to take action to cool the core. Although the plant's emergency cooling systems began to work according to design, the operating crew decided to reduce the flow from them to a trickle. By the time that the nature of the accident was recognized and the core was flooded with coolant, the reactor had suffered irreparable damage."

There was some good news: "In some ways, the TMI accident produced reassuring, or at least encouraging, information for reactor experts about the design and operation of the safety systems in a large nuclear plant. Despite the substantial degree of core melting that occurred, containment was not breached. From all indications, the amount of radioactivity released into the environment as a result of the accident was very low. One estimate suggested that of 66 million curies of iodine-131 in the reactor at the time of the accident, only 14 or 15 curies escaped. Further, the emergency core cooling systems worked effectively once plant operators allowed them to run according to design."

From that same document, we also learned that before TMI, another significant event took place, this one much closer to home:

"(The event was)...a major fire at TVA's Browns Ferry nuclear plants near Decatur, Alabama in March 1975. In the process of looking for air leaks in an area containing trays of electrical cables that operated the plants' control room and safety systems, a technician set off the fire. He used a lighted candle to conduct the search, and the open flame ignited the insulation around the cables. The fire raged for over seven hours and nearly disabled the safety equipment of one of the two affected units."

This document is a very candid look at the checkered past of the Atomic Energy Commission, which was responsible for the development of nuclear power, as well as overseeing the safety of it (like the "fox guarding the hen house," according to the same document). The AEC was eventually abolished and replaced with the Nuclear Regulatory Commission, whose sole purpose is nuclear safety. Clearly there were some serious issues to contend with early on, and not a little bit of plain old stupidity... using an open flame to check for air leaks?? Did they not know that the sealant was highly flammable, and, if not, why not? The fire "raged for over seven hours" because they did not want to use water to extinguish it because of the wiring. When they finally did turn the water on it, it was out within minutes.

As a result of Three Mile Island, the NRC now has two full time staffers ON SITE at every operating nuclear plant in the US. There is a process in place that constantly reviews operating procedures, contingency plans, design updates, and so on, that contribute to make nuclear power safe, and even more reliable. It is not at all unusual for a unit to run "breaker to breaker", that is, from one refueling outage to the next (512 days at Watts Bar in September, 2000), producing anywhere from 800 to 1200 megawatts without having to be fed a constant stream of coal. This is why we desire to see nuclear power replace fossil: fossil fuels are damaging this planet far more than even the fiasco at Chernobyl. (Speaking of which, while we will present some facts about what happened at Chernobyl, we believe those facts will show that Chernobyl cannot be logically used as an argument against nuclear power... the situation was that bizarre.) Acid rain is real. Greenhouse gases are real. Nuclear waste? Drive by Georgia Power's Plant Bowen near Rockmart, and witness the residue from a large coal plant. Do your research and found out what, and how much, is produced by the burning of coal versus the fissioning of uranium. We hope it scares you as much as it does us, and that you will re-evaluate nuclear power. One last item to consider: completely fissioning one pound of uranium releases the equivalent energy of burning 1500 TONS of coal. And, as we said elsewhere, it takes about a pound of coal to burn a 100 watt light bulb for an hour.