Friday, April 11, 2008
THE 18 YEAR OLD REPORTER AND A NUCLEAR DISASTER
When I was young and working at little WBUX Radio in Doylestown, Pennyslvania I used to love the clanking sounds of the old Associated Press wire machine in the hallway.
The big, black machine would pump out miles of news stories. The other day while cruising the web, I found a picture of one of the old clunkers.
It brought back one very, vivid memory. It was a sunny spring day in my senior year in high school in 1979 and I'll never forget the loud bells going off when a bulletin came over the AP machine at the little radio station where I worked as a teenager. I'll also never forget the scary, vague alert.
"There's been an accident at the Three Mile Island Nuclear plant."
First thing I think, it blew up and I felt a chill go through my body, as if the radiation from the plant, 150 miles away had already reached suburban Philadelphia.
"What kind of accident?," I wondered. Did some guy stub his toe? Did a water main break or was this a real catastrophe? Well, it turns out , it was somewhere in between. There had been a partial meltdown of the reactor and a release of radiation, enough to force the Governor to call for the evacuation of young children and pregnant women.
Cue the harpsicord and let's go back in time and read what the Nuclear Regulatory Commission concluded in its final, very eerie report....
Summary of Events
The accident began about 4:00 a.m. on March 28, 1979, when the plant experienced a failure in the secondary, non-nuclear section of the plant. The main feedwater pumps stopped running, caused by either a mechanical or electrical failure, which prevented the steam generators from removing heat. First the turbine, then the reactor automatically shut down. Immediately, the pressure in the primary system (the nuclear portion of the plant) began to increase. In order to prevent that pressure from becoming excessive, the pilot-operated relief valve (a valve located at the top of the pressurizer) opened. The valve should have closed when the pressure decreased by a certain amount, but it did not. Signals available to the operator failed to show that the valve was still open. As a result, cooling water poured out of the stuck-open valve and caused the core of the reactor to overheat.
As coolant flowed from the core through the pressurizer, the instruments available to reactor operators provided confusing information. There was no instrument that showed the level of coolant in the core. Instead, the operators judged the level of water in the core by the level in the pressurizer, and since it was high, they assumed that the core was properly covered with coolant. In addition, there was no clear signal that the pilot-operated relief valve was open. As a result, as alarms rang and warning lights flashed, the operators did not realize that the plant was experiencing a loss-of-coolant accident. They took a series of actions that made conditions worse by simply reducing the flow of coolant through the core.
Because adequate cooling was not available, the nuclear fuel overheated to the point at which the zirconium cladding (the long metal tubes which hold the nuclear fuel pellets) ruptured and the fuel pellets began to melt. It was later found that about one-half of the core melted during the early stages of the accident. Although the TMI-2 plant suffered a severe core meltdown, the most dangerous kind of nuclear power accident, it did not produce the worst-case consequences that reactor experts had long feared. In a worst-case accident, the melting of nuclear fuel would lead to a breach of the walls of the containment building and release massive quantities of radiation to the environment. But this did not occur as a result of the Three Mile Island accident.
At the ripe young age of 18, on March 28, 1979 I had just covered one of the biggest stories of my generation.