Beginning at about 4:00 A.M. on Wednesday, March 28, 1979, the reactor core at Three Mile Island Nuclear Station located at Harrisburg, PA was uncovered and deprived of proper cooling for several hours through a litany of operator errors that resulted in the worst nuclear accident to ever occur in the United States. Unlike the meltdown that occurred at the nuclear reactors in Japan, which were caused by a catastrophic earthquake and resulting tsunami, the accident at Three Mile Island was exacerbated by human error because operators were overwhelmed with information, much of it irrelevant, misleading, or incorrect.
On Friday morning, March 30, my supervisor gathered all the operators- in- training at Grand Gulf Nuclear Station and asked if anyone would be interested in going to Three Mile Island to help the Pennsylvania utility recover from the accident that had had occurred two days earlier. All indications were that the immediate problems caused by the accident had been resolved, and a long period of recovery would begin. The utility did not know to what extent the core had been uncovered and how much actual damage had been done to the reactor. Because large amounts of radioactive water had been released throughout the plant, this problem would have to be evaluated before any other recovery efforts could be begin. At that time, operator radiation exposure or “dose” was measured on a three month basis. Because of the release of the highly radioactive water into the plant, several TMI operators had received their quarterly dose in one day and were in danger of receiving their yearly dose, which would have disqualified them from performing any further work in the plant. Three Mile Island sent out a request to any power plant in the United States, nuclear or non nuclear, for operators willing to come and support their recovery effort. Since Grand Gulf Nuclear Station had not loaded fuel at that time, it would not create a problem for us to receive our quarterly dose in a short period of time. Four operators volunteered, and I was one of them. We were instructed to go home and pack what we thought we would need for an extended stay. The company had arranged a flight for us leaving Jackson on Saturday, March 31, at 4:00 P.M. We were told to be at the airport and that someone would meet us with tickets and expense money for the first couple of weeks. It also turned out to be the weekend of the Easter flood that dumped 10” of rain on Jackson and flooded hundreds of homes. It also knocked out power to the airport, and we were not able to get a flight out until 4:00 A.M. Sunday morning.
We arrived in Philadelphia, Pennsylvania, and had missed our connecting flight to Harrisburg. A call was made back to Mississippi. To find out if we needed to wait and connect with a flight or rent a car and drive to Harrisburg. The PA utility wanted us there as soon as we could get there. Entergy made arrangements for a rental car, and we loaded up and headed to Harrisburg. We got to Harrisburg and immediately reported in. Needless to say there was a lot of confusion, not so much about what was going on at the plant, but what we needed to do to get through security and get into the plant itself. We got our security badges and were told to report back the next day on the evening shift and go to the control room. At that time I would have to say that the unknowns far outweighed the knowns. The other three guys and I reported to the control room the next day at 3:00 P.M. and marched into the control room ready to save the world. The shift supervisor asked if we would get some sweep brooms and sweep out the control room as it had not been done for several days. I thought about the mad rush we had been in for three days to get there and we started out as janitors!
As previously stated, the main plant building itself had been flooded with highly radioactive water, which had now been pumped into holding tanks, but the building itself was still highly contaminated. Any entrance into the building required full anti-contamination clothing and a backpack breathing pack similar to that worn by underwater divers . One of the first things that had to be done was for maintenance personnel to enter the building and check pumps and motors that might possibly have been underwater but were required to be operational. As it turned out the radiation levels had dropped rapidly, but there were still hot spots that had to be avoided. All entrances into the building were done on a team basis with a minimum of two people working together. I would go with different maintenance personnel and help carry measuring devices and tools as necessary to complete the assigned task. One problem that the air packs created was that they were good for about a 30 minute supply of air. At about 25 minutes a bell rang indicating that you had five minutes of air remaining. Regardless of what I was doing and where I was located, my partner and I had to stop and return to the entrance point for a new air supply. Part of the preplanning was to carry a map with us so we knew the shortest route back to the entrance point when the bell when off. During the first few days. we averaged about four or five back pack trips in the morning and a couple after supper. One of the most important jobs we performed was to check the ventilation system fans to ensure they were keeping a negative pressure on the buildings to prevent radiation from being released to the environment. The air in the building was circulated continuously thru a filtration system which removed any airborne radioactive particles.
As it turned out the radiation that was released inside the building had a short half-life and decayed away rapidly. Some of the rooms that we checked with telescoping radiation meters while performing our assigned maintenance tasks had trapped concentrated amounts of radioactive material in the pumps and sumps that were intense enough to kill a human being if exposed for an hour or more. Needless to say, the maintenance man and I noted these areas on our maps and quickly moved on. One of the operators who traveled with us had to return to Jackson almost immediately after arriving in Harrisburg because his home in north Jackson had flooded. The two remaining operators and I stayed and worked helping restore the crippled plant back to a safe condition for 22 days. At the time radiation exposure for workers was measured in millirems. A worker was allowed 1250 millirems in a three month period. I received 255 millirems during the entire time I was there. By comparison a person living in Mississippi receives about that much radiation in a year’s time from being exposed to the sun. One side note about the confusion at the time was that all operators’s had to be tested and fitted prior to wearing a back pack air unit in an actual radioactive environment such as that we encountered at TMI. On the 22nd day as we were checking out and returning our security badges, someone realized we had not been tested and fitted for the back packs. We were reissued our security badges and shuffled off to a Health Physics trailer and fitted and qualified to wear a back pack respirator! We were then allowed to leave.
As a result of the accident many improvements to operator training, quality assurance, engineering, operational surveillance, and emergency planning have been instituted. In addition, each nuclear site now has an approved emergency plan to direct the evacuation of the public within a ten mile Emergency Planning Zone (EPZ), and to facilitate rapid notification and evacuation. This plan is periodically rehearsed with federal and local authorities to ensure all groups work together quickly and efficiently. Copiah County is part of the evacuation route and several evacuee shelters have been designated in the county and can be activated in an emergency. I read with interest the events surrounding Chernobyl and have been following the events in Japan, both of which were far more catastrophic than what occurred at Three Mile Island. My heart goes out to the Japanese and Russian people and even more so to the workers who risked and are still risking their lives to try and recover from the events that have occurred. I have been there in my own small way and will never forget the experience.