by Christine Perham
[EPA Journal - October 1980]

When mechanical failure and human error resulted in the now-famous accident at Three Mile Island in Middletown, Pennsylvania, March 28, 1979, EPA swiftly began monitoring operations to ensure that public health was protected from the discharge of radioactive materials into the environment from the crippled reactor.

Within hours, EPA's Office of radiation Programs began what became daily sampling at three stations located closest to the damaged reactor. By March 30, as the implications of the accident became clearer, the Nuclear Regulatory Commission notified EPA of the seriousness of the malfunction.

Three days after the first glimmering of trouble in the reactor, a team of 19 technicians from the Office of Research and Development's Environmental Monitoring Systems Laboratory in Las Vegas were in Pennsylvania with monitoring equipment and a specially-equipped plane for more intensive monitoring. Volunteers from EPA's Region 3 office in Philadelphia and the Chesapeake Bay Program also began taking samples from the Susquehanna River and the Chesapeake Bay.

The staff from Las Vegas had to move 10,000 pounds of radiation monitoring and sampling equipment more than 2,000 miles and the logistics were complicated by an airline strike -- but they managed within 24 hours of being called.

The continuous monitoring network that Agency staff set up began operation on Sunday, April 1, with 11 stations, and two days later expanded to 31. Technicians placed 12 monitoring stations in a relatively circular pattern within a three-mile radius of the reactor. They located 10 additional stations within a six or seven mile radius. Nine more monitors were set in populated locations more than seven miles from Three Mile Island. These 31 stations remained in operation throughout the month of April until EPA officials were convinced that the situation had stabilized and there was less threat to public health and safety.

At each site scientists collected information from an air sampler, a gamma rate recorder, and a thermoluminescent dosimeter. The air samplers measured particulate contamination from air drawn through paper and charcoal filters. The gamma rate recorder measured radiation levels and displayed the results on a tape read-out. The thermoluminescent dosimeters are small squares of crystalline material that recorded total exposure from gamma radiation.

Cramped Quarters

At first, EPA established an analytical laboratory in nearby Harrisburg to process samples while staff members were working out of temporary quarters in Capitol City airport and later two trailers parked just outside the high-security area on the Island itself. Eventually the Agency rented office space in a small shopping mall in Middletown amidst a small hardware store, credit office and bookstore in order to improve the public's access to Agency representatives. Desks, telephones, computer terminals, laboratory space and a briefing room were set up there to help the staff process and relay information.

After positioning the air monitoring stations, the staff had many other tasks to pursue. Scientists in the research plane flew two missions to make measurements of airborne radioactivity and to track the very narrow plume from the reactor. At other times the plane was on emergency standby to track and sample radioactivity in case the accident suddenly became critical. Compressed air samples were taken at on-the-ground locations for noble gas analysis. (So-called noble or inert gases are a group including krypton. The presence of krypton in excess of normal background concentrations would have indicated a leak from the reactor.)

EPA set up two water sampling stations on the Susquehanna River below the plant and three more downstream on the Chesapeake Bay. The staff began testing drinking water samples for contamination two days after their arrival, one week after accident.

One staff member noted, "You can imagine what we were up against. We had to find all the wells and reservoirs. There wasn't even a central source of information to tell us where these things were." Scientists located 21 surface sources of drinking water and gave these spots top priority in the sampling because the danger of radiation contamination was considered to be highest there.

Other aspects of the environment required immediate attention as well. Technicians working from aerial photographs located 570 dairies within 25 miles of the disabled reactor. On April 5, EPA started sampling milk from nine selected dairy farms. In order to get a full picture of the environment, EPA and the other Federal agencies also collected samples of water, vegetation, air, and river sediment for study.

Scientists and Ecopolitics

As scientists and engineers worked feverishly to control the mechanical aspects of the TMI situation, the overtones of "ecopolitics" continually had to be dealt with. One example involved a sampling device, designed to set off an alarm when it detected a given level of radioactivity in the discharge to the river from a low-level waste storage tank.

The monitor alarm was set to trigger a device that automatically dialed a certain phone number, which in turn tripped portable beepers worn by scientists on the scene. In the early days after the accident, this alarm went off with disturbing frequency, but scientists found no corresponding "peak" of radiation on the recorded print-out at the monitor. Coincidentally someone notified the news media about the large number of alarms from the power plant monitor. Agency staffers inferred that someone had learned the alarm number and was dialing it for nefarious reasons. They changed the phone number and the alarms stopped. (In fact, EPA scientists now report that the water contained no appreciable levels of gamma radiation contamination.)

Getting the device installed underscored another human relations problem at Three Mile Island. EPA staff members developed within weeks the system which continuously monitored radionuclides in the contaminated water, since some feared that contaminated water from the plant would be discharged to the river.

The system uses a sodium iodide crystal, which is sensitive to radiation, to monitor radiation levels in the effluent and then record results on a strip chart. Effluent passes through a tank shielded by lead bricks to reduce background radiation from impacting the crystal. A separate tank retains additional water samples for further testing by EPA and the State.

Staff members noted that Metropolitan Edison was less than cooperative to this effort at first. "We had to bring it over in a boat," said one scientist, since the company controlled access to the island over two bridges. Now the company allows Agency scientists free access to the island and to the device, which is enclosed in a metal shed in the shadow of the damaged reactor.

Historic Role

At the time the Three Mile Island crisis erupted a year and a half ago, many outsiders were unaware that EPA had an involvement in radiation. The fact is, however, that EPA's Offices of Radiation Programs and Research and Development have maintained nationwide radiation sampling programs and monitored the fallout from nuclear testing for years. The Agency received its primary mandate to manage radiation protection through the Reorganization Order #3 of 1970, which created EPA, and the National Environmental Policy Act of 1969. Six other laws, including amendments to the Atomic Energy Act of 1954 and the Clean Air and Water Acts, give EPA responsibility for protecting public health from radioactive contamination.

As EPA Administrator Douglas M. Costle declared at the outset of the crisis in Pennsylvania, "It is of the utmost importance to the Federal Government that people and the environment be protected from unnecessary exposure to ionizing radiation from radioactive material that may be released from Reactor # 2 at Three Mile Island. We are working with other involved Federal agencies to provide the best possible information from environmental radiation monitoring."

Initially EPA was a quiet partner in the Federal presence at Three Mile Island. Information about what was happening in and around the reactor reached the public through the Nuclear Regulatory Commission, Metropolitan Edison, and the Pennsylvania Department of Environmental Resources. Metropolitan Edison conducted its own environmental surveillance program, as did the State.

As the hazards of the situation became more apparent, however, the public feared the possibility of a nuclear core meltdown, a drastic increase in temperature in the reactor that could breach the containment building and release massive amounts of radiation into the atmosphere.

On April 13, 1979, the White House designated EPA as the lead Federal agency to develop a long-ter monitoring plan and coordinate all Federal environmental monitoring in the area. EPA immediately approved a preliminary monitoring plan and started to put it into action.

Assistant Administrator for Research and Development Stephen Gage outlined the aims of the long-term surveillance program. The plan would 1) provide a measure of the radiological quality of the environment around the power plant, 2) help keep people informed about radiation levels, 3) confirm and check on how well we could control radioactive releases to the environment, and 4) ensure equipment was ready in case of an accidental release. He added that plans would be assessed periodically to ensure they were appropriate for the changing operations at TMI.

Gage named Erich Bretthauer, Director of the Las Vegas Laboratory's Nuclear Radiation Assessment Division, to manage the emergency project. His staff routinely monitors fallout from nuclear weapons testing, and their expertise has proven invaluable at Three Mile Island. "In the past we've not been geared up for this sort of thing, because there was more emphasis on nuclear armaments," said Bretthauer. "But our people responded admirably to the situation."

The results of the sampling have been reassuring. EPA scientists found only very low levels of radiation in the area. The total maximum radiation exposure, according to a White House-sponsored report on Three Mile Island, is roughly equivalent to the amount of radiation a person would absorb from living in a brick rather than a frame house, or by moving to an area at higher altitude like Denver, Colorado where the natural background radiation is higher.

When the first threat from the emergency passed, EPA scaled down its efforts at Three Mile Island. The staff shrank from its emergency level of 31 to five scientists and technicians who maintained the 18 remaining monitoring stations. Staff members prepared six volumes of environmental information for the President's Commission on the accident.

An interagency analysis concluded that the accident did not raise radioactivity far enough above background levels to cause even one additional cancer death among the people in the area. They found no contamination in water, soil, sediment or plant samples.

According to Charles Cox, Public Health Service on-site coordinator at Three Mile Island, out of over 800 milk samples collected from local dairy farms during the period of March 29 to April 20, 1979, a total of 69 were reported to have trace amounts of radioactive contamination, the highest level being 36 picocuries per liter. He stated that this level of activity was less by a factor of 35 to 40 than that measured in the fallout from Chinese nuclear testing in October 1976 which passed across the United States. The levels measured after the TMI accident were far below the protective action level, which according to Public Health Service guidelines is 12,000 picocuries per liter. Since March 1980 the Service has curtailed its milk monitoring, but is prepared to reinstitute its sampling program in the event of an unexpected release from the reactor. Currently the Commonwealth of Pennsylvania's Department of Environmental Resources is sampling milk as part of its routine surveillance program.

Gold Medal Award

Administrator Costle in December 1979 awarded the EPA Gold Medal to the team from Las Vegas for their dedication during the emergency. He cited their efforts as an example of the commitment of 'bureaucrats' to the ideal of public service. But the Agency's mission there was far from over. In some respects it had hardly begun. As the utility moved ahead with efforts to clean up the damaged nuclear reactor, EPA continued to coordinate the government involvement in the cleanup. The long-term surveillance plan was updated twice to reflect changes in operations as each aspect of the cleanup presented a different challenge to the Agency.

For instance, local residents had become increasingly critical of the way cleanup activities were being monitored by the utility and Federal Government. Many people questioned the credibility of Metropolitan Edison and the NRC. The White House received several requests for an independent agency to be put in charge of monitoring and reporting radiation levels around Three Mile Island. Although EPA had been continuously monitoring the situation, the Agency's presence was masked because all information was funneled to the public through NRC and the State.

In response to those reports, on March 5, 1980, the White House expanded EPA's role by designating it the lead agency for reporting as well as coordinating the Federal monitoring program. Assistant Administrator Gage assigned Matt Bills, Associate Deputy Assistant Administrator, Office of Monitoring and Technical Support, to coordinate EPA activities and continued Erich Bretthauer as project manager.

Venting Krypton

The next phase of the cleanup was beginning. Several months after the accident, Metropolitan Edison applied to the NRC for permission to vent the radioactive gas that has accumulated inside the containment building. The gas, krypton 85, had to be removed before workers in protective gear could enter to assess the extent of damage to the reactor. Venting was set to begin June 28 and to continue until the krypton was removed. Local anti-nuclear groups petitioned the U.S. District of Court of Appeals for an order to halt the venting until a public hearing could be held on the safety of the procedure, but the appeals court denied their petition.

The approved venting plan called for controlling the flow rate of krypton so that a person standing at the boundary of the nuclear power plant would be exposed to no more than 15 millirems of beta radiation to the skin. Federal authorities felt that dispersal and dilution of the radioactive gas would keep people in the area from experiencing untoward exposure, and EPA's monitoring system was set up to ensure that these safety standards were upheld.

The expanded responsibilities came as EPA was gearing up to deal with the venting operation. While the Agency had no direct control over the conduct of the venting, acting only as an observer and monitor, the surveillance plan called for round-the-clock sampling to keep a constant watch for any excessive levels of radiation. The Office of Research and Development brought in additional personnel to help with the monitoring and also borrowed staff from the Department of Energy and Public Health Service. The Agency opened the Middletown office at this time to provide a better base for scientists to work from and to give citizens improved access to information.

Tracking The Plume

On a large wall-map of the area surrounding Three Mile Island, EPA scientists plotted the trail of the krypton. The map is divided into 16 pie-shaped wedges radiating out from the power plant, with colored dots showing the location of permanent sampling sites. Other markers show the placement of the mobile sampling units, which were kept constantly informed of changes in the direction of the plume by radio contact.

The markers on the map represented two pick-up trucks and trailers bearing the EPA seal and the legend "EPA TMI Monitoring Team." Following the prevailing winds and directions from the Middletown office, a team of researchers would pull the trucks and their trailers off the road near a farm field or a ranch house. Soon the sound of generators and compressors would fill the air as the scientists forced air samples into containers that looked like yellow watermelons. The contents would later be tested for concentrations of krypton.

EPA's two teams were stationed on the east and west banks of the Susquehanna opposite the power plant. A monitoring team from the Nuclear Engineering Department at Pennsylvania State University took measurements at locations further out to provide an independent check of EPA's samples. The data obtained by Penn State researchers also served as an assurance that the krypton plume was dispersing as predicted and not touching in high concentrations at remote locations.

Establishing a Dialogue

Representatives from EPA and NRC met with many interested citizens in the TMI area to explain the responsibilities and actions of their agencies prior to the venting. In almost 40 meetings they sat down with elected officials, school boards, doctors, citizen groups, and anti-nuclear organizations. Matt Bills negotiated a meeting of TMI Alert members with officials of EPA, NRC, and the State. The group's staff director later wrote to EPA, "I do not know if anyone 'learned' from the meeting; it did prove that a dialogue can be held between us all. In the long run that may be the most important benefit of our efforts."

Local people were not just observers of the venting operation. The State trained some 40 volunteers to help with surveillance activities. They assisted in air sampling activities and collected data from sites around the area.

Senior citizens pitched in to help during the venting as well. Through the Senior Environment Employment program EPA supplemented its staff in Middletown with 13 retired people who helped with the monitoring, administrative, and information tasks.

The krypton venting continued rapidly without incident and was completed July 12. Company officials stated that the amount of krypton actually released was closer to 43,000 curies than the 57,000 they had first estimated.

Off-site readings of radiation were well below Federal safety standards throughout the venting. Analyses of EPA samples showed lower readings than originally expected. This was "probably due to the lesser amounts (of krypton) in the containment" than originally calculated, said project manager Bretthauer. He added, "We detected nothing in the environment except krypton 85."

EPA's conduct of the krypton monitoring system was praised by Middletown Mayor Robert G. Reed, who said the Agency "did an excellent job." He said that the presence of EPA staff and the citizen monitors "helped to relieve the frustration and stress as far as the townspeople were concerned."

With the end of the venting, the extra staff members have returned to their regular jobs and the EPA Middletown office is back on its regular schedule. Bretthauer wound up his tour as project manager and was replaced by Dr. Bill Kirk, a radiologist from ORD in Research Triangle Park, North Carolina. Before leaving, Bretthauer said, "The pattern we've established will continue, with slight changes in emphasis. The air monitoring will be less in the spotlight, water monitoring will become more important." The next major phase of TMI cleanup will be to filter and dispose of contaminated cooling water from the reactor.

Bill Kirk and Matt Bills have initiated a new series of meetings and briefings with people who live downstream of the power plant. When asked how long EPA would be involved at TMI, Bills said, "We've taken a 5-year lease on the building in Middletown. I expect we're in for a long haul. There's a great deal of work left to be done."

The long hours, the anxiety and the conflicts are over for the present. Most of the scientists, students and senior citizens have returned to their normal duties, each with the knowledge that their efforts have not gone unrecognized. A message from the White House, sent to them last July 4, declared:

"Your dedication and personal commitment in carrying out a sensitive and difficult task are appreciated by the President."

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Christine Perham was Assistant Editor of EPA Journal.