Of all the words in the lexicon of nuclear power, none is more hideous than "meltdown," an event so sinister that many physicists find it distasteful to talk about.
It is an simple as it is sinister: the nuclear fuel overheats to such a degree that it melts through the floor of the reactor vessel and the rock beneath it, resulting in the release of deadly radioactive contamination into the air or water.
By the night of Friday, March 30, the third day of the Three Mile Island incident, the possibility of a meltdown had become frighteningly real.
But that wasn't all. There was also a chance that the reactor might explode with enough force to shatter the containment and shower nuclear rain over a Pennsylvania countryside beginning to show signs of spring.
All of this because of a bubble.
This bubble had appeared late Thursday or early Friday. At first the Metropolitan Edison people believed it was a steam bubble. Then the experts from Babcock & Wilcox, which built the plant, and the Nuclear Regulatory Commission agreed that, with pressures of up to 1,000 pounds per square inch in the reactor, it couldn't be a steam bubble. A steam bubble would have collapsed.
That left only one possibility: a gas bubble containing hydrogen, temperamental, volatile hydrogen.
The bubble, 1,000 cubic feet and growing, would make Saturday the worst day of the crisis.
Shortly after 1 p.m. on Friday, a giant Sikorsky helicopter with Air Force markings began circling Three Mile Island, then put down in a cornfield behind the Met Ed command post on the west bank of the Susquehanna River. A tall husky man with thinning, sandy hair and long sideburns jumped out, followed by nearly a dozen aides.
Earlier, when the chairman of the NRC, Joseph Hendrie, briefed President Carter on the situation, the president had asked for one good man at the scene, someone who could speak authoritatively for the government about what was going on. He's on his way, Mr. President, Hendrie replied. His name is Harold Denton.
Terrible events have a way of distorting and enlarging personalities, of turning unknowns into heroes. At Three Mile Island there would be no heroes, but in the tension and confusion of the weekend. Harold Ray Denton, a Washington bureaucrat, would come to symbolize a kind of technocratic reasonableness that helped to ease the public mind.
As he arrived at the command post, Denton also knew he was there to end as much as possible the public bickering between the company and the government. "We plan to work very closely with the governor," Denton said as he walked past the guards at the door of the command post.
He did not mention Metropolitan Edison.
The specialists he had brought included some of the nation's top experts in reactor safety, in meteorology (to track wind patterns in hopes of keeping an explosive shower from drifting too far), and-more ominously-in treating victims of nuclear exposure. More specialists were on the way from Washington.
Denton's team was ushered into a windowless room in the command post for a briefing from Met Ed's John Herbein. He assured Denton things were under control. At about that time, monitors in the NRC's mobile trailer measured a 90-millirem "spike" of radiation. Two workers in the plant had uncoupled a hose full of radioactive water. They were quickly hustled off the site to be checked for radiation.
Herbein's briefing continued, but just as he raised the question of coexistence between the NRC and Met Ed, Denton was summoned to a greenhouse next door.
It was the president calling.
Denton found himself momentarily at a loss for works. "I relayed to him whatever I knew at the time," he recalled. "He wanted me to get on top of the situation, to keep him informed, and provide the full resources of the government to do whatever was necessary to protect the public health and safety."
Back in Washington, the bureaucracy under presidential assistant Jack Watson had begun to do the same. Because of the danger of possible radiation contamination, Watson's office authorized the Food and Drug Administration to contract for the manufacture, packaging and shipping to Harrisburg of 240,000 one-ounce vials of potassium iodide. It could be administered orally to collect in the thyroid, hopefully saturating the gland with this non-radioactive and non-cancer-causing agent before any radioactive iodine could reach it.
For evacuation planning, Watson had dispatched Robert Adamcek, a regional director of the Federal Disaster Assistance Administration, from Philadelphia to Harrisburg to coordinate with Gov. Richard Thornburgh. He had sent John McConnell, assistant director of the Defense Civil Preparedness Agency, to consult with county civil defense officials in the region surrounding the plant.
Watson's office also coordinated the shipment of 70 tons of lead bricks from depots around the country to the Three Mile Island plant. Dosimeters, blankets and cots were gathered and sent to centers that could be used in the event of evacuation.
These preparations, according to quick estimates, cost the government $1.7 million.
Denton hung up after conferring with the president, then walked out to the lawn in front of the house to brief the press. Before he could begin, a television reporter asked him to move-once, twice, a third time-so that the huge cooling towers of the nuclear plant formed the backdrop for the cameras.
Denton's remarks to the press were short. The White House, he said, was concerned that the reports being given the public weren't "hard firm facts." To dispel this concern, Denton said he would send his team of experts onto the island for a first-hand inspection. They would report to the governor early in the evening, and a press conference would follow around 8:30 p.m.
But there was much to learn on the island and they stayed longer than expected. It was nearly 8 p.m. before the Denton team arrived at Thornburgh's office to give the governor his first full report.
He would hear two pieces of alarming news.
The first was that the reactor core was more badly damaged than first believed-at least one-third of it. This had occurred on Wednesday when the falling coolant levels in the core exposed the top of the fuel rods. Unprotected by cooling water, the cladding on the outside of the fuel rods heated up rapidly. The zirconium in the cladding oxidized, releasing more heat, which in turn ballooned and split the cladding, allowing radioactive gases like xenon-133, krypton-85 and iodine-131 to seep out through the cracks.
NRC investigators had first learned of the extent of the damage to the core when they got back an analysis of the primary coolant sample. The damage, according to Denton, suggested that the radioactivity in the system of water in the containment was "hotter than hell."
The second alarming development was the gas bubble containing hydrogen, 1,000 cubic feet in size, at the top of the reactor. The reactor had become so hot that the coolant water had decomposed into its primary elements: oxygen and hydrogen.
The biggest danger was the possibility that the bubble would continue to grow, forcing all the coolant water out of the reactor allowing the temperature of the fuel rods to build up until they reached 5,000 degrees.
At that heat, the uranium would begin to melt.
Short of the meltdown, there was the possibility of an explosion, either in the containment building or in the reactor core. On the first day of the accident, there had been a small hydrogen explosion in the containment-an event Met Ed officials didn't tell state or federal authorities about. When NRC experts found out, they launched an immediate effort to analyze the physical chemistry of the bubble.
Thornburgh was told that the NRC's analysis showed that the hydrogen could become flammable or explosive in a matter of days.
A Princeton University scientist calculated that the energy in the bubble was enough to set off an explosion equal to three tons of TNT. Such a force could rip the top of the reactor dome right off, flooding the containment with radioactive debris. There were also fears that the hydrogen would escape to the containment and explode there. One engineer calculated that a hydrogen explosion three times the force of Wednesday's blast might break the four-foot-thick walls of the containment, releasing radioactive material into the air.
Thornburgh wanted to know about the worst case, a meltdown.
Once the core reaches 5,000 degrees, he was told, the rods begin to melt, and once the melting is under way, the heavy metals like uranium and strontium begin to run right through the floor of the reactor.
Even after a loss of coolant, there would still be a four-foot pool of water below the fuel rods at the bottom of the reactor vessel that had not boiled off. The melting core would fall into that pool of water, possibly producing a steam explosion that would blow the reactor dome off like a missile and break through the containment walls.
Meanwhile, the molten core would continue to bore down through the concrete floor of the containment and into the ground. A report on reactor safety prepared by Dr. Norman Rasmussen of MIT talks about the core boring at least 40 feet into the earth, stopping only when enough rock and soil have mixed with it to dissipate its heat.
In the worst possible case, a meltdown at Three Mile Island that forced a break in the containment and poured radioactive debris into the atmosphere could trigger a catastrophe.
One of the first and most abundant fission products released in a meltdown would be a swarm of radioactive iodine, a mix of gas and liquid that could be carried far downwind in the plume escaping the plant. People living downwind would almost surely inhale some of the iodine. Rain would bring more of the iodine out as a kind of fallout, settling on the ground and dosing anybody nearby with as much as 150 rems of radiation in a single day.
The lethal dose is described as 400 rems, but the sick, the elderly, young and unborn children could easily die from a dose of 150 rems. A dose that strong could begin to kill bone marrow so fast that death might follow in a matter of months.
To many scientists, the worst consequence of an overdose of radioiodine is not the lethal does a few might get. It is the non-lethal dose which would concentrate in the thyroid gland in the throat, where radiation might produce tumors in thousands of people over a period of 30 years.
MIT's Rasmussen postulated that in the worst possible case as many as 60,000 thyroid operations would be required over 30 years to cure the after-effects of a massive radioiodine fallout.
The long-term effects of a meltdown are felt if radioactive cesium and strontium get into the air and water. They contaminate the land for years to come.
The half-life of cesium-137 is almost 30 years, during which time it emits gamma rays so penetrating that no living thing could survive for long on ground badly contaminated by cesium fallout.
Denton's briefing of Thornburgh ran 90 minutes. Despite the seriousness of the situation at the plant, there was no imminent danger that would force an evacuation. Thronburgh was relieved.
At 10 p.m. he and Denton arrived in the cramped press room on the sixth floor of the Capitol. Public television carried the briefing live to hundreds of thousands of homes.
Thornburgh spoke briefly, to say he would order no evacuation at that time but would reconsider as events warranted. Then he turned it over to Denton.
"This is easily the most serious situation in the life of the reactor program," Denton said. And in the next few days, he said, the federal government, not Metropolitan Edison, would be making the crucial decisions.
In the corporate boardroom in Reading, where the bottom line is black ink, the long view about Metropolitan Edison Co. was upbeat, for good reason. The darling of the system, the new nuclear unit No. 2 at Three Mile Island, had begun delivering power last Dec. 30.
As books are balanced and tax laws written, the date-one day before the federal tax year ended-would play an important role in the flow of black ink in Reading. By getting TMI 2 into service 25 hours before the new year, Met Ed saved itself upwards of $40 million in taxes.
For such decisions, corporate managers win praise. Met Ed's annual recport took note of the tax advantages gained by putting TMI 2 into service. Walter M. Creitz, the graying company president who wears designer eyeglasses, wrote that that would make 1978 "a memorable year."
TMI 2 meant more to Met Ed and its parent holding company, General Public Utilities Corp. (GPU) of Parsippany N.J., than just another marvel of modern engineering. It was the $180 million vehicle that would get Met Ed stockholders' return on their investment back up near the 13.6 percent level allowed by the state Public Utility Commission. In ledger books where black ink is measured in decimals, 1978 had not been all that good-megawatt-hour sales were up about 7 percent, but revenues climbed only 2 percent. The rate of return on common stocks was 12.9 percent, down slightly from the 13.1 percent of 1977.
Met Ed is one of three electric companies that operate under the umbrella of GPU, and it owns half of the Three Mile Island complex. The other partners are Jersey Central Power & Light Co., and the Pennsylvania Electric Co. Among them, they provide most of the electricity used in Pennsylvania and New Jersey.
By getting TMI 2 into service before the end of the year, Met Ed, as principal operator of he plant, stood to gain in three ways.
Its pending rate-increase request with the state (a 19 percent boost took effect the day after the accident) hinged on geeting the plant into operation. The sooner it went on the line, the sooner the new rate could be collected.
And there were two other considerations. The company was able to claim about $20 million for six months' federal tax depreciation by putting TMI 2 into service before the end of the year. And according to data Met Ed filed with the Federal Energy Regulatory Commission, it expected to gain between $17 million and $28 million in investment tax credits-direct write-offs.
Creitz conceded to reporters after the accident that Met Ed had gained tax advantages by getting TMI 2 into service in 1978. But he and John G. Herbein, his vice president for power generation, insisted that there had been no "rush" to beat the calender at the expense of safety.
Yet, the record suggested questions. Between March 28, 1978, when the chain reaction began in the nuclear unit, and its December entry into commercial service, the plant had been shut down for repairs 195 of the 274 days-71 percent of the time. That was no typical of the industry as a whole, which reports about a 40 percent malfunction rate during early reactor operations. And during those 274 days, Met Ed found problems that were similar to those that occurred on the day of the Big Accident. Operating problems continued after the plant was put into service, but, Creitz said, they had nothing to do with a rush for money.
"We certainly never would have put it in service unless we were convinced it could be safely operated," Creitz said.
The NRC, in its preliminary reports, said that human errors as well as trouble with valves, within the plant's cooling system were major contributors to the accident. Warning signals had shown up earlier. In January, TMI 2 was shut down for two weeks because of problems with the cooling system.
But the men at Met Ed apparently felt confident. The NRC had licensed the plant in February 1978 after a decade of hassling and citizen protests in Dauphin County. And in September, Deputy Energy Secretary John F. O'Leary had flown to Three Mile Island to dedicate the plant as another "success" in the nation's effort to wean itself from dependency on oil.
Success, of course, is relative, and the accident has dealt a severe blow to the electrical system's financial stability, even though Met Ed has $33 million of liability insurance on the plant. GPU has stopped all bu the most critical construction work to conserve cash it may need for rehabilitation. GPU stock that was selling at 17-7/8ths before the disaster closed at 14 Friday.
The bottom line still is written in black ink, Six days after the accident, GPU Chairman William G. Kuhns hastened to reassure stockholders. Public health and safety were being dealt with at the plant, he wrote in a mimeographed letter which included a lengthy report on the financial picture.
Kuhn's letter did not mention this among the steps taken to preserve Met Ed's fiscal integrity: The firm ruled that pregnant employes who were evacuated from the radiation danger area would not be paid for time away from work.
By Saturday morning the two central institutions in the Three Mile island crisis, the corporation and the federal agency charged with regulating it, were drawing into open conflict with each other. The corporation was Metropolitan Edison; the federal watchman was the Nuclear Regulatory Commission.
It was a familiar adversary drama and the press, with clamoring insistence, poked and probed at the widening public contradictions between the two sets of briefing officials.
At 11 a.m. Met Ed president Walter M. Creitz held what he announced to be the last press conference the utility would hold. His tone was terse and subdued. Only a few in the room knew that the White House had decreed that the NRC would assume the role of public explainer for the balance of the crisis period. In effect the company had been told to shut up by the administration, which held full licensing powers over the plant.
The transfer of responsibility for telling the Three Mile Island story to the public was made at back-to-back press conferences, first by Metropolitan Edison and then a separately scheduled session by Harold R. Denton, the NRC's chief for reactor safety.
Met Ed's Creitz turned the floor over to John Herbein, a voice president of the utility, who told the conference that the deadly gas bubble in the reactor had dropped in size Friday night from 1,000 to 800 cubic feet. The NRC publicly disagreed, saying there had been no significant shrinkage.
Reporters, openly skeptical of Met Ed reassurances that everything was under control, now battered Herbein with questions. They extracted from him the information that the company's engineers had to abandon their efforts to shrink the bubble for 2 1/2 hours for fear of a hydrogen gas explosion.
Herbein nonetheless insisted that "I personally think the crisis is over."
At his own press conference an hour later, Denton contradicted Herbein openly. The crisis would not be over, he said, until the reactor was in a state of cold shutdown. One problem Herbein failed to mention was that inside the reactor the oxygen level in the bubble was climbing, thereby heightening danger of a gas explosion.
Herbein retreated from his earlier prediction that cold shutdown would be achieved within a day. Now, he acknowledged, it would be a matter of days.
"We attempted to tell the president and the country to the best of our ability what we thought was happening," said the utility executive. "This is the first time, I guess, that anything of this magnitude has happened."
Denton, in a later interview, described in sympathetic terms the plight of Met Ed when he arrived to take over, at Washington's direction.
"I was dealing with absolute chaos," he said. "They (Met Ed) were tighting fires. They were trying to cope with all the demands being placed on them and they didn't have enough staff to turn to."
"I was concerned that they were so thin technically at that time, that I couldn't find anyone who would gice me the kind of information I would have expected," Denton said. "And I was getting more hard facts from my staff in terms of analysis and potential seriousness than I could get out of them."
As the NRC officials who were arriving at the scene in greater numbers began taking a more direct role, however, Metropolitan Edison rebelled.
During one angry encounter with Denton, Metropolitan Edison officials threatened to pull all of their operators and technical personnel out of the Three Mile Island plant and dump the whole mess into the NRC's lap. The company retreated from its threat.
But by the end of the week, while NRC officials continued to pay lip service to the notion that Metropolitan Edison was making the decisions subject to their approval, it was clear who was really calling the shots.
"Since I'm the director of the office of nuclear reactors, I can issue, modify or suspend licenses," Denton said repeatedly through the days. "So I never had any doubt that if I didn't like the way they were running it, I could issue an order on the spot."
Meanwhile, in Washington, NRC Chairman Joseph Hendrie was issuing grim news. Residents of the central Pennsylvania area round Three-Mile Island ought to be prepared to evacuate from a downwind swatch of up to 20 miles. Since no one would know which way the wind would blow, it was the farthest-out evacuation warning yet and stretched the perimeter for evacuation to cover 630,000 persons.
Just before 8:30 p.m. came the final straw. Associated Press sent out a urgent story warning that the bubble situation had become extremely dangerous. In fact the story warned, the unnamed experts were warning that the bubble might explode at any minute.
Denton, on his way to brief Gov. Richard Thornburgh at the Capitol, was hastily taken before the skeptical and by-now panicky press in the Capitol to assure them that the situation was not that critical.
The press, no matter its nationality, thrives on red meat. Red meat is disaster, tragedy, conflict-wars, assassinations, a Jonestown massacre, exploding coal mines.
The Three Mile Island nuclear accident was red meat, of a sort never before experienced by the press: all the fine fiber of a Delmonico. It was a story of technology run amok, man forced from his home by the peaceful atom, the prospect of a stretch of the eastern seaboard being turned into an irradiated wasteland.
It was a helluva story and the media turned out in force. They came from around the world to witness this "event," as the nuclear technicians were calling it, and they came in droves.
By conservative estimates, there were 300 journalists and media technicians on the scene. No one knew who all of them were, where they all came from, or how many there were, but it was plain that few red meat events had ever drawn this kind of attention. It was a media event of such dimension that the Columbia Journalism Review sent two reporters to write a piece about the reporters. Rolling Stone magazine contracted with Mike Gray, an engineer who did the screenplay for "The China Syndrome," to tell the story of Three Mile Island-chillingly similar to his film fantasy.
The United States, Canada, England, West Germany, Japan, France, Australia, Switzerland, Denmark, Sweden-all were represented. Radio and television independents and networks. Large papers, small papers, magazines. Vans from Action News and Eyewitness News and See It Now cruised the streets of Middletown and lined the road across from Three Mile Island. Camera crews roamed through little Middletown.
Mayor Robert Reid, an easygoing and gracious schoolteacher, said he gave at least 100 interviews. He took calls from all over the country and from abroad. His fellow townsmen adjusted to the invasion as well as he did. They willingly gave interviews and many kept count of which papers and which stations had sought their views. A civil defense worker who was pictured in Newsweek's post-accident coverage was teasingly called "star" by his pals. A drugstore clerk, having read her remarks in a newspaper, thanked a reporter the next day for the "miracle" of quoting her correctly. She said it with a smile.
The volume of material sent from the area was prodigious. Major newspapers printed two, four, eight stories each day on the event. The Philadelphia Inquirer sent more than a dozen reporters to turn out a special section each day. During the daytime cycle on Friday, March 30-the tense day of the hydrogen bubble crisis-the Associated Press rewrote its lead story a record 27 times because of the fastchanging situation.
Just as unrelenting was the quest for local color, the seasoning of red meat stories. Reports quickly identified the Railroad House, a Middletown bar adjacent to the Penn Central tracks, as the place to go to rub shoulders with workers from the plant. Workers were not all that communicative-many felt the press was blowing the incident out of proportion.
No wonder. An NBC camera crew showed up at the bar to film the scene of distraught workers crying in their beer. The network men played the same jukebox song over and over to provide appropriate sound backup. Not long after that, an ABC crew showed up with the same idea. They fed coins into the jukebox, playing the same country song again to get just the right effect.
Middletown dealt with these intrusions in good spirit. A downtown merchant reacted to the ubiquitous camera crews with his own spoof. He stationed a youngster with a minicamera inside the front window, filming passersby and projecting the image onto a large TV screen facing the street. At Karl Kupp's diner, a gathering spot that features homebaked pies and classic smalltown banter, out-of-town reporters were joshed by Kupp and patrons alike. For all the grimness of events unfolding down the road at Three Mile Island, Middletown could smile at itself and these newsgathering strangers.
The logistics became an enormous problem. When President Carter decided to visit Middletown, the gym in the borough hall was converted into a press center by the Nuclear Regulatory Commission. The daily press briefings were held there, almost as raucous as the briefings by Three Mile Island operator Metropolitan Edison Co, and NRC press aide Joe Fouchard pleaded with the reporters to "discipline yourselves."
Because of the complexity of the story, NRC brought press assistants from field offices around the country. They were available to answer technical questions, and often did so with careful detail. But even the flacks had problems. "I finally did something right," said NRC's Karl Abraham after arranging with a printer to have a briefing transcript delivered in 90 minutes. The printer missed his deadline by several hours and reporters were seething. Abraham could only shrug his shoulders.
NRC's words and those of anyone else who was quoted were sent to the outside world by telephone, facsimile machine, radio, air. NBC ferried its crews between a motel and the plant site by helicopter. The New York Times sent an editor from the home office to direct its news team. One organization dedicated an editor fulltime to harassing Pennslvania Bell until it installed a telephone in the Middletown press center for private use of the newspaper. Newsweek had a team of nine on the scene, CBS more than 40.
Reporters in some cases ended up interviewing each other. In Middletown, a TV crew photographed two reporters standing on a corner eating slices of pizza. On the Friday when Pennsylvania Gov. Richard Thornburgh warned area residents to take cover, the community of Falmouth, a mile or so south of the plant, became a ghost town. Helen Rank, reporting for the weekly in nearby Elizabethtown, stopped in the village to conduct interviews. She found only a reporter from Washington, D.C. They exchanged views and took notes.
Looking back on it, Jim Hill, a reporter for the York Daily Record, a paper published about a dozen miles from the island, wrote: "After three days feeding on the carcass of Three Mile Island, I was benining to feel as ugly as what I ate. There was nothing delicious about this story."
Hill was right. There was nothing delicious about the story. It was a painful, distasteful one for some, who feared its potential. Reporters themselves could be victims of the ultimate disaster. Unlike a war or a riot, where refuge can be found from bullets and bricks, there was no refuge from invisible, tasteless, odorless radiation. If the unthinkable happened at Three Mile Island, if there was a core meltdown in the reactor, radiation would not discriminate.
Most editors understood that. Some sent in radiation exposure badges for their staffs. Other rotated reporters in and out of the area as a precaution against possible overexposure. AP shipped breathing devices and protective clothing for its staffers.
The fear was real. Jack Knarr, a columnist for the Philadelphia Journal, stayed at home. He wrote a piece saying "these people are nuts." An editor wanted him to go to Harrisburg and Knarr said, no way.
Paul Critchlow, the governor's press secretary, saw it from another angle. He remembered the Saturday night, just after 9 o'clock, when the Associated Press reported that the hydrogen bubble in the reactor was about to explode.
"About 20 or 30 reporters burst through the door of this office," he said, "They said: 'we want to know if our lives are in danger. What the hell's going on here? We want to know if we have to get out.'...They were plae. They were frightened. At that point, they had lost all interest in the story they were supposed to be covering."
There was cloak-and-dagger stuff, too, which would be humorous in movies but was even richer in reality. One night, alerted by a rumor that Carter was arriving any moment, a gaggle of photographers burst out of Lombardo's restaurant in Harrisburg, each toting uneaten, expensive, Italian dinner in doggy bags. Another evening, two Philadelphia Inquirer reporters monitored a radio conversation between two Met Ed employes on a secret channel. They were talking about a leak of hydrogen. "Shut the damn thing down and quit screwing around," one man said. The next day, the NRC's Harold Denton was startled when the Inquirer reporters read him a transcript of the confidential conversion. He explained, after hearing the details, what was going on. No great revelation.
If it was a fear-inspiring story, it also was a confusing and complicated one for most reporters, unschooled in the language and the complexities of nuclear science. The Chicago Tribune hired a professor as a technical adviser. A network did likewise. It was, ultimately, a story in which answers could be provided only by a small group of experts.
Before the NRC on Sunday, April 1, took over the sole role of issuing formal statements, confusion and contradiction had been rampant. Met Ed's press conferences degenerated into shouting matches, frustated and belligerent reporters challenging John Herbein, the company's vice president for power generation.
Herbein brought it on himself, in a way. His style was clear on the afternoon of the first day, when he sat down with Lt. Gov. William Scranton III to explain the situation. He provided an "encouraging picture," Critchlow said, with "the situation very much under control." No radiation emissions, he reported. Then the state people confronted him: Their own enviromental resources teams had detected radiation. What about it?
Oh, yes, Herbein acknowledged, between 11 a.m. and 1:30 p.m. the company has been putting gas into the air above the island. Had Herbein told the press? "They didn't ask," he told Critchlow.
An oversight, for certain. CAPTION: Graphic-Caption Picture 1, Revisting accident scene, chief nuclear regulator Joseph Hendrie, left, is guided by on-site boss Harold Denton. AP; Picture 2, Over crippled Three Mile Island reactor, a helicopter gathers radiation samples.AP; Picture 3, 1978 photo shows inside of Three Mile Island containment building, with walls four feet thick; upper ring of lights marks the bottom of the dome. AP; Picture 4, State trooper at plant gate admits Navy flatbed loaded with lead bricks for use as radiation shields. AP; Picture 5, Among the Med Ed safety precautions were radiation suits for the workers. UPI; Picture 6, The NRC's Denton assumed responsibility and control over the operations. AP; Picture 3, Middletown Mayor Robert Reid, an easygoing and gracious school teacher, says he gave atleast 100 interviews.