FROM PBS: AMERICAN EXPERIENCE
People & Events
Meltdown at TMI and the Hydrogen Bubble
Friday night, the word leaked out from the NRC emergency center down
in Washington that the NRC had some serious concern that a hydrogen
bubble had formed directly above the accident and that there was
actually hydrogen in the containment building and also in the reactor
vessel itself. And at
that point, the chairman of the Nuclear Regulatory Commission
directed Roger Mattson, the top technical guy, to form what was known
as the Bubble Squad.
And the Bubble Squad
was to determine, if a hydrogen bubble did exist in the reactor and
in the reactor building. If it did exist, when would it become
explosive. And if it exploded, what would happen.
So those questions were addressed sometime during the day on Friday.
Mattson from the Nuclear Regulatory Commission and several other
people began assembling this Bubble Squad, which consisted of the top
scientists from Livermore and all the nuclear labs in the country, as
well as the major universities and research institutions, Matel, and
so forth. The top thinkers in nuclear physics in the country who knew
anything about nuclear power plant design or construction were called
upon that night to assemble, you know, either physically or by
telephone to start studying this problem. Word
of that leaked out,
naturally, because there were calls going all over the country and
people were saying, "Well, why? What's happening here? Why this
urgent demand for concentration on this hydrogen? What is the
hydrogen problem?" And so a
story then hit the wire service "NRC Considering Danger of
Well, at that point the press corps inside the state house crashed
into the press room and demanded details from Paul Crichlow, Governor
Thornburgh's press aide -- you know, they
didn't want people to know, they didn't want a story.
What they wanted to know was, "Is it time to get out,"
because these guys had their equipment under the arm. They were ready
to head for the gate. And there
Harrisburg on that night. I was there and certainly I had the full
sense of the experience -- that we were faced with a potential
Harold Denton, the NRC Official, leaves the NRC emergency center in Bethesda, he pulls Victor Stello and Roger Mattson aside, his two top technical deputies. He tells them, "This technology, to a large extent, has relied on specifications that you guys laid out here for the emergency safety systems. Don't tell me those safety systems don't work. You find us a way to get out of this," and with that, he leaves. Stello goes with him to Three Mile Island as his technical deputy. Mattson stays in Bethesda to try to -- well, he's in charge of the Bubble Squad. So, these two guys are separated for like 24 hours, working from entirely different perspectives. Mattson's seeing the situation as the information comes in from his technical advisors in the universities and research laboratories that are now connected to the Bubble Squad. Victor Stello is up in Three Mile Island with Harold Denton and they are talking to the reactor operators, and actually eye-balling the plant, and looking over the print-outs and so forth. So they have a divergence of opinion about this. The President announces that he's arriving on Sunday for a personal tour. There were two reasons for this. The panic on Saturday night was palpable. Not only among the citizens of Middletown and Harrisburg, but among the press, among newscasters, and among senators and congressmen in Washington. The President felt that it was necessary to show the flag. And not only was he going to make a personal appearance at Three Mile Island, he brought his wife with him. And Rosalyn Carter went in a very brave show of support for the mothers and wives of the citizens of Middletown.
A few moments before the President is due to arrive by helicopter, Roger Mattson shows up. Mattson and the NRC commissioners had driven up from Washington to be there ahead of the President. As a top bureaucrat, of course, you know, the one thing you don't want to do is you don't want to be late for a meeting with the President. So they had arrived just minutes before the President. Here comes Roger Mattson into the hangar and here's Victor Stello, the other top NRC expert, and Stello says, "Mattson, you son-of-a-bitch! How could you be spreading these rumors about this hydrogen bubble," and Mattson is saying, "Victor, that bubble is ready to explode and if you can't see that, you're crazy." And they're screaming back and forth at each other inside this hangar. This had to be a fairly thrilling moment for Harold Denton as the President's deputy because here is the President, the chief executive, due to arrive at any moment with his wife. And here are his two top technical experts slugging it out there in the hangar over whether or not the place is about to blow up.
So the President lands. The entourage comes in. Everybody is with him. And they go in and the President is introduced to the various players and Harold Denton says, "Mr. President, regarding the hydrogen bubble, there are two schools of thought on this issue." But the consensus was, as a result of that meeting, that at least they had some time, that Victor Stello and Roger Mattson may have been at each other's throats over whether or not it was going to explode right now, but that there was a feeling overall among the various technical experts that they had a few days to resolve this issue before it actually exploded. With that, President Carter said, "Okay. I want to see the plant." So they left the hangar at Harrisburg airport and the motorcade went down the River Road to Three Mile Island.
In terms of the analysis of the hydrogen bubble, it turns out that Victor Stello's experts were right and Roger Mattson's experts were wrong. While it's true that there was a tremendous hydrogen build-up, in order to make it explosive. You have to have the right amount of oxygen. It's hydrogen combining with oxygen, poom, to make H2O that is explosive. Stello was convinced that the amount of oxygen inside the reactor was not sufficient to explode at this time. He believed that there was time to, somehow or other, start bleeding that hydrogen out of there. The problem was they had no way to get the hydrogen out of the reactor vessel. Having looked at the blue prints of a nuclear power plant, let me tell you that the simplest version of these blue prints, the ones that just show the essential instruments and essential pipes and valves, is a document that's this size and that thick. There and these guys were going through it day and night, looking for any little quarter-inch pipe somewhere in that whole labyrinth of pipes that would allow them to open a valve somewhere from the control room that would start bleeding that hydrogen out of the system. And they could not find one. The reason is they had designed the system so perfectly to avoid any kind of a leak like this that they had prevented anybody from creating a leak if they needed one. If they had had a major break in the pipe, if they had had a huge fracture, if one of the pumps had split open, they were preparing to deal with that. They had emergency core cooling water. They could have opened the tanks and flooded the core. As long as the reactor vessel was still intact, they could have filled it up somehow or other, if they had blown the pressure out of there with some kind of a major break. But they didn't have a major break. They had a little tiny leak. And there was no way that they could get that hydrogen out of there instantly. So what was required was, they would have to go through what they called a "blow-down." They would have to open the systems and blow the pressure down to nothing, at which point the water in the reactor core would probably sink to nothing and the whole core -- whatever was left of it -- would be completely uncovered and would begin heating up at the rate of three to five degrees a second. If that core reaches 5000 degrees, it's irrecoverable. There's nothing you can do to save it. Now, what they did not know, of course, was that the core in places had already reached a temperature of 4300 degrees. So they were within 700 degrees of the "China Syndrome."
Roger Mattson and Victor Stello went
back a long way. Together they had worked as part of the Atomic
Energy Commission, when nuclear power was in its infancy. The two
men, though different in demeanor and approach, held each other in
high regard. In the early days of the accident they worked together
at the Emergency Management Center, established by the NRC. Little
did either man know that later a rift would develop between the two
engineers that would send a shock wave through the entire nation.
Mattson, who was considered the nation's leading expert on emergency core cooling, came to the startling conclusion that a hydrogen gas bubble had formed above the reactor core. Speaking to NCR Chairman Dr. Joseph M. Hendrie, Mattson said, "They can't get rid of the bubble. They have tried cycling and pressurizing and depressurizing; they have tried natural convection a couple of days ago; they have been on forced circulation; they have steamed out the pressurizer; they have liquided out the pressurizer. The bubble stays." Mattson explained that in order to shut the reactor down, they must reduce the pressure. But lowering the pressure caused the bubble to get bigger. A bigger bubble could push all the water right out of the core and lead to a meltdown. Mattson told Hendrie they were involved in a "horse race," and he was quite unsure as to whether they could win it. Meanwhile, word of a possible meltdown begin to ripple through to the press. That night news anchorman Walter Cronkite, one of the most trusted men in America, updated the nation as to the gravity of events at Three Mile Island: "The world has never known a day quite like today. It faced the considerable uncertainties and dangers of the worst nuclear power plant accident of the atomic age. And the horror tonight is that it could get much worse. The potential is there for the ultimate risk of meltdown at Three Mile Island...."
Victor Stello traveled to Harrisburg with Harold Denton on Friday, March 30, the day of Cronkite's somber broadcast. According to Mike Gray, the screenwriter of the film "The China Syndrome," Mattson confronted Stello on Sunday as they waited for Carter to arrive and the two men engaged in a heated debate over the potential for the hydrogen bubble to explode. At the time President Carter entered the plant, the legitimacy of the hydrogen bubble risk was still undetermined.
On Sunday afternoon, while Carter was still there, Victor Stello found the proof he needed. They discovered that Mattson and his team of consultants had been using the wrong formula to determine the risk posed by the hydrogen bubble. Stello concluded that "hydrogen under pressure will prevent water from breaking apart into hydrogen and oxygen because it will tend to suppress the creation of more hydrogen. Without free oxygen, there can be no explosion." Plant operators began hooking devices to the containment building in order to slowly burn away the hydrogen, thereby bleeding away the bubble.
Three years after the accident, a robotic camera was lowered into the Unit 2 core, providing the first look at what really had happened. Roger Mattson, a senior NRC engineer, describes what was revealed: "We had a meltdown at Three Mile Island. Fifty percent of the core was destroyed or molten and something on the order of twenty tons of uranium found its way to the bottom head of the pressure vessel. That's a core meltdown. No question about it."
The damaged reactor at Three Mile Island was not the first President Jimmy Carter had viewed up close. While in the Navy, Carter was part of a team that helped dismantle the damaged nuclear reactor at the Chalk River plant in Ontario, Canada. A trained nuclear engineer, Carter worked under famed Admiral Hyman Rickover, the father of the Navy's nuclear program, on the "Sea Wolf," an atomic submarine. He also studied nuclear physics at Union College in New York. Given his background, Carter had a firm grasp of the potential disaster that would ensue should a nuclear meltdown occur. As a seasoned politician, he was also aware of the possible panic that would ensue should people come to believe a meltdown was imminent.
Upon hearing of the situation at Three Mile Island, Carter dispatched Harold Denton, the director of the Division of Nuclear Reactor Regulation at the Nuclear Regulatory Commission, to Harrisburg, Pennsylvania as his personal representative. The president was frustrated by his inability to establish telephone contact with Pennsylvania Governor Dick Thornburgh. To solve this problem, he ordered dedicated phones lines be connected between the White House, the NRC, and the State House at Harrisburg. By Saturday, March 31, Carter had decided to pay a personal visit to Harrisburg. The national and international media had given the accident at Three Mile Island front page attention for days and venerable network newsman Walter Cronkite was speaking of a "horror" that "could get much worse." Carter believed that the people of Pennsylvania and the nation were looking to him for leadership, so on April 1, Carter inspected the damaged plant. Middletown, Pennsylvania, Mayor Robert Reid later spoke of Carter's visit as providing a much-needed morale boost. "People weren't talking to one another. They were cooped up in their homes, and when he came, it seemed like everyone came out to see the president and it was really a shot in the arm," Reid recounted to writer Mark Stephens.
Harold Denton, director of the Division of Nuclear Reactor Regulation at the Nuclear Regulatory Commission, was President Carter's personal representative to Harrisburg "for the duration of the problem" at the Three Mile Island nuclear power plant. The arrival of Denton seemed to immediately calm the frayed nerves of public officials and stem the anger of a frustrated press corps. Reporter Steve Liddick of WCMB radio explained to writer Mark Stephens that "Harold Denton was trusted because he looked like a regular, down-to-earth kind of guy. And people wanted someone to believe."
Denton's job was far from easy. It fell to him to inform Thornburgh and Carter about a possibly explosive hydrogen bubble discovered above the cooling water, at the top of the reactor pressure vessel. That bubble-and whether or not it would mix with oxygen and set off a devastating explosion -- proved to be the source of intense debate, and fueled nightmarish images of a meltdown.
At the time of Carter's arrival on Sunday morning, April 1, the question as to whether the bubble would explode was still under debate. Denton informed the president of the risk just as he was preparing to enter the plant. "...I briefed the president on this bubble and the possibility of an explosive mixture and tried to give him the two sides that were out there, but we still didn't have single view on that," Denton remembered.
It was Mike Pintek's job to know what was going on in Dauphin County, Pennsylvania. Twenty-seven-year-old Pintek was the news director at radio station WKBO and a life-long resident of the county. On March 28, 1979, Pintek's traffic reporter Dave "Captain Dave" Edwards was cruising the streets of Dauphin County in his trademark yellow Camaro (the small radio station could not afford a traffic helicopter) when he began to hear an unusual amount of activity on his CB scanner. Edwards phoned Pintek to inform him that the Middletown police and fire departments were mobilizing. Then Edwards mentioned that he hadn't seen any steam coming out of the power plant's cooling towers. Edwards assumed that the plant had shut down for some reason. Hearing this, Mike Pintek began to make some calls. No one at the Dauphin County Civil Defense office knew what was going on. Pintek then decided to call Three Mile Island. To his surprise, a harried switchboard operator put Pintek's call straight through to the plant's control room. Through the telephone line, Pintek could hear a lot of commotion. After introducing himself, a person in the control room informed Pintek, "I can't talk now. We got a problem. Call Reading and talk to them."
Suddenly, small town reporter Mike Pintek was thrust into the middle of a very big story -- a story with national and international significance. He just didn't know it yet. After hanging up with the Three Mile Island control room, Pintek placed a call to Metropolitan Edison Company, the parent company for Three Mile Island, in Reading, Pennsylvania, and asked to speak with Blaine Fabian, the director of communications. Fabian was already aware of the situation at Three Mile Island and was busy working on a statement that would prevent a panic. Working with Jack Herbein, a Met Ed vice president, Fabian had crafted a two-sentence statement: "The nuclear reactor at Three Mile Island Unit Two has shut down as prescribed when a malfunction related to a feed-water pump occurred about 4 am, Wednesday. The entire unit was systematically shut down and will be out of service for about a week while equipment is checked and repairs made." Fabian went on to tell Pintek that a "general emergency," which Fabian described as a "red-tape type of thing required by the NRC (Nuclear Regulatory Commission)," was taking place at the plant. Fabian assured Pintek that there was "no danger to the general public."
At 8:25 am, Mike Pintek delivered to his listeners throughout Dauphin County news that would greatly impact their lives for the next several days. Following a top-40 pop song, Pintek announced, "There is a general emergency at Metropolitan Edison Company's Three Mile Island nuclear power plant. A utility spokesman says there is a problem with a feed-water pump..." Pintek included in his report Met Ed's assurance that the public was in no danger.
For the next five days, Pintek struggled in his dual role of objective journalist and concerned citizen. At times, his conflicted impulses got the best of him. "I remember feeling very angry," he later said. "I guess at that moment I was not a journalist any more. I lived here and I was mad." Pintek inadvertently ignited a panic in the area when he broadcast the conclusions of Dr. Ernest Sternglass, a professor of radiology at the University of Pittsburgh. Sternglass had expressed concern that any radiation released from Three Mile Island would pose a threat to unborn babies and infants. "I'm particularly concerned with the possibility of an increased risk of leukemia and cancer among the very young," Sternglass said. He continued, "...pregnant women should very seriously consider leaving." Pintek was torn about using the story, but finally decided to do so. He later told writer Mark Stephens, "At that point, after hearing so many contradictory statements, I felt Dr. Sternglass was just as much a legitimate authority as anybody else was. ...So I said use him. Let's do it." Immediately following the broadcast, WKBO was flooded with calls from frightened residents wondering if they should leave. Like the rest of his fellow residents of Dauphin County, Mike Pintek had no answers. He only had more questions.
Prior to March 28, 1979, Middletown, Pennsylvania mayor Robert Reid considered the nuclear power plant at Three Mile Island to be a blessing to his small town of 11,000 citizens. Millions of dollars had been poured into Middletown's economy during the plant's construction, and many residents collected their weekly paycheck from the plant. Three Mile Island took its place beside Bethlehem Steel and Fruehauf Trailer Factory in providing jobs and a measure of middle-class prosperity to the people of Middletown. In 1979, Robert Reid had lived all of his 46 years in Middletown. He'd made a name for himself as a star fullback for the Middletown High School Blue Raiders. While serving as mayor he continued to teach a course in American Government at that same high school. Hard-working and feisty, Reid maintained the physique that made him a boxing champ in college. He was also, in 1979, the only African American mayor in Pennsylvania.
Reid took his job as mayor seriously. He was interested in the lives and well-being of the people of Middletown. Three nights a week he would ride along in the patrol car of a policeman friend, Earl Anderson, making his presence known on Middletown's streets. Reid went to work on Wednesday, March 28, having no knowledge that a crisis had been unfolding at Three Mile Island. Midway through his first class of the day, Middletown's Civil Defense director, Butch Ryan, informed Reid that something was up at TMI. When he reached his office in the town municipal building, located less than 6,000 yards from Three Mile Island, the first challenge Reid faced was obtaining accurate information. "All that I learned when I got to the office was that there had been an on-site emergency declared," Reid recalled for writer Mark Stephens. "So we sat there and we listened to the television. We changed from channel to channel, and each channel gave us different information."
Reid would need as much accurate information as he could gather over the coming days in order to prepare for a possible evacuation of Middletown. At the time of the Three Mile Island accident, Middletown had no formal emergency evacuation plans in place, and Reid, like other state and federal officials, was growing frustrated with Met Ed. "I was angry from that Wednesday," Reid recalled. "I was upset with the way things were being handled and the way we were lied to." When Pennsylvania Governor Dick Thornburgh's office recommended a limited evacuation, Reid had his hands full. He recalled, "People left their jobs, came home, packed their cars and their children. And I remember standing on the corner and cars zipping past me and people hollering out the window, 'Watch the town.' ...Things were starting to get a little hectic." As he tried to calm the frayed nerves of Middletown citizens, Reid also had to take measures to make sure no one took advantage of the disruption.
"There had never been anything like this,...it wasn't something you could see or feel or taste or touch. We were talking about radiation, which generated an enormous amount of fear." As Lieutenant Governor of Pennsylvania during the Three Mile Island crisis, William Scranton III observed and experienced much of that pervasive fear. Scranton, along with being second in command of state government, was titular head of Pennsylvania's State Emergency Management Agency and Chairman of the State Civil Defense Council. Ironically, Scranton, who'd only been in office for 68 days, had had several meetings already with various members of each emergency management team. When news of the crisis reached his office via Oran Henderson, the actual head of the State Emergency Management Agency, Scranton at least had the advantage of knowing which individuals to contact. In this capacity, he would prove quite valuable to his boss. Scranton also possessed a quality of familiarity and media savvy that would serve him well during the coming hectic days.
Pennsylvanians were familiar with Scrantons. The young lieutenant governor hailed from one of the state's oldest political dynasties. Bill Scranton's father had been a popular governor and a viable presidential candidate during the 1960s. His great, great grandfather had a city named after him. Young Bill had made a name for himself working on newspapers owned by his powerful family. When the accident at Three Mile Island became news, it was William Scranton, representing the Thornburgh administration, who faced the press first. During his first press conference, Scranton essentially reiterated what officials at Metropolitan Edison, the owners of Three Mile Island, had told him: "Everything is under control. There is and was no danger to public health and safety." In short order Scranton found out that everything was not under control. What was termed a small amount of radioactive iodine had, indeed, been released. Scranton later expressed frustration that he "couldn't count on anybody at Met Ed for any type of information," and spoke of how "the indignation that welled up in me was memorable" when he learned of the offsite release.
Throughout Thursday, March 29, the governor's office in Harrisburg was buffetted with often-conflicting reports concerning events at Three Mile Island. It was decided that someone should pay a visit to the Island to obtain a first-hand assessment. William Scranton volunteered. "It occurred to me, 'Someone's got to go down there and look at that place...' and being 30 years old, and maybe thinking I was more immortal than I really was, I said, 'I'm going to go down there," he later recounted. Scranton revealed a sense of forboding as he arrived at the plant, "...You just drive up and there they are. They're magnificently huge, beautifully engineered symbols of the power of technological society to do good and the power of technological society to do harm." Scranton's visit was no mere photo opportunity. He asked to see the source of the radiation releases and was fitted with a protective suit. He made his way to the auxiliary building and viewed the radioactive water collected on the floor. He described it as looking "like water in your basement, except it happened to be in...a nuclear power plant. I realized that what was all around me was highly contaminated. ...I came back with a much clearer understanding of what was going on that island." Scranton's visit to Three Mile Island did not signal the end of the crisis, but it did remove some of the haunting mystery of the event for the Lieutenant Governor and those he worked with.
Pennsylvania Governor Dick Thornburgh had been in office a mere 68 days when he came face-to-face with the biggest crisis of his professional life. Retired Colonel Oran Henderson, the head of Pennsylvania's Emergency Management Agency, informed Thornburgh of the incident at Three Mile Island on the morning of March 28, 1979. "The minute I heard that there had been an accident at a nuclear facility, I knew we were in another dimension," Thornburgh later recalled. He was a Republican governor of a largely Democratic state, a career attorney who had risen through the ranks to gain national prominence as United States Assistant Attorney General. But in March, 1979, in his new role as Governor of Pennsylvania, Thornburgh would gain a level of media exposure he had never seen before. Thornburgh knew next to nothing about nuclear power, radiation, or evacuation management. Still, he found himself in a position of having to assure the citizens of his state that everything was, or soon would be, under control. Working against him was the fact that he was being given information by officials at Three Mile Island, Metropolitan Edison Company, and the Nuclear Regulatory Commission that was often incomplete, contradictory, and confusing.
On Thursday, March 29, Thornburgh made his first public comments since the accident occurred. "Good afternoon, I'd like to address my initial remarks to the people of central Pennsylvania. I believe, at this point, that there is no cause for alarm, nor any reason to disrupt your daily routine, nor any reason to feel that public health has been affected by the events on Three Mile Island. This applies to pregnant women, this applies to small children and this applies to our food supplies. I realize that you are being subjected to a conflicting array of information from a wide variety of sources. So am I. I spent virtually the entire last 36 hours trying to separate fact from fiction about this situation. I feel that we have succeeded on the more important questions." Thornburgh had dispatched his Lieutenant Governor, William Scranton, to Three Mile Island to bring back a first-hand assessment. Scranton's visit seemed encouraging. He told Thornburgh that the problem seemed fixable.
What little relief Thornburgh felt at hearing Scranton's report, dissolved the next day when it was reported that a large burst of radioactive gas had escaped from Three Mile Island. Suddenly, Thornburgh was placed in the position of having to make a decision regarding a recommendation from Washington, D.C., to evacuate thousands of people from the area surrounding the plant. Adding to the surreal atmosphere in Harrisburg that day was the sounding of an air raid siren that rang out through the capital city. "That siren was like a knife in my chest," Thornburgh recalled. "I thought, 'What on Earth? Where did that come from?'" The ringer of the siren never came forward. Even though the release of radioactive gas was found to have been overstated, Thornburgh, on the advice of NRC Chairman Joseph Hendrie, advised the evacuation "of pregnant women and pre-school age children...within a five-mile radius of the Three Mile Island facility until further notice." Within days, 140,000 people fled the area.
On April 1, Thornburgh accompanied President Jimmy Carter on a tour of Three Mile Island. The outcome of the accident was still uncertain, but Thornburgh and Carter knew that their appearance might boost local morale. It was not until April 9 that the Governor felt confident enough to call back any pregnant women and pre-school children who had evacuated the area.
In the aftermath of Three Mile Island, President Carter ordered the creation of a special commission, headed by Dartmouth College president John Kemeny, to review the event. The resultant report found fault with the NRC. Carter ordered a re-shuffling of key NRC personnel, but no substantial overhaul.