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Mike Gray on: The Hydrogen Bubble
Mike Gray Q: Do you know anything about the reporters who barged into the governor's office?

MG: Yes. On 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 Hydrogen Explosion." 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 was genuine terror, in Harrisburg on that night. I was there and certainly I had the full sense of the experience -- that we were faced with a potential catastrophe.

Sometime in the late hours Saturday afternoon, early evening, this contingent of the Bubble Squad phoned in their results and they said, "If that bubble explodes, it will create a ringing within the system, a shock that will reverberate back and forth and, they said," "you're going to lose pumps, seals, valves, and you will also have a ring fracture around the reactor vessel itself." Well, that's an irrecoverable disaster. Once the vessel splits open, there's nothing you can do about it. It's going to go down through the bottom of the plant and that's that. So the mere fact that this possibility existed finally crept into the consciousness of the five Nuclear Regulatory commissioners. These guys are Presidential appointees. They are not all technical people. They're lawyers and just people who the President felt, for one reason or another, would be nice to have on the Nuclear Regulatory Commission. So they're dealing from a tremendous disadvantage here. And once they get the word that this bubble could conceivably be explosive, that word leaked out to the press at the very moment that the governor of Pennsylvania is trying to calm everyone's fears and say, "There's no danger as of this moment and everyone can go to sleep."

MG: 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.

Q: Who was right, Mattson or Stello?

MG: Well, 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."

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