The No. 2 reactor at the Fukushima No. 1 nuclear power plant was facing a critical development at 6 p.m. on March 14, 2011, three days after the Great East Japan Earthquake and tsunami triggered the crisis there.
Venting the reactor containment vessels proved difficult at the No. 1 and No. 3 reactors, and all venting efforts had failed at the No. 2 reactor.
Workers were also having a hard time trying to manually open a safety relief valve designed to release steam from the pressure vessel surrounding the No. 2 nuclear reactor core. The plan was to release the steam to lower the internal pressure so that a fire engine could pump in water to cool the reactor.
Question: Some time after that, let’s say, from the time you were having a hard time trying to open the safety relief valve until it was night … well, let’s set aside if the head office (of Tokyo Electric Power Co., operator of the Fukushima No. 1 nuclear plant) was also involved. Your workers eventually went to 2F (the Fukushima No. 2 nuclear plant) to take shelter. Was there any talk about things like … having workers take shelter?
Yoshida: Yes, there was. Well, that would have turned into a really big matter, and it was not our head office that brought up the subject. If I had brought up the subject at the round table … well, there was the round table, and out in the hallway, too, were people from our partner companies. We had come to a situation where (nuclear) fuel was really exposed but we could not lower pressure or pump in water, so really, this is the hardest part for me to remember. I thought then, though not for the first time, that we were going to die. I thought we were really going to die. With no water coming in, the No. 2 reactor was going to melt. All fuel was going to really override pressure in the containment vessel and escape outside. That would have been a worst-case accident, with corresponding amounts of radioactive substances all spewed outside. That would no longer be on a Chernobyl class--maybe not a “China Syndrome,” but something like that. If that were to happen, we would have had to stop pumping water into the No. 1 and No. 3 reactors, and they would have fallen into similar states sooner or later.
Photo: Tsunami debris lies scattered to the north of a protection and control gate for the No. 1 and No. 2 reactors at the Fukushima No. 1 nuclear power plant on March 23, 2011. (Provided by the Nuclear and Industrial Safety Agency)
On March 13, workers had opened both valves along a vent line that connected the No. 2 reactor containment vessel to an exhaust stack so that venting could be done at any time. But an explosion in the No. 3 reactor building at 11:01 a.m. on March 14 left one of them stuck in a shut position.
At 4:15 p.m., a phone call came directly from Haruki Madarame, chairman of the Nuclear Safety Commission of Japan, who said workers should immediately open the safety relief valve for the reactor pressure vessel if venting remained impossible. But it still stayed shut one hour after work began to try to open it.
Much like vent valves, simple operations are usually enough to open the safety relief valves. But they were totally unresponsive after the disaster started, possibly because of the failure of battery that supplied a direct-current power of 125 volts.
Workers at the Fukushima No. 1 nuclear plant collected 12-volt automobile batteries, some of them removed from their own cars and others procured at auto supplies shops in Fukushima Prefecture. They also had batteries sent in from the TEPCO head office and from other power plants, including the Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture.
They connected 10 of them in a series to make a 120-volt battery, but it never worked when attached to the equipment.
——‘I THOUGHT THEN, THOUGH NOT FOR THE FIRST TIME, THAT WE WERE GOING TO DIE. I THOUGHT WE WERE REALLY GOING TO DIE.’
One worker proposed connecting 11 batteries because the series of 10 batteries was 5 volts short of the rated voltage.
Another said the shortage was in the electric current, not in the voltage, and proposed making another 120-volt battery and connecting the two sets in parallel. But the trial and error process did little to open the valve.
If the safety relief valve stayed shut, pressure would remain high in the pressure vessel, and a fire engine, with its modest pump pressure, would be unable to pump water into the reactor.
The temperature and pressure in the reactor would rise unless water was soon pumped in to cool it. The existing water in the reactor would evaporate, water levels would fall, and nuclear fuel would be exposed above the surface. Nuclear fuel would melt due to its own intense heat in only two hours of exposure above the water line.
In another two hours, it would melt through the walls of the pressure vessel.
The “China Syndrome” that Yoshida referred to is the title of a U.S. movie starring Jane Fonda. It is themed on a fictional story of a melt-through at a nuclear plant in the United States, whereby hot and pulpy nuclear fuel penetrates the containment vessel, melts everything it comes into contact with, is led by gravity toward the center of Earth and ends up in China on the opposite side of the planet.
If nothing could be done about the situation at the Fukushima plant, the No. 2 reactor was inching toward a melt-through of its containment vessel. That penetration would have led to enormous amounts of highly toxic radioactive substances, such as plutonium, uranium and americium, spewing into the living environment of humans. Plant workers would be exposed to huge doses of radiation.
Yoshida took action, expecting a horrendous, triple melt-through to occur after it became impossible to cool the No. 1 and No. 3 reactors.
Photo: Workers keep records of measurements at the shift supervisor’s seat in the central control room for the Fukushima No. 1 nuclear power plant’s No. 1 and No. 2 reactors on March 23, 2011. (Provided by the Nuclear and Industrial Safety Agency)
Yoshida: In the end, that would have obliged us to take shelter from here. Many people would have been victimized. Radioactive substances would, of course, have covered broader areas, and at higher levels, than what we have now. They would have been spread out to some extent, but I thought that people who were there--I mean, people staying near the quake-proof control center building--would be the first to have their lives at risk. But if I had discussed the subject there in the quake-proof control center building, that would have scared everybody, so I think I told Muto about that over the phone. I said, for one thing, the situation was such and such and was very dangerous. I remember telling him that I would keep a minimum required operation staff and restoration staff, but it was probably time to think about having them take shelter. I told Mr. Hosono about the situation, in short, that the No. 2 reactor was in a critical state (and) whether we should take shelter or not. I told him that something terrible would happen if water wasn’t coming in, and I think I told him that workers at the site should take shelter, except for minimum staff, in that case. I told him that over the phone. Many people would have heard me if I had said that there, and that would have frightened them, so I remember stepping aside to talk about that over the phone. This is, frankly, the hardest part for me to remember.
The action Yoshida took was to talk directly to TEPCO’s highest leadership corps and to Goshi Hosono, Prime Minister Naoto Kan’s special adviser who was at the prime minister’s office, about the disastrous state of the No. 2 reactor. Yoshida advised them that it was time to think about withdrawing workers.
He stepped into the hallway, where he used his cellphone to talk to them in private. If he had used the teleconferencing system, all plant workers in the emergency response room would have overheard him.
In fact, Yoshida ordered his workers several times to take shelter when he thought he had to defend them against explosions or radiation exposure during the efforts to bring the situation under control at the Fukushima plant.
When pressure in the No. 3 reactor containment vessel rose sharply on the morning of March 14, for example, Yoshida used the teleconferencing system to obtain approval before ordering workers to take shelter.
“Can I have on-site workers and our employees take temporary shelter here, although we will not be able to do anything (if I do so)?” he asked.
Yoshida’s use of his cellphone to talk in private to TEPCO’s head office and the prime minister’s office shows his extreme anxiety.
Photo: Hidehiko Nishiyama, the industry ministry’s spokesman for the Nuclear and Industrial Safety Agency, explains about the falling water level in the Fukushima No. 1 nuclear plant’s No. 2 reactor during a news conference in Tokyo at 9:54 p.m. on March 14, 2011. (Shogo Koshida)
Question: When you made the phone calls to both individuals--Mr. Muto, or anybody else in the (TEPCO) head office--how did they react?
Yoshida: There was nothing in particular. It was like, “OK, that’s the current state.” It’s not that they gave the green light or didn’t, but it was like I said there were such and such dangers, and (they said), “I see.” What I did was to go to people from our partner companies who were in the hallway. They were all watching idly or something like that because they didn’t understand what was going on. I thought I shouldn’t be getting these people into trouble, so I said: “We have done our best, but the situation is really bad, so gentlemen, please leave. I am not asking you to take shelter. I am asking you to leave. I’d be happy if you left.” Then I came back here, and I was speechless at the time because all we could do was wait. We were, like, taking a chance to pump water in. When I was through with all that, I hardly ever spoke and remained asleep. Maybe I was not asleep; I was totally at a loss.
Q: Was that because the safety relief valve would not open?
Yoshida: It did. It did open, but the pressure would not go down. When we were trying to open the safety relief valve, it was all about our operations, so we were like: “What are you doing? What’s the matter?” But even with the safety relief valve open, the pressure wouldn’t go down. We were like, “There it is, I knew that.” After all, the suppression chamber (to which the valve is connected) had higher (pressure). Some had doubted (the pressure) would fall. We were like, “You see, (the pressure) isn’t falling, and the fuel water levels are only going down.” In addition, we never had enough time, so the pump--the fire engine--ran out of fuel, and it could no longer pump water in when it was time to do so when reactor pressure had fallen. That gave us another letdown, and we talked about sending (workers) to pump in (water). That was when I thought we were coming to the end. I was, like, the closest to death at that moment.
Photo: A containment vessel for the No. 2 reactor is assembled at the Fukushima No. 1 nuclear power plant in 1970.
Following 90 minutes of struggles, the safety relief valve for the No. 2 reactor finally opened at 6 p.m., and reactor pressure began to fall some time later.
A sense of relief spread among plant workers, who thought the fire engine would now be able to pump in water. But the relief was short-lived.
A report arrived at 6:28 p.m. that the fire engine was out of fuel. That meant the reactor would not receive even a drop of water until the fire engine was refueled with gas oil.
“It’s like, ‘Is this the end?’” someone at the site shouted. A report also arrived that a compact tank truck, which was carrying gas oil to refuel the fire engine, had a flat tire.
As tensions rose at the Fukushima No. 1 nuclear plant, Yoshida updated the prime minister’s office and TEPCO’s head office on the state of the No. 2 reactor. He then began advising people from TEPCO’s “partner companies,” or subcontractors, to leave the Fukushima No. 1 plant.
——‘MAYBE I WAS NOT ASLEEP; I WAS TOTALLY AT A LOSS’
The TEPCO head office also began preparing to move staff from the Fukushima No. 1 nuclear plant to the Fukushima No. 2 nuclear plant. It counted the number of staff workers and began checking the possibility of transporting all of them in buses at one time.
“TEPCO has two 20-seat minibuses and one 30-seat midsize bus,” a worker reported at 7:40 p.m. “There are seven more buses on the plant grounds, but I am waiting to confirm how many drivers will be available.”
The TEPCO head office began preparing the Fukushima No. 2 nuclear plant to accommodate incoming workers. Plans were also under way to move the Fukushima No. 1 nuclear plant’s emergency response room, which Yoshida presided over, to the Fukushima No. 2 nuclear plant.
At 8:17 p.m., Naohiro Masuda, general manager of the Fukushima No. 2 nuclear plant, advised: “We, at 2F, will accommodate all injured evacuees from 1F (the Fukushima No. 1 nuclear plant) in the visitors’ hall beside our main gate. And we will bring all others to our gymnasium.”
Masuda added: “We will have two emergency response rooms--our own for the four reactors of 2F, and a former one that 1F people can use. So I just hope the head office knows there will be the two of them.”
But in the end, TEPCO transferred no workers to the Fukushima No. 2 nuclear plant on the night of March 14.
“Let us first confirm that we have yet to decide on a final evacuation at this moment,” TEPCO President Masataka Shimizu said at 8:20 p.m. “So we are currently making arrangements with, uh, relevant authorities.”
The arrangements with those “relevant authorities” failed.
Japan has no nuclear disaster suppression unit whose mission is to face a crisis and bring a nuclear disaster under control.
The Self-Defense Forces say they are maintaining and improving their preparedness so they can respond promptly and appropriately to situations that seriously affect Japan’s peace and security and in the face of large-scale disasters. But their plans presuppose cooperation with relevant organizations, and SDF members have no technological expertise for controlling nuclear reactors.
Only power utility workers can control nuclear reactors and end crises there. But there has never been a provision, now or before the Fukushima nuclear disaster, to constrain their actions. Nor has there been vocal debate over whether binding their actions would be the right thing to do.