Early on March 14, 2011, three days after the Great East Japan Earthquake, the No. 3 reactor at the Fukushima No. 1 nuclear power plant continued to face a crisis similar to the one on the previous day. A delay in realizing that the source of water to pump into the reactor had dried up led to a situation in which both the No. 1 and No. 3 reactors were not being adequately cooled.
Question: At about that time, I believe there is one method of venting called wet well venting, but was there any consideration about venting using the dry well?
Yoshida: Of course, we made such a consideration.
Q: So you were also making such a consideration? But, in fact, no such consideration was being made regarding the No. 3 reactor, was there?
Yoshida: We had gone ahead with wet well (venting). But as we were doing that, an explosion occurred, and, for some reason, the pressure fell. Because it fell considerably, the timing for the dry well venting had (passed), but conversely speaking, I believe it was a situation in which we had been considering it.
Q: So are you saying that after doing only wet well venting at the No. 1 reactor, consideration for the No. 2 reactor included both dry well and wet well venting?
Yoshida: The No. 3 reactor.
Q: Oh right, the No. 3 reactor. But are you also saying that you never reached the point of actually going ahead with an operation, such as opening a valve?
Yoshida: That is right. Fundamentally, regarding the appraisal of radiation that was being considered at the TEPCO head office, I believe that was premised on dry well venting.
Q: That is what it looks like, doesn’t it, based on the context.
Yoshida: That is correct. That is why I believe, at that point, the appraisal being made at the head office by Sugai had dry well venting as the premise.
Q: I see. So just as you were beginning to consider it, the explosion occurred at the No. 3 reactor, right?
Yoshida: That is correct.
Although seawater was being pumped into the No. 1 and No. 3 reactors at the Fukushima No. 1 nuclear plant, the water was not actually coming from the inexhaustible Pacific Ocean laying before the plant.
A pit connected to the valve for pipe cleaning on the ocean side of the No. 3 reactor was flooded by the tsunami. The seawater in the pit was pumped up using fire trucks. However, the water in the pit was running out, and soon there would be nothing to cool the reactor.
When the water stopped being pumped into the No. 3 reactor, the water level dropped noticeably. The nuclear fuel became exposed and started to incur damage from the high temperature of the fuel, just like during the previous day.
Based on the amount of gamma rays being emitted, the appraisal was made that about 25 percent of the fuel had been damaged by 4:20 a.m.
The pressure within the reactor containment vessel also began rising sharply. If nothing was done, the hydrogen emitted from the damaged nuclear fuel could leak from the containment vessel and cause an explosion, like at the No. 1 reactor, with the potential to blow off parts of the reactor building.
There was also the possibility that the containment vessel itself could be damaged from the increased pressure. For those reasons, the first attempt made at the Fukushima No. 1 nuclear plant was wet venting that would release gases in the containment vessel through the suppression chamber.
There are two venting methods to remove gases in the containment vessel. Wet venting involves removing gases through the suppression chamber at the lower part of the containment vessel, while dry venting involves removing the gases through the dry well at the upper part of the vessel.
Because wet venting releases gases after being forced through the water in the suppression chamber pool, it can remove about 99 percent of the radioactive iodine, which is easily dissolved in water.
However, wet venting was not working and pressure within the containment vessel actually rose. Left with no other choice, preparations began for dry venting that would release large amounts of radioactive iodine into the atmosphere. This was at about 6:23 a.m.
As those preparations were being made, the safety group at the TEPCO head office used company equipment to begin estimating the amount of radioactive iodine that would be released through dry venting. That equipment was similar to the System for Prediction of Environmental Emergency Dose Information (SPEEDI) operated by the science ministry.
Criticism was raised because the ministry did not publicize the results of its SPEEDI calculations.
The TEPCO estimate was that radiation levels in Soma county about 20 kilometers north of the Fukushima No. 1 nuclear plant would reach 250 millisieverts in three hours.
Just when the situation had reached a point when it was possible for the deliberate release of radioactive materials into the atmosphere, an agency released a comment that raised eyebrows among those gathered at the TEPCO head office. That agency was the Nuclear and Industrial Safety Agency (NISA).
Graphic: Created from documents of the secretariat of the Nuclear Regulation Authority
Question: As a way of confirmation, the situation at the No. 3 reactor was so dangerous that an evacuation order had to be issued to workers there. Those circumstances were naturally transmitted through both phone calls and the online system from the TEPCO head office that were reaching NISA and the prime minister’s office. What you are about to see is related to a press release that was being discussed by NISA and the prime minister’s office. This is a point when it is unclear if press releases have been stopped or have not yet been stopped.
Yoshida: Press release?
Q: In other words, we want you to recall the situation that unfolds in the document you are about to see. They are saying that they have stopped press releases for information related to the situation at the No. 3 reactor.
Yoshida: This is the first time I have heard of this. Does it involve part 33?
Q: Yes. Page 9. The exchange from there is somewhat summarized, so please view it, and if you can recall what that was all about, we want to ask you about it.
Photo: Residents evacuating from Futaba receive radiation exposure testing by a specialized agency and the Self-Defense Forces at Kawamata, Fukushima Prefecture, on March 13, 2011. (Yoshinori Mizuno)
What NISA officials began saying was the need to stop providing information to the media. In other words, they wanted a media blackout.
The drying up of the water source led to a lack of cooling at the No. 3 reactor, creating an unusual increase in pressure within the containment vessel and forcing the temporary evacuation of workers at the Fukushima No. 1 nuclear plant. The media blackout was intended to keep such information about the crisis at the No. 3 reactor from reaching TV stations and newspaper companies.
Although somewhat hesitant, TEPCO officials agreed to the instruction for information control issued by the agency that was supervising the company on nuclear energy. At 7:49 a.m., the leader of the group serving as a liaison to government agencies at the TEPCO head office passed on that decision to the Fukushima No. 1 nuclear plant and the offsite center in Fukushima Prefecture.
But there was no detailed explanation of the background to the decision. The only thing the individual said was: “NISA officials told those at the prime minister’s office that they were working in conjunction with TEPCO, but press releases have apparently been stopped. That is why no information is being released to the press.”
Although Yoshida said he understood, he had not actually listened to the contents of what was said to him.
——‘THAT IS THE FIRST TIME I HAVE EVER HEARD IT’
At that time, Yoshida was simultaneously trying four different ways to supply water to the pit outside the No. 3 reactor. He was extremely busy contacting the individuals in charge of each method.
Even Sakae Muto, the TEPCO executive vice president in charge of nuclear energy who was at the off-site center in Fukushima Prefecture, did not understand what message was being conveyed.
At one point, Muto said, “I'm sorry, what did you say?” At another, he said, “What has been stopped?” He goes on to ask, “Are you talking about the situation at the No. 3 reactor?”
He finally ended the conversation by saying, “I understand.”
Meanwhile, Fukushima prefectural government officials were preparing to rise against NISA’s outrageous decision. They began saying that the meeting of department heads scheduled for 9 a.m. would be open to the media so that they could publicize the emergency at the No. 3 reactor in place of central government officials.
But NISA officials strongly insisted that no announcement should be made to the media and managed to stop the prefectural government from releasing the information. About 30 percent of the nuclear fuel at the No. 3 reactor had already been damaged, so it was estimated that gases within the containment vessel likely contained large amounts of radioactive materials.
If nothing was done, there was the danger that the dry venting would deliberately release radioactive materials while residents remained in the dark about what they faced.
Photo: Lights can be seen in almost all of the classrooms at the former Kisai Senior High School in Saitama Prefecture on March 31, 2011. The Futaba town government had evacuated to the school along with town residents. (Toshiyuki Takeya)
Question: In other words, there was probably the thinking that unless the information was released after a situation had been created where water was being pumped in, there might be further confusion or it could lead to unnecessarily raising concerns among the public by releasing the information when that situation had not yet been created. The exchange can be read as one of the government not immediately notifying the public. But fundamentally, would this be a matter that is handled by the TEPCO head office?
Yoshida: That is how it would be. I have almost no recollection of this exchange. My feeling about how to conduct public relations or whether information should be given to the press or not was basically to do as you please. On my side, my position was that we had our hands full, so I think that almost nothing of what was being said entered my ears.
Q: Is that why you felt somewhat surprised?
Q: So fundamentally, the public relations group at the TEPCO head office would play a central role and deal with media representatives.
Yoshida: (first part omitted) He was the head of the group serving as liaison to government agencies. I don’t know who was saying that it should be stopped and I also do not know who was making the comments among the public relations group. Basically, it is the head of the public relations group who deals with the press, and since the other discussion was about liaising with government agencies, both matters would be handled by the TEPCO head office. Those at the Fukushima plant would know nothing. It comes down to do as you please regarding such matters.
Q: So in other words, from the standpoint of the central government, I believe their position was to inform them immediately once water pumping has started, and as they are being informed of the situation up-to-the-minute, they were trying to determine the proper timing for making the announcement to the press. That would be handled by the public relations group at the TEPCO head office, or perhaps Takahashi. Those in charge of liaison passed on the information and thought that the government would determine the timing, but Japan Broadcasting Corp. (NHK) scooped the information about the temporary evacuation of workers. Because of that experience, the decision was made to change how information was passed on. But on such matters, did you leave matters up to the head office?
Yoshida: That is correct. We left everything related to external matters to the head office. We were only concerned about the fact pressure was increasing and when we should begin supplying water. This was after the workers temporarily evacuated. My mind was fully taken up by such matters, so that is why I said I knew nothing about public relations.
Photo: TEPCO President Masataka Shimizu is surrounded by reporters after a news conference at 10:54 p.m. on March 13, 2011, at the company’s head office. (Toshiyuki Takeya)
Yoshida was doing everything he could to supply water to the pit on the ocean side of the No. 3 reactor so that water could be pumped into the reactor. He had to do something about cooling the out-of-control No. 3 reactor.
Of the four measures being considered for supplying water to the pit, the moving of 2,000 tons from the filtered water tank failed because the tank had unexpectedly become empty. This was a major failure because if that measure succeeded, it would have provided enough water to pump for 30 hours.
The measure to pump up water that had accumulated in the basement of the No. 4 reactor turbine building also failed because workers realized the water had drained.One successful measure involved pumping up seawater through the connection of hoses at two fire engines located on the pier near the No. 1 reactor. The connecting of the fire engines increased the pumping power, and a report was made at 9:20 a.m. that the measure had worked. That meant 30 tons of seawater could be pumped in hourly.
The decision had also been made to have the SDF transport a water supply truck to the Fukushima No. 1 nuclear plant.
However, a careful watch had to be kept on the continually increasing pressure in the No. 3 reactor containment vessel. At 10:10 a.m., the water level in the reactor began dropping again after once rising. That meant nuclear fuel had again become exposed.
——‘THOSE AT THE PLANT HAVE OUR HANDS FULL’
Still, the media blackout was not lifted. That blackout was kept in place even after NHK reported around 9:30 a.m. that pressure in the No. 3 reactor containment vessel had increased to dangerous levels and workers had temporarily evacuated.
In the end, an explosion occurred at the No. 3 reactor at 11:01 a.m. According to Yoshida, that led to a decrease in the reactor pressure and eliminated the need for dry venting.
While the folly of deliberately releasing large amounts of radioactive materials into the atmosphere without informing residents was avoided, SDF members who had not been informed in detail about the crisis at the No. 3 reactor went to supply water.
Just as they began supplying water, they encountered the explosion. They were lucky to be alive because the explosion threw large chunks of concrete into the air that could have killed SDF members if the slabs landed on their heads.
Yoshida’s words show that those on the front lines trying to bring the nuclear plant under control did not have the mental leeway to be thinking about local residents. However, the only ones who can understand the ever-changing situation of the reactor are the workers on the front lines.
Without creating a philosophy and structure for urging residents to evacuate based on the information transmitted from the front lines, it would be close to impossible to have residents living near nuclear plants flee in an appropriate manner.
In a nation where the government agency overseeing nuclear plants and electric power companies has no qualms about hiding crisis information, the situation can only be called hopeless.