Chapter 2: Can residents be evacuated? Fresh water or seawater?

japanese 日本語版

Photo: The tsunami hits the Fukushima No. 1 nuclear power plant on March 11, 2011. (Provided by TEPCO)

Masao Yoshida, the plant manager at the Fukushima No. 1 nuclear power plant, was considered a hero of sorts when he continued pumping seawater into the No. 1 reactor.

Yoshida ignored concerns that the salt water would lead to the decommissioning of the reactor and brushed aside instructions to stop using seawater from Ichiro Takekuro, a senior official at plant operator Tokyo Electric Power Co. who was based at the prime minister’s office at the time of the accident.

What is less well known is that Yoshida followed the instructions of someone at the prime minister’s office who asked that fresh water be used at the No. 3 reactor to prevent it from being decommissioned. Despite the additional trouble, Yoshida ordered workers pumping seawater into the No. 3 reactor to switch to fresh water, which may have added to the danger at that reactor.

Fukushima nuclear crisis: major events, radiation levels per hour near main gate to Fukushima No. 1 nuclear plant

Yoshida: I think it was likely Takekuro, in the sense of who gave the instruction. For that reason, there is the possibility that Takekuro made that one point, and I cannot deny the possibility that he also talked about that to someone who was standing near him, either Yasui or someone else. If I had to narrow down the possibilities, my feeling is that it may have been Takekuro or someone who was by him, like Yasui. Those are the only possibilities I can think of.

Question: So after 6 a.m. on March 13, you received a phone call from the prime minister’s office that was routed through TEPCO headquarters. In summary, one comment during the call was that it was premature to be using seawater because using seawater would lead to decommissioning. So the caller asked to use filtered water or fresh water as much as possible. Is that what you are saying?

Yoshida: I am sorry, but as I said previously, my memory of that moment is missing, so I only recalled what happened then after watching the video. For that reason, I have no recollection of who it was that I spoke to. I can only talk in terms of what may have been possible.

Photo: Shortly after 7 p.m. on March 17, 2011, a department store in the Ginza district of Tokyo is pitch-black after closing early to prepare for a blackout. (Shogo Koshida)

Early on March 13, 2011, two days after the Great East Japan Earthquake, the No. 3 reactor at the Fukushima No. 1 nuclear power plant was facing its first crisis.

The crisis was triggered by workers who at 2:42 a.m. manually turned off the high pressure coolant injection (HPCI) system pumping in water to the reactor without adequately confirming the existence of an alternative water-pumping method. That operation was conducted without informing Yoshida.

The water level within the No. 3 reactor plummeted because pumping had stopped.

At 5:14 a.m., the technical team at the Fukushima No. 1 nuclear plant submitted a report estimating that nuclear fuel damage would begin around 7:30 a.m. and that a core meltdown would start from about 9:30 a.m.

Workers at the plant considered a new way of pumping water into the reactor. They had to abandon the idea of restarting the HPCI system because they could not obtain the necessary battery.

Yoshida came up with two alternatives. One was to use a boric acid solution pump that could inject water even if pressure within the reactor was high.

The other method was to open the safety relief (SR) valve attached to the reactor pressure vessel to reduce pressure within the core and inject water using fire engine pumps.

Although the boric acid solution pumping system was a key tool that allowed for the injection of high-pressure water, an AC source of 480 volts was needed for the operation.

The earthquake toppled steel towers at the nuclear plant, leading to the loss of all external sources of AC electricity.

To obtain electricity, a generator vehicle capable of producing 6,900 volts would be attached to the distribution equipment at the No. 4 reactor that was not damaged by the quake or tsunami. The electricity would be reduced to 480 volts and distributed through a cable attached to the No. 3 reactor.

Yoshida had also decided to begin pumping seawater using the fire engine once the SR valve was open and pressure had fallen. He made the decision because he thought there was insufficient fresh water, given the report at 5:42 a.m. that all tanks attached to fire hydrants were empty.

Audio: Plant manager Yoshida instructs pumping of seawater into No. 3 reactor on morning of March 13.

At 6:43 a.m., Yoshida received a phone call, “Emergency, emergency, this is an emergency interruption.” It was from Susumu Kawamata, general manager of TEPCO’s Nuclear Quality and Safety Management Department, who was at the prime minister’s office along with Takekuro.

Question: So there was talk of placing priority on using fresh water, but regarding the reasons that led to that statement, what was the most important factor?

Yoshida: That would be the prime minister’s office.

Q: So you are saying that was the most important factor?

Yoshida: Absolutely. As I said at that time, I always felt in my heart that using seawater would be unavoidable. So I believe I said from the very beginning that we had to go with seawater. However, I later received a phone call from the prime minister’s office and was told to do something, so I responded that we would try our best to find water. However, we alone could not find the needed water, so I asked for help, including from the Self-Defense Forces. So at that time, there were various efforts being made to get the water. If the SDF acted to a certain degree, I thought it was still possible to receive a supply of water, so that was a time when I still had expectations for that happening. So I did not think at that time to switch to seawater. I believe that was an extremely delicate situation.

Q: (first part omitted) Regarding the concept of water, you said that it might be better to use seawater. But in the end, while there was talk of various agencies providing help, like the Fire and Disaster Management Agency or the Sendai Fire Station, in fact, the only information you had was the one water truck from the Chiba branch and with that the only one that was actually working. You must have thought that there was no way you could look after both the No. 2 reactor and No. 3 reactor. That likely led to your statement about using seawater, but your comment about expectations likely meant the fire truck to come from the Chiba branch could be used as a water source for the No. 2 reactor. As the plant manager, if it came to the situation of not having any water at all, then did you mean that would leave you no choice but to go with seawater?

Yoshida: Yes.

Photo: Workers use a flashlight to check meters at the central command room for the No. 1 and No. 2 reactors of the Fukushima No. 1 nuclear power plant on March 23, 2011. (Provided by Nuclear and Industrial Safety Agency)

The gist of the call from the prime minister’s office was that it was still too early to make a decision to use seawater. The caller wanted to use filtered or fresh water as much as possible because seawater would lead to the need to decommission the reactor.

Yoshida told the government panel investigating the Fukushima accident that he had a memory lapse regarding the phone call from the prime minister’s office. He was referring to the call from Susumu Kawamata, general manager of TEPCO’s Nuclear Quality and Safety Management Department.

Yoshida said someone took the phone from Kawamata and talked in his place, but Yoshida said he could not recall who that person was.

Yoshida first mentioned Takekuro and Masaya Yasui, a high-ranking official of the Nuclear and Industrial Safety Agency. However, by saying that his memory of that moment was missing, he strongly implied that neither of those two was the actual caller.

At the same time, Yoshida clearly explained that the caller was not Haruki Madarame, chief of the Nuclear Safety Commission, Chief Cabinet Secretary Yukio Edano or Prime Minister Naoto Kan.

In the end, Yoshida stuck to his argument that he could not remember the identity of the caller. In any case, Yoshida went along with the instruction from someone at the prime minister’s office to use fresh water, not seawater, for the No. 3 reactor to avoid having to decommission that reactor.


What is unfathomable is the fact that Yoshida quickly agreed to the request from the caller even though he had ignored instructions from Takekuro and continued to pump in seawater to the No. 1 reactor.

Those at the Fukushima No. 1 nuclear plant site were saying out loud that there was no water.

Later, Sakae Muto, the TEPCO executive vice president in charge of nuclear energy who was at the off-site center in Fukushima Prefecture, raised doubts about pumping in fresh water.

“We have to begin thinking about using seawater,” he said. “Have you discussed this with the prime minister’s office?"

Akio Takahashi, another senior TEPCO official at the head office, said: "Plant manager Yoshida, where are you going to get the water? Do you have means to find that water?”

That raises questions of how strongly the caller made the request to use fresh water. Yoshida switched to using fresh water despite the various concerns raised by those working with him.

The result was a series of difficult problems for the workers at the Fukushima No. 1 nuclear plant. The only fresh water immediately available was the 80 tons that could be pumped in using fire trucks and the 800 tons that could be used with a diesel-powered fire-extinguishing pump.

That water would run out in two hours and 20 hours, respectively.

Efforts were made to gather all the fresh water on the plant site, including water in the pool of the technical training building. However, because of the suddenness of the switch, things did not proceed smoothly. The reinforcement fire trucks were also slow to arrive on the scene. Water from the SDF also did not arrive on that day.

The pump for the boric acid solution system also could not be used because the electric cable that was to have transmitted electricity from the distribution equipment at the No. 4 reactor had been damaged by the explosion at the No. 1 reactor.


As workers were scrambling to find water, the pressure in the No. 3 reactor was rising. High pressure in the reactor core would make it difficult to use the diesel-powered fire-extinguishing pump because it was only capable of emitting water at a low pressure.

That meant the only fresh water available was the 80 tons to be pumped in by the single fire truck. That water ran out at 12:20 p.m.

Yoshida gave the orders to pump in seawater, saying at the time, “Listen, we have run out of water.”

He thought it would take about 10 minutes to switch to the pumping of seawater. However, the pumping of seawater did not begin until 1:12 p.m., meaning no water entered the No. 3 reactor for 52 minutes.

Yoshida completely ignored the behavior of the reactors before him as well as the prospects for acquiring fresh water. He accepted the request from someone who wanted to avoid decommissioning reactors and was based in the prime minister’s office in Tokyo, far removed from the actual accident. By doing so, Yoshida ended up allowing the crisis to expand.

Audio: Yoshida reported around noon March 13, 2011, that fresh water had run out.

Photo: Prime Minister Naoto Kan, third from left, prepares to start a meeting of the emergency disaster management task force set up at the Prime Minister’s office. (Satoru Iizuka)

Question: With the decision to go with seawater at the No. 2 reactor, but although there was no specific mention of that matter at that time, were there any instructions coming from the prime minister’s office about that matter?

Yoshida: There was no such instruction. I have no recollection of that happening.

Q: Next, what position did the person named Yamashita hold?

Yoshida: Yamashita was in charge of TEPCO’s group for resuming operations at the plant. (latter part omitted)

Q: Did Yamashita say it was his understanding that since seawater would corrode materials and break down equipment, which would be a waste of the equipment, there was the choice of waiting for as long as possible for fresh water to arrive? Naturally, if there was such thinking, the person would likely take such a position. But that was a time when one could not be asking for what they did not have. Was that such a time?

Yoshida: That is right.

With no water reaching the No. 3 reactor for 52 minutes, the condition of the reactor core was steadily worsening.

The water level in the reactor core did not recover. At 1:23 p.m., a report was made that extremely high radiation levels of 300 millisieverts per hour had been recorded on the inside of the double doors of the reactor building. The inside of the building had become hazy, and there was the possibility that steam, including explosive hydrogen, was leaking from the reactor containment vessel.

At that time, a decision had to be made about the method for pumping water into the No. 2 reactor. Because of what had transpired, Yoshida declared that seawater would be pumped in from the start to the No. 2 reactor. This order was given at 1:13 p.m. Perhaps because officials at the prime minister’s office also realized what the situation had turned into, they gave their consent for pumping in seawater if that was what the plant operator wanted.

Audio: Yoshida receives a report about rising reactor core pressure at the No. 3 reactor.

However, within TEPCO, even after all the problems that had been experienced, the thinking of not using seawater to avoid decommissioning the reactor did not go away.

For example, the head of the group set up at TEPCO headquarters to work toward resuming plant operations continued to argue for using fresh water even seven hours after Yoshida declared that seawater would be pumped into the No. 2 reactor.

“Laying out the selfish thinking on our side, starting with seawater from the beginning will lead directly to decaying of materials, which would be wasteful,” the group leader said. “Can we have the understanding that there is also the option of waiting for fresh water as long as possible?”

Yoshida said: “It is not about understanding, but we have already decided on the lineup that would be used, and since we chose to make the ocean the source of the water, we do not have the option of going with fresh water from now. That would only lead to a loss of time, again.

“What you want to say is using fresh water, will, in the end, make it possible to use it again in the future because it will not have been damaged by the salt.”

Even with those arguments made by Yoshida, the individual did not say, “That is correct” and back down.

Yoshida went on to explain: “I also thought about that for a long time, but at a time like this when the supply of water needed is overwhelmingly large, it will be incredibly difficult if we were to insist on using fresh water. That is why now is a time when we have to resort to seawater, and the thinking becomes we have no choice but to go with seawater under the current circumstances.”

The individual finally said, “Yes, I now understand what the current situation is like.”

The only way to stop the nuclear plant from going out of control was to cool the reactors by pumping in water. The Pacific Ocean that lay before them held an inexhaustible supply of water. With insufficient fresh water, it was only natural to use that seawater.

However, because the nuclear plant consists of precision equipment made from steel, it will become unusable once seawater is pumped in and the equipment rusts. That means the reactor would have to be decommissioned. In that event, the electric power company would have to take on huge losses that could lead to bankruptcy.

That is the reason those in the prime minister’s office and TEPCO continued to want to avoid decommissioning reactors if at all possible even as the crisis reached an advanced stage.

To be followed by Chapter 2, Section2: “Public relations: Who cares?”