When the danger at the Fukushima Daiichi nuclear power plant was reported to TEPCO, the faces of the senior technicians were not even calmer than the front-line personnel.

You know your own business.

The boiling water reactor power generation structure at the Fukushima nuclear power plant is technically something that should have long since disappeared into history. Both power stations are currently using single-layer circulating boiling water reactors that are no longer used by the state.

In order to save costs, the cooling water is directly introduced into the seawater, which is ...... safety There was not much hope in the first place. For Japan, a region with frequent earthquakes, it is very unreasonable to use such a structure. At the time of the completion of the Fukushima power plant, some nuclear experts in Japan protested to the IAEA, arguing that it was irresponsible for the people to use such a nuclear reaction structure in a region with a high incidence of earthquakes and natural disasters such as Japan.

Now that such a thing has happened, it is really in response to the old saying that self-inflicted.

A characteristic feature of nuclear reactors is the need to cool the core even after the shutdown.

This is because nuclear fuel has self-decaying residual heat, which is much smaller than that generated by human-controlled fission, but if it is not cooled for a long time, it will also make the core reach a temperature of thousands of degrees.

Such a temperature will undoubtedly cause the nuclear fuel rods to melt and burn through the steel shell, concrete and other structures protected by the outer layer, causing nuclear leakage.

However, after the earthquake, Japan's Fukushima Daiichi nuclear power plant was completely paralyzed, and its own emergency diesel generators were all lost due to the tsunami after an hour of operation, which led to the loss of all external power supplies and the loss of forced cooling means for the reactor core.

"Mr. Takahashi, what should we do now?" Seeing that Takahashi Nagaken, the head of TEPCO's technical department, was silent, his subordinates asked anxiously like ants on a hot pot.

"Activate the emergency plan!" Takahashi ordered, slamming his pencil on the table.

Before he finished speaking, a subordinate pushed the door directly, and a message that made everyone feel panicked shouted out of this person's mouth;

"Oh no, due to the tsunami, the six units of the first nuclear power plant and the four units of the second nuclear power plant have now been completely shut down!"

Hearing this, Takahashi slumped in his chair.

The shutdown of the reactor means that the situation at the Daiichi Nuclear Power Plant has been hit to the extreme.

However, this is not the worst case, and in the case of a reactor shutdown, the power required for the working pumps of the waste heat cooling system needs to be imported from the outside. In general, the power station will prepare multiple external grid inputs, and each unit will generally have 2 emergency diesel generators for power supply, and the emergency diesel generators of other units in the same power plant can also be used by each other.

The simultaneous collapse of the first and second nuclear power plants means that the two power plants in Fukushima have lost their relationship with each other.

However, with the emergency diesel generators alone, in the case of a complete shutdown, no one can guarantee whether the temperature in the reactor can be maintained within the safe limit.

"Mr. Takahashi! The Daiichi Nuclear Power Plant has sent a message that most of the emergency generators are currently wading through the water, and Unit 1234 is currently unable to activate the emergency plan!"

Takahashi's body shrank imperceptibly: "That...... Let the maintenance department of the power station drain the stagnant water as soon as possible and start the backup motor! At the same time, urge the power supply part of the external network to restore the power supply as soon as possible!"

Takahashi's lips twitched twice, and he quickly recovered his state and ordered.

"Hey!"

After receiving the order, the people below immediately moved. Just as these people were about to leave to communicate, Takahashi stopped them again.

"Also, report this matter to the local area, so that they can quickly send additional firefighters to the scene and use fire pumps to help the shutdown unit cool down!"

"Hey!"

……

In a short time, the order was transmitted to the nuclear power plant via satellite phone. At this time, more than 30 minutes have passed since the tsunami impact power station.

Inside the No. 1 reactor of the Daiichi Nuclear Power Plant, the safety monitoring panel is already mottled red. The number of meters that marked the temperature and coolant water level at various locations in the reactor made the emergency maintenance personnel of the No. 1 reactor even more striking.

"The temperature inside the furnace has exceeded the safe limit by 40 percent!"

"The cooling water level has dropped below the danger line!"

"Hurry up, start the backup motor and get the cooling pump working again!"

Even without receiving orders from superiors, the emergency response plan at the scene has been activated. However, due to the large amount of seawater brought by the tsunami, the backup motor could not work for a long time.

"What? Let's drain the stagnant water? What are you kidding!

After receiving instructions from the top, the leader of the on-site emergency response team, Hanayama Yuan, scolded angrily.

The crowd is inside the nuclear reactor. Now, the stagnant water outside has not subsided, and if it weren't for the presence of the reactor's anti-radiation blast door, I am afraid that the turbid seawater would have poured in.

In such a situation, the above order to drain the stagnant water and restart the cooling pump motor is simply an impossible task.

"Team Leader! The temperature of the core has exceeded the safe value by 400 percent! What should we do?!"

"Team leader, the coolant water level can no longer cover the fuel rods, and the pipes have fully entered a state of overheating!"

Huashan Yuan really listened to the bad news one after another, and gritted his teeth fiercely, "Organize people and drain water!"

"Hey!"

After receiving the order, several people immediately tidied up the radiation protection suits a little and began to move the drainage equipment.

As the sound of gasoline generators resounded around the perimeter of the first reactor, something invisible to people was quietly going on in the nuclear reactor of Unit 1.

Inside the reactor, the cladding of the nuclear fuel rods has now turned bright red.

This protective shell is made of a metal element called zirconium. This metal has a low thermal neutron absorption cross-section, as a nuclear fuel cladding and structural material, it is at the release site of nuclear energy fission reaction and nuclear energy conversion into heat energy in nuclear reactors, and is the first barrier to prevent reactor radioactive fission products from escaping.

For every million kilowatts of power generated by nuclear power, 20 to 25 tonnes of zirconium metal are consumed in a year.

But at this time, the zirconium shell, which had been turned red by the heat of the fuel rods, was scorching the water vapor in the reactor.

At high temperatures, zirconium undergoes a violent chemical reaction with water vapor.

At this time, a large amount of water vapor in the No. 1 reactor was roasted by the zirconium shell and decomposed into hydrogen and oxygen.

When designing the reactor, experts took into account such a situation. So above Unit 1, there is a special air outlet similar to a central air conditioner.

This is the gas port of the hydrogen exhaust system.

According to the normal process, when a large amount of hydrogen is produced in the reactor, the hydrogen exhaust system should step in at this time.

But above the No. 1 reactor, the originally tightly knit hydrogen discharge port is now crooked. Obviously, after receiving the impact of the earthquake, the impact of the tsunami, and the high temperature scorching, the hydrogen exhaust system has been completely hung up!

"Sneer,"

"Sneering 、、、"

As the temperature of the zirconium shell gets higher and higher, more and more of the white vapor inside the reactor becomes two extremely flammable gases.

And it was at this time that the Fukushima Prefecture Fire Brigade, which had come to assist in cooling the reactor, arrived.

It didn't take long for a fire hose to be plunged into the reactor. The water, which can be called a drop in the bucket, spilled and fell on the zirconium shell.

As if the beast had felt more food, the red zirconium shell let out a moan of pleasure.