Yes, Aleksandr Akimov, the shift supervisor, ordered Leonid Toptunov (the senior reactor engineer) to press the AZ-5 (emergency shutdown) button at the end of the safety test, which Toptunov did, leading to the Chernobyl disaster's power surge and explosion due to design flaws in the RBMK reactor. Akimov then tried to intervene further by trying to drop control rods manually, but it was too late.
Aleksandr Fyodorovich Akimov (Russian: Александр Фёдорович Акимов; 6 May 1953 – 10 May 1986) was a Soviet engineer who was the supervisor of the shift that worked at the Chernobyl Nuclear Power Plant Reactor Unit 4 on the night of the Chernobyl disaster, 26 April 1986.
The emergency button (AZ-5) was pressed by the operator. Control rods started to enter the core, increasing the reactivity at the bottom of the core. Power excursion rate emergency protection system signals on; power exceeded 530 MWt.
In order to maintain power at a reduced level, control rods had to be removed. But the operators did something wrong in maintaining the power level (exactly what is uncertain), and the power level dropped precipitously. To compensate, they removed nearly all of the control rods.
Reactor shutdown and power excursion
The scram was started when the AZ-5 button of the reactor emergency protection system was pressed: this engaged the drive mechanism on all control rods to fully insert them, including the manual control rods that had been withdrawn earlier.
The reason why the EPS-5 button was pressed may never be known, whether it was done as an emergency measure or simply as a routine method of shutting down the reactor upon completion of the experiment.
The emergency stop is wired into the control circuit of the equipment and is in series with other safety devices. When the E-Stop is activated, it breaks the circuit, immediately preventing power from reaching the machine's motor or other critical components and shutting it down.
Lots of people from the control room survived, including the operators Stolyarchuk and Kirschenbaum. There's a survivor who was very close to the reactor, his name is Oleg Genrikh . There are also lots of survivors that were elsewhere in the reactor building, the vent block, or the turbine hall.
Why can't a scientist say just remove the elephant foot? This mass of death is a huge blob of radioactive goo that formed after the Chernobyl nuclear disaster in 1986. It's made of corium, which is a mix of melted nuclear fuel and other stuff that got melted by the heat and radiation.
The April 1986 disaster at the Chernobyla nuclear power plant in Ukraine was the product of a flawed Soviet reactor design coupled with serious mistakes made by the plant operatorsb. It was a direct consequence of Cold War isolation and the resulting lack of any safety culture.
The episode's title refers to the exact time of the clock when the reactor 4 of the Chernobyl nuclear plant exploded, at 1:23:45 AM on April 26, 1986. It also depicts the exact time of when Legasov committed suicide in order to coincide with the second anniversary of the Chernobyl explosion.
Chernobyl Nuclear Power Plant's unit 4 was destroyed in the April 1986 accident (you can read more about it in the World Nuclear Association's Chernobyl Accident information paper) with a shelter constructed in a matter of months to encase the damaged unit, which allowed the other units at the plant to continue ...
Alexei Ananenko, Valeri Bespalov and Boris Baranov are the three men who made up Chernobyl's so-called 'Suicide Squad'. They bravely entered the basement of the nuclear reactor to try and save the lives of millions of people.
On December 15, 2000, the last reactor in operation at the Chernobyl site was shut down and the phase of decommissioning began. This involves the removal and disposal of fuel and wastes, decontamination of the plant and the area surrounding it, including any soil and water that may be radioactive.
In April 1988, a top Soviet scientist, Valery Legasov, died by suicide. He was 51 years old. Before his death, he recorded a series of chilling deathbed confessions concerning one of the world's deadliest disasters: the Chernobyl nuclear explosion.
In response to the disaster, the former Soviet Union established a 30-km exclusion zone around the facility and evacuated over 120,000 people from 189 cities and communities. The evacuees were not allowed to bring anything that they could not carry, and their pets had to be left behind.
What did Russia think of HBO's Chernobyl? There has been plenty of praise in Russia for the authenticity of Chernobyl. Izvestia newspaper declared it a more 'realistic' portrayal of the era than most Russian films manage. There's also admiration of how the series conveys the heroism of ordinary people.
Valery Khodemchuk literally vanished on April 26, 1986, when reactor 4 at the Chernobyl nuclear power plant exploded. Valery was in the reactor's water circulation pump room. His body was never found, but he was recorded as the first fatality of the worst nuclear disaster in history.
The three men would live longer than a few weeks and none would succumb to ARS, as modern myth would have you believe. As of 2015, it was reported that two of the men were still alive and still working within the industry. The third man, Boris Baranov, passed away in 2005 of a heart attack.
All six were found guilty and Dyatlov was given the maximum sentence of ten years. From prison, he wrote letters trying to explain RBMK reactor flaws he had discovered, as well as to restore his and the other operators' reputations.
Yes, Chernobyl is still highly radioactive in many areas, especially near the damaged reactor, but radiation levels vary significantly; some parts of the exclusion zone have contamination low enough for potential limited agriculture, while a 2025 drone strike damaged the New Safe Confinement (NSC) structure, raising concerns about long-term containment, although immediate levels stayed stable as the NSC's function is to contain the original sarcophagus's radioactive material, not the entire zone.
But are emergency stop buttons normally open or normally closed? In most cases, emergency stop buttons are normally closed (NC). This means that when the button is not pressed, the circuit is closed, and power continues to flow, allowing the machine or equipment to operate normally.
Many people worry about accidentally pressing the emergency button in elevators, but it's not as serious as you might think. When the button is pressed, the system typically starts with an automated message or a ringtone. Within moments, someone from a monitoring center will respond to check on the situation.
According to EN/IEC 60947-5-5, EN/IEC 60204-1, and EN ISO 13850, buttons used as actuators of an emergency stop device shall be colored red. When a background exists behind the actuator, and as far as it is practicable, it shall be colored yellow.