48 Hours a Day-Chapter 1175: Safety Tests and Accident Cause

Fomin calculated well. A training session was going on right now, but it wasn’t aimed at a newcomer like Zhang Heng. Rather, it was for the older workers who had been at the power plant for some time, equivalent to a refresher course. Those who were on the list were more likely to be promoted after the training ended.

Fomin did not greet the chief engineer of Zhang Heng’s department, but when he received the list, he realized that Ivan’s name was also on it.

Shocked, Fomin didn’t know if he should laugh or cry when he saw that. He had thought that Zhang Heng wouldn’t mention this, but he went straight to the head of the department, and he pulled the wool over Zhang Heng’s eyes. Many people already knew that he had spoken up for Zhang Heng during the interview and spoke to Zhang Heng in private afterward.

Fomin initially wanted to show his approachable side and win over the people’s hearts, but he didn’t expect to be used by Zhang Heng instead. Furthermore, the latter didn’t even say anything about it, only hinting that the head of the department had added his name. After all, as the chief engineer of the Nuclear Power Plant Operation Department, no department wanted to offend him.

Even those who didn’t like him usually avoided clashing with him over something so trivial. It was just a training spot, and no one even came to him to ask for credit. This was also why Fomin did not know that Zhang Heng was on the list until he received it.

However, the list still needed his approval in the end. Fomin’s pen paused on Ivan’s name for a moment before it finally moved to the bottom right corner. He wrote the word “agreed” and left his signature.

Even though Fomin was slightly unhappy with Zhang Heng’s decision, his intention to recruit him had not changed. Not greeting Zhang Heng was one thing, but taking the initiative to cross out his name was another. Doing that would’ve completely shunned Zhang Heng to the opposite side. Thus, Fomin finally pinched his nose and accepted the matter.

Reality proved that Zhang Heng, who had been baptized by the Pirates in the Blacksail quest, could easily handle the factional struggles of a mere nuclear power station. Even if there were ten Fomin, they wouldn’t be a match for him.

In less than a year and a half, Zhang Heng had already figured out all the relevant physics, reactor design and principles, and even all the equipment and circuits of the entire nuclear power plant. Furthermore, in his second year at Chernobyl, he received a safety test proposal designed by Fomin and even witnessed the failure of the first safety test.

During the day, he worked at a nuclear power plant. At night, when he returned to his residence, he would continue to learn Russian and Ukrainian from the receptionist. In addition, Zhang Heng also took the time to go to the hospital in Kiev for two checkups. Probably because he was young and strong enough, that his body seemed to be recovering quite well. No malignant tumors were also detected, at least for now.

After Zhang Heng practiced his Ukrainian language to a level where he could normally communicate, his language proficiency skill, which had been quiet all this time, was finally upgraded from level 2 to level 3. At this point, including his mother tongue, Zhang Heng had reached a level where he could communicate in 11 languages daily.

Furthermore, this parallel dungeon had also allowed him to gain another skill in nuclear engineering, which was now at level 2. Of course, Zhang Heng’s biggest gain was still understanding the flaws in Fomin’s safety experiment and reactor design.

It had to be admitted that compared to pressurized water reactors used by most countries, the RMBK had a natural flaw from the inception of its design—it compromised a part of its safety in exchange for faster construction and lower operating costs. It could be recharged without stopping the reactor and was also able to produce military-grade plutonium.

In the people’s eyes at that time, if there was any flaw in the RMBK reactor, it would have to be its slightly more radioactive emissions, and it was not as clean as the VVER-type pressurized water reactor.

However, the more serious problem was the design of the control rod. Previously, Dyatlov had said that control rods were used to regulate the nuclear fission reaction because the boron it was made up of could absorb neutrons and thus reduce the reactor’s power. However, the problem was that there was still a tiny graphite section at the bottom of the control rod. The graphite acted as a neutron moderator, which was the opposite of boron. This element was used to slow down fast neutrons to increase the reactor’s power.

Of course, the previous designers did not design this so that reactor operators would be caught by surprise by the reversal. The graphite at the bottom also had a role—because graphite could significantly slow down neutrons, it could also appropriately use reduced-purity uranium fuel, thus saving costs.

This wasn’t a problem from an economic standpoint, but the low-enriched uranium fuel would react unstably, especially when the reactor was operating at low power. At that time, the graphite at the bottom of the control rod could play a role—it would allow the reactor to be better controlled.

However, this design brought with it a potential risk. When the control rod was removed entirely from the reactor and then reinserted quickly, the graphite would first come into contact with the reactor core instead of boron. At that time, not only would the reaction power not decrease, but it would increase exponentially, even though just for a brief moment.

What surprised Zhang Heng was that according to the information he had gathered, before the accident at the Chernobyl Nuclear Power Plant, other nuclear power plants had already discovered the problem of the power suddenly rising before decreasing when control rods were reinserted into the reactor. Although reports had been made to the relevant authorities, it was probably because no accidents had happened yet that it was not taken seriously.

On the other hand, it had to be acknowledged that the designers of the RMBK reactor had also made a lot of efforts to ensure its safety. The safety manual, for instance, clearly stated that during any given moment of the reactor’s operation, at least 28 to 30 control rods had to be inserted.

In addition, the reactor was equipped with an emergency core cooling system. When the void coefficient in the reactor increased, the water tank of the emergency core cooling system would immediately open and inject water into the reactor. However, in order to prevent the cool water from entering the high-temperature reactor and causing heat shock, Fomin disconnected the device, which could save lives at critical moments, through the multiple forced circulation circuits during the experiment.

After seeing Fomin’s first failed experiment, Zhang Heng was almost certain that the people in the central control room did not follow the safety manual as they had previously said.

The situation on the night of the explosion was also much more complicated than the first experiment because the safety test did not go according to plan. Previously, the reactor had been operating at low power for quite some time and had fallen into the iodine pit. In order to climb out of the iodine pit, the operator pulled out too many control rods, eventually causing the reactor power to rise rapidly. The people in the central control room could only hurriedly insert all the control rods back into the reactor’s core. They wanted to suppress the fission reaction, but because the safety system was cut off, it could not take effect immediately.

They did not expect that the design flaw of the reactor would eventually lead to the entire nuclear power plant declaring a GG.