Individual involvement in the Chernobyl disaster

Nikolai Gorbachenko

Gorbachenko, a radiation monitoring technician, at the beginning of his shift checked Unit 3; he skipped the check of Unit 4 as it was being shut down, so at the moment of the accident he was located in the duty room. A flat and powerful thud shook the building; he and his assistant Pshenichnikov thought it was a water hammer occurring during a turbine shutdown. Another flat thud followed, accompanied by lights going out, the control panel of Unit 4 losing signal, latched double doors being blown apart by the blast, and black and red powder falling from the ventilation vent; emergency lights then switched on. Telephone connection with Unit 4 was cut. The corridor to the deaerator galleries was full of steam and white dust. The radiation counters went off-scale, and the high-range one burned out when switched on; the portable instruments were capable of showing at most 4 roentgens per hour (36 nA/kg), while the radiation on the roof ranged between 2,000 and 15,000 roentgens per hour (18 and 130 µA/kg). He went to the turbine hall to survey the damage, saw scattered pieces of concrete, and returned to the duty room. Meeting two men there, together with them he went to search for Shashenok, found him unconscious in a damaged instrument room, and carried him down. Gorbachenko returned to his post and changed clothes and shoes. He was then ordered to look for Khodemchuk, but the search was unsuccessful. He went to the control room and with Dyatlov went outside to survey the reactor building. At 5:00 am, he began feeling weak and vomiting and was transported to hospital, from where he was released on 27 October.

Valery Khodemchuk

The night shift main circulating pump operator, Khodemchuk, was likely killed immediately; he was located in the collapsed part of the building, in the far end of the southern main circulating pumps engine room at level +10. His body was never recovered and is entombed in the reactor debris.

Vladimir Shashenok

Shashenok, the automatic systems adjuster from Atomenergonaladka (the Chernobyl startup and adjustment enterprise), was supposed to be in Room 604, the location of the measurement and control instruments, on the upper landing across the turbine room, on level +24, under the reactor feedwater unit; he was reporting the states of the pressure gauges of the profile of the multiple forced circulation circuit to the computer room by telephone. The communication lines were cut during the explosion. Shashenok received deep thermal and radiation burns over his entire body when the overpressure spike destroyed the isolation membranes and the impulse pipes of the manometers in his instrument room just before the explosion, which then demolished the room itself. The landing was found damaged, covered with ankle-deep water, and there were leaks of boiling water and radioactive steam. Shashenok was found unconscious in Room 604, pinned under a fallen beam, with bloody foam coming out of his mouth. His body was severely contaminated by radioactive water. He was carried out by Gorbachenko and Palamarchuk and died at 6:00 am in the Pripyat hospital under care of the chief physician, Leonenko Vitaliy, without regaining consciousness. Gorbachenko suffered a radiation burn on his back where Shashenok's hand was located when he helped carry him out. Khodemchuk and Shashenok were the first two victims of the disaster.

Oleg Genrikh, Anatoly Kurguz

Genrikh, an operator of the control room on Level +36, was taking a nap in a windowless room adjacent to the control room. The window in the control room was broken and the lights went out. His colleague Kurguz was in the control room with three open doors between him and the reactor room; at the moment of the explosion, he suffered severe burns from steam entering the control room. Genrikh received less serious burns as he was protected by the windowless room. The stairs on the right side were damaged; he managed to escape by the stairs on the left. On the way back they were joined by Simeonov and Simonenko, the gas loop operators, all four heading to the control room. Kurguz was shortly afterwards evacuated by an ambulance; aware of dangers of radiation contamination, Genrikh took a shower and changed his clothes.

Alexander Yuvchenko

Yuvchenko was located in his office between reactors 3 and 4, on Level 12.5; he described the event as a shock wave that buckled walls, blew doors in, and brought a cloud of milky grey radioactive dust and steam. The lights went out. He met a badly burned, drenched and shocked pump operator, who asked him to rescue Khodemchuk; that quickly proved impossible as that part of the building did not exist anymore. Yuvchenko, together with the foreman Yuri Tregub, ran out of the building and saw half of the building gone and the reactor emitting a blue glow of ionized air. They returned to the building and met Valeri Perevozchenko and two junior technicians, Kudryavtsev and Proskuryakov, ordered by Dyatlov or Akimov to manually lower the presumably seized control rods. Tregub went to report the extent of damage to the control room. Despite Yuvchenko's explanation that there were no control rods left, the four climbed a stairwell to Level 35 to survey the damage; Yuvchenko held open the massive door into the reactor room and the other three proceeded in to locate the control rod mechanism; after no more than a minute of surveying the reactor debris, enough for all three to sustain fatal doses of radiation, they returned, their skin darkened with "nuclear tan" in reaction to the high radiation dose. The three were the first to die in the Moscow hospital. Yuvchenko meanwhile suffered serious beta burns and gamma burns to his left shoulder, hip and calf as he kept the radioactive-dust-covered door open. It was later estimated he received a dose of 4.1 Sv. At 3:00 am, he began vomiting intensely; by 6:00 am, he could no longer walk. He later spent a year in the Moscow hospital receiving blood and plasma transfusions and received numerous skin grafts.

Valeriy Perevozchenko

Perevozchenko, the reactor section foreman, was present on the open platform at Level +50 shortly before the explosion. He witnessed the 350 kg blocks atop the fuel channels of the Upper Biological Shield jumping up and down and felt the shock waves through the building structure; the rupture of the pressure channels was in progress. He ran down the spiral staircase to Level +10, through the deaerator gallery and the corridor to the control room, to report his observations, arriving shortly after the explosions, then returned to search for his comrades. He witnessed the destruction of the reactor building from the broken windows of the deaerator gallery. With his face already tanned by the radiation, he went to the dosimetry room and asked Gorbachenko for radiation levels; Gorbachenko left with Palamarchuk to rescue Shashenok while Perevozchenko went through the graphite and fuel containing radioactive rubble on Level 10 to the remains of Room 306 in an unsuccessful attempt to locate Khodemchuk, close to debris emitting over 10,000 roentgens per hour (90 µA/kg). He then went to the control room of Genrikh and Kurguz and found it empty; vomiting and losing consciousness, he returned to the control room to report on the situation.

Vyacheslav Brazhnik, Pyotr Palamarchuk, Razim Davletbayev

Brazhnik, the senior turbine machinist operator, ran into the control room to report fire in the turbine hall. Palamarchuk, the Chernobyl enterprise group supervisor, together with Davletbayev, followed him back to the turbine room. They witnessed fires on Levels 0 and +12, broken oil and water pipes, roof debris on top of turbine 7, and scattered pieces of reactor graphite and fuel, with the linoleum on the floor burning around them. Palamarchuk unsuccessfully attempted to contact Sashenok in Room 604, then ran around the turbogenerator 8, down to Level 0 and urged the two men from the Kharkov mobile laboratory, assigned to record the turbine 8 vibrations, to leave; they, however, had both already received a lethal radiation dose. Akimov asked Palamarchuk to look for Gorbachenko and then rescue Sashenok as the communication with the dosimetry room was cut. Palamarchuk met Gorbachenko by the staircase on Level +27, then they together found and recovered Shashenok's unconscious body.

Aleksandr Kudryavtsev, Viktor Proskuryakov

Kudryavtsev and Proskuryakov, the SIUR trainees from other shifts, were present to watch Toptunov and learn. After the explosion they were sent by Dyatlov or Akimov to the central hall to turn the handles of the system for manual lowering of the presumably seized control rods. They ran through the de-aerator gallery to the right to the VRSO unit elevator, found it destroyed, so climbed up the staircase instead, towards Level 36; they missed Kurguz and Genrikh, who used another stairwell. Level 36 was destroyed, covered with rubble. They went through a narrow corridor towards the central hall, entered the reactor hall, and found it blocked with rubble and fragments; dangling fire hoses were pouring water into the remains of the reactor core, the firemen not there anymore. The Upper Biological Shield was slanted, jammed into the reactor shaft; a blue and red fire raged in the hole. The minute the two stood above the reactor was enough to darken their bodies with "nuclear tan" and give them a fatal radiation dose. They returned to Level 10 and to the control room, reporting the situation; Dyatlov insisted they were wrong, assuming the explosion had been caused by hydrogen-oxygen mixture in the 110 m³ emergency tank and the reactor itself was intact.

Anatoly Dyatlov

Anatoly Dyatlov, the deputy chief engineer, supervised the test. At the moment reactor power slipped to 30MW, he insisted the operators continue the test. He overrode Akimov's and Toptunov's objections, threatening to hand the shift to Tregub (the previous shift operator who had remained on-site), intimidating them into attempting to increase the reactor power. During this period of time the reactor protection system was vetoed to prevent automatic shutdown of the reactor. The power stabilized at 200MW at around 1:00 am and did not rise further, due to continued xenon poisoning of the core. Later the test was commenced, then the reactor showed power excursion and was scrammed. As the control rods dropped into the core, their design (which incorporated a graphite plug at the bottom of each rod) introduced additional moderation and hence reactivity into the reactor system. The explosion occurred as the control rods were falling, and the subsequent damage prevented insertion into the reactor. Dyatlov ordered reactor cooling with emergency speed, assuming the reactor was intact and the explosion had been caused by hydrogen accumulating in the emergency tank of the safety control system. Other employees went to the control room, reporting damage. Dyatlov went to the backup control room, pressing the AZ-5 button there and disconnecting power to the control rod servodrives; despite seeing the graphite blocks scattered on the ground outside the plant, he still believed the reactor was intact. Kudryavtsev and Proskuryakov returned to report the reactor damage they had seen, but Dyatlov insisted what they had seen was the results of an explosion of the emergency tank, claiming the explosion of the 110 m³ tank at Level +71 was sufficient to destroy the central hall roof. Dyatlov reported his assumptions as reality to Bryukhanov and Fomin, the higher-level managers. In the corridor, he met Genrikh and Kurguz and sent them to the medical station. He ran to the control room of Block 3, ordered Bagdasarov to shut down Reactor 3, then returned to control room 4 and ordered Akimov to call the daytime shift and get people to the affected unit; namely Lelechenko, whose crew had to remove hydrogen from the Generator 8 electrolyzer. At 2:00, Dyatlov ordered Akimov to feed water to the reactor, and together with Gorbachenko went to survey the plant from the outside. Despite seeing the fuel and graphite scattered around, he still believed the reactor was intact. They then returned to the control room. At 5:00 am, he got sick and together with Gorbachenko went to the medical unit. Fomin replaced him at his post with Sitnikov.

Aleksandr Akimov

Aleksandr Akimov, the unit shift chief, was in charge of the test itself. He took over the shift at midnight from Tregub, who stayed on-site. The drop in reactor power from 1500 MWt to 30 MWt was disconcerting; he wanted to abort the test. He supported Toptunov's decision to shut down the poisoned reactor, but was over-ridden by Dyatlov and forced to continue. At 1:23:04 am the test began, and the main circulation pumps started cavitating due to the too high temperature of inlet water. The coolant started boiling in the reactor, and the reactor power slowly increased. Toptunov reported a power excursion to Akimov. At 1:23:40, Akimov pressed the AZ-5 button, class-5 emergency. The control rods, according to the synchro indicators, seized at a depth of between 2 and 2.5 meters instead of the entire core depth of 7 meters. Akimov disconnected the clutches of the control rod servos to let the rods descend into the core by their own weight, but the rods did not move. The reactor was now making rumbling noises. Akimov was confused. The reactor control panel indicated no water flow and failure of pumps. The explosion occurred, the air filled with dust, power went out, and only battery-powered emergency lights stayed in operation. Perevozchenko ran into the control room, reporting the collapse of the reactor top. Brazhnik ran in from the turbine hall, reporting fire there. Brazhki, Akimov, Davletbayev, and Palamarchuk ran into the turbine hall, having seen scattered debris and multiple fires on Levels 0 and +12. Akimov called the fire station and the chiefs of electrical and other departments, asking for electrical power for coolant pumps, removal of hydrogen from hydrogen generators, and other emergency procedures to stabilize the plant and contain the damage. Internal telephone lines were disabled; Akimov sent Palamarchuk to contact Gorbachenko. Kudryavtsev and Proskuryakov returned from the reactor and reported its state to Akimov and Dyatlov. Insisting the reactor was intact, Akimov ordered Stolyarchuk and Busygin to turn on the emergency feedwater pumps. Davletbayev reported loss of electrical power, torn cables, and electric arcs. Akimov sent Metlenko to help in the turbine hall with manual opening of the cooling system valves, which was expected to take at least four hours per valve. Perevozchenko returned and reported that the reactor was destroyed, but Akimov insisted it was intact. At 3:30 am, Telyatnikov contacted Akimov, asking what was happening to his firemen; Akimov sent him a dosimetrist. Akimov, already nauseous, was replaced at 6:00 am by the unit chief Vladimir Alekseyevich Babychev, but together with Toptunov stayed in the plant. Believing the water flow to the reactor to be blocked by a closed valve somewhere, they went to the half-destroyed feedwater room on Level +24. Together with Nekhayev, Orlov, and Uskov, they opened the valves on the two feedwater lines, then climbed over to Level +27 and almost knee-deep in a mixture of fuel and water, opened two valves on the 300 line; due to advancing radiation poisoning caused by a dose of over 15 Grays (4 being the LD50), they did not have the strength to open the valves on the sides. Akimov and Toptunov spent several hours turning valves; the radioactive water in Room 712 was half submerging the pipeline. Smagin went in to open the third valves, spent 20 minutes in the room, and received 280 rads. Akimov was evacuated to the hospital. Until his death, he insisted he had done everything correctly and had made no mistakes.

Viktor Bryukhanov

Bryukhanov, the plant manager, arrived at 2:30 am. Akimov reported a serious radiation accident but intact reactor, fires in the process of being extinguished, and a second emergency water pump being readied to cool the reactor. Due to limitations of available instruments, they seriously underestimated the radiation level. At 3:00 am, Bryukhanov called Maryin, the deputy secretary for the nuclear power industry, reporting Akimov's version of the situation. Maryin sent the message further up the chain of command, to Frolyshev, who then called Vladimir Dolgikh, who called Gorbachev and other members of the Politburo. At 4:00 am, Moscow ordered feeding of water to the reactor.

Nikolai Fomin

Chief engineer Fomin arrived in the Block 4 control room at 4:30. Akimov reported an intact reactor and explosion of the emergency water feed tank. He ordered continuous feeding of water into the reactor, which was already in progress by emergency pump 2 from the deaerators. Fomin kept pressing the staff to feed water to the reactor and transferred more people to Unit 4 to replace those being disabled by radiation. After Dyatlov left, Fomin ordered Sitnikov, his replacement, to climb to the roof of Unit C and survey the reactor; Sitnikov obeyed and received a fatal radiation dose there; at 10:00 am he returned and reported to Fomin and Bryukhanov that the reactor was destroyed. The managers refused to believe him and ordered continued feeding of water into the reactor; the water, however, flowed through the severed pipes into the lower levels of the plant, carrying radioactive debris and causing short circuits in the cableways common to all four blocks. Later, before trial he had mental breakdown and tried to kill himself. Fomin had broken his glasses and slit his wrists with the shards, but they have saved his life.

Victims and other on-site persons

The following is a table of victims and other involved people of the Number Four reactor accident (still alive unless date of death is specified or died from explosions or related causes).