It collapsed Destroying the bulkheads between the first three compartments and all the decks , tore Destroying a large hole in the hull , destroyed Destroying compartments four and five , and killed Killing everyone still alive forward of the nuclear reactor in the fifth compartment .

4 nuclear reactor in the Chernobyl Nuclear Power Plant , near the city of Pripyat in the north of the Ukrainian Soviet Socialist Republic .

The accident Catastrophe started Process_start during a safety test Testing on an RBMK-type nuclear reactor , which was commonly used Using throughout the Soviet Union .

This operating Being_in_operation gap was about one minute and had been identified Check as a potential safety problem that could cause Causation the nuclear reactor core to overheat Destroying .

The test Testing supervisor then failed to follow procedure , creating Creating unstable operating Being_in_operation conditions that , combined Cause_to_amalgamate with inherent RBMK reactor design flaws and the intentional disabling Destroying of several nuclear reactor safety systems , resulted in Causation an uncontrolled nuclear chain reaction .

The test Testing supervisor then failed to follow procedure , creating Creating unstable operating Being_in_operation conditions that , combined Cause_to_amalgamate with inherent RBMK reactor design flaws and the intentional disabling Destroying of several nuclear reactor safety systems , resulted in Causation an uncontrolled nuclear chain reaction .

A large amount of energy was suddenly released , vapourising superheated Change cooling Change water and rupturing Destroying the reactor core in a highly destructive Destroying steam explosion Attack .

This was immediately followed by an open-air reactor core fire that released considerable airborne radioactive contamination for about nine days that precipitated onto parts of the USSR and western Europe , before being finally contained Containing on 4 May 1986 .

To reduce Cause_change_of_position_on_a_scale the spread Dispersal of radioactive contamination from the wreckage Catastrophe and to protect Preventing_or_letting the site from further weathering , the remains of reactor No .

4 reactor were further enclosed in 2017 by the Chernobyl New Safe Confinement , a larger enclosure that allows Preventing_or_letting the removal of both the sarcophagus and the reactor debris , while containing the radioactive hazard .

4 reactor were further enclosed in 2017 by the Chernobyl New Safe Confinement , a larger enclosure that allows Preventing_or_letting the removal of both the sarcophagus and the reactor debris , while containing the radioactive hazard .

The reactor explosion killed Killing two of the reactor operating Being_in_operation staff .

The reactor explosion killed Killing two of the reactor operating Being_in_operation staff .

The Three Mile Island accident was a partial meltdown Catastrophe of reactor number 2 of Three Mile Island Nuclear Generating Station ( TMI-2 ) in Dauphin County , Pennsylvania , near Harrisburg and subsequent radiation leak Reveal_secret that occurred Coming_to_be on March 28 , 1979 .

The accident began Process_start with failures in the non-nuclear secondary system , followed Motion by a stuck-open pilot-operated relief valve in the primary system , which allowed large amounts of nuclear reactor coolant to escape .

In particular , a hidden Hiding_objects indicator light led to Causation an operator manually overriding the automatic emergency cooling system of the reactor because the operator mistakenly believed Know that there was too much coolant water present in the reactor and causing Causation the steam pressure release .

In particular , a hidden Hiding_objects indicator light led to Causation an operator manually overriding the automatic emergency cooling system of the reactor because the operator mistakenly believed Know that there was too much coolant water present in the reactor and causing Causation the steam pressure release .

It has been cited Judgment_communication as a contributor to the decline of a new reactor construction program , a slowdown that was already underway in the 1970s .

Operation Opera ( ) , also known as Operation Babylon , was a surprise Israeli air strike Attack carried out Military_operation on 7 June 1981 , which destroyed Destroying an Iraqi nuclear reactor under construction 17 kilometers ( 10.5 miles ) southeast of Baghdad .

In 1976 , Iraq purchased Commerce_buy an `` Osiris '' -class nuclear reactor from France .

While Iraq and France maintained that the reactor , named Name_conferral `` Osirak '' by the French , was intended for peaceful scientific research , the Israelis viewed Perception_active the reactor with suspicion , believing it was designed Creating to make Manufacturing nuclear weapons .

While Iraq and France maintained that the reactor , named Name_conferral `` Osirak '' by the French , was intended for peaceful scientific research , the Israelis viewed Perception_active the reactor with suspicion , believing it was designed Creating to make Manufacturing nuclear weapons .

on 7 june 1981 , a flight of israeli air force f-16a fighter aircraft , with an escort of unk , bombed Attack and heavily damaged Damaging the `` osirak '' reactor .

Israel called Name_conferral the operation an act of self-defense said Statement that the reactor had `` less than a month to go '' before `` it might have become Becoming critical . ''

the main target Aiming of the strike Attack was the tuwaitha nuclear research Research center near baghdad , which was the site of the osirak nuclear reactor that was attacked Attack by the iranian air force in 1980 and again by the israeli air force in 1981 , along with many other military sites across the city .

Because of the reactor trips and other grid problems , the electricity supply failed , and the reactors ' emergency diesel generators automatically started Process_start .

The earthquake generated Creating a 14-meter-high tsunami that arrived Arriving 46 minutes later , sweeping Scouring over the plant 's seawall and flooding Destroying the plant 's lower grounds around the Units 1-4 reactor buildings with sea water , which filled Filling the basements and knocked out the emergency generators .

This was the first attack Attack on a nuclear reactor and only the third on a nuclear facility in history .

operation scorch sword ( ) was a surprise airstrike Attack carried out Action by islamic republic of iran air force ( iriaf ) on 30 september 1980 , that damaged Damaging an unk nuclear reactor 17 km south-east of baghdad , iraq .

They flew Motion stealthily to Tuwaitha , a city ten miles ( 17.58 km ) southeast of Baghdad , home to the `` Osirak '' nuclear reactor .

It was also the first instance of a preventive attack Attack on a nuclear reactor , the intent of which was to forestall the development of a nuclear weapon .

the reactor was completely destroyed Destroying in another airstrike Attack about eight months later on 7 june 1981 by the israeli air force , in an operation called Name_conferral operation opera .