chernobyl disaster

chernobyl disaster

The Chernobyl disaster was a catastrophic nuclear 

accident that occurred on 26 April 1986 at the Chernobyl 

Nuclear Power Plant in Ukraine, which was under the 

direct jurisdiction of the central authorities of the Soviet 

Union. An explosion and fire released large quantities of 

radioactive particles into the atmosphere, which spread 

over much of the western USSR and Europe.

The Chernobyl disaster is widely considered to have 

been the worst nuclear power plant accident in history, 

and is one of only two classified as a level 7 event on 

the International Nuclear Event Scale (the other being 

the Fukushima Daiichi nuclear disaster in 2011). The 

battle to contain the contamination and avert a greater 

catastrophe ultimately involved over 500,000 workers 

and cost an estimated 18 billion rubles  The official 

Soviet casualty count of 31 deaths has been disputed, 

and long-term effects such as cancers and deformities 

are still being accounted for.

Accident

increase, leading to explosions in its four suffered a 

catastrophic power 

core. This dispersed large quantities 

of radioactive fuel and core materials 

into the atmosphere and ignited the 

combustible graphite moderator. The 

burning graphite moderator 

increased the emission of radioactive 

particles, carried by the smoke, as 

the reactor had not been 

encased by any kind of hard containment vessel. The 

accident occurred during an 

experiment scheduled to test a 

potential safety emergency core cooling feature, which took 

place during a normal shutdown procedure.

Causes

Operator error

There were two official explanations of the accident: the first, 

later acknowledged to be erroneous, was published in 

August 1986 and effectively placed the blame on the power 

plant operators. To investigate the causes of the accident 

the IAEA created a group known as the International Nuclear 

Safety Advisory Group (INSAG), which in its report of 1986, 

INSAG-1, on the whole also supported this view, based on 

the data provided by the Soviets and the oral statements of 

specialists.^[79] In this view, the catastrophic accident was 

caused by gross violations of operating rules and 

regulations. "During preparation and testing of the turbine 

generator under run-down conditions using the auxiliary 

load, personnel disconnected a series of technical protection 

systems and breached the most important operational safety 

provisions for conducting a technical exercise."^[80]:311

The operator error was probably due to their lack of 

knowledge of nuclear reactor physics and engineering, as 

well as lack of experience and training. According to these 

allegations, at the time of the accident the reactor was being 

operated with many key safety systems turned off, most 

notably the Emergency Core Cooling System (ECCS), LAR 

(Local Automatic control system), and AZ (emergency power 

reduction system). Personnel had an insufficiently detailed 

understanding of technical procedures involved with the 

nuclear reactor, and knowingly ignored regulations to speed 

test completion

Effects

International spread of radioactive substances

It was Sweden's search for the source of radioactivity, 

after they had determined there was no leak at the 

Swedish plant, that at noon on 28 April led to the first 

hint of a serious nuclear problem in the western Soviet 

Union. Hence the evacuation of Pripyat on 27 April 36 

hours after the initial explosions, was silently 

completed before the disaster became known outside 

the Soviet Union. The rise in radiation levels had at 

that time already been measured in  finland, but a civil 

service strike delayed the response and 

publication.The initial evidence that a major release 

of radioactive material was affecting other countries 

came not from Soviet sources, but from Sweden, 

where on the morning of 28 April workers at the 

Forsmark Nuclear Power Plant(approximately 1,100 

km (680 mi) from the Chernobyl site) were found to 

have radioactive particles on their clothes.

Human impact

The Chernobyl Forum first met on 3 February 2003 for 

a three-day meeting. It consisted of the International 

Atomic Energy Agency (IAEA), other United Nations 

organizations (FAO, UN-OCHA, UNDP, UNEP, 

UNSCEAR, WHO, and the World Bank), and the 

governments of Belarus, Russia, and Ukraine. A 

second meeting was held on 10–11 March 2004, and 

a third on 18–20 April 2005. The aim of the Forum 

was to "scientifically clarify the radiological 

environmental and health consequences of the 

Chernobyl accident, to provide advice on and to 

contribute to a scientifically sound remediation and 

health care programmes, and to consider the 

necessity of, and opportunities for continued 

research/learning lessons.

The following images are not suitable 

for the faint 

hearted,

who does not want to 

see retire ... and do not blame me

if they give you nightmares