Individual involvement in the Chernobyl disaster

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (August 2013) (Learn how and when to remove this message) This article's lead section may be too short to adequately summarize the key points. Please consider expanding the lead to provide an accessible overview of all important aspects of the article. (May 2019) (Learn how and when to remove this message)

The Chernobyl disaster was a catastrophic nuclear disaster rated a level 7 accident on the International Nuclear Event Scale, alongside the Fukushima nuclear accident. The accident occurred at 01:23 MSD on April 26th, 1986, at the Chernobyl Nuclear Power Plant in Soviet Ukraine. The accident occurred during an intended safety test for Reactor Number 4, the conditions the test were under accidentally triggering the power to drop, then to follow it, a power surge. This caused an explosion and destroyed most of the reactor building due to operator error and reactor design flaws. The explosion spread debris and radioactive material across the surrounding area, and over the following days and weeks, most of mainland Europe was contaminated with radionuclides that emitted dangerous amounts of ionizing radiation. On the night of April 25th and the early hours of April 26th, there had been 160 personnel on duty across the facility, while 300 more workers were on site at the building site of reactors 5 and 6.