I did a study of this event as part of a degree course. I anyones interested in this I can recomend a book called "the truth about Chernobyl" by Grigori Medviedev.
He was a very senior engineer involved with the construction of various reactors including Chernobyl, and had a hand in some of the recrutment of engineers on site, He was deeply involved with the aftermath days after the disaster.
The book is highly detailed, starts with a back round to the politicaly driven mind set underlying the industry. the backrounds and personality traits of those in the control room at the time. which had a very significant bearing on the causes.
A detailed step by step account of what happened on that night based on many first hand accounts from all those still alive straight after. although this may be quite technical for most without some backround knowlege of a nuclear reactor (Walter Patterson's "Nuclear power" is considered the bible in getting any layman up to speed on nuclear power generation withou getting bogged down in technicalities. And concidered as an essential read for any one in government wishing to concern themselfs with nuclear power generation and easy to read, I first read it at the age of 13)
The epiloge I should warn is horrific to read, it deals with the medical state of the station survivors during their last days in hospital. Not for the slightly squeamish.
the one main down side to this book is the author does push his ego forward quite a bit, I felt it was his way of trying to wash his hands of his responsibility in this disaster yet being such a key figure in the setting up of the industry which is something he does brag a little about.
It not only gives a good view of atomic energy and how not to do it from a technical point, but also how hubris in management attitude in any industry can cause "problems"