The chernobyl accident updating of insag 1
Over 100 fire-fighters from the site and called in from Pripyat were needed, and it was this group that received the highest radiation exposures.Reinforcements were brought in until about , when 250 firemen were available and 69 firemen participated in fire control activities.As the shutdown proceeded, the reactor was operating at about half power when the electrical load dispatcher refused to allow further shutdown, as the power was needed for the grid.In accordance with the planned test programme, about an hour later the ECCS was switched off while the reactor continued to operate at half power.
It was decided to take advantage of this shutdown to determine whether, in the event of a loss of station power, the slowing turbine could provide enough electrical power to operate the main core cooling water circulating pumps, until the diesel emergency power supply became operative.
During the course of a safety system test being carried out just before a routine maintenance outage, Chernobyl 4 was destroyed as a result of a power transient on 26 April 1986.
The accident at Chernobyl was the product of a lack of safety culture.
Unfortunately, this test, which was considered essentially to concern the non-nuclear part of the power plant, was carried out without a proper exchange of information and coordination between the team in charge of the test and the personnel in charge of the safety of the nuclear reactor.
Therefore, inadequate safety precautions were included in the test programme and the operating personnel were not alerted to the nuclear safety implications of the electrical test and its potential danger.