#Chernobyl meltdown generator#
#Chernobyl meltdown full#

When these conditions were achieved, the steam supply for the turbine generator was to be closed off.

#Chernobyl meltdown full#

The steam-turbine generator was to be run up to full speed.

The reactor was to be running at a low power level, between 700 MW and 800 MW.

The experimental procedure was intended to run as follows: The station managers presumably wished to correct this at the first opportunity, which may explain why they continued the test even when serious problems arose, and why the requisite approval for the test had not been sought from the Soviet nuclear oversight regulator (even though there was a representative at the complex of 4 reactors). The Chernobyl power plant had been in operation for two years without the capability to ride through the first 60вЂ“75 seconds of a total loss of electric power and thus lacked an important safety feature. If test conditions had been as planned, the procedure would almost certainly have been carried out safely the eventual disaster resulted from attempts to boost the reactor output once the experiment had been started, which was inconsistent with approved procedure. Instead, it was approved only by the director of the plant (and even this approval was not consistent with established procedures).ДЄccording to the test, the thermal output of the reactor should have been no lower than 700В MW at the start of the experiment.

No detrimental effect on the safety of the reactor was anticipated, so the test program was not formally coordinated with either the chief designer of the reactor or the scientific manager.

The test procedure was to begin with an automatic emergency shutdown. The test focused on the switching sequences of the electrical supplies for the reactor. The test procedure was to be repeated again in 1986, and it was scheduled to take place during the maintenance shutdown of Reactor Four. In 1985, the tests were attempted a third time but also yielded negative results. The system was modified, and the test was repeated in 1984 but again proved unsuccessful. An initial test carried out in 1982 showed that the voltage of the turbine-generator was insufficient. This potential still needed to be confirmed, and previous tests had ended unsuccessfully. Analysis indicated that this residual momentum and steam pressure might be sufficient to run the coolant pumps for 45 seconds, bridging the gap between an external power failure and full power from the emergency generators. To solve this one-minute gap, considered an unacceptable safety risk, it had been theorised that rotational energy from the steam turbine (as it wound down under residual steam pressure) could be used to generate the electrical power required. The Chernobyl reactors used water as a coolant with reactor 4 fitted with 1,600 individual fuel channels each requiring a coolant flow of 28,000 litres per hour.ДЄs the cooling pumps require electricity to cool the reactor, in the event of a power failure, ChernobylвЂ™s reactors had three backup diesel generators these would start up in 15 seconds, but took 60вЂ“75 seconds to attain full speed and reach the 5.5вЂ‘megawatt output required to run the main pump. RBMK reactors, like those in use at Chernobyl, following an emergency shutdown will continue to emit 7 % of their thermal output and therefore must continue to be cooled. The testДЄn inactive nuclear reactor continues to generate a significant amount of residual heat. The testВ was incorporated into a scheduled shutdown of reactor 4.

The accident occurred during anВ experiment to test a way of coolingВ the core of the reactor in an emergency situation.