Is RBMK a BWR?
There are two types of reactors used in the U.S. for the production of electricity: the Pressurized Water Reactor (PWR) and the Boiling Water Reactor (BWR). Chernobyl is a type of reactor called an RBMK (Russian acronym) which uses a graphite moderator and water coolant.
What does RBMK mean?
reaktor bolshoy moshchnosty kanalny
The Soviet-designed RBMK (reaktor bolshoy moshchnosty kanalny, high-power channel reactor) is a water-cooled reactor with individual fuel channels and using graphite as its moderator. It is also known as the light water graphite reactor (LWGR).
How does a RBMK work?
A series of graphite blocks surround, and hence separate, the pressure tubes. They act as a moderator to slow down the neutrons released during fission so that a continuous fission chain reaction can be maintained. Heat conduction between the blocks is enhanced by a mixture of helium and nitrogen gas.
Why is graphite bad in Chernobyl?
Although the Chernobyl reactor was also cooled by water, the water was essentially only used for cooling, but not slowing down the neutrons. Instead, enormous blocks of graphite surrounded the fuel and were used to slow down the neutrons. The graphite blocks caught fire causing more heat and damage.
Why did RBMK reactor explode?
“The hot fuel particles reacted with water and caused a steam explosion, which lifted the 1,000-metric-ton cover off the top of the reactor, rupturing the rest of the 1,660 pressure tubes, causing a second explosion and exposing the reactor core to the environment.