2. Description

2.1 Heart

The core of an RBMK reactor (figure 2 ) consists of a vertical-axis graphite stack 7 m high and 11.8 m in diameter. This stack is crossed by pressure tubes in which fuel elements, absorbers or control rods are placed. The heat transfer fluid is ordinary water, which, along with graphite, contributes to neutron moderation, albeit to a lesser extent. As it circulates up and down the pressure tubes, the water heats up to boiling point on contact with the fuel elements, producing a mixture of water and steam...