3.2 The Fukushima Daiichi reactor
The Fukushima Daiichi nuclear power plant lies on the east coast of Japan in the Futaba District.
It is one of two nuclear power stations in the vicinity – the other is Fukushima Daini, sited a little further south. Both are owned and run by the Tokyo Electricity Production Company (TEPCO).
Fukushima Daiichi is a large plant containing six boiling water reactors (BWRs) with water used as both the moderator and coolant. The reactors are referred to by numbers 1–6. You can see the reactor buildings in Figure 5.
The BWR reactors were old and of a design popular in the 1960s. The first reactor connected to the Japanese grid in 1971.
Japan is situated near the boundary of several tectonic plates so it is a region where earthquakes are relatively frequent and can occur at all magnitudes.
In the next section, find out what happened when the reactor was affected by an earthquake.