Normal operation
正常状态

In operation since the early 1970s, Japan's Fukushima Daiichi nuclear plant uses six boiling water reactors, which rely on uranium nuclear fission to generate heat. Water surrounding the core boils into steam that drives turbines to generate electricity.
从19世纪70年代投入运行以来，日本福岛第一核电站利用六个沸水堆，通过铀核裂变来产生热能。核心周围的水沸腾后变成水蒸气，推动涡轮从而发电。

The reactor vessel is surrounded by a thick steel-and-concrete primary containment vessel, equipped with a water reservoir designed to suppress overheating of the vessel.
反应堆由一个钢与混凝土构成的厚实外壳（第一层安全壳）保护着，另外还配有一个蓄水库，防止反应堆过热。

The suppression pool is designed to protect the primary vessel if the core gets too hot. Valves release steam into the pool, where it condenses, relieving dangerous pressure.
当核心过热时，抑压池可以起到保护第一层安全壳的作用。这时阀门会打开，水蒸气就能进入抑压池内冷凝，减缓压力过大造成的危险。