The suppression pool is designed to protect the primary vessel if the core gets too hot.

当核心过热时，抑压池可以起到保护第一层安全壳的作用。

youdao

So the big difference between a PWR and BWR is that a BWR has a built in suppression pool for the steam that maybe released.

所以加压水反应堆和沸水反应堆的不同，就是沸水反应堆的在抑压池里有个装置，使得蒸汽能够释放出来。

youdao

At 6:14 a.m. on 15 March, the pressure-suppression pool beneath the containment vessel of unit 2 was rocked by a blast.

3月15日6点14分，2号反应堆的安全壳下的抑压池发生爆炸。

youdao

The telltale sign of trouble at reactor No. 2, Tokyo Electric Power Co. officials said, was that pressure had dropped in the "suppression pool" the part of the reactor that converts steam to water at the bottom of the container.

WSJ: Japan's Nuclear Crisis Escalates