It didn't come as a shock to learn that the fuel and cooling systems are the most common causes of breakdown.

不足为怪的是，燃料和冷却系统是故障的最常见原因。

《柯林斯英汉双解大词典》

The pools, which sit atop the reactor buildings and are meant to keep spent fuel submerged in water, have lost their cooling systems.

乏燃料池位于反应堆建筑的顶部，它们本应浸泡在冷却水中，但是它们的冷却系统已经损坏。

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When auxiliary batteries were exhausted, the plant was without power to continue cooling reactor cores and spent fuel pools.

一旦辅助电池用尽，核电站将无法继续冷却反应堆内核以及乏燃料池。

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As many as 15 percent of the 5, 000 previously approved welds in the reactor's auxiliary plumbing, containment dome and spent-fuel cooling systems were X-rayed and found to be defective due to air pockets, poor soldiering and heat damage.

CENTERFORSECURITYPOLICY: A Chernobyl reminder just off our shores

The power cut last month shut down cooling systems for four spent fuel ponds at reactors 1, 3 and 4, although cooling for the reactors themselves was not affected.

BBC: Fukushima nuclear plant: Cooling system power restored

The power cut shut down cooling systems for four spent fuel ponds at reactors 1, 3 and 4 on Monday evening, although cooling to the reactors themselves was not affected.

BBC: Fukushima: Rat linked to outage at Japan nuclear plant