The reactor core which includes these rods, and the water it sits in, are contained within a thick steel pressurevessel.
这些燃料棒就是反应堆的核心，它位于水中，并包裹在厚厚的钢制压力容器中。
2
Water in the core began to boil off, raising the temperature and pressure inside the massive steel containment vessel.
堆芯的水开始沸腾，导致钢结构的安全壳内部的温度和压力开始升高。
3
This prolongs the reactors core life by preventing the embrittlement of the steel of the pressurevessel, with some reactors being designed to last between 40 and 50 years.