求翻译：随着化石能源的逐渐枯竭，核能逐渐被认为是人类重要的高效能源。由于各方面原因核电站出现事故并导致严重的后果，使得人们更加重视核电站的安全稳定运行。核电站蒸汽发生器（SG）是核一级部件，换热管材耐蚀性一直是核能大国重点研究的对象。核电站蒸汽发生器换热管在使用过程中，常因为晶间腐蚀和晶间腐蚀破裂而损坏，因此蒸汽发生器换热管的耐晶间腐蚀性能又是耐蚀性能中的重点研究内容。20世纪70年代，美国研制了690合金，由于690合金在高温水环境中具有优良的抗应力腐蚀开裂（SCC）性能，该合金被认为是核电站压水堆蒸汽发生器换热管的最佳材料。是什么意思？

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As the fossil energy sources, nuclear energy has been depleted over time is considered the most important energy-efficient. Because of the reasons why nuclear power plant accidents and lead to serious consequences, and the people pay more attention to the safety of nuclear power plants. Nuclear Powe

With the gradual depletion of fossil fuels, nuclear energy are gradually being considered human important energy efficiency. Due to various reasons nuclear power plant accidents, causing serious consequences occurred, making people