SEC (essential service water system) for dismantling series of nuclear power station

The utility model discloses an SEC for dismounting series of a nuclear power station. The SEC for dismounting series of the nuclear power station comprises multiple groups of SECs all arranged between a water taking area and a water drainage area, wherein each group of SECs comprise two series of SEC pumps, shellfish capturing devices and heat exchangers which are sequentially connected through pipelines; and pipelines for connecting the SEC pumps and the shellfish capturing devices on a first series and a second series of each group of SECs are communicated through first connecting pipelines. According to the SEC for dismounting the series of the nuclear power station, two series of SECs of each group are provided with the connecting pipelines, so that the SECs have the capacity of responding superimposed single faults of initiative accidents and can continuously superimpose preventative maintenance, the safety criterion is remarkably improved while compared with that before the series are dismounted, and th