Steam dump device for a nuclear power plant

1. A steam dump device for a nuclear power plant, configured to be installed within a bypass line leading from a boiler to a condenser comprising:

an elongated header vessel comprising a means for receiving steam, the elongated header vessel extending horizontally and comprising at least a top perforated diaphragm and at least a bottom perforated diaphragm opposed thereto, said top and bottom perforated diaphragms arranged on respective top and bottom portions of the elongated header vessel, the top perforated diaphragm having a greater area than the bottom perforated diaphragm area; and

an external baffle plate assembly partially enclosing the elongated header vessel the external baffle plate assembly comprising a top plate and a bottom plate, wherein each of the top and bottom plates comprises lateral steam openings along the length of the plate.

2. The steam dump device of claim 1 , wherein a ratio between the areas of said top perforated diaphragm and said bottom perforated diaphragm is comprised within a ratio of 1:1 to 4:1.

3. The steam dump device of claim 2 , wherein said ratio is equal to 2:1.

4. The steam dump device of claim 1 , comprising a plurality of consecutive and separated top perforated diaphragms arranged along the top portion of the elongated header vessel, and a plurality of consecutive and separated bottom perforated diaphragms arranged along the bottom portion of the elongated header vessel.

5. The steam dump device of claim 1 , wherein the elongated header vessel comprises an elliptical terminal head at both ends.

6. The steam dump device of claim 5 , wherein at least one elliptical terminal head comprises at least one steam inlet and a multi holed hemispherical diaphragm.

7. The steam dump device of claim 1 , further comprising sliding support feet configured to allow a longitudinal movement of the elongated header vessel on a supporting structure.

8. A condenser of a nuclear power plant, comprising at least one or more steam dump devices according to claim 1 , wherein each steam dump device is located inside the condenser.

9. The steam dump device of claim 1 , wherein the elongated header vessel comprises a primary orifice stage and a secondary orifice stage.

10. The steam dump device of claim 9 , wherein the primary orifice stage comprises a multi-holed hemispherical diaphragm and the secondary orifice stage comprises at least a top perforated diaphragm and at least a bottom perforated diaphragm.