Nuclear reactor downcomer flow deflector
View Patent ↗A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.
1. A nuclear reactor comprising:
a pressure vessel having an axial dimension;
a fluid inlet nozzle extending through the wall of the pressure vessel;
an internal structure supported within the pressure vessel in spaced relationship with and opposite a pressure vessel interior side of said inlet nozzle; and
a deflector positioned between the internal support structure and the fluid inlet nozzle, having a concave face in-line with the inlet nozzle, for deflecting substantially all of the fluid flowing through the inlet nozzle into the pressure vessel, the deflector having a main body with a front side facing the fluid inlet nozzle and a rear side facing the internal support structure, the rear side of the main body having at least one protrusion affixed to the internal support structure, so that a gap exists between the rear side of the main body adjacent the protrusion and the internal support structure.
2. The nuclear reactor of claim 1 wherein the protrusion is welded to the internal support structure.
3. The nuclear reactor of claim 2 wherein the protrusion is shaped as a “J” weld prep.
4. The nuclear reactor of claim 3 wherein a reinforcing weld is laid over the weld in the “J” weld prep.
5. The nuclear reactor of claim 4 wherein the reinforcing weld has a 0.25 in (0.64 cm) width.
6. The nuclear reactor of claim 2 wherein the weld that welds the protrusion to the internal support structure is a full penetration weld.
7. The nuclear reactor of claim 1 wherein the protrusion extends around a periphery of the rear side of the main body.
8. The nuclear reactor of claim 7 including a vent for relieving gas pressure that can build up between the rear side of the main body and the internal structure.
9. The nuclear reactor of claim 8 wherein the vent comprises a hole through the internal structure.
10. The nuclear reactor of claim 8 wherein the vent comprises a hole in the main body.
11. The nuclear reactor of claim 1 wherein the protrusion is approximately 0.5 in. (1.27 cm) in width.
12. The nuclear reactor of claim 1 wherein the protrusion is approximately 0.346 in. (0.88 cm) in height.
13. The nuclear reactor of claim 1 wherein the internal support structure is a reactor core barrel.
14. The nuclear reactor of claim 1 wherein the deflector is a metal block having an axial groove machined into its front side extending from below a top surface of the metal block to and through a bottom of the metal block.
15. The nuclear reactor of claim 14 wherein a periphery of the metal block is substantially round.
16. The nuclear reactor of claim 1 wherein the rear side of the deflector has a groove machined therein adjacent the protrusion.
17. The nuclear reactor of claim 16 wherein the groove is annular and extends around the main body inside the protrusion.