Vessel for removing radionuclides from a liquid

1. A vessel for removing radionuclides from a liquid that flows through the vessel, said vessel being constructed as a pressure vessel comprising:

a shielded housing comprising an outer shell and an inner shell disposed within said outer shell, said housing defining an ion exchange chamber between said inner and outer shells, said housing having a shielding that inhibits escape of radiation from the ion exchange chamber;

an inlet diffuser located inside said ion exchange chamber;

an outlet collection structure located inside said ion exchange chamber;

a base supporting said housing;

a process inlet in fluid communication with said inlet diffuser;

a process outlet in fluid communication with said outlet collection structure; and

a first fluid passage extending between an exterior of said vessel and said inner shell and a second fluid passage extending between the exterior of said vessel and said inner shell,

wherein said vessel permits convective air flow between said first fluid passage, said inner shell, and said second fluid passage.

2. The vessel of claim 1 , wherein said inlet diffuser is located proximate a bottom of said ion exchange chamber and said outlet collection structure is located proximate a top of said ion exchange chamber.

3. The vessel of claim 1 , wherein said housing further comprises a riser defining an upper chamber therein.

4. The vessel of claim 3 , wherein said upper chamber is filled with lead shot.

5. The vessel of claim 1 , wherein said housing is shielded by a plurality of lead sheets wrapped around an outer surface of said housing.

6. The vessel of claim 1 , wherein said first fluid passage extends through said base.

7. The vessel of claim 6 , said base comprising a plurality of stacked base plates arranged horizontally, wherein at least one of said stacked base plates is a slotted base plate defining at least one slot forming part of the first fluid passage.

8. The vessel of claim 7 , further comprising a vent shield stack disposed along said first fluid passage.

9. The vessel of claim 7 , wherein at least one of said stacked base plates defines a central aperture axially aligned with an interior of said inner shell.

10. The vessel of claim 9 , wherein multiple of said stacked base plates each define a respective said central aperture which collectively define a base hole axially aligned with an interior of said inner shell.

11. The vessel of claim 10 , further comprising a vent shield stack disposed along said first fluid passage, said vent shield stack comprising a plurality of stacked vent shield plates located in said base hole.

12. The vessel of claim 11 , wherein said vent shield plates define respective radial slots forming part of said first fluid passage.

13. The vessel of claim 12 , wherein said radial slots of respective ones of said vent shield stacks are angularly offset but partially overlap.

14. The vessel of claim 7 , wherein said slotted base plate is positioned on top of an imperforate bottom plate and another one of the plurality of base plates is positioned on top of said slotted base plate.

15. The vessel of claim 14 , wherein said slotted base plate has a plurality of slots that form part of the first fluid passage.

16. The vessel of claim 15 , wherein said slotted plate has a diameter less than that of the bottom plate and the another one of the plurality of base plates to define an annular groove around the base.