Patent Number: 052727327
Section: claims

1. A permanent seal for providing an effective water barrier over an annular space between a nuclear reactor vessel flange and a surrounding annular ledge comprising: an annular space-spanning deck structure;  a first annular seal member for providing a support of the deck and a seal between said deck structure and the surrounding annular ledge; and  a second flexible annular seal member for providing a seal between said deck structure and the vessel flange and wherein a portion of said second seal member is straight walled and another portion of said second seal member is force absorbing.  an annular space-spanning deck structure;  a first annular seal member for providing a seal between said deck structure and the surrounding annular ledge; and  a second flexible annular seal member for providing a seal between said deck structure and the vessel flange and wherein a portion of said second seal member is a straight walled cylinder and another portion of said second seal member is arcuate. 2. The seal according to claim 1 wherein said force absorbing section of said second seal member is arcuately shaped wall section. 3. The seal according to claim 1 wherein said arcuate section of said second seal member is composed of at least one coil shaped section. 4. The seal according to claim 3 wherein said at least one coil shaped section is two coil shaped sections. 5. The seal according to claim 1 wherein said cylindrical section of said second seal member is sealed to said deck structure and said force absorbing portion of said second seal member is sealed to the vessel flange. 6. The seal according to claim 1 wherein said deck structure further comprises hatches which may be opened to provide access to and ventilation of the reactor vessel cavity below the vessel flange and surrounding annular ledge. 7. The seal according to claim 1 wherein the material for the second seal member is metal. 8. The seal according to claim 7 wherein said metal is stainless steal. 9. The seal according to claim 7 wherein the material for said deck structure and said first seal member is metal. 10. The seal according to claim 9 wherein the material for said deck structure, said first seal member and said second seal member is stainless steal. 11. A permanent seal for providing an effective water barrier over an annular space between a nuclear reactor vessel flange and a surrounding annular ledge comprising: 12. The seal according to claim 11 wherein said arcuate section of said second seal member is a coil and ring shaped structure. 13. The seal according to claim 11 wherein said arcuate section of said second seal member is composed of at least one coil shaped section. 14. The seal according to claim 13 wherein said at least one coil shaped section is two coil sections. 15. The seal according to claim 11 wherein said cylindrical section of said second seal member is sealed to said deck structure and said arcuate portion of said second seal member is sealed to the vessel flange. 16. The seal according to claim 11 wherein said deck structure further comprises hatches which may be opened to provide access to and ventilation of the reactor vessel cavity below the vessel flange and surrounding annular ledge. 17. The seal according to claim 11 wherein the material for the second seal member is metal. 18. The seal according to claim 17 wherein said metal is stainless steal. 19. The seal according to claim 17 wherein the material for said deck structure and said first seal member is metal. 20. The seal according to claim 19 wherein the material for said deck structure, said first seal member and said second seal member is stainless steal.