Dry containment of radioactive materials
AssigneeN L Industries, Inc.
InventorCharles E. Williams
Life of this patent
Estimating the term…
Abstract
A cask for the dry containment of radioactive fuel elements. The cask has a cover which contains valved drain and purge passageways. These passageways are sealed by after purge cover seals which are clamped over them and to the outer surface of the cover. The cover seals are tested by providing them with a pair of concentric ring seal elements squeezed between the cover seal and the outer surface of the cover and by forcing a gas under pressure into the annular region between the seal element.
Claims11
A shipping container for dry containment of radioactive materials, said container comprising
- a cannister-like body open at one end for receiving radioactive materials to be shipped,
- a radiation absorbing material supported by said body to surround the interior thereof,
- a removeable cover shaped to fit over and close said one end of said body and to form a annular seal therewith,
- means for clamping said cover to said body at said one end to form a gas tight vessel for containing said radioactive materials,
- a fluid purging system for controlling the atmospheric conditions inside said vessel, said fluid purging system including fluid passageway means extending into said vessel and communicating between the interior and exterior thereof, a fluid flow control valve arranged along said passageway at the exterior of said vessel, and
- an after purge seal cap means comprising a cover seal extending over said valve and clamped to said vessel and a circumferential fluid tight seal surrounding said passageway and clamped between said cap and said vessel.
A method of preparing radioactive materials for transportation, said method comprising the steps of
- inserting said materials into an open end of a radiation protective fuel cask,
- positioning a cover over said one end of said fuel cask to close same and clamping said cover in place to seal the interior thereof,
- purging the interior of said fuel cask by forcing a gas into said cask via a first penetration passageway containing a first closure valve while venting liquid from said cask via a second passageway containing a second closure valve,
- closing said first and second closure valves, and
- clamping after purge sealing cap means to the outer surface of said cask to cover said penetration passageways and said closure valves and to seal said passageways by means of annular seals surrounding said passageways at said outer surface.
A method of storing radioactive fuel rods for transportation, said method comprising the steps of
- submerging a radiation resistant fuel cask, open at one end, into a pool containing said fuel rods and inserting said fuel rods into said cask while submerged,
- positioning a cover over said one end of said fuel cask to close same and clamping said cover in place to form an annular seal with said cask at said open end,
- purging the interior of said fuel cask of liquid from the region of said annular seal by forcing air into said cask via a first penetration passageway containing a first closure valve while venting liquid from said cask via a second penetration passageway containing a second closure valve,
- checking the integrity of said annular seal by applying pressure through one of said penetration passageways while the valve contained in the other penetration passageway is closed and while the region of said annular seal outside said cask is submerged in a liquid so that any leakage through said annular seal will be manifested in the form of gas bubbles in said liquid,
- therefter continuing to purge the interior of said cask via said first and second penetration passageways until all moisture is removed from said cask,
- closing said first and second closure valves,
- clamping after purge cover seals to the outer surface of said cask to cover said penetration passageways and said closure valves and to seal said passgeways by means of further annular seals surrounding them at said outer surface, and
- testing the integrity of said further annular seals by applying pressure to the region between each said further annular seal and an outer concentric seal formed between each cap and the outer surface of said cask.
Dependencies are inferred from the claim text.