NEUTRON SHIELDING RING, APPARATUS AND METHOD USING THE SAME FOR STORING HIGH LEVEL RADIOACTIVE WASTE

1 . An apparatus for transporting and/or storing radioactive materials comprising:

a containment structure forming a cavity for receiving radioactive materials, the containment structure forming a containment boundary about the cavity;

a plurality of ring-like structures, each of the ring-like structures comprising a top surface, a bottom surface and an inner surface forming a central passageway extending-axially through the ring-like structure;

the plurality of ring-like structures arranged in a stacked assembly so that a ring-to-ring interface is formed between the top and bottom surfaces of adjacent ring-like structures, the containment structure extending through the central passageways of the ring-like structures in the stacked assembly; and

a collar located at each ring-to-ring interface and extending above and below the ring-to-ring interface.

2 . The apparatus of claim 1 wherein the ring-like structures are constructed of a gamma radiation absorbing material and comprise a plurality of voids adapted to receive a neutron radiation absorbing material; and wherein the collars are constructed of a gamma radiation absorbing material.

3 . The apparatus of claim 2 wherein the voids are sized, shaped and/or arranged so that a linear path does not exist from an axis of the central passageways of the ring-like structures to an outer surface of the ring-like structures without passing through one or more of the voids.

4 . The apparatus of claim 1 wherein the containment structure comprises a tubular shell having a closed bottom end and an open top end, the tubular shell having an outer surface and an inner surface that forms the cavity.

5 . The apparatus of claim 1 further comprising:

the containment structure comprising a tubular shell having a closed bottom end and an open top end, the tubular shell having an outer surface and an inner surface that forms the cavity;

a channel in either one of the top or bottom surfaces of each of the ring-like structures and one of the collars connected to each of the ring-like structures so as to protrude from the other one of the top or bottom surfaces; and

the collars and channels located on the ring-like structures so that the collars slidably extend into the channels of adjacent ring-like bodies in the stacked assembly.

6 . The apparatus of claim 1 further comprising:

the containment structure having an outer surface; and

the inner-surfaces of the ring-like structures of the stacked assembly being in substantially continuous surface contact with the outer surface of the containment structure.

7 . The apparatus of claim 1 further comprising:

one of the collars connected to each of the ring-like structures;

the containment structure having an outer surface; and

the inner surfaces of the ring-like structures being a stepped surface having a first riser surface, a tread surface and a second riser surface, the first riser surface being in substantially continuous surface contact with the outer surface of the containment structure, the second riser surface spaced from the outer surface of the containment structure thereby forming a channel between the second riser surface of the ring-like structure and the outer surface of the containment structure for receiving a portion of the collar of an adjacent ring-like structure in the stacked assembly.

8 . The apparatus of claim 6 wherein the collars, comprise the first riser surface.

9 . The apparatus of claim 1 wherein each of the ring-like structures comprise a series of voids that extend from the top surface of the ring-like structure to the bottom surface of the ring-like structure; wherein the voids are sized, shaped and/or arranged so that a neutron absorbing liquid can be poured into an uppermost ring-like structure in the stacked assembly and fill all of the voids of all the ring-like structures in the stacked assembly irrespective of rotational orientation of the ring-like structures.

10 . The apparatus of claim 1 further comprising:

each of the ring-like structures comprising an outer wall, a middle wall and an inner wall, the outer wall being spaced from and concentric with the middle wall, the middle wall being spaced from and concentric with the inner wall;

a first set of fins connecting the inner wall to the middle wall and a second set of fins connecting the middle wall to the outer wall;

a void between each of the fins of the first and second set of fins, the voids extending from the top surface of the ring-like structure to the bottom surface of the ring-like structure; and

the first and second set of fins circumferentially offset from one another so that a linear radial path does not exist from the inner wall to the outer wall without passing through one or more of the voids.

10 . (canceled)

11 . The apparatus of claim 1 further comprising:

the containment structure comprising a tubular shell constructed of a gamma radiation absorbing material, the tubular shell having an inner surface that forms the cavity;

a base made of a gamma radiation absorbing material and having a top surface; and

the tubular shell positioned atop the base in a substantially vertical orientation.

12 . The apparatus of claim 11 further comprising a lid that substantially encloses an open end of the tubular shell, the lid assembly constructed of a gamma radiation absorbing material, the lid being a non-unitary and removable structure with respect to the tubular shell.

13 . The apparatus of claim 1 wherein the ring-like structures are constructed of a material that expands when heated.

14 . The apparatus of claim 1 wherein the central passageways have a horizontal cross-sectional profile that is sized so that when the ring-like structures are at ambient temperature, the inner surfaces of the ring-like structure compress against an outer surface of the containment structure.

15 . The apparatus of claim 1 further comprising:

a basket assembly positioned within the cavity, the basket assembly having a honeycomb-like grid forming a plurality of substantially vertically oriented elongated cells;

the basket assembly comprising one or more flux traps; and

wherein the basket assembly is constructed of a metal matrix composite material.

16 . The apparatus of claim 15 further comprising:

the containment structure comprising a tubular shell having an inner surface that forms the cavity, the inner wall of the tubular shell having a circular horizontal cross-sectional profile, wherein the basket assembly has a horizontal cross-sectional profile having a perimeter shape that is not circular;

a spacer having an inner surface forming a central passageway and an outer surface, the spacer having a horizontal cross-sectional profile having an internal perimeter formed by the inner surface of the spacer and a circular external perimeter formed by the outer surface of the spacer;

the internal perimeter of the horizontal cross-sectional profile of the spacer corresponding in shape to the perimeter of the horizontal cross-sectional profile of the basket assembly;

the circular external perimeter formed by the outer surface of the spacer being smaller than the circular horizontal cross-sectional profile of the inner wall of the tubular shell so that a clearance exists;

the spacer positioned in the cavity so that the basket assembly extends through the central passageway of the spacer, the spacer surrounding the basket assembly.

17 . The apparatus of claim 15 further comprising:

the containment structure comprising a tubular shell having an inner surface that forms the cavity;

a plurality of spacers, each spacer having an inner surface that forms a central passageway, the spacers positioned within the cavity in a stacked orientation so that the basket assembly extends through the central passageways of the spacers; and

wherein the spacers are constructed of a material that has a greater coefficient of thermal expansion than the material of which the tubular shell is constructed.

18 . The apparatus of claim 1 further comprising:

the containment structure comprising a tubular shell having a height and an inner surface forming the cavity; and

wherein substantially the entire height of the tubular shell is surrounded by the stacked assembly of ring-like structures.

18 . (canceled)

19 . An apparatus for providing radiation shielding for radioactive materials enclosed in a particulate and fluidic containment boundary, the apparatus comprising:

a ring-like body constructed of a gamma radiation shielding material, the ring-like body comprising a top surface, a bottom surface and an inner surface forming a central passageway;

the ring-like body comprising a collar protruding from the top or bottom surfaces of the ring-like body;

a series of voids in the ring-like body for receiving a neutron radiation shielding material, the voids surrounding the central passageway; and

wherein when two of the ring-like bodies are stacked atop one another so as to form a ring-to-ring interface, the collar of one of the ring-like bodies extends beyond the ring-to-ring interface.

20 . The apparatus of claim 19 further comprising:

a channel in the other of the top or bottom surfaces of the ring-like body as the collar; and

the collar and channel positioned on the ring-like body so that when two of the ring-like bodies are stacked atop one another, the collar of one of the ring-like bodies slidably extends into the channel of the other ring-like body, thereby aligning the central passageways of the two ring-like bodies.

21 . The apparatus of claim 20 wherein the inner surface of the ring-like body is a stepped surfaces having a first riser surface, a tread surface and a second riser surface, the first riser surface being closer to an axis of the central passageway than is the second riser surface; the channel being formed by the second riser surface and tread surface.

22 . An apparatus for transporting and/or storing radioactive materials comprising:

a containment structure forming a cavity for receiving radioactive materials, the containment structure forming a containment boundary about the cavity;

a plurality of ring-like structures constructed of a gamma radiation absorbing material, each of the ring-like structures comprising a top surface, a bottom surface and an inner surface forming a central passageway extending axially through the ring-like structure; and

each of the ring-like structures comprising a plurality of spaces for receiving a neutron radiation absorbing material, the spaces sized, shaped and/or arranged so that a linear path does not exist from an axis of the central passageways of the ring-like structures to an outer surface of the ring-like structures without passing through one or more of the spaces.

23 . The apparatus of claim 22 further comprising neutron radiation shielding material filling the spaces.

24 . An apparatus for providing radiation shielding for radioactive materials enclosed in a particulate and fluidic containment boundary, the apparatus comprising:

a ring-like body constructed of a gamma radiation shielding material, the ring-like body comprising a top surface, a bottom surface and an inner surface forming a central passageway;

the ring-like body comprising a plurality of voids in the ring-like body for receiving a neutron radiation shielding material; and

wherein the plurality of spaces are sized, shaped and/or arranged so that a linear path does not exist from an axis of the central passageways of the ring-like structures to an outer surface of the ring-like structures without passing through one or more of the spaces.

25 . The apparatus of claim 24 further comprising neutron radiation shielding material filling the spaces.

26 . An apparatus for providing radiation shielding for radioactive materials enclosed in a particulate and fluidic containment boundary, the apparatus comprising:

a ring-like body constructed of a gamma radiation shielding material, the ring-like body comprising a top surface, a bottom surface and an inner surface forming a central passageway;

the ring-like body comprising a plurality of voids in the ring-like body for receiving a neutron radiation shielding material; and

wherein the plurality of spaces are sized, shaped and/or arranged so that a linear path does not exist from an axis of the central passageways of the ring-like structures to an outer surface of the ring-like structures without passing through one or more of the spaces.

27 . The apparatus of claim 9 further comprising:

a neutron radiation absorbing material filling the voids; and

wherein the containment structure, the ring-like structures and the collars are constructed of a gamma radiation absorbing material.

28 . The apparatus of claim 1 comprising three or more of the ring-like structures.