APPARATUS FOR PROVIDING ADDITIONAL RADIATION SHIELDING TO A CONTAINER HOLDING RADIOACTIVE MATERIALS, AND METHOD OF USING THE SAME TO HANDLE AND/OR PROCESS RADIOACTIVE MATERIALS

• US 20080265182A1
• Filed: 10/11/2007
• Published: 10/30/2008
• Est. Priority Date: 10/11/2006
• Status: Active Grant

• Current Assignee: Holtec International, Inc.
• Original Assignee: Holtec International, Inc.
• Inventors: Singh, Krishna P., Agace, Stephen
• Granted Patent: US 7,786,456 B2
• Time in Patent Office: Days
• US Class Current: 250/506.1
• CPC Class Codes: G21F 5/005 Containers for solid radioactive wastes, e.g. for ultimate disposal
• CPC Class Codes: G21F 5/10 Heat-removal systems, e.g. using circulating fluid or cooling fins

Abstract

A system, method and apparatus for providing additional radiation shielding to a container holding radioactive materials. The invention utilizes a sleeve-like structure that is slid over a container holding high level radioactive materials to add radiation shielding protection. Because the sleeve-like structure and container are non-unitary and slidably separable from one another, crane lifting capacity is not affected. In one aspect, the invention is an apparatus comprising: a tubular shell constructed of a gamma radiation absorbing material and having an inner surface that forms a cavity having an axis, the cavity having an open top end and an open bottom end; a plurality of spacers extending from the inner surface of the shell toward the axis of the cavity, the spacers extending a first height from the inner surface of the tubular shell; and one or more flange members located at or near the open top end of the cavity extending from the tubular shell toward the axis of the cavity, the flange member extending a second height from the inner surface of the shell, the second height being greater than the first height.

Claims

1. An apparatus for providing additional radiation shielding to a container holding radioactive materials comprising:

a tubular shell extending from a first end to a second end, the tubular shell constructed of a gamma radiation absorbing material and having an inner surface that forms a cavity;

a first opening in the first end of the tubular shell that provides a passageway into the cavity;

a second opening in the second end of the tubular shell that provides a passageway into the cavity, the second opening being larger than the first opening; and

a plurality of spacers extending from the inner surface of the shell.

2. The apparatus of claim 1 further comprising a ring-like member connected to the first end of the shell, the ring-like plate comprising the first opening.

3. The apparatus of claim 1 wherein the spacers are circumferentially spaced from one another about an axis of the cavity.

4. The apparatus of claim 1 further comprising:

a ring-like member connected to the first end of the tubular shell, the ring-like member comprising the first opening and having a bottom surface; and

wherein the spacers are a plurality of L-shaped plate structures extending from the inner surface of the shell and the bottom surface of the ring-like plate.

5. The apparatus of claim 4 further comprising:

the cavity having an axis; and

the L-shaped plate structures being substantially parallel to the axis of the cavity and arranged in a spaced relation to one another so as to form channels therebetween.

6. The apparatus of claim 1 further comprising means on the first end of the tubular shell for lifting the apparatus.

7. The apparatus of claim 1 further comprising one or more channels that extend from along the inner surface of the tubular shell from the first end of the tubular shell to the second end of the tubular shell.

8. An apparatus for providing additional radiation shielding to a container holding radioactive materials comprising:

a tubular shell constructed of a gamma radiation absorbing material and having an inner surface that forms a cavity having an axis, the cavity having an open top end and an open bottom end;

a plurality of spacers extending from the inner surface of the shell toward the axis of the cavity, the spacers extending a first height from the inner surface of the tubular shell; and

one or more flange members located at or near the open top end of the cavity extending from the tubular shell toward the axis of the cavity, the flange member extending a second height from the inner surface of the shell, the second height being greater than the first height.

9. The system of claim 8 further comprising one or more channels extending from the open bottom end of the cavity to the open top end of the cavity.

10. The system of claim 8 wherein the flange members and spacers are formed by upside-down L-shaped plates connected to the inner surface of the tubular shell in a circumferentially spaced arrangement about the axis.

11. The system of claim 10 further comprising a ring-like member connected to a top of the tubular shell.

12. A system for handling and/or processing radioactive materials comprising:

a container having a first cavity for holding radioactive materials, the container having an outer surface and a top surface;

a tubular shell having an inner surface that forms a second cavity for receiving the container, the tubular shell comprising at least one spacer extending from the inner surface of the shell toward an axis of the second cavity;

the container positioned in the second cavity of the tubular shell, the at least one spacer maintaining the inside surface of the tubular shell in a spaced relationship from the outer surface of the container; and

wherein the tubular structure is non-unitary and slidably removable from the container.

13. The system of claim 12 wherein the at least one spacer extends a first height from the inner surface of the tubular shell toward the axis of the second cavity;

and wherein the tubular shell further comprises one or more flange member extending from the tubular shell toward the axis of the second cavity, the one or more flange members extending a second height from the inner surface of the shell, the second height being greater than the first height; and

wherein the one or more flange members rest atop the top surface of the container and the at least one spacer rests against the outer surface of the container.

14. The system of claim 12 wherein the second cavity of the tubular shell has an open top end defined by a first opening and an open bottom end defined by a second opening.

15. The system of claim 14 wherein the second opening is sized and shaped to allow a body portion of the container to slidably pass therethrough in an unobstructed manner.

16. The system of claim 15 wherein the container further comprises a lid positioned atop the body portion of the container that substantially encloses a top end of the first cavity;

and wherein the first opening is sized and shaped to allow the lid to slidably pass therethrough in an unobstructed manner.

17. The system of claim 12 wherein the at least one spacer maintains the inside surface of the tubular shell in the spaced relationship from the outer surface of the container so as to form an annular gap between the tubular shell and the container.

18. The system of claim 17 wherein the annular gap comprises one or more channels that extend from an inlet at or near a bottom of the tubular shell to an outlet at or near a top of the tubular shell.

19. The system of claim 12 wherein the container comprises both gamma radiation absorbing material and neutron absorbing material and the tubular shell is constructed of a gamma radiation absorbing material.

20. The system of claim 12 wherein the second cavity of the tubular shell has an open top end defined by a first opening and an open bottom end defined by a second opening;

and wherein a top of the container protrudes from the first opening.

21. The system of claim 12 wherein the container has a height that is greater than a height of the tubular shell.

22. A method of handling and/or processing radioactive materials comprising:

a) placing a container having a first cavity containing radioactive materials in a staging area, the container having an outer surface and a top surface;

b) providing a tubular shell having an inner surface that forms a second cavity for receiving the container, the second cavity having an open top end and an open bottom end, the tubular shell also comprising at least one spacer extending from the inner surface of the shell toward an axis of the second cavity; and

c) positioning the tubular sleeve above the container and lowering the tubular shell so that the container slidably inserts through the open bottom end and into the second cavity, the at least one spacer maintaining the inside surface of the tubular shell in a spaced relationship from the outer surface of the container so as to form a gap between the container and the tubular shell.

23. The method of claim 22 wherein the at least one spacer extends a first height from the inner surface of the tubular shell toward the axis of the second cavity;

and wherein the tubular shell further comprises one or more flange member extending from the tubular shell toward the axis of the second cavity, the one or more flange members extending a second height from the inner surface of the shell, the second height being greater than the first height.

24. The method of claim 23 wherein step c) comprises lowering the tubular shell until the one or more flange members contact and rest atop the top surface of the container, the tubular shell being supported by the one or more flange members.

25. The method of claim 22 further comprising:

d) cool air entering the gap at or near a bottom of the tubular shell, the cool air becoming warmed from heat emanating from the container, the warmed air rising within the gap and exiting the gap at or near a top of the tubular shell.

26. The method of claim 22 further comprising:

wherein step c) comprises sliding the tubular shell over the container until a top portion of the container protrudes from a top end of the tubular shell;

d) securing a lid to the top portion of the container; and

e) lifting the tubular shell until the container slidably exits the second cavity.