Method of determining a content of a nuclear waste container

• US 6,553,094 B1
• Filed: 08/25/2000
• Issued: 04/22/2003
• Est. Priority Date: 08/25/2000
• Status: Expired due to Fees

• Current Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Original Assignee: Bio-Imaging Research, Inc. (Siemens AG)
• Inventors: Entwistle, David, Bernardi, Richard T.
• Primary Examiner(s): Dunn, Drew A.
• Assistant Examiner(s): THOMAS, COURTNEY D
• Application Number:
  US09/648,676
• Time in Patent Office: 970 Days
• Field of Search: 378/57, 378/88, 378/4, 378/21, 378/22, 378/23, 378/901
• US Class Current: 378/57
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01T 1/167 Measuring radioactive content of objects, e.g. contamination whole body counters G01T1/163

Abstract

A method and apparatus are provided for identifying contents of a nuclear waste container. The method includes the steps of forming an image of the contents of the container using digital radiography, visually comparing contents of the image with expected contents of the container and performing computer tomography on the container when the visual inspection reveals an inconsistency between the contents of the image and the expected contents of the container.

Claims

1. A method of identifying contents of a nuclear waste container, such method comprising the steps of:

forming an image of the contents of the nuclear waste container using digital radiography;

visually comparing contents of the image with expected contents of the container; and

performing a CT scan on the nuclear waste container and forming at least one tomographic image, but only when the visual inspection reveals an inconsistency between the contents of the image and the expected contents of the container.

2. The method of identifying a content of a nuclear waste container as in claim 1 wherein the step of forming an image using digital radiography further comprises forming a first and second DR image from orthogonal perspectives.

3. The method of identifying a content of a nuclear waste container as in claim 1 wherein the step of forming an image using digital radiography further comprises tilting the container.

4. The method of identifying a content of a nuclear waste container as in claim 3 wherein the step of tilting the container further comprises forming an image of the tilted container.

5. The method of identifying a content of a nuclear waste container as in claim 4 wherein the step of forming an image of the tilted container further comprises detecting a liquid within the container based upon corresponding horizontal transition lines found within the tilted and untilted images of the container.

6. The method of identifying a content of a nuclear waste container as in claim 1 further comprising determining the expected content of the container by reading a manifest of container contents prepared at a time of filling of the nuclear waste container.

7. The method of identifying a content of a nuclear waste container as in claim 6 wherein the step of visually comparing a content of the image with an expected content of the container further comprises identifying visual elements of the formed images as items found within the manifest.

8. The method of identifying a content of a nuclear waste container as in claim 7 wherein the step of identifying visual elements of the formed images as items found within the manifest further comprises determining that an inconsistency exists when an item found within the image does not match any item listed on the manifest.

9. The method of identifying a content of a nuclear waste container as in claim 7 wherein the step of determining that an inconsistency exists further comprises finding multiple superpositioned matrices within the formed images.

10. The method of identifying a content of a nuclear waste container as in claim 7 wherein the step of determining that an inconsistency exists further comprises finding a prohibited item within the formed image.

11. The method of identifying a content of a nuclear waste container as in claim 1 wherein the step of performing the CT scan on the nuclear waste container and forming the tomographic image further comprises choosing a scan time for the computed tomography based upon a perceived density of any inconsistent item of the formed image.

12. An apparatus for identifying contents of a nuclear waste container, such apparatus comprising:

means for forming an image of the contents of the nuclear waste container using digital radiography;

means for visually comparing contents of the image with expected contents of the container; and

means for performing a CT scan on the nuclear waste container and forming at least one tomographic images but only when the visual inspection reveals an inconsistency between the contents of the image and the expected contents of the container.

13. The apparatus for identifying a content of a nuclear waste container as in claim 12 wherein the means for forming an image using digital radiography further comprises means for forming a first and second DR image from orthogonal perspectives.

14. The apparatus for identifying a content of a nuclear waste container as in claim 12 wherein the means for forming an image using digital radiography further comprises means for tilting the container.

15. The apparatus for identifying a content of a nuclear waste container as in claim 14 wherein the means for tilting the container further comprises means for forming an image of the tilted container.

16. The apparatus for identifying a content of a nuclear waste container as in claim 15 wherein the means for forming an image of the tilted container further comprises means for detecting a liquid within the container based upon corresponding horizontal transition lines found within the tilted and untilted images of the container.

17. The apparatus for identifying a content of a nuclear waste container as in claim 12 further comprising means for determining the expected content of the container by reading a manifest of container contents prepared at a time of filling of the nuclear waste container.

18. The apparatus for identifying a content of a nuclear waste container as in claim 17 wherein the means for visually comparing a content of the image with an expected content of the container further comprises means for identifying visual elements of the formed images as items found within the manifest.

19. The apparatus for identifying a content of a nuclear waste container as in claim 18 wherein the means for identifying visual elements of the formed images as items found within the manifest further comprises means for determining that an inconsistency exists when an item found within the image does not match any item listed on the manifest.

20. The apparatus for identifying a content of a nuclear waste container as in claim 18 wherein the means for determining that an inconsistency exists further comprises means for finding multiple superpositioned matrices within the formed images.

21. The apparatus for identifying a content of a nuclear waste container as in claim 18 wherein the means for determining that an inconsistency exists further comprises means for finding a prohibited item within the formed image.

22. The apparatus for identifying a content of a nuclear waste container as in claim 12 wherein the means for performing the CT scan on the nuclear waste container to form the tomographic image further comprises means for choosing a scan time for the computed tomography based upon a perceived density of any inconsistent item of the formed image.

23. An apparatus for identifying contents of a nuclear waste container, such apparatus comprising:

an x-ray viewer adapted to form an image of the contents of the nuclear waste container using digital radiography;

a display adapted to visually compare contents of the image with expected contents of the container; and

an x-ray source adapted to scan the container to form at least one tomographic image, but only when the visual inspection reveals an inconsistency between the contents of the image and the expected contents of the container.

24. The apparatus for identifying a content of a nuclear waste container as in claim 23 wherein the x-ray viewer further comprises first and second windows adapted to form a first and second DR image from orthogonal perspectives.

25. The apparatus for identifying a content of a nuclear waste container as in claim 24 wherein the first and second windows further comprises a third window adapted to show a tilted view of the container.

26. The apparatus for identifying a content of a nuclear waste container as in claim 23 wherein the x-ray source further comprises an input device adapted to allow the choosing of a scan time for a computed tomography scan based upon a perceived density of any inconsistent item of the formed image.