System and Method for Detecting Nuclear Material in Shipping Containers

Abstract

A system and method for detecting metal contraband such as weapons related material in shipping containers where a container is scanned with at least one penetrating beam, preferably a tomographic x-ray beam, and at least one image is formed. The image can be analyzed by a pattern recognizer to find voids representing metal. The voids can be further classified with respect to their 2 or 3-dimensional geometric shapes. Container ID and contents or bill of lading information can be combined along with other parameters such as total container weight to allow a processor to generate a detection probability. The processor can use artificial intelligence methods to classify suspicious containers for manual inspection.

1 . A method for scanning shipping containers for nuclear material comprising:
 scanning a shipping container with an x-ray device producing CT scan data;   processing said scan data into a set of visual regions;   locating nuclear weapon component target shapes in said visual regions using pattern classification techniques;   outputting scan recognition signals to an artificial intelligence processor relating to detection of any nuclear weapon component target shapes in a particular container;   comparing at said artificial intelligence processor said scan recognition signals with data such as a bill of lading, container contents, port of origin data or container weight to produce an event probability number;   outputting a risk alarm from any container having an event probability greater than a predetermined value;   quantifying a total metal content for said container;   raising said event probability number when a contents list for said container does not contain information indicating a total metal content compatible with the total metal content of the container.   
     
     
         2 . (canceled) 
     
     
         3 . The method of  claim 1  wherein said x-ray device is a rotating CT-based x-ray device. 
     
     
         4 . The method of  claim 3  further comprising slicing said scan data into 2-dimensional slices. 
     
     
         5 . The method of  claim 4  further comprising:
 locating voids in said 2-dimensional slices; 
 examining said voids along different slice axes. 
 
     
     
         6 . The method of  claim 5  further comprising examining said voids with different x-ray energies. 
     
     
         7 . The method of  claim 1  further comprising raising said event probability when said container contains a plurality of small metal parts. 
     
     
         8 . The method of  claim 1  further comprising raising said event probability when said container contains piped-shaped objects. 
     
     
         9 . The method of  claim 1  wherein said nuclear component target shapes include sphere, cylinders, cannon barrels or pellets. 
     
     
         10 . A method for detecting nuclear weapon components in a shipping container comprising:
 scanning a shipping container with a rotating CT-based x-ray device as said shipping container moves through a scan area, said scan producing scan data;   slicing said scan data into a sequence of 2-dimensional slices;   locating nuclear weapon component target shapes in said 2-dimensional slices using pattern classification techniques;   re-slicing said scan data along at least one other axis to verify possible shapes;   outputting recognition signals to an artificial intelligence processor relating to detection of predetermined target shapes;   comparing said recognition signals with shipping data to produce an event probability;   outputting a risk alarm for any container having an event probability greater than a predetermined value;   quantifying a total metal content for said container;   raising said event probability when contents data for said container does not indicate a possible metal content compatible with the total metal content for the container.   
     
     
         11 . The method of  claim 10  wherein said shipping data includes a bill of lading, container content list, port of origin data or container weight. 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 10  further comprising:
 locating voids in said 2-dimensional slices; 
 examining said voids along different slice axes. 
 
     
     
         14 . The method of  claim 13  further comprising examining said voids with different x-ray energies. 
     
     
         15 . The method of  claim 10  further comprising raising said event probability when a container is determined to contain a plurality of small metal parts.