Method and apparatus for detecting radioactive contamination in steel scrap

• US 5,705,818 A
• Filed: 02/29/1996
• Issued: 01/06/1998
• Est. Priority Date: 02/29/1996
• Status: Expired due to Fees

• Current Assignee: ISG Technologies, Inc. (International Business Machines Corporation)
• Original Assignee: Bethlehem Steel Corporation (ArcelorMittal SA)
• Inventors: Kelbel, Clinton J., Johnston, Floyd A.
• Primary Examiner(s): Porta, David P.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US08/609,043
• Time in Patent Office: 677 Days
• Field of Search: 250/361 R, 250/362
• US Class Current: 250/361.00R
• CPC Class Codes: B61L 1/10 actuated by electromagnetic radiation; actuated by particle radiation
• CPC Class Codes: B61L 25/048 using programmable tags
• CPC Class Codes: G01T 1/167 Measuring radioactive content of objects, e.g. contamination whole body counters G01T1/163

Abstract

A method of monitoring for radioactive contamination of scrap contained in a railroad car comprises the steps of detecting the presence of a moving railroad car. The railroad car is scanned for radioactive contamination upon being detected, and scanning continues thereafter. The identification of the railroad car is then determined by an RFID system. The scintillator scanning for radiation is deactivated when the vehicle is no longer detected. Once scanning is completed, then a determination is made whether the scanned vehicle is contaminated with radiation, and an indication that the vehicle is contaminated is made in that event.

Claims

1. A system for detecting radioactive contamination of scrap in a vehicle, comprising:

a first detector positioned proximate a roadway for detecting the presence of a moving vehicle;

at least first and second laterally spaced scintillators downstream of said first detector, said scintillators being disposed on opposite sides of the roadway for therebetween defining a scan zone;

a second detector positioned proximate the roadway downstream of said scintillators for detecting the presence of the moving vehicle;

a vehicle identifier proximate one of said scintillators for identifying the vehicle detected by said detector;

a controller operably associated with at least said first detector, said scintillators, and said identifier for activating said scintillators upon said first detector detecting a vehicle, for determining whether the vehicle contains radioactive contamination upon completion of a scan made by the scintillators, and for activating an indicator system should radioactive contamination be detected; and

a visual indicator operably associated with said controller for identifying the vehicle having the contamination and an audible indicator operably associated with said controller for indicating the detection of contamination.

2. The system of claim 1, wherein:

said visual indicator is a fixed position indicator; and

said audible indicator is movable with a transport vehicle.

3. The system of claim 2, wherein:

said audible indicator includes an electromagnetic energy source; and

said indicator system includes an electromagnetic energy generator operably associated with said controller.

4. The system of claim 1, wherein:

said vehicle identifier includes a first component fixed proximate one of said scintillators and a second component carded by the vehicle.

5. The system of claim 4, wherein:

said first component includes means for interrogating said second component for identifying the vehicle.

6. The system of claim 4, wherein:

said first component is a tag affixed to the vehicle, and said second component is a radio frequency identification transceiver.

7. The system of claim 1, further comprising:

a printer operably associated with said controller for printing a permanent record of the scan made by the scintillators.

8. The system of claim 1, wherein:

each of said scintillators scans for gamma radiation.

9. A method for automatically monitoring for radioactive contamination in transport vehicles, comprising the steps of:

automatically detecting the presence of a moving transport vehicle;

commencing to scan the vehicle for radiation after the vehicle has been detected and continuing to scan for radioactive contamination;

automatically determining the identity of a vehicle;

ceasing to scan for radioactive contamination after the vehicle is no longer detected;

automatically determining whether the scanned vehicle contains radioactive contamination, and automatically indicating the detection of radioactive contamination in that event;

implementing the step of detecting the presence of the vehicle with first and second spaced photoelectric sensors, and determining the speed of the vehicle after it has been detected by the sensors; and

determining whether the vehicle speed exceeds a preselected speed.

10. The method of claim 9, including the step of:

providing a through-beam sensor as each of the photoelectric sensors.

11. The method of claim 9, including the step of:

continuing to scan the vehicle while the vehicle is detected by the second sensor.

12. A method of automatically detecting radiation contamination in scrap steel, comprising the steps of:

providing a moving railroad car in which scrap material is contained;

automatically commencing to scan the scrap material for radiation contamination by moving the railroad car beyond a radiation scanned;

automatically determining the identity of the railroad car while it is being scanned;

ceasing to scan for radiation contamination after the railroad car has moved beyond the radiation scanner;

automatically determining whether the railroad car contains scrap material contaminated by radiation, and automatically identifying the railroad car containing the contaminated scrap material in that event;

providing at least a first scintillator as the radiation scanner;

detecting the presence of the railroad car prior to commencing to scan for radiation contamination;

implementing the step of detecting the presence of a railroad car with a through-beam optical detector comprising first and second spaced optical detectors;

calculating the speed of the railroad car while the railroad car is moving between the detectors; and

automatically actuating an indicator when the railroad car exceeds a predetermined speed.