Sorting method for radioactive waste

• US 4,762,280 A
• Filed: 09/08/1986
• Issued: 08/09/1988
• Est. Priority Date: 09/10/1984
• Status: Expired due to Fees

• Current Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Prisco, Anthony J., Johnson, Alfred N.
• Primary Examiner(s): Echols, P. W.
• Assistant Examiner(s): Gorski, Joseph M.
• Application Number:
  US06/905,000
• Time in Patent Office: 701 Days
• Field of Search: 241/68, 241/79.1, 241/101.2, 241/101.3, 241/101.5, 241/DIG. 38, 241/3, 241/24, 241/30, 209/576, 209/589, 209/3, 209/3.1, 209/4, 209/936, 100/39
• US Class Current: 241/3
• CPC Class Codes: B07C 5/02 Measures preceding sorting, e.g. arranging articles in a stream orientating sorting and transport of caps B67B3/06
• CPC Class Codes: B07C 5/346 according to radioactive properties material testing G01N23/00; radiation measurement G01T
• CPC Class Codes: Y10S 209/936 Plural items tested as group

Abstract

This invention relates to a method for sorting radioactive waste. The method comprises the steps of reducing the waste to pieces of substantially uniform size, detecting radiation with first and second radiation detecting structure, conveying the pieces from the reducing step to the first and second radiation detecting structure, and dispersing the pieces of waste between the first and second detecting structure so that the pieces which are collected together in clusters can separate from each other to thereby increase the likelihood of detecting radiation emanating from the pieces.

Claims

1. A method for detecting radioactive components in dry active waste, comprising the steps of:

providing a substantially airtight housing,

withdrawing air from said housing,

putting dry active waste in said housing,

reducing the waste to pieces of substantially uniform size,

providing a first conveyor in said housing, said first conveyor having a receiving portion and a discharge portion,

discharging said pieces of reduced waste onto said first conveyor,

flattening said pieces of reduced waste,

detecting radiation emanating from said pieces of reduced waste from a position closely overlying said first conveyor, after said pieces are flattened,

removing from said first conveyor said pieces of reduced waste from which radioactive radiation above a determined level is detected,

providing a second conveyor in said housing, said second conveyor having a receiving portion and a discharge portion,

disposing said second conveyor so that its receiving portion is below and spaced from the discharge portion of said first conveyor,

discharging said pieces of reduced waste from the discharge portion of said first conveyor so that they fall onto the receiving portion of said second conveyor;

the space between said last named discharge portion and said last named receiving portion being sufficiently great so that said pieces of reduced waste are substantially overturned and dispersed as they fall to said last named receiving portion,

flattening the dispersed and overturned pieces of waste,

detecting radiation emanating from said pieces of dispersed and reduced waste from a position closely overlying said second conveyor, after said pieces are flattened,

and removing from said second conveyor pieces of waste from which radioactive radiation above a predetermined level is detected.

2. The method defined in claim 1 wherein said steps of detecting radiation include the step of detecting beta particle radiation.

3. The method defined in claim 1 wherein said steps of detecting radiation include the step of detecting gamma rays.

4. The method as defined in claim 1 including the step of discharging said pieces of reduced waste from which radiation above said predetermined level is not detected into a container.

5. The method defined in claim 4 including the step of reducing the volume of the pieces of reduced waste in said container.