skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Sorting method for radioactive waste

Abstract

This paper describes a method for detecting radioactive components in dry active waste, comprising the steps of: providing a substantially airtight housing, withdrawing air from the housing, reducing the waste to pieces of substantially uniform size, providing a first conveyor in the housing, the first conveyor having a receiving portion and a discharge portion, discharging the pieces of reduced waste onto the first conveyor, flattening the pieces of reduced waste, detecting radiation emanating from the pieces of reduced waste from a position closely overlying the first conveyor, after the pieces are flattened, removing from the first conveyor the pieces of reduced waste from which radioactive radiation above a determined level is detected, providing a second conveyor in the housing, the second conveyor having a receiving portion and a discharge portion, disposing the second conveyor so that its receiving portion is below and spaced from the discharge portion of the first conveyor, discharging the pieces of reduced waste from the discharge portion of the first conveyor so that they fall onto the receiving portion of the second conveyor; the space between the last named discharge portion and the last named receiving portion being sufficiently great so that the pieces of reducedmore » waste are substantially overturned and dispersed as they fall to the last named receiving portion.« less

Inventors:
;
Publication Date:
OSTI Identifier:
6630466
Patent Number(s):
US 4762280
Application Number:
TRN: 89-003426
Assignee:
Westinghouse Electric Corp., Pittsburgh, PA NOV; NOV-89-034352; EDB-89-024980
Resource Type:
Patent
Resource Relation:
Patent File Date: Filed date 8 Sep 1986
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; RADIOACTIVE WASTES; SORTING; SOLID WASTES; AIRTIGHTNESS; CONTAINMENT BUILDINGS; CONVEYORS; RADIATION DETECTION; RADIOACTIVE WASTE FACILITIES; RADIOACTIVE WASTE PROCESSING; RADIOACTIVITY; REDUCTION; TRANSPORT; BUILDINGS; CHEMICAL REACTIONS; CONTAINMENT; DETECTION; EQUIPMENT; HAULAGE EQUIPMENT; MANAGEMENT; MATERIALS; MATERIALS HANDLING EQUIPMENT; NUCLEAR FACILITIES; PROCESSING; RADIOACTIVE MATERIALS; WASTE MANAGEMENT; WASTE PROCESSING; WASTES 052001* -- Nuclear Fuels-- Waste Processing

Citation Formats

Prisco, A.J., and Johnson, A.N.. Sorting method for radioactive waste. United States: N. p., 1988. Web.
Prisco, A.J., & Johnson, A.N.. Sorting method for radioactive waste. United States.
Prisco, A.J., and Johnson, A.N.. 1988. "Sorting method for radioactive waste". United States. doi:.
@article{osti_6630466,
title = {Sorting method for radioactive waste},
author = {Prisco, A.J. and Johnson, A.N.},
abstractNote = {This paper describes a method for detecting radioactive components in dry active waste, comprising the steps of: providing a substantially airtight housing, withdrawing air from the housing, reducing the waste to pieces of substantially uniform size, providing a first conveyor in the housing, the first conveyor having a receiving portion and a discharge portion, discharging the pieces of reduced waste onto the first conveyor, flattening the pieces of reduced waste, detecting radiation emanating from the pieces of reduced waste from a position closely overlying the first conveyor, after the pieces are flattened, removing from the first conveyor the pieces of reduced waste from which radioactive radiation above a determined level is detected, providing a second conveyor in the housing, the second conveyor having a receiving portion and a discharge portion, disposing the second conveyor so that its receiving portion is below and spaced from the discharge portion of the first conveyor, discharging the pieces of reduced waste from the discharge portion of the first conveyor so that they fall onto the receiving portion of the second conveyor; the space between the last named discharge portion and the last named receiving portion being sufficiently great so that the pieces of reduced waste are substantially overturned and dispersed as they fall to the last named receiving portion.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1988,
month = 8
}
  • A method is described for continuously sorting radioactive material from nonradioactive material comprising the steps of providing material containing radioactive and nonradioactive material, placing the material in a first detection station, providing means at the first detection station for detection radiation above a first predetermined level emanating from the radioactive material and removing material which is detected as being radioactive at the first detection station, conveying the remainder of the material to a second detection station, providing means at the second detection station for detecting radiation above a second predetermined level emanating from the remainder of the material, removing materialmore » which is detected as being radioactive at the second detection station, placing the remainder of the material in a container, delivering the remaining material to a third radiation detection station, providing means at the third detection station for detecting radiation which is at a predetermined level, and storing the container if radiation is not detected at the third detector station.« less
  • An apparatus is described for detecting radioactive components in dry active waste, the apparatus comprising: means for reducing the waste to pieces of substantially uniform size, first and second conveyors and a housing for the conveyors; means for conveying the pieces from the means for reducing the waste to the first and second conveyors; each of the first and second conveyors includes a receiving portion and a discharge portion; the discharge portion is spaced above and upstream from the receiving portion to disperse the pieces as they are transferred from the first conveyor to the second conveyor so that piecesmore » which are in clusters are separated from each other to increase the likelihood of detecting radiation emanating means for detecting radioactive radiation emanating from the pieces, at least one of radiation detector means is located on each of the conveyors. Each is disposed in close overlying relation to its respective conveyor so that low levels of radiation emanating from the pieces can be detected; each of the conveyors includes means for flattening the pieces of waste before the pieces pass under the radiation detector means; and the means for flattening disposed between the receiving portion of each conveyor and the radiation detector means; the housing is generally closed; and means for providing a generally closed connection between the housing and the means for reducing the waste so that air that is in the housing and in the means for reducing the waste can be controlled.« less
  • A description is give of a method of and apparatus for sorting pieces or particles of radioactive ore where the particles are moved through the apparatus in an asynchronous or non-constant manner. The particles are moved one at a time to a position in front of a radiation detector where they are temporarily stopped. The counts from the particle are accumulated with respect to time. In a control unit of the apparatus there is data representing a cutoff grade radiation rate and early upper and lower decision limits are established with regard to the cut-off rate. As soon as themore » accumulated count/time ratio from the detector exceeds the upper limmit or falls below the lower limit, the control unit is able to provide a decision to accept or reject the particle. If the particles are not closely sized then the size of each particle is determined before it is positioned in front of the radiation detector and the size determination is used to modify the cut-off grade and upper and lower early decision limits. Particles which are well above cut-off or well below cut-off (i.e. above the upper early decision limit or below the lower early decision limit) are disposed of very quickly. Those particles having a value close to cut-off assessed for a longer time. A maximum assessment time is determined for the ore and accuracy required. Because the particles may be assessed for only a short interval, the throughput is increased considerably over prior art arrangements where the feed rate is synchronous or constant and the rate of feed is set for assessment of the smallest and most difficult particles handled.« less
  • A container is disclosed for enclosing particulate or piece-formed radioactive material which is to be converted into a solid body by isostatic pressing at a high temperature and a high pressure. The container may have a corrugated sheath and suitably a plane lid and a plane bottom. The corrugation makes possible axial compression of the container prior to the pressing. The container may also have a cylindrical sheath and bellows projecting into the sheath and joining the sheath of the container to a lid and a bottom. The bellows make it possible to insert the lid and the bottom bymore » gas pressure, so that the material present in the container is axially compressed.« less