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US4235738A Expired / Lapsed US ⏱️ 0.0 years remaining

Technique for converting spent radioactive ion exchange resins into a stable and safely storable form

Assignee: Vereinigte Edelstahlwerke AG
•
Filing: 1976-06-22
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Granted: 1980-11-25
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Expires: 1996-06-22
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Abstract

Abstract An improved heat treatment for spent ion exchange resins containing radioive inorganic compounds is described for converting the resin into a form which can be safely stored, either directly or embedded in concrete or bituminous. The resin is heated, in the presence of an inert gas such as nitrogen or a reducing gas such as carbon monoxide, to a temperature sufficient to effect a carbonization of the resin but too low to cause the radioactive compounds in the resin to evaporate or sublimate. The resulting low-temperature carbonization of the resin effectively fixes the non-volatile compound to the resin, and prevents a later radiolytic decomposition of such compounds during storage. Preferably, such technique is carried out in a combined furnace-condenser apparatus, wherein the condenser is disposed below and in communication with the lower end of the furnace for effecting a condensation of the volatile carbonization products of the resin while the latter is heated in the furnace in the required non-oxidizing atmosphere.

Inventors

  • 👤 Karl Knotik
  • 👤 Peter Leichter
  • 👤 Heinz Jakusch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 08:40
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/28; G21F9/30; G21F9/32

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 93 words
In a method of converting ion exchange resins containing radioactive inorganic compounds into a stable and safely storable form, the method comprising the step of thermally treating the spent resin, the improvement wherein the thermal treating step comprises surrounding the spent resin with a high-temperature boiling point oil that does not support combustion, and then heating the oil-surrounded spent resin to a temperature sufficient to effect a decomposition of the resin by carbonization but below the temperature at which the radioactive compounds in the resin evaporate or sublimate, as the case may be.
Claim 2
Dependent Claim 93 words
In a method of converting ion exchange resins containing radioactive inorganic compounds into a stable and safely storable form, the method comprising the step of thermally treating the spent resin, the improvement wherein the thermal treating step comprises surrounding the spent resin with a high-temperature boiling point oil that does not support combustion, and then heating the oil-surrounded spent resin to a temperature sufficient to effect a decomposition of the resin by carbonization but below the temperature at which the radioactive compounds in the resin evaporate or sublimate, as the case may be.
Claim 3
Dependent Claim 27 words
A method as defined in claim 1, in which the method comprises the further step of distilling off the oil after the termination of the heating step.

References Cited (Backward Citations)

US2361844A Cited
US3334050A Cited
US3673101A Cited
US3791981A Cited
US3792136A Cited
US3856622A Cited
DE2251246A1 Cited
US3971732A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-11-25 1984-05-26 1984-11-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-11-25 1988-05-26 1988-11-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-11-25 1992-05-26 1992-11-25 $7700.00 Window Closed / Lapsed

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