Method and apparatus for eliminating volatiles or airborne entrainments when vitrifying radioactive and/or hazardous waste

• US 5,678,236 A
• Filed: 01/23/1996
• Issued: 10/14/1997
• Est. Priority Date: 01/23/1996
• Status: Expired due to Term

• Current Assignee: De Macedo; Pedro Buarque, Theodore Aaron Litovitz
• Original Assignee: De Macedo; Pedro Buarque, Theodore Aaron Litovitz
• Inventors: Macedo, Pedro B., Hojaji, Hamid, Pegg, Ian L., Mohr, Robert K., Brandys, Marek
• Primary Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US08/589,252
• Time in Patent Office: 630 Days
• Field of Search: 588/11, 588/16, 588/251, 588/252, 588/201, 65/134.8, 65/27, 65/134.6, 110/345
• US Class Current: 588/11
• CPC Class Codes: B09B 3/0066 Disposal of asbestos
• CPC Class Codes: C03B 5/005 of glass-forming waste materials disposal or transformation of solid waste in general B09B; treatment of radioactive waste G21F9/00

Abstract

In this invention radioactive or hazardous containing materials are vitrified in a melter having two or more chambers. Glass feed materials are added to the primary chamber of the melter and they are heated to a molten glass which is then transported to one or more secondary chambers where hazardous and/or radioactive containing materials are added and are encapsulated and/or melted. In addition, the non-plutonium part of a glass feed can be melted in a non-radioactive environment which permits contact operations and maintenance; no radioactive shielding; and a conventional off gas system-similar to commercial vitrification plants. The hot molten "clean" glass is directed into a radioactive containment such as a "glove box"; shielded "glove box"; or hot cell, or a combination of these. By delivering hot "clean" glass from a melter including non-radioactive materials, 90% of the off gases will be non-radioactive. Thereby only minimum heating is needed in the radioactive containment resulting in very significant reductions in size of the maintenance requirements for the radioactive portion of the process. In the radioactive portion, the glove box will include means for adding plutonium feed. The glass melt will be homogenized with the plutonium feed, optionally by additional stirring. Once the plutonium glass is sufficiently homogeneous, it can be cooled in the container in the glove box or the container becomes a disposal container for the glass. If the melt chamber is different than the container, the melt is discharged to a separate container, all within the glove box, for subsequent disposal.

Claims

1. A process for melting glass and encapsulating radioactive components in a melter having two or more chambers, said process comprising

adding glass feed material to a primary chamber of the melter,

heating said feed material to molten glass,

transporting said molten glass to one or more secondary chambers of the melter, and

adding radioactive components to said glass melt in said secondary chamber to encapsulate the radioactive components.

2. A process for melting glass and encapsulating radioactive components as claimed in claim 1, wherein said one or more secondary chambers are located in a controlled environment containment.

3. A process for melting glass radioactive components and encapsulating radioactive components as claimed in claim 2, wherein said controlled environment containment includes a one way device through which said molten glass is transported into said one or more secondary chambers.

4. A process for melting glass radioactive components and encapsulating radioactive components as claimed in claim 1, wherein said radioactive components include actinides.

5. A process for melting glass radioactive components and encapsulating radioactive components as claimed in claim 1, wherein said radioactive components include plutonium.

6. A process for melting glass containing hazardous and/or radioactive components in a melter having two or more chambers, said process comprising

adding feed material containing said components to a primary chamber of the melter,

heating said feed to molten glass,

volatilizing said components into an off-gas stream,

capturing said components from the off-gas stream in a filter cake,

transporting said molten glass to one or more secondary chambers of the melter, and

adding said filter cake to said glass melt in said secondary chamber to melt and/or encapsulate the filter cake.

7. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein said filter cake includes a filter aid.

8. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 7, wherein said filter aid is a powder having high silica content.

9. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 8, wherein said high silica powder contains diatomaceous earth.

10. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 8, wherein said high silica powder contains perlite.

11. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein said secondary chamber is a discharge container.

12. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein said secondary chamber is a forehearth.

13. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein flux is added with the filter cake.

14. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 7, wherein flux is added with the filter cake.

15. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein the volatile components include C5.

16. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein the volatile components include Tc.

17. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein the volatile components include RCRA materials.

18. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein the volatile components include TSCA materials.

19. A process for melting glass containing hazardous and/or radioactive components as claimed in claim 6, wherein the volatile components include asbestos containing materials.

20. A process for melting glass and encapsulating radioactive components in a melter having at least two chambers, said process comprising

adding glass feed material to a primary chamber of the melter,

heating said feed material to molten glass,

transporting said molten glass to one or more secondary chambers located in a controlled environment containment having a negative air pressure, and

adding said radioactive components to said glass melt in said secondary chamber to encapsulate the radioactive components.

21. A process for melting glass radioactive components and encapsulating radioactive components as claimed in claim 20, wherein said radioactive components include actinides.

22. A process for melting glass radioactive components and encapsulating radioactive components as claimed in claim 20, wherein said radioactive components include plutonium.