US4094809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for solidifying high-level nuclear waste
Assignee: United States Department of Energy
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Filing: 1977-02-23
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Granted: 1978-06-13
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Expires: 1997-02-23
Abstract
Abstract The addition of a small amount of reducing agent to a mixture of a high-level radioactive waste calcine and glass frit before the mixture is melted will produce a more homogeneous glass which is leach-resistant and suitable for long-term storage of high-level radioactive waste products.
Inventors
- 👤 Wayne A. Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:38
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/14; C03C14/00; C03C14/004; G; G21; G21F; G21F9/00; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/305; C03C2214/00; C03C2214/04; C03C2214/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
145 words
In the process of solidifying high-level radioactive waste solutions containing molybdenum (VI) for long-term storage by heating the waste solutions to calcining temperatures whereby the solutions are dried to form a radioactive calcine, mixing the calcine with a glass frit containing alkali metals to form a mixture, heating the mixture to melting temperature to form a molten glass and cooling the molten glass to form a solid containing high-level radioactive waste, the improvement comprising adding to the calcine-frit mixture before melting, an effective amount of reducing agent having a free energy of formation higher than molybdenum to reduce the molybdenum (VI) compounds to a lower valence state whereby the molybdenum (VI) compounds are reduced to a lower valence state which dissolves or disperses in the molten glass whereby the molten glass when cooled forms a leach-resistant solid containing high-level radioactive waste suitable for long-term storage.
Claim 2
Dependent Claim
145 words
In the process of solidifying high-level radioactive waste solutions containing molybdenum (VI) for long-term storage by heating the waste solutions to calcining temperatures whereby the solutions are dried to form a radioactive calcine, mixing the calcine with a glass frit containing alkali metals to form a mixture, heating the mixture to melting temperature to form a molten glass and cooling the molten glass to form a solid containing high-level radioactive waste, the improvement comprising adding to the calcine-frit mixture before melting, an effective amount of reducing agent having a free energy of formation higher than molybdenum to reduce the molybdenum (VI) compounds to a lower valence state whereby the molybdenum (VI) compounds are reduced to a lower valence state which dissolves or disperses in the molten glass whereby the molten glass when cooled forms a leach-resistant solid containing high-level radioactive waste suitable for long-term storage.
Claim 3
Dependent Claim
27 words
The improvement process of claim 1 wherein the reducing agent is selected from the group consisting of elemental silicon, aluminum, zirconium, chromium, titanium, carbon and silicon carbide.
Claim 4
Dependent Claim
20 words
The process of claim 2 wherein the reducing agent is from 3/4 to 3 weight percent of the calcine-frit mixture.
Claim 5
Dependent Claim
16 words
The process of claim 3 wherein the reducing agent is a powder -325 mesh in size.
Claim 6
Dependent Claim
20 words
The process of claim 3 wherein the mixture contains from 1 to 11/2 weight percent of -325 mesh elemental silicon.
Claim 7
Dependent Claim
20 words
The process of claim 3 wherein the mixture contains from 1/2 to 1 weight percent of -325 mesh silicon carbide.
References Cited (Backward Citations)
US3110557A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |