US4376792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for primary containment of cesium wastes
Assignee: United States Department of Energy
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Filing: 1981-09-03
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Granted: 1983-03-15
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Expires: 2001-09-03
Abstract
Abstract A method for producing a cesium-retentive waste form, characterized by a high degree of compositional stability and mechanical integrity, is provided by subjecting a cesium-loaded zeolite to heat under conditions suitable for stabilizing the zeolite and immobilizing the cesium, and coating said zeolite for sufficient duration within a suitable environment with at least one dense layer of pyrolytic carbon to seal therein said cesium to produce a final, cesium-bearing waste form. Typically, the zeolite is stabilized and the cesium immobilized in less than four hours by confinement within an air environment maintained at about 600 DEG C. Coatings are thereafter applied by confining the calcined zeolite within a coating environment comprising inert fluidizing and carbon donor gases maintained at 1,000 DEG C. for a suitable duration.
Inventors
- 👤 Peter Angelini
- 👤 Walter J. Lackey
- 👤 David P. Stinton
- 👤 Raymond E. Blanco
- 👤 Walter D. Bond
- 👤 Wesley D. Arnold, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:48
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/04; G21F9/06; G21F9/12
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
155 words
A method for producing a cesium-specific waste form, characterized by a high degree of mechanical integrity and compositional stability, comprising, in combination, the steps of: (a) subjecting a cesium-specific zeolite containing cesium values to a rapid heating schedule within an air environment of about 100° C./hour until a temperature within the range of about 550° C. to 650° C. is attained; (b) maintaining this temperature for up to about four hours to effect removal of volatiles and moisture from the zeolite thereby retentively immobilizing cesium within stablized zeolite; and (c) coating the zeolite with at least one dense layer of pyrolytic carbon by confinement for sufficient duration within a suitable coating environment operating at about 1,000° C. while utilizing a carbon-donor gas selected from the group consisting essentially of acetylene and propylene and an inert fluidizing gas selected from the group consisting essentially of argon, nitrogen, and helium to effect a solidifed, cesium-retentive waste form.
Claim 2
Independent Claim
155 words
A method for producing a cesium-specific waste form, characterized by a high degree of mechanical integrity and compositional stability, comprising, in combination, the steps of: (a) subjecting a cesium-specific zeolite containing cesium values to a rapid heating schedule within an air environment of about 100° C./hour until a temperature within the range of about 550° C. to 650° C. is attained; (b) maintaining this temperature for up to about four hours to effect removal of volatiles and moisture from the zeolite thereby retentively immobilizing cesium within stablized zeolite; and (c) coating the zeolite with at least one dense layer of pyrolytic carbon by confinement for sufficient duration within a suitable coating environment operating at about 1,000° C. while utilizing a carbon-donor gas selected from the group consisting essentially of acetylene and propylene and an inert fluidizing gas selected from the group consisting essentially of argon, nitrogen, and helium to effect a solidifed, cesium-retentive waste form.
Claim 3
Dependent Claim
43 words
A method for packaging the cesium-retentive waste of claim 1 comprising the step of incorporating said waste form into solid waste processes for storing radioactive wastes, selected from the group of packaging materials consisting of glass, asphalt, cement, concrete, metal, and alternate ceramics.
References Cited (Backward Citations)
US2616847A
Cited
US3101998A
Cited
US3153566A
Cited
US3364148A
Cited
GB1456980A
Cited
US4172807A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-14 | 1986-09-13 | 1987-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-14 | 1990-09-13 | 1991-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-14 | 1994-09-13 | 1995-03-15 | $7700.00 | Window Closed / Lapsed |