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US4080273A
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Method for photochemical reduction of uranyl nitrate by tri-N-butyl phosphate and application of this method to nuclear fuel reprocessing
Assignee: United States Department of Energy
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Filing: 1976-09-07
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Granted: 1978-03-21
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Expires: 1996-09-07
Abstract
Abstract Uranyl ion in solution in tri-n-butyl phosphate is readily photochemically reduced to U(IV). The product U(IV) may effectively be used in the Purex process for treating spent nuclear fuels to reduce Pu(IV) to Pu(III). The Pu(III) is readily separated from uranium in solution in the tri-n-butyl phosphate by an aqueous strip.
Inventors
- 👤 Gerald L. De Poorter
- 👤 Cheryl K. Rofer-De Poorter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:16
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/007; G21C; G21C19/00; G21C19/42; G21C19/44; G21C19/46; Y; Y02; Y02E; Y02E30/00; Y02E30/30; Y02W; Y02W30/00; Y02W30/50
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
62 words
A method of reducing uranyl ion to U(IV) which consists of contacting tri-n-butyl phosphate with an aqueous solution of uranyl nitrate for a time sufficient for the uranyl ion to partition between said aqueous solution and said tri-n-butyl phosphate, and irradiating the resultant solution of uranyl ion in tri-n-butyl phosphate with light in the spectral range of 350 nm to 520 nm.
Claim 2
Independent Claim
62 words
A method of reducing uranyl ion to U(IV) which consists of contacting tri-n-butyl phosphate with an aqueous solution of uranyl nitrate for a time sufficient for the uranyl ion to partition between said aqueous solution and said tri-n-butyl phosphate, and irradiating the resultant solution of uranyl ion in tri-n-butyl phosphate with light in the spectral range of 350 nm to 520 nm.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said aqueous solution contains about 1 to about 4 M HNO 3 .
Claim 4
Dependent Claim
16 words
The method of claim 2 wherein said aqueous solution contains about 1 M HNO 3 .
Claim 5
Dependent Claim
35 words
The method of claim 2 wherein said solution of uranyl ion in tri-n-butyl phosphate is irradiated with light in the spectral range at which the interaction of said U(IV) with NO 2 - is minimized.
Claim 6
Dependent Claim
19 words
The method of claim 4 wherein said light is in the spectral range of 400 nm to 520 nm.
Claim 7
Dependent Claim
15 words
The method of claim 5 wherein said light has a wavelength of about 414 nm.
Claim 8
Dependent Claim
13 words
The method of claim 5 wherein said solution is in equilibrium with air.
Claim 9
Dependent Claim
156 words
In a method for treating irradiated nuclear fuel elements to separate the fission products, uranium, and plutonium contained therein which comprises (a) dissolving said fuel elements in nitric acid to produce a feed solution of fission product nitrates, UO 2 (NO 3 ) 2 , and Pu(NO 3 ) 4 , (b) contacting said feed solution with tri-n-butyl phosphate for a time sufficient for substantially all the uranium and plutonium contained therein to partition into said tri-n-butyl phosphate, (c) reducing said plutonium in said tri-n-butyl phosphate to Pu(III) and contacting said tri-n-butyl phosphate containing said Pu(III) with an aqueous phase for a time sufficient for said Pu(III) to partition into said aqueous phase, the improvement consisting of irradiating uranyl ion in solution in tri-n-butyl phosphate with light of a wavelength which reduces said uranyl ion to U(IV) and contacting said U(IV) with the Pu(IV) in solution in said tri-n-butyl phosphate to reduce said Pu(IV) to Pu(III).
Claim 10
Dependent Claim
156 words
In a method for treating irradiated nuclear fuel elements to separate the fission products, uranium, and plutonium contained therein which comprises (a) dissolving said fuel elements in nitric acid to produce a feed solution of fission product nitrates, UO 2 (NO 3 ) 2 , and Pu(NO 3 ) 4 , (b) contacting said feed solution with tri-n-butyl phosphate for a time sufficient for substantially all the uranium and plutonium contained therein to partition into said tri-n-butyl phosphate, (c) reducing said plutonium in said tri-n-butyl phosphate to Pu(III) and contacting said tri-n-butyl phosphate containing said Pu(III) with an aqueous phase for a time sufficient for said Pu(III) to partition into said aqueous phase, the improvement consisting of irradiating uranyl ion in solution in tri-n-butyl phosphate with light of a wavelength which reduces said uranyl ion to U(IV) and contacting said U(IV) with the Pu(IV) in solution in said tri-n-butyl phosphate to reduce said Pu(IV) to Pu(III).
Claim 11
Dependent Claim
20 words
The method of claim 8 wherein said light is light in the spectral range of 400 nm to 520 nm.
Claim 12
Dependent Claim
26 words
The method of claim 9 wherein said light is in the spectral range at which the interaction of said U(IV) with NO 2 - is minimized.
Claim 13
Dependent Claim
20 words
The method of claim 9 wherein said feed solution is about 1.0 to about 4.0 M in HNO 3 .
Claim 14
Dependent Claim
20 words
The method of claim 8 wherein said tri-n-butyl phosphate solution containing uranyl ion and Pu(IV) is irradiated with said light.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |