US4131527A
Expired / Lapsed
US
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Method for selectively reducing plutonium values by a photochemical process
Assignee: United States Department of Energy
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Filing: 1977-03-30
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Granted: 1978-12-26
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Expires: 1997-03-30
Abstract
Abstract The rate of reduction of Pu(IV) to Pu(III) in nitric acid solution containing a reducing agent is enhanced by exposing the solution to 200-500 nm electromagnetic radiation. Pu values are recovered from an organic extractant solution containing Pu(IV) values and U(VI) values by the method of contacting the extractant solution with an aqueous nitric acid solution in the presence of a reducing agent and exposing the aqueous solution to electromagnetic radiation having a wavelength of 200-500 nm. Under these conditions, Pu values preferentially distribute to the aqueous phase and U values preferentially distribute to the organic phase.
Inventors
- 👤 Horace A. Friedman
- 👤 Louis M. Toth
- 👤 Jimmy T. Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:03
CPC Classifications
C; C01; C01G; C01G56/00; C01G56/001; G; G21; 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
66 words
A method for enhancing the rate of reduction of Pu(IV) to Pu(III) in an aqueous nitric acid solution having dissolved therein hydrazine, Pu(IV) values, and U(VI) values, said method comprising exposing said solution to a source of 200-500 nm electromagnetic radiation of sufficient intensity to cause Pu(IV) and U(VI) values in said solution to absorb at least 100 watts per mole per hour of Pu(IV) reduced.
Claim 2
Independent Claim
66 words
A method for enhancing the rate of reduction of Pu(IV) to Pu(III) in an aqueous nitric acid solution having dissolved therein hydrazine, Pu(IV) values, and U(VI) values, said method comprising exposing said solution to a source of 200-500 nm electromagnetic radiation of sufficient intensity to cause Pu(IV) and U(VI) values in said solution to absorb at least 100 watts per mole per hour of Pu(IV) reduced.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said electromagnetic radiation is 200-350 nm.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein said nitric acid concentration is 0.2-4 M.
Claim 5
Dependent Claim
32 words
The method of claim 1 wherein said radiation is of sufficient intensity to cause said Pu(IV) and U(VI) values to absorb at least 1000 watts per mole per hour of Pu(IV) reduced.
Claim 6
Independent Claim
165 words
A method for recovering Pu values from an organic extractant solution having dissolved therein Pu(IV) and U(VI) values, comprising the steps of: a. contacting said organic extractant solution containing Pu(IV) and U(VI) values with an aqueous HNO 3 solution containing hydrazine whereby a portion of the Pu(IV) and U(VI) values distribute to the aqueous solution; b. exposing the aqueous solution containing Pu(IV) and U(VI) values to a source of 200-500 nm electromagnetic radiation of sufficient intensity to cause Pu(IV) and U(VI) values in said aqueous solution to absorb at least 100 watts per mole per hour of Pu(IV) reduced to enhance the rate of reduction of Pu(IV) to Pu(III) in said aqueous solution and cause Pu values to preferentially distribute to said aqueous solution whereby uranium values preferentially distribute to the organic extractant solution, said organic extractant solution being substantially shielded from said electromagnetic radiation to prevent photolytic degradation of said organic extractant; and c. then separating the aqueous solution from the organic extractant solution.
Claim 7
Independent Claim
165 words
A method for recovering Pu values from an organic extractant solution having dissolved therein Pu(IV) and U(VI) values, comprising the steps of: a. contacting said organic extractant solution containing Pu(IV) and U(VI) values with an aqueous HNO 3 solution containing hydrazine whereby a portion of the Pu(IV) and U(VI) values distribute to the aqueous solution; b. exposing the aqueous solution containing Pu(IV) and U(VI) values to a source of 200-500 nm electromagnetic radiation of sufficient intensity to cause Pu(IV) and U(VI) values in said aqueous solution to absorb at least 100 watts per mole per hour of Pu(IV) reduced to enhance the rate of reduction of Pu(IV) to Pu(III) in said aqueous solution and cause Pu values to preferentially distribute to said aqueous solution whereby uranium values preferentially distribute to the organic extractant solution, said organic extractant solution being substantially shielded from said electromagnetic radiation to prevent photolytic degradation of said organic extractant; and c. then separating the aqueous solution from the organic extractant solution.
Claim 8
Dependent Claim
15 words
The method of claim 5 wherein said HNO 3 concentration is 0.2 to 4 M.
Claim 9
Dependent Claim
12 words
The method of claim 5 wherein said electromagnetic radiation is 200-350 nm.
Claim 10
Dependent Claim
33 words
The method of claim 5 wherein said electromagnetic radiation is of sufficient intensity to cause said Pu(IV) and U(VI) values to absorb at least 1000 watts per mole per hour of Pu(IV) reduced.
Claim 11
Dependent Claim
12 words
The method of claim 5 wherein said electromagnetic radiation is 350-500 nm.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein said electromagnetic radiation is 350-500 nm.
Claim 13
Dependent Claim
13 words
The method of claim 1 wherein said HNO 3 concentration is 0.5-1.5 M.
Claim 14
Dependent Claim
13 words
The method of claim 5 wherein said HNO 3 concentration is 0.5-1.5 M.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1981-12-25 | 1982-06-26 | 1982-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-25 | 1986-06-26 | 1986-12-26 | $3760.00 | Window Closed / Lapsed |
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