US3657012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for decontaminating radioactive objects
Assignee: Pechiney SA
•
Filing: 1968-08-14
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Granted: 1972-04-18
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Expires: 1988-08-14
Abstract
Abstract A process for decontaminating radioactive objects by washing them in a solution of Alpha -amino (alkane-phosphonic) acid and a tensio-active substance that has been neutralized to a pH from 7 to 7.5 and diluted to a 10 percent concentration. The wash effluents are decontaminated by adding to the effluents sufficient calcium-ions to displace the rare earths and strontium from their complexes with Alpha -amino (alkane-phosphonic) acid and thereafter scrubbing.
Inventors
- 👤 Jean-Louis Verot
- 👤 Rene Sarfati
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:55
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/16; C11D3/36; C11D3/364
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
101 words
A process for the decontamination of radioactive objects having radioactive rare earths or strontium particles thereon comprising: A. preparing a solution of from 10 to 500 g/liter of Alpha -amino (alkane-phosphonic) acid and from 10 to 500 g/liter of a tensio-active substance in deionized water; B. neutralizing said solution to a pH of from about 7 to about 7.5 with sodium hydroxide; C. washing said radioactive object with said solution, such that said particles are complexed with said Alpha -amino (alkane-phosphonic)acid; and, D. treating said solution with calcium ions sufficient to displace said particles from their complexes and scrubbing said solution.
Claim 2
Dependent Claim
11 words
The process of claim 2 wherein said tensio-active substance is biodegradable.
Claim 3
Dependent Claim
18 words
The process of claim 2 wherein said tensio-active substance is a heavy alcohol with a straight oxyethylated chain.
Claim 4
Dependent Claim
21 words
The process of claim 2 wherein said solution after neutralization is diluted in deionized water to a concentration of 10 percent.
Claim 5
Dependent Claim
19 words
The process of claim 2 wherein said solution has added thereto at least one of disinfectants and optical brighteners.
Claim 6
Dependent Claim
12 words
The process of claim 2 wherein the solution is scrubbed by coprecipitation.
Claim 7
Dependent Claim
16 words
The process of claim 2 wherein the solution is scrubbed by scattering with zeolite and filtering.
Claim 8
Dependent Claim
12 words
The process of claim 2 wherein said acid is amino-tri (methane-phosphonic) acid.
Claim 9
Dependent Claim
20 words
The process of claim 9 wherein the calcium ions are supplied by adding calcium nitrate to the solution after washing.
Claim 10
Dependent Claim
24 words
The process of claim 10 wherein the solution is scrubbed by coprecipitation of a salt selected from the group calcium phosphate and calcium sulphate.
References Cited (Backward Citations)
US2924576A
Cited
US3234124A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |