Patent US5429983A successfully refreshed from Google Patents.
Patent EP0089580A1 successfully refreshed from Google Patents.
EP0089580A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for solidifying radioactive waste
Assignee: Hitachi Ltd
•
Filing: 1983-03-11
•
Granted: —
•
Expires: 2003-03-11
Abstract
Abstract A solid radioactive waste can be solidified by a process comprising packing a solid radioactive waste in a container, adding to the container an aqueous solution comprising an alkali silicate, a hardening agent and a fluidity-improving agent for the aqueous solution and conducting the solidification of the alkali silicate, the resulting solidified radioactive waste being excellent in weather resistance, showing no cracks and having sufficient strength.
Inventors
- 👤 Fumio Kawamura
- 👤 Tetsuo Fukasawa
- 👤 Naohito Uetake
- 👤 Kiyomi Funabashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:50
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/008; G21F9/28; G21F9/30; G21F9/301; G21F9/302
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
60 words
A process for solidifying a radioactive waste which comprises packing a solid radioactive waste in a container, adding to the container an aqueous solution comprising an alkali silicate as a filler, a hardening agent for the alkali silicate, and a fluidity-improving agent for the aqueous solution, and conducting the solidification of the alkali silicate to give a solidified radioactive waste.
Claim 2
Dependent Claim
60 words
A process for solidifying a radioactive waste which comprises packing a solid radioactive waste in a container, adding to the container an aqueous solution comprising an alkali silicate as a filler, a hardening agent for the alkali silicate, and a fluidity-improving agent for the aqueous solution, and conducting the solidification of the alkali silicate to give a solidified radioactive waste.
Claim 3
Dependent Claim
15 words
A process according to Claim 1, wherein the hardening agent is an inorganic phosphate compound.
Claim 4
Dependent Claim
20 words
A process according to Claim 1, wherein the fluidity-improving agent is a naphthalenesulfonic acid-formaldehyde high condensate or a salt thereof.
Claim 5
Dependent Claim
25 words
A process according to Claim 1, wherein the salt of naphthalenesulfonic acid-formaldehyde high condensate is an alkali metal salt or alkaline earth metal salt thereof.
Claim 6
Dependent Claim
57 words
A process according to Claim 4, wherein the salt of naphthalene-sulfonic acid-formaldehyde high condensate is an alkali metal salt or an alkaline earth metal salt of a mixture containing 8% by weight or less of unreacted naphthalenesulfonic acid salt, and 70% by weight or more of naphthalenesulfonic acid-formaldehyde high condensate salt having 5 or more naphthalene rings.
Claim 7
Dependent Claim
27 words
A process according to Claim 1, wherein the container is a drum containing therein a basket with a constant distance from the inner walls of the container.
Claim 8
Dependent Claim
32 words
A process according to Claim 1, wherein the aqueous solution is obtained by mixing an alkali silicate powder and a hardening agent powder, followed by addition of water and the fluidity-improving agent.
Claim 9
Dependent Claim
45 words
A process according to Claim 1, wherein the aqueous solution contains 25 to 65% by weight of alkali silicate, 3 to 50% by weight of a hardening agent, 10 to 25% by weight of water, and 0.6 to 2.4% by weight of a fluidity-improving agent.
Claim 10
Dependent Claim
15 words
A process according to Claim 1, wherein the solid radioactive waste is radioactive waste pellets.
Claim 11
Dependent Claim
37 words
A process according to Claim 3, wherein the salt of naphthalenesulfonic acid-formaldehyde high condensate is represented by the formula: wherein M is Na, K, Li, Ca or Mg; and n is an integer of 5 or more.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.