Ceramic waste form production from used nuclear fuel

Patent metadata

Field	Value
Publication number	US-10600527-B1
Application number	US-201816127611-A
Country	US
Kind code	B1
Filing date	Sep 11, 2018
Priority date	Sep 11, 2018
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

According to one aspect of the invention, a method to create a ceramic waste form from used nuclear fuel. An active metal salt waste, a rare earth metal waste, and raw materials are received. The active metal salt waste is combined with the rare earth metal waste, forming a waste salt. The waste salt is then heated to approximately 500° C. The raw materials are also heated to approximately 500° C. The waste salt and raw materials are then blended to form a homogenous waste mixture. The homogenous waste mixture is heated to a first predetermined temperature for a predetermined amount of time, creating a ceramic waste form. The ceramic waste form is cooled to a second predetermined temperature.

First claim

The invention claimed is:

1. A method to create a ceramic waste form from used nuclear fuel, the method comprising:
(a) receiving used nuclear fuel, the nuclear fuel including an active metal salt waste, a rare earth metal waste, and raw materials;
(b) combining the active metal salt waste and the rare earth metal waste to form a waste salt;
(c) heating the waste salt to between approximately 400-660° C.;
(d) heating the raw materials to between approximately 400-660° C.;
(e) blending the waste salt and raw materials to form a homogenous waste mixture;
(f) heating the homogenous waste mixture to a first predetermined temperature for a predetermined amount of time, creating a ceramic waste form; and
(g) cooling the ceramic waste form to a second predetermined temperature.

2. The method of claim 1 , wherein the raw materials comprise zeolite and borosilicate glass.

3. The method of claim 1 , wherein the raw materials comprise approximately 760 kg of zeolite and approximately 250 kg of borosilicate glass.

4. The method of claim 1 , wherein the active metal salt waste comprises active metal and divalent rare earth fission products.

5. The method of claim 4 , wherein the divalent rare earth fission products comprise samarium and europium.

6. The method of claim 4 , wherein the active metal fission products comprise alkali, alkaline earth and actinide elements.

7. The method of claim 1 , wherein the active metal salt waste comprises sodalite.

8. The method of claim 1 , wherein the step of combining the active metal salt waste and rare earth metal waste includes the sub steps of:
(a) combining the active metal salt waste salt and the rare earth metal waste in a transport tank; and
(b) heating the active metal salt waste and the rare earth metal waste in a transport tank.

9. The method of claim 1 , wherein the raw materials are heated in a ceramic waste blender.

10. The method of claim 1 , wherein the step of blending the waste salt and raw materials includes the sub step of:
(a) blending the waste salt and raw materials for approximately three to four days.

11. The method of claim 1 , wherein the step of blending waste salt and raw materials includes the sub step of:
(a) maintaining the waste salt and raw materials at a temperature between approximately 500-600° C.

12. The method of claim 1 , wherein the first predetermined temperature is between approximately 900-950° C.

13. The method of claim 1 , wherein the predetermined amount of time is between approximately three to four days.

14. The method of claim 1 , wherein the second predetermined temperature is between approximately 150-600° C.

15. The method of claim 1 , wherein the step of cooling occurs in incremental cooling zones, each cooling zone cooling the ceramic waste form to a lower temperature.

16. The method of claim 1 , further comprising repeating steps (a) through (g) to generate an integrated process for the continuous output of ceramic waste forms based upon a continuous input of metal salt waste, rare earth metal waste, and raw materials.

17. A method to create a ceramic waste form from used nuclear fuel, the method comprising:
(a) receiving used nuclear fuel, the nuclear fuel including an active metal salt waste, a rare earth metal waste, and raw materials;
(b) combining the active metal salt waste and the rare earth metal waste to form a waste salt;
(c) heating the waste salt to approximately 500° C.;
(d) heating the raw materials to approximately 500° C.;
(e) blending the waste salt and raw materials in a ceramic waste blender to form a homogenous waste mixture;
(f) placing the homogenous waste mixture into a waste canister;
(g) conveying the waste canister to a ceramic waste furnace;
(h) heating the homogenous waste mixture to a first predetermined temperature for a predetermined amount of time, creating a ceramic waste form within the waste canister; and
(i) conveying the canister through at least two cooling zones to cool the ceramic waste form to a second predetermined temperature.

18. The method of claim 17 , further comprising repeating steps (a) through (i) to generate an integrated process for the continuous output of ceramic waste forms based upon a continuous input of metal salt waste, rare earth metal waste, and raw materials.

Assignees

• Us Energy
• Us Dept Energy

Inventors

• Williamson Mark A
• Willit James L
• Wiedmeyer Stanley G
• Johnson Terry R
• Figueroa Javier

Classifications

• C04B2235/3436

  Alkaline earth metal silicates, e.g. barium silicate · CPC title

• C04B35/62204

  using waste materials or refuse (clay-wares containing waste materials C04B33/132) · CPC title

• C04B33/1327

  containing heavy metals · CPC title

• C03C4/0042 Primary

  for glass comprising or including particular isotopes · CPC title

• C04B2235/3224

  Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide · CPC title