Post-accident fission product removal system and method of removing post-accident fission product

Patent metadata

Field	Value
Publication number	US-9484122-B2
Application number	US-201113340943-A
Country	US
Kind code	B2
Filing date	Dec 30, 2011
Priority date	Dec 30, 2011
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A post-accident fission product removal system may include an air mover, a filter assembly, and/or an ionization chamber. The air mover may be configured to move contaminated air through the filter assembly to produce filtered air. The ionization chamber may be connected to the filter assembly. The ionization chamber may include an anode and a cathode. The ionization chamber may be configured to receive the filtered air from the filter assembly and to ionize and capture radioisotopes from the filtered air to produce clean air.

First claim

The invention claimed is:

1. A post-accident fission product removal system, comprising:
an air mover connected to a filter assembly, the air mover configured to move contaminated air containing radioisotopes through the filter assembly to produce filtered air; and
an ionization chamber connected to the filter assembly, the ionization chamber including an anode and a cathode, the ionization chamber configured to receive the filtered air from the filter assembly and to ionize and electrostatically capture the radioisotopes from the filtered air on a surface of the anode or the cathode to produce clean air.

2. The post-accident fission product removal system according to claim 1 , wherein the air mover is a blower or a vacuum.

3. The post-accident fission product removal system according to claim 1 , wherein the filter assembly includes:
a centrifugal separator configured to receive the contaminated air and to initially separate out larger-sized debris from the contaminated air so as to output centrifuged air;
a charcoal filter connected to the centrifugal separator, the charcoal filter including activated carbon, the charcoal filter configured to receive the centrifuged air and to remove gases with an affinity to the activated carbon so as to output carbon-filtered air; and
a high-efficiency particulate air (HEPA) filter connected to the charcoal filter, the high-efficiency particulate air filter configured to receive the carbon-filtered air and to remove smaller particulates missed by the charcoal filter so as to output HEPA-filtered air.

4. The post-accident fission product removal system according to claim 1 , wherein the anode and the cathode are in the form of charged plates in the ionization chamber.

5. The post-accident fission product removal system according to claim 4 , wherein the charged plates are arranged in parallel.

6. The post-accident fission product removal system according to claim 4 , wherein each of the anode and the cathode are in the form of at least two charged plates.

7. The post-accident fission product removal system according to claim 6 , wherein the at least two charged plates of each of the anode and cathode are alternately arranged with each other.

8. The post-accident fission product removal system according to claim 1 , wherein the ionization chamber is configured such that the filtered air from the filter assembly is directed to a flow path passing between the anode and the cathode.

9. The post-accident fission product removal system according to claim 1 , wherein the ionization chamber is configured to permit sealing and detachment from the post-accident fission product removal system prior to excessive accumulation of the radioisotopes in the ionization chamber.

10. The post-accident fission product removal system according to claim 9 , wherein the ionization chamber has a battery power source configured to maintain a charge on the anode and cathode to prevent escape of the radioisotopes during the sealing and detachment of the ionization chamber.

11. The post-accident fission product removal system according to claim 1 , further comprising:
a laser separator connected between the filter assembly and the ionization chamber, the laser separator configured to separate the radioisotopes based on mass.

12. A method of removing a post-accident fission product, the method comprising:
filtering contaminated air containing radioisotopes to produce filtered air;
ionizing the filtered air within an ionization chamber to produce ionized radioisotopes; and
electrostatically capturing the ionized radioisotopes on a surface of an anode or cathode of the ionization chamber to produce clean air.

13. The method of removing a post-accident fission product according to claim 12 , wherein the filtering includes:
centrifuging the contaminated air to separate out larger-sized debris so as to output centrifuged air;
carbon filtering the centrifuged air with activated carbon to remove gases with an affinity to the activated carbon so as to output carbon-filtered air; and
directing the carbon-filtered air through a high-efficiency particulate air (HEPA) filter to remove smaller particulates missed by the carbon filtering so as to output HEPA-filtered air.

14. The method of removing a post-accident fission product according to claim 12 , wherein the ionizing the filtered air includes exposing the filtered air to an electric potential of a magnitude that is sufficient to ionize the radioisotopes in the filtered air.

15. The method of removing a post-accident fission product according to claim 12 , wherein the ionizing the filtered air is performed with charged plates.

16. The method of removing a post-accident fission product according to claim 15 , wherein the ionizing the filtered air includes flowing the filtered air between the charged plates.

17. The method of removing a post-accident fission product according to claim 15 , wherein the ionizing the filtered air includes using a battery power source to maintain a charge on the charged plates to prevent escape of the radioisotopes during a removal of the ionization chamber.

18. The method of removing a post-accident fission product according to claim 12 , wherein the ionizing the filtered air is performed with at least two pairs of oppositely charged plates.

19. The method of removing a post-accident fission product according to claim 12 , wherein the ionizing the filtered air is performed with at least two pairs of alternately arranged plates.

20. The method of removing a post-accident fission product according to claim 12 , further comprising:
exposing the filtered air to a laser to separate the radioisotopes based on mass prior to ionizing the filtered air.

21. The method of removing a post-accident fission product according to claim 12 , further comprising:
sealing and removing the ionization chamber after the electrostatically capturing the ionized radioisotopes.

Assignees

• Siewert Mark W
• Ellison Phillip G
• Bass John R
• Ge Hitachi Nuclear Energy Americas Llc

Inventors

• Siewert Mark W
• Ellison Phillip G
• Bass John R

Classifications

• G21F9/001 Primary

  Decontamination of contaminated objects, apparatus, clothes, food; Preventing contamination thereof · CPC title

• G21F9/02

  Treating gases · CPC title