Decontamination method reducing radioactive waste

Patent metadata

Field	Value
Publication number	US-10762997-B2
Application number	US-201715712616-A
Country	US
Kind code	B2
Filing date	Sep 22, 2017
Priority date	Oct 12, 2016
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A decontamination method that includes the steps of decontaminating an object containing radioactive contaminated metals or alloys with a chemical decontamination agent including sulfuric acid (H 2 SO 4 ) and forming a Ba or Sr precipitate by adding a Ba or Sr cation and a hydroxylion or halogen anion salts to the decontamination waste water.

First claim

What is claimed is:

1. A decontamination method comprising the following steps:
decontaminating an object containing radioactive contaminated metals or alloys with a chemical decontamination agent comprising sulfuric acid (H 2 SO 4 ) (step 1);
forming a Ba or Sr precipitate by adding Ba or Sr cation and hydroxyl ion or halogen anion salts to a decontamination waste water generated in step 1 (step 2); and
separating the precipitate and a supernatant after being treated with an ion exchange resin(step 3 ),
wherein the Ba or Sr cations in step 2 form the precipitate with sulfuric acid ions (SO 4 2− ), and the precipitate is co-precipitated with radioactive materials and metal ions included in the decontamination waste water.

2. The decontamination method according to claim 1 , wherein the chemical decontamination agent of step 1 is an oxidative decontamination agent, a reductive decontamination agent, or a combined decontamination agent thereof.

3. The decontamination method according to claim 1 , wherein the decontamination method additionally includes a step of separating the precipitate (step 3).

4. The decontamination method according to claim 2 , wherein the oxidative decontamination agent includes an oxidizing agent and a metal ion.

5. The decontamination method according to claim 4 , wherein the oxidizing agent is one or more agents selected from the group consisting of KMnO 4 , NaMnO 4 , H 2 CrO 4 , and HMnO 4 .

6. The decontamination method according to claim 2 , wherein the reductive decontamination agent includes a reducing agent and a metal ion.

7. The decontamination method according to claim 6 , wherein the reducing agent is one or more agents selected from the group consisting of NaBH 4 , H 2 S, N 2 H 4 , and LiAlH 4 .

8. The decontamination method according to claim 1 , wherein the object containing radioactive contaminated metals or alloys in step 1 is generated from the inner system of a nuclear power plant.

9. The decontamination method according to claim 1 , wherein the metal or alloy in step 1 is one or more materials selected from the group consisting of stainless steel, inconel steel, and zirconium alloy.

Assignees

• Korea Atomic Energy Res

Inventors

• Park Sang Yoon
• Won Hui-Jun
• Kim Seonbyeong
• Choi Wangkyu
• Choi Mansoo
• Jung Chong-Hun
• Yoon In-Ho
• Moon Jeikwon
• Jung Jun Young
• Park Jungsoon

Classifications

• Y02E30/30

  Nuclear fission reactors · CPC title

• C23G1/10

  Other heavy metals · CPC title

• C23G1/106

  refractory metals · CPC title

• G21F9/06

  Processing (separating different isotopes of the same chemical element B01D59/00) · CPC title

• G21F9/10

  by flocculation · CPC title