Decommissioning method of biodegradable concrete of PWR type nuclear power plant

Patent metadata

Field	Value
Publication number	US-11715573-B2
Application number	US-201917047826-A
Country	US
Kind code	B2
Filing date	Apr 17, 2019
Priority date	Apr 17, 2018
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

A decommissioning method of biological shielding concrete of a nuclear power plant according to an exemplary embodiment includes: decommissioning a neutron detector positioning device installed to biological shielding concrete surrounding a nuclear reactor to form a plurality of penetrated parts in the biological shielding concrete; inserting a part of a cutting device into the plurality of penetrated parts; and decomposing the biological shielding concrete into a plurality of sub-concrete parts by using the cutting device.

First claim

The invention claimed is:

1. A decommissioning method of biological shielding concrete of a nuclear power plant, comprising:
decommissioning a neutron detector positioning device installed in the biological shielding concrete surrounding a nuclear reactor thereby exposing a plurality of penetrated parts in the biological shielding concrete, wherein the plurality of penetrated parts are cavities formed in the biological shielding concrete for accommodating the neutron detector positioning device and therefore pre-exist before decommissioning the neutron detector positioning device, the plurality of penetrated parts being defined by an external surface of the biological shielding concrete;
inserting a part of a cutting device into the plurality of penetrated parts, wherein, during the inserting, the cutting device directly contacts the external surface of the biological shielding concrete in the plurality of penetrated parts; and
breaking up the biological shielding concrete into a plurality of sub-concrete parts by using the cutting devices, wherein the biological shielding concrete has an inner wall and an outer wall, the penetrated parts extend from the inner wall to the outer wall, the inner wall is curved and the outer wall is flat.

2. The decommissioning method of claim 1 , wherein
the penetrated parts have a diameter that is smaller at the inner wall than at the outer wall.

3. The decommissioning method of claim 1 , wherein
the neutron detector positioning device includes:
a neutron sensor adjacent to the nuclear reactor;
an external adjuster disposed outside of the biological shielding concrete and configured to move the neutron sensor; and
a connection member connecting the neutron sensor and the external adjuster to each other and penetrating the biological shielding concrete, and
the decommissioning of the neutron detector positioning device installed to the biological shielding concrete includes:
moving the neutron sensor toward the biological shielding concrete inner wall by pulling the external adjuster;
cutting the external adjuster and the connection member; and
separating the connection member from the biological shielding concrete to expose the penetrated parts in the biological shielding concrete.

4. The decommissioning method of claim 3 , wherein
the neutron detector positioning device further includes a transferring unit installed under the neutron sensor, and
the neutron sensor is moved to the biological shielding concrete inner wall riding on the transferring unit.

5. The decommissioning method of claim 1 , wherein
the cutting device includes a wire saw.

Assignees

• Korea Hydro & Nuclear Power Co

Inventors

• Hwang Seok-Ju
• Hong Sung-Hoon
• Lee Mi-Hyun
• Kim Cheon-Woo

Classifications

• G21D1/003 Primary

  Nuclear facilities decommissioning arrangements (decontamination arrangements, treating radioactively contaminated material G21F9/00) · CPC title

• G21C17/116

  Passages or insulators, e.g. for electric cables · CPC title

• Y02E30/00

  Energy generation of nuclear origin · CPC title

• G21F9/28

  Treating solids · CPC title

• G21F9/30

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