Remote-controlled mobile cleaning apparatus for removal and collection of high radioactive waste debris in hot-cell

• US 6,625,843 B2
• Filed: 05/24/2001
• Issued: 09/30/2003
• Est. Priority Date: 08/02/2000
• Status: Expired due to Fees

• Current Assignee: Korea Hydro and Nuclear Power Company Limited (Government of South Korea)
• Original Assignee: Korea Electric Power Corporation (Government of South Korea), Korea Atomic Energy Research Institute (Government of The Republic of Korea)
• Inventors: Kim, Ki-Ho, Park, Jang-Jin, Yang, Myung-Seung, Park, Hyun-Soo
• Primary Examiner(s): Till, Terrence R.
• Application Number:
  US09/863,444
• Publication Number:
  US 20020017005A1
• Time in Patent Office: 859 Days
• Field of Search: 153/19, 153/401, 153/39, 153/04
• US Class Current: 15/319
• CPC Class Codes: A46B 13/001 Cylindrical or annular brush bodies
• CPC Class Codes: A46B 2200/3073 Brush for cleaning specific unusual places not otherwise covered, e.g. gutters, golf clubs, tops of tin cans, corners
• CPC Class Codes: A46B 2200/3093 Brush with abrasive properties, e.g. wire bristles
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 7/0071 with containers for ash, soot, contaminant or harmful materials suction devices for removing ashes F23J1/02
• CPC Class Codes: A47L 9/00 Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
• CPC Class Codes: B08B 5/02 Cleaning by the force of jets, e.g. blowing-out cavities airguns or nozzles per se B05B1/005

Abstract

A remote-controlled mobile cleaning device for removal and collection of high radioactive waste debris in a spent nuclear fuel process and fabrication area, such as a hot-cell, is disclosed. The device includes navigation means for moving it to the desired cleaning location and climbing over such obstacles as electrical cables and pneumatic tubes placed on the hot-cell floor to be cleaned, suction and collection means for dislodging, filtering, and capturing high radioactive waste debris, and cover means for protecting suction and collection means. The device that is operated by remote control cleans and collects loose dry spent nuclear fuel powder and other high-radioactive waste debris adhered to both the contaminated in-cell floor and the in-cell spent nuclear fuel process and fabrication equipment, without spreading inside the hot-cell.

Claims

1. A remote-controlled mobile cleaning apparatus for removing and collecting highly contaminated radioactive waste debris deposited on the hot-cell floor and the surface of spent nuclear fuel process and fabrication equipment located on said hot-cell floor where humans are inaccessible due to the high radiation level of spent nuclear fuel, comprising:

a navigation means provided at a lower portion of said apparatus for moving on a surface of said hot-cell floor;

a suction and collection means connected with the navigation means for dislodging, sucking and collecting highly contaminated radioactive waste debris; and

a cover part mounted on the top of the suction and collection means so as to cover and protect the suction and collection means, wherein said suction and collection means comprises;

a primary suction unit to dislodge and suck radioactive waste debris adhered to the surface of the hot-cell floor;

a flexible suction unit to clean up areas where the primary suction unit is inaccessible or the surface of the equipment located on the hot-cell floor;

a primary collection unit to firstly filter and store radioactive waste debris sucked both by the primary suction unit and by the flexible suction unit;

a secondary collection unit to filter and capture more fine radioactive waste debris filtered from the primary collection unit;

a blower unit to generate a suction force for the suction and collection means; and

a housing holding all of the above units,

whereby each unit is separately constructed in modules and connected to each of said other units by first, second, third, and fourth feed pipes in sequence.

2. A remote-controlled mobile cleaning apparatus as defined in claim 1, wherein said primary suction unit comprises:

a brush roller made of a cylindrical bar inserted with a bundle of thin bronze strings in a double spiral shape;

a suction port housing the brush roller, wherein fringe made of a bundle of thin bronze strings is inserted at the base of said suction port in the form of a rectangle;

a drive motor installed at a position above the suction port; and

a plurality of gears connecting the output shaft of the brush roller with the one of the drive motor, thus making the brush roller rotate in conjunction with the drive motor.

3. A remote-controlled mobile cleaning apparatus as defined in any one of claims 1 and 2, wherein the navigation means and the suction and collection means are assembled or disassembled only by use of both an adjustable locking unit at the front and a plurality of locking bolts at the rear.

4. A remote-controlled mobile cleaning apparatus as defined in claim 3, wherein said adjustable locking unit comprises:

an upper holder mounted to the front bottom of the housing of the suction and collection means, wherein said upper holder has a downward channel;

an adjustable bolt vertically set by a pin within the downward channel of the upper holder, thus enabling said adjustable bolt to swing with respect to the pin;

an adjusting holder mounted to the outer surface of the front support beam of the mobile body unit, wherein said adjusting holder has upper and lower bosses with a horizontal channel defined between the two bosses; and

a fan-shaped adjusting nut having internally-threaded central opening, wherein said fan-shaped adjusting nut is engaged with the adjustable bolt at a position between the upper and lower bosses of the adjusting holder.

5. A remote-controlled mobile cleaning apparatus as defined in claim 4, wherein the adjustable locking unit controls the gap between the end of the bronze strings of the brush roller and the hot-cell floor surface to be cleaned by rotating the fan-shaped adjusting nut engaged with the adjustable bolt in a clockwise or counter-clockwise direction, and wherein fastening the fan-shaped adjusting nut in a clockwise direction lowers down both the housing and the primary suction unit relative to the hot-cell floor surface and makes the end of the bronze strings of the brush roller to be in contact with the floor surface.

6. A remote-controlled mobile cleaning apparatus as defined in claim 4, wherein the adjustable bolt engaged with the upper holder primarily passes through the upper boss of the adjusting holder downward, and secondarily the central opening of the fan-shaped adjusting nut prior to being finally inserted into the lower boss of the adjusting holder, thus completing the adjustable locking unit.

7. A remote-controlled mobile cleaning apparatus as defined in claim 6, wherein the adjustable locking unit controls the gap between the end of the bronze strings of the brush roller and the hot-cell floor surface to be cleaned by rotating the fan-shaped adjusting nut engaged with the adjustable bolt in a clockwise or counter-clockwise direction, and wherein fastening the fan-shaped adjusting nut in a clockwise direction lowers down both the housing and the primary suction unit relative to the hot-cell floor surface and makes the end of the bronze strings of the brush roller to be in contact with the floor surface.

8. A remote-controlled mobile cleaning apparatus as defined in claim 3, wherein the adjustable locking unit controls the gap between the end of the bronze strings of the brush roller and the hot-cell floor surface to be cleaned by rotating the fan-shaped adjusting nut engaged with the adjustable bolt in a clockwise or counter-clockwise direction, and wherein fastening the fan-shaped adjusting nut in a clockwise direction lowers down both the housing and the primary suction unit relative to the hot-cell floor surface and makes the end of the bronze strings of the brush roller to be in contact with the floor surface.

9. A remote-controlled mobile cleaning apparatus as defined in claim 1, wherein said flexible suction unit comprises:

a suction nozzle having a predetermined length;

a flexible hose connected to the suction nozzle;

a connection hose extended from a control valve and connected to the primary collection unit; and

a control valve to control the operation of said flexible suction unit, wherein said control valve connects the flexible hose and the connection hose and is fixedly mounted to the outer side of the housing.

10. A remote-controlled mobile cleaning apparatus as defined in claim 3, wherein said primary collection unit comprises:

a storage case to collect radioactive waste debris sucked either through the primary suction unit or through the flexible suction unit, wherein said storage case has a circular plate at its lower part by which said storage case is sat in the interior of the housing;

a sealing cap covering the top of the storage case completely by fastening a plurality of clamps mounted on the outer surface of the storage case;

a perforated conduit pipe fixed concentrically at a bottom center hole of the sealing cap; and

a cylindrical ceramic filter to primarily filter sucked radioactive waste debris, wherein said cylindrical ceramic filter encircles the perforated conduit pipe concentrically.

11. A remote-controlled mobile cleaning apparatus as defined in claim 10, wherein the top end of the cylindrical ceramic filter is engaged with the bottom of the sealing cap at a depression with predetermined depth, wherein the bottom end of the cylindrical ceramic filter is covered with a lower support member that passes through the lower part of the perforated conduit pipe and is tightly sealed with the lower support member by fastening a locking nut through a thread made on the lower part of the perforated conduit pipe, thereby making the ceramic filter to firmly be held below the sealing cap.

12. A remote-controlled mobile cleaning apparatus as defined in claim 10 or 11, wherein the sealing cap assembled with the ceramic filter, the perforated conduit pipe and the lower support member are held on the top of the storage case, and wherein the interior of the ceramic filter is completely isolated from the interior of the storage case, thereby creating a room for collecting radioactive waste debris.