Background
Development of nuclear emergency response robots after the JCO criticality accident
JAEA’s response to the Fukushima accident using nuclear emergency response robots
Preparation of the JAEA-3 robot system
Unitizing and deployment of the JAEA-3 robot
Actual situation and requirements for deployment at Fukushima Daiichi Nuclear Power Plants
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The radiation level was so high the JAEA-3 operator would be exposed to, too much radiation if the robot control vehicle RC-2 is used in the truck-lock of unit 2 of the Fukushima Daiichi NPPs.
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In order to deploy JAEA-3 robot to survey for hot spots using Gamma Eye in unit 2 of the Fukushima Daiichi NPPs, operators would have to carry robot and accessory components from the turbine building to the reactor building.
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There is a long corridor the from turbine building to reactor building where there were temporary cables and hoses that were used to stabilize and cool the reactor cores. A temporary walkway covered the cables and hoses and let operators walk over the cables and hoses.
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The smallest opening was 700 mm wide × 700 mm high.
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The floor of the turbine building was contaminated and components temporarily put on the floor while being transported through the building would become contaminated.
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The turbine building did not have sufficient ventilation for an internal combustion engine to be run inside the building.
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Operations, including carrying units, disassembly, and reassembly, would require operators and technicians to be in a radiation protection suit with full face mask for 3–4 h.
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Disassembly and reassembly requiring special operator’s skill or tools would require more time that operators and technicians need to be in radiation protective gear.
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A deployed robot would become contaminated.
Unitization policy for the JAEA-3 robot system
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Unitization should be completed in 1 month.
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Support would not be available from the maker.
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It would be difficult to procure special parts.
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Each unit should weigh less than 25 or 35 kg, so that one operator could carry it.
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Each unit should be smaller than 400 mm depth, 600 mm width and 1000 mm high, to allow the unit to be carried through the 700 mm wide × 1000 mm high opening.
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Each unit should fit on a three-wheel-carrier (Fig. 8) to limit the contamination of the unit and to make the units easier to carry and back pack.×
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Each unit should be assembled with waterproof connectors and without special tools.
Units of the JAEA-3 robot system
Unit 1
Unit 2
Unit 3
Unit 4
Unit 0: JAEA-3 robot equipped with Gamma Eye
Unit no. | Contents | Remarks |
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0 | JAEA-3 robot | Equipped with “Gamma Eye” |
1 | Area camera | Picture as shown in unit 2 on monitor |
2 | Controller | Includes servo divers, camera control units and monitors and PC for gamma camera |
3 | Cable | Consists of multi-line cable, a twisted pair cable and a stainless steel wire |
4 | Battery module | Consists of two 12 V lead acid batteries and DC/AC inverter |