Cutting & dismantling techniques JRC – 6th International Summer School

11 September 2014

Bernard Rottner

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Cutting technologies,

field experience and examples

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Foreword

• Cutting in situ

• For dismantling

• Cutting in a workshop

• Or in a glove box or in a cell

• For segmentation and waste management

• Hot technologies

• Plasma, laser, flame cutting, thermal lance

• Quick

• No recoil force ⇒ easy to operate remotely (generally)

• But dispersion of radionuclides

• Cold technologies

• Mechanical: alternative saw, band saw, diamond cable,

shear…

• Disk saw, grinder: hot technologies?

• High pressure water

• Exotic technologies, for instance with explosives

4

Optimization of the cutting time

• Cutting a furnace inside a glove box in la Hague

• Alpha environment

• Not enough space

• Furnace with thick parts

Reciprocating saw: 70 h

Orbital machining: 8 h

Band saw: 1.5 h

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Reciprocating saw

• And sabre saw

• Advantages

• No hot point

• Able to cut large pieces

• Short installation time (and

then sawing without hands

on works)

• Drawback

• Slow

• Risk of braking blades

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Orbital machining

• Advantages

• No hot point

• Able to cut large pieces

• Short installation time (and

then sawing without hands

on works)

• Drawback

• Slow

Mock-up of an annular tank of UDG

(enrichment plant), with the

cutting tool under testCutting a SG into 2 parts

Dampierre , April 1990

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Dismantling of Chinon A3 heat exchangers

• Reciprocating saw

• Rotating saw

• Orbital machining

• Plasma

• 4500 tons of metal

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Nibbler

• Advantages

• No hot point

• Able to cut large pieces

• Quick

• Drawbacks

• Full hands on work

• Thin sheets (< 1mm)

• Starting hole (on closed

tanks)

Dismantling of LHA (hot cells) - CEA site of Saclay

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Other mechanical cutting technologies

• Hydraulic shear

• No hot point

• Quick

• Closes the pipes when cutting

them

• Diamond cable

• Able to cut very very large

pieces

• Cuts steel and concrete

• Usually with cooling water,

could be used without

• Difficulties with lead, and

multilayer pieces

• Chain saw

• For lead

• Core cutter

• For concrete slabs

• Holes one after another, all

around the part to cut

Dismantling of TU2 tanks, AREVA

site in Pierrelatte

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Plasma cutting

• Advantages

• Quick

• Easy to handle

• Could be used underwater

• Drawbacks

• Hot (dispersion)

• Not easy to operate remotely

• Limited thickness (about 50mm, depending on

the power of the torch)

Dismantling of Chooz A gallery to the grass

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Other cutting technologies

• Laser

• Thickness up to 100mm

• Low emission of airborne particles

• High pressure water jetting

• 3000 to 5000 bars

• With abrasive

• For steel and concrete

• Hydraulic splitters

• For concrete

• Bore holes, put a splitter in each

• The concrete slab breaks

• Expansive cement can be use instead of

hydraulic splitter

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Dismantling technologies,

field experience and examples

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The most popular dismantling technology

• Rock climbing!

• Very sloppy gallery in Chooz A

(underground power reactor)

• From the reactor cave to the grass

• We dismantled the gallery in 2006

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Dismantling of the technical gallery 001

• Remote operation

• Brokk (vehicle) with different tools

• Disk saw

• Vacuum cleaner with rotating brushes

• High pressure water jetting tool with camera

and lightning

• Gripper

• Waste bucket

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Dismantling of the DMC

• Remote operation

• Hydraulic manipulator (HIAB), with:

• A specific wrist

• A bucket

• Hydraulic drill

• Cutting rail

• 600kg at 10m

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Large dismantlings

• Conventional excavator, modified for operating in a nuclear environment

• Electric powering (no emission of toxic gases)

• Remote operation

• Used at CEA Grenoble and at SICN Veurey

Plastic containment covering the building

under dismantling

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Dismantling of the Vibratechnic

• Between remote and hands on operation

Sas en dur Sas vinyle

Pot blindéégoutures

T H P

CameraTete de lançage

Platelageblindé

Récupération effluents et déchets

Principe dedécontamination des vis

Poste decontrôle

commandeexterieur

Poste de contrôle interne

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Dismantling of the dissolvers

• Main features of the work:

• Duration : 6,5 years (2011 – 2018)

• 15,000 h engineering, including safety cases

• 11t of primary waste

• 60t of secondary waste

• Maestro manipulator:

• Develloped by CEA and Cybernetix

• Hydraulic

• Master and slave manipulators

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3D modelling

• Check that the design fits the installation (room is sufficient, movements are possible)

• Good support for dialog with the client and with the authorities

• Simulation of the lightening

• Training

• Evaluation and optimization of the productivity.

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DFD: decontamination for dismantling

• EPRI patent

• Bradtec (now Onet Technologies subsidiary) designed the

process on behalf of EPRI

• OT has a licence

• Full system decontamination

• Bradtec participated to Main Yankee, Big Rock Point and

Zorita

• OT is preparing Bohunice (Slovakia), for FSD in 2014

• Dose saving: connect the system to the primary (main)

loops, and then the chemistry transfers the activity from

the circuits to ion exchange resins, without hands on

work.

• In bath decontamination

• Free release of metallic scraps

• System available in UK

• Waste optimization

• Small amount of resins

• May be regenerated : the waste is a liquid concentrate

• The concentrate may be solidified for final disposal.

Pump skid

Resins skids

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Concrete decontamination

• Mechanical scabbling: ATUE

(CEA/Cadarache, 30,000m2)

• Hammer (thick layers)

• Rotating shaver (thin layers)

• Shot blasting (thin layers)

• High pressure water jetting:

FBFC Pierrelatte, 5000m2

• From 100 to 2500 bars

• Laser

• 10m2/h, 1cm

Water jetting

Floor scabbling or shaving

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Thank you for your attention