Dismantling Techniques applied at MZFR - Nuclear … Workshop, Karlsruhe Research Center, July 6th –10th, 2009, E. Prechtl 2 Nachhaltiger Rückbau: NPP and Prototype Reactors in

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Wiederaufarbeitungsanlage Karlsruhe Rückbau- und Entsorgungs- GmbH

The The DecommissioningDecommissioning Project Project MultiMulti--PurposePurpose Research Research ReactorReactor

( MZFR ) ( MZFR )

Dismantling Techniques applied at MZFR Dismantling Techniques applied at MZFR

E. PrechtlProjekt MZFRWAK GmbH

Research Reactor Decommissioning Demonstration Project (R²D²P)IAEA Workshop “Decommissioning Technologies”

Forschungszentrum Karlsruhe 6 – 10 Juli 2009

2IAEA Workshop, Karlsruhe Research Center, July 6th – 10th, 2009, E. Prechtl

Nachhaltiger Rückbau: NPP and Prototype NPP and Prototype ReactorsReactors in Germany in Germany ( > 20 ( > 20 MWeMWe ))

Nuclear Facilitiesin the formerresponsibility of Karlsruhe Research Center and EWN, sinceJuly 1st 2009: EWN

NPP in Operation: 17

NPP and Prototype Reactors underDecommissioning: 15

NPP and Prototype Reactors in safeEnclosure: 3

Prototype NPP complete dismantled: 2


FR 2 Research Reactor

Safe enclosure

Central Waste Treatment

Department

HDB

Compact Sodium-Cooled Nuclear

Reactor

KNK

Multi-Purpose Research ReactorMZFR

Karlsruhe Reprocessing Plant

WAK(VEK)

Superheated Steam Reactor at Karlstein

Green field

HDR

Green field

NiederaichbachNuclear Power Station

KKN

DecommissioningDecommissioning Projects on Site of Projects on Site of thetheKarlsruhe Research CenterKarlsruhe Research Center

( incl. ( incl. DismantledDismantled FacilitiesFacilities KKN and HDR, State of Bavaria )KKN and HDR, State of Bavaria )


Type: Pressurized water reactorHeavy water moderated and cooled

Power: 200 MWth, 57 MWel (242 fuel elements)

Erection: 1961 - 1965

Operation: 1965 – 1984Purposes: → Development and testing of nuclear

materials→ Testing of heavy water systems→ Testing of fuel elements→ Staff training

Decommissioning: 1987 – 2013

Decom. Strategy: Dismantling and Removal in 8 steps (= 8 partial licences)

Objective: Green field (IAEA Level 3)

MultiMulti-- PurposePurpose Research Research ReactorReactor ( MZFR ):( MZFR ):BasicsBasics


Perform the work safely(radiological and non-radiological)

Dose minimization(but as low as reasonably achieviable „ALARA“)

Cost reduction as much as reasonably possible

Waste minimization

„KIS“- principle ( keep it simple )

MZFR MZFR DecommissioningDecommissioning: : Fundamental Goals of DismantlingFundamental Goals of Dismantling


The Main Basic The Main Basic ObjectivObjectiv: : SafetySafety

Radiation Protection: workers, population, environment

Technical Safety:selecting and developing dismantling techniquesselecting and developing handling techniques


TypicalTypical RadiologicalRadiological and and Non Non –– RadiologicalRadiological HazardsHazards

High Dose RatesKontaminationChemical exposure: asbestos, etc. Welding and cutting: fireOperation of heavy equipment and power toolsErgonomics: heavy equipment, lifting, etc.Explosives: facility, demolitionEnvironmental conditions: heat, cold, wet, slippery, limited visibilityConfined spaces


The activity level of the systems, componentsand partsThe selection of technologies depends also on the space conditionsThe physical/chemical properties of the systemsand comp. to be dismantled (e.g. metal, concrete) Radioisotopes and contamination layerThe type of isotopes present (Co60, H3, …)

MZFR Dismantling TechnologiesMZFR Dismantling Technologies

There is no single technique to address all dismantlingboundary conditions on the MZFR decommissioningproject, the techniques depends on


Remote controlled dismantling (dry)for large and activated RPV components (metal):Band saw; > 500 T€

Autogenius burner(flame cutting under air);~ 50 T€

MZFR Dismantling Technologies MZFR Dismantling Technologies ( ( contcont‘‘dd ))



Remote controlled dismantling (dry) foractivated metals and concrete (bioshield):RC jackhammer (excavator), with tools: ~ 1.500 T€


Under water remote controlled dismantling(thermal and electrical tec. for high activated metals):

Plasma Cutting (UW); toolcarrier, equipment: ~ 1.000 T€

CAMC (Contact arc metal cutting (UW), adapted: ~ 100 T€(without tool carrier)




Mech. hand held tools (activated and cont. metals) :Orbital saw (< 1 T€)

Hydraulic cutter (~ 2 T€)

Nibbler (tanks, ~ 5 T€)

Angle grinder(decontamination, < 500 €)

Mechanical saws (< 1 T€)


MZFR Dismantling / MZFR Dismantling / DecontaminationDecontamination Technologies Technologies

Contaminated concrete:Diamant wire saw (~50 T€)

Scarifier (~10 T€)

Hammers drills, Comb. Hammer (> 1 T€)

Air needle scaler (> 1 T€)


Controlled AreaRad. Prot. Area

MZFR Plant, 1987MZFR Plant, 1987( ( ActivityActivity InventoryInventory approxapprox. 5.0 E16 Bq ) . 5.0 E16 Bq )



MZFR Plant MZFR Plant ((contcont‘‘dd))

1992



1992




1996




1998




1999

1964: Pressure test at the manufacturer’s




2001




MZFR Plant, 2009MZFR Plant, 2009( ( ActivityActivity InventoryInventory approxapprox. 2.0 E13 Bq ). 2.0 E13 Bq )


• Mass: RPV – Total mass approx. 403 Mg

• Dimensions: Height: 7.7 m, Ø: 4.4 m

• Geometrical Conditions: Dismantling in present position(from top to bottom and from outside to inside)

• Dose Rate: DLCore-inside ≥ 11 Sv/h (01/1999)

• Radioactivity Inventory: Approx. E 16 Bq ( key nuclide: Co-60 )

• Packaging and Disposal: 178 casks and containers(104 type II Konrad containers and 74 MOSAIK casks), interim storage at the Central Waste Treatment Department (HDB)

RPV Dismantling: RPV Dismantling: ConditionsConditions at at thethe BeginningBeginning( Jan. 1999 )( Jan. 1999 )


Ventilation area

Packingarea

Band saw1: In intervention

area2: In dismantling

position

Dismantling table

RPV lid

Intervention area

Dismantling area

InstallationsInstallations on on ReactorReactor Building Level +10 m Building Level +10 m

Staffentrance

Lifting, moving, and sawing RPV componentsCut-off piecesSecondary waste

2 1

Ventilation

Repositorycasks .


Manual Dismantling of all Manual Dismantling of all ComponentsComponentsaboveabove thethe RPV RPV ( Dez. 1999 ( Dez. 1999 –– Feb. 2000 )Feb. 2000 )

BiologicalShield

Dismantling of• absorber rods, • guiding tubes, • measurement systems, etc.

Criteria: dose rate < 500 µSv/h


On the reactor lid: Dismantling of the absorber rod drives

On the reactor lid: Cutting of measurement tubes on the RPV lid

Manual Dismantling of all Manual Dismantling of all ComponentsComponentsaboveabove thethe RPV RPV ( Dez. 1999 ( Dez. 1999 –– Feb. 2000 )Feb. 2000 )


RemoteRemote OneOne--piecepiece Removal of Removal of thethe RodRod––shapedshapedComponentsComponents insideinside thethe RPV RPV ( April ( April –– Sept. 2000 )Sept. 2000 )

BiologicalShield

Coolingchannels, guidingtubes, etc.

272 components

212 local transfers and transports to HDB (cuttingin a hot cell)

Difficulty: 5 unremovablecooling channels


Five Five UnremovableUnremovable CoolingCooling ChannelsChannels: : Solution of Solution of thethe ProblemProblem

Leaving in core positionPlanning of back-updismantling technology:

Solution: Dismantling in theunderwater campaign(2004) with the hydraulicshears

BiologicalShield

Typical hazard: fragmentation


Removal and Removal and RemoteRemote Dismantling of Dismantling of thethe RPV LidRPV Lid( Band Saw, April ( Band Saw, April –– JulyJuly 2002 )2002 )

6: Manipulator system

1: Crane2: Support system3: Dismantling table4: Band saw5: Reactor

Longitudinal sectionof the dismantlingarea in reactorbuilding


Dismantling of the RPV lid bolts: Cutting off the 2 bolts, that could not be loosenened

PreparationPreparation of Removal and of Removal and RemoteRemoteDismantling of Dismantling of thethe RPV LidRPV Lid( Band Saw, April ( Band Saw, April –– JulyJuly 2002 )2002 )


Removal and Removal and RemoteRemote Dismantling of Dismantling of thethe RPV LidRPV Lid( Band Saw, April ( Band Saw, April –– JulyJuly 2002 )2002 )

BiologicalShield


Part I: Pulling up, transporting, and putting down onto the base structure

OptimizationOptimization of Safe Handling and of Safe Handling and Training, Trials, and Demonstration Training, Trials, and Demonstration withwith 1:1 Dummy 1:1 Dummy


Part II: Removal of the upper filler piece with base structure to core position (in case of interventions)

Training, Trials, and Demonstration Training, Trials, and Demonstration withwith 1:1 Dummy 1:1 Dummy


Upper Spacer

Removal and Removal and RemoteRemote Dismantling of Dismantling of thethe Upper Upper SpacerSpacer( Band Saw, ( Band Saw, DecDec. 2002 . 2002 –– April 2003 )April 2003 )

BiologicalShield

Optimizing the type of saw bandOptimizing the chip sucking systemOptimizing the grippers


40 t – Dismantling Crane

Sledge 1 withManipulator

RotatingRing

Sledge 2 with Tool Carrier and Plasma

Burner

Bridge Manipulator

Mast with2 Sledges

Tests and Qualifikation in an external Mock- up

Drying Unit

UnderwaterUnderwater Dismantling Equipment Dismantling Equipment ( ( ““WetWet dismantlingdismantling““ ))


Moderator Tank

RemoteRemote Dismantling of Dismantling of thethe Moderator Tank Moderator Tank ( RC Plasma ( RC Plasma CuttingCutting System, Sept. 2004 System, Sept. 2004 –– JuneJune 2005 )2005 )

BiologicalShield

1. Mock-up tests with dummies

2. Real remote dismantling


CoolingChannels

CuttingCutting of of thethe RemainingRemaining Five Five CoolingCooling ChannelsChannelsunderunder Water Water ( RC ( RC HydraulicHydraulic ShearsShears, Nov. 2004 ), Nov. 2004 )

BiologicalShield


Experience with Sediments Experience with Sediments and Slag Residuesand Slag Residues

Deposits between the upper round cover plate and stagnation sheets

Optimization of the cutting process

Deposits and slag residues on the moderator tank bottom:

Development of new tools


Segmentation of the Cylindrical Wall of the Segmentation of the Cylindrical Wall of the Moderator Tank: Experience with the Cladding Moderator Tank: Experience with the Cladding


Cleaning of the Moderator Tank Bottom Cleaning of the Moderator Tank Bottom before Cuttingbefore Cutting


11.01.200511.01.2005

14.01.200514.01.2005

The Importance of the The Importance of the WaterWater--Purifying SystemPurifying System

Change of filter Change of filter cartridges of the cartridges of the

waterwater--purifying purifying systemsystem


Thermal shield( five segments )

BiologicalShield

RC Dismantling of RC Dismantling of thethe Thermal Thermal ShieldShield( Plasma ( Plasma CuttingCutting System, System, JulyJuly –– OctOct. 2005 ). 2005 )


Boundary conditions: • Increase in wall thickness:

From 70 mm up to 130 mm• Gap between TS and RPV

body: Only 20 mm, filledwith slag and sediments

• No gap between TS and lower spacer (support)

Thermal shield

RPV body

Special Special RequirementsRequirements forfor RemoteRemote DismantlingDismantlingof of thethe Thermal Thermal ShieldShield, Segment No. Five, Segment No. Five

((contcont‘‘dd))


BackBack--upup Dismantling Dismantling TechniqueTechnique““ContactContact Arc Metal Arc Metal CuttingCutting““ ( CAMC ) ( Nov. 2005 )( CAMC ) ( Nov. 2005 )

Teaching, Cutting,

Preparation, Result:

((contcont‘‘dd))


Lifting and Lifting and RemoteRemote Dismantling of Dismantling of thetheLowerLower SpacerSpacer ( Band Saw, Jan. ( Band Saw, Jan. -- JulyJuly 2006 )2006 )

RPV body

Lower spacer (two pieces)BiologicalShield


Removing of the upper RPV insulation (11/2000)

Removing of the lower RPV insulation(03/2007)

RemovingRemoving of of thethe RPV RPV InsulationInsulation


Computer simulationRPV flange

Dismantling of Dismantling of thethe CylindricalCylindrical Part of Part of thethe RPV RPV ( ( AutogenousAutogenous BurnerBurner and Band Saw, and Band Saw, JuneJune –– Nov. 2007 )Nov. 2007 )

RPV

Real dismantling


Dismantling area

Dismantling of Dismantling of thethe RPV RPV BottomBottom( Band Saw, Nov. ( Band Saw, Nov. –– DecDec. 2007 ) . 2007 )

RPV bottom


MockMock-- up up dismantlingdismantling equipmentequipment in in thethe turbineturbine hall:hall:excavatorexcavator withwith dismantlingdismantling toolstools


MockMock-- up up dismantlingdismantling equipmentequipment in in thethe turbineturbine hall:hall:excavatorexcavator withwith dismantlingdismantling toolstools ((contcont‘‘dd))


DecontaminationDecontamination WorkWork in in thethe Pool Pool StorageStorage BuildingBuilding


DecontaminationDecontamination WorkWork in in thethe Pool Pool StorageStorage BuildingBuilding

DecontaminationDecontamination of of thetherecirculationrecirculation ventilationventilation

shaftsshafts


DecontaminationDecontamination of of thethe ConcreteConcrete ShieldingsShieldings


DismantlingDismantling and and DecontaminationDecontaminationin in thethe AuxiliaryAuxiliary BuildingBuilding

DismantlingDismantling of of thethe 200 m200 m33

liquid liquid wastewaste tank No. 4 (of 4)tank No. 4 (of 4)

MillingMilling of of thethecontaminatedcontaminatedscreedscreed

DismantlingDismantlingof of thethe tank tank basesbases


DismantlingDismantling and and DecontaminationDecontaminationin in thethe AuxiliaryAuxiliary Building: Building: completedcompleted areasareas


Waste Management: Containers, Waste Management: Containers, boxesboxes and and drumsdrums((forfor lowlow activeactive oror contaminatedcontaminated wastewaste ))

2020‘‘ Container andContainer and

1010‘‘ ContainerContainer200 l drum 200 l drum

Transport Transport boxesboxes


Waste Management: Waste Management: RepositoryRepository CaskCask Type PSC Type PSC –– V1V1( different ( different shieldingsshieldings forfor lowlow and and middlemiddle activeactive wastewaste ))

Shielding lid Concrete nozzle17

00

1600

Net weight: 14.5 Mg Max. Weight: 20.0 Mg

Price: 15 – 20 T€

Wall shielding[mm]:

Steel: 10 Concrete: 180 Steel: 70


Lid with shielding

Outer wall:cast iron withspheridiodalgraphit160 mm

Leadshielding: 60 / 80 mm

Net weight: 8.30 MgLoad: 0.52 MgPrice: 40 – 50 T€

1500

1060

Waste Management: Waste Management: RepositoryRepository CaskCask Type MOSAIKType MOSAIK( ( middlemiddle activactiv wastewaste ))


concept plan detail planning real(1995) (ab 1999) (2008)

Primary waste (disposal): approx. 403 MgSecondary waste (treatment): approx. 95 Mg, (approx. 80 Mg

contaminated water)Tertiary waste (new installations), decont. or reuse: approx. 250 Mg

Waste Waste MinimizationMinimization StepStep 7 7 ““RemoteRemote Dismantling Dismantling of of thethe RPV incl. RPV incl. InternalsInternals““


10851177

145219

318

0

Plan Real

6.SG 7.SG 8.SG

CollectiveCollective Dose, Dose, StepsSteps 6 to 8 [mSv] 6 to 8 [mSv] ( as of 31.12.2008 )( as of 31.12.2008 )

6.SG: Dismantling primary system

7.SG: Remote dismantling RPV

8.SG: Dismantling bioshield and plant decontamination


CollectiveCollective Dose of Dose of StepStep 7: RC Dismantling RPV + 7: RC Dismantling RPV + InternalsInternals( as of 31.12.2008 )( as of 31.12.2008 )

Plan: 1177 mSv, Ist: 318 mSv (27%)


nderungsanzeigen MZFR Gesamt / nur 7 SG von 1999 - 2008

hr Anzahl (7. SG) Gesamt1999 0 172000 14 382001 16 332002 7 332003 4 172004 6 232005 3 62006 4 122007 8 262008 0 8

0

17

14

38

16

33

7

33

4

17

6

23

3

64

12

8

26

0

8

02468

10121416182022242628303234363840

Anzahl

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Jahr

Änderungsanzeigen MZFR Gesamt / nur 7. SG von 1999 - 2008

7. SG

Gesamt

ModificationsModifications / Revision / Revision ProceduresProcedures underunder thetheAtomicAtomic LawLaw ((SupervisorySupervisory AuthorityAuthority ApprovalApproval) )

( 01/1999 ( 01/1999 –– 12/2008 )12/2008 )

Total: 208

Step 7 (RPV-Dis.): 62


970 Mg 400 MgMass of reactor

pressurevessel

11,500 MgMass of conta-minated systemand installations

3,500 Mg

157,000 Mg 44,000 MgMasses of buildings

2.6E17 Bq 3.6E16 Bq

Activity afterdefueling

DWR: 1300 MWel MZFR: 57 MWel

ComparisonComparison of MZFR Data of MZFR Data withwith ThoseThose of a of a ReferenceReference PWRPWR--TypeType Power Power ReactorReactor


Special Experience from MockSpecial Experience from Mock--up Testing and up Testing and the Underwater Cutting the Underwater Cutting

Elaboration, optimization, and implementation of the dismantling concept and objectives in close cooperation with industry, university and research institutes

Simulation of all cutting steps as a basis of a safe cutting procedure as well as for high availability and performance during mock-up tests and real cutting

3-D-simulation to demonstrate collision-free operation and accessibility of all cutting areas as well as implementation of locking and interlocking systems

Allow sufficient time for testing and training on a mock-up

Implementation of a powerful control unit for the process, parameter variations and documentation

High cutting flexibility by separate use of tool carrier and manipulator system

Elaboration and optimization of maintenance plan and repair strategies

Short technical examination periods of documentation and equipment for all relevant cutting steps in close cooperation with the independent experts starting with mock-up testing

Development of back-up techniques


8 partial atomic licences: High quality of application documents

New technical developments and designs necessary

High activity inventory: Remote dismantling techniques (mechanical and underwater thermal dismantling techniques)

Complete dismantling of the highly activated reactor

Mock-ups and simulations

Treatment of H3-contaminated concrete structures

Expected total collective dose: < 1 man Sv

Project costs: Approx. EUR 320 million

MZFR MZFR DecommissioningDecommissioning Project: Project: Short Short SummarySummary


Criteria for selection of dismantling tools and techniquesStaff safetyRadioprotection optimizationWaste minimization Cost reduction

Further criteria :Installation durationReliabilityMaintenance Waste minimizationReplacement equipment disposabilityNo primary criteria is the cutting speed

DismantlingDismantling TechniquesTechniques SummarySummary


Dismantling technologies are based on methods and processes applied in conventional areas

Special developments and optimizations are required to fulfilspecial boundary conditions and to reduce the costs

Remote dismantling of highly activated and contaminated RPV components is the technically most challenging step

Early planning and demonstration of the interaction of thehandling system and dismantling technologies in test rigsreduce the dismantling times and, hence, the costs

Advanced planning tools (3D simulation, modern control and robot techniques) increase the overall system availability

Experience gained from the dismantling of prototype facilitiesmay well be used for the dismantling of industrial NPPs

ConclusionsConclusions


The MZFR The MZFR –– Site Site todaytoday ………… and in and in thethe nearnear FutureFuture

ThankThank YouYou forforYourYour AttentionAttention !!

Documents

Dismantling Techniques applied at MZFR - Nuclear … Workshop, Karlsruhe Research Center, July 6th –10th, 2009, E. Prechtl 2 Nachhaltiger Rückbau: NPP and Prototype Reactors in