TOKAMAK ARCHITECTURE FOR PRACTICAL REMOTE MAINTENANCE

Transcription

1 TOKAMAK ARCHITECTURE FOR PRACTICAL REMOTE MAINTENANCE ERIC VILLEDIEU IAEA WORKSHOP DAEJEON KOREA 2018, 7 TH 10 TH OF MAY ISFNT September 2O15 PAGE 1

2 CONTENT o o Problematic CFETR exercice Tokamak design modification proposal Magnet design Vacuum vessel Blanket modules Divertor cassettes Hot cells arrangement In-vessel components maintenance Blanket Divertor Remote handling equipment Port plug maintenance In-Cryostat maintenance o o Inspection Discussion PAGE 2

3 PROBLEMATIC Experimental tokamaks Designed for physics / Conventional maintenance (except JET) DEMO tokamak = Nuclear Facility Radiation - Remote operations - Bioshielding Contamination - Confinement - Transfert systems Safety - Control PAGE 3

4 PROBLEMATIC DEMO tokamak = Power station demonstrator Reliability - Complexity Availability - Maintenance time DEMO tokamaks Designed for remote maintenance PAGE 4

5 PROBLEMATIC Main design drivers Keep it simple o o Tokamak RH equipment Minimize maintenance operations Minimize transfers Ease control operations Adress and trade off all these points together PAGE 5

6 PROBLEMATIC Horizontal Maintenance ARIES, SLIMCS, PAGE 6

7 PROBLEMATIC From Horizontal to Vertical Maintenance Demo horizontal maintenance analysis Need to remove auxiliary equipment Need for very large casks Issues with structural support for overturning loads. PAGE 7

8 PROBLEMATIC Vertical Maintenance Main DEMO projects (present consensus) EU DEMO, KDEMO, JA DEMO, CFETR PAGE 8

9 Review of a preliminary design from a maintenance point of view and propose modification of the tokamak component to facilitate and speed-up the remote operations PAGE 9

10 TOKAMAK DESIGN MODIFICATION PROPOSAL MAGNETS Previous configuration 16 TF coils New configuration 12 TF coils The maintenance concept will be based on vertical handling of large components Advantage of large vertical ports Proposal: Increase of the top PF coil diameter 12 instead of 16 TF coils Validation: PF conductor technology compatible with the increased field TF ripple compatible with the 12 coils configuration PAGE 10

11 TOKAMAK DESIGN MODIFICATION PROPOSAL VACUUM VESSEL Minimization of maintenance port number PAGE 11

12 TOKAMAK DESIGN MODIFICATION PROPOSAL BLANKETS Previous configuration 4 blocs design Standard blanket New configuration Monobloc design Maintenance port blanket Compartmented pipes to individually control the breeding modules cooling PAGE 12

13 PIPE CONNECTION KDemo EU Demo PAGE 13

14 TOKAMAK DESIGN MODIFICATION PROPOSAL BLANKETS Pipe arrangement Toroidal corridor zone for robot access PAGE 14

15 TOKAMAK DESIGN MODIFICATION PROPOSAL BLANKETS Strong configuration with respect of the electromagnetic moments Direct mechanical force path at the botom of the vessel avoiding large forces on the vessel walls No need for flexible attachment PAGE 15

16 TOKAMAK DESIGN MODIFICATION PROPOSAL DIVERTOR Divertor cassette Pipe arrangement PAGE 16

17 TOKAMAK DESIGN MODIFICATION PROPOSAL HOT CELLS A top hot cell in direct communication with the Maintenance hot cell and the Remote handling tool hot cell. Contamination free circular corridor and pits for the cask transport transfers Hybrid linear and circular cranes for all transfers of tools and tokamak components PAGE 17

18 IN-VESSEL COMPONENTS MAINTENANCE BLANKETS AND DIVERTOR PAGE 18

19 IN-VESSEL COMPONENTS MAINTENANCE MAINTENANCE PORT BLANKET AND DIVERTOR PAGE 19

20 IN-VESSEL COMPONENTS MAINTENANCE MAINTENANCE PORT OPENING ANIMATION PAGE 20

21 IN-VESSEL COMPONENTS MAINTENANCE MAINTENANCE PORT BLANKET AND DIVERTOR PAGE 21

22 IN-VESSEL COMPONENTS MAINTENANCE FIRST BLANKET AND DIVERTOR REMOVAL ANIMATION PAGE 22

23 IN-VESSEL COMPONENTS MAINTENANCE STANDARD DIVERTOR PAGE 23

24 IN-VESSEL COMPONENTS MAINTENANCE STANDARD DIVERTOR An alternative solution is a conventionnal maintenance using the lower ports PAGE 24

25 IN-VESSEL COMPONENTS MAINTENANCE STANDARD BLANKET PAGE 25

26 IN-VESSEL COMPONENTS MAINTENANCE STANDARD BLANKET PAGE 26

27 IN-VESSEL COMPONENTS MAINTENANCE CFETR Exercice STANDARD DIVERTOR and BLANKET REMOVAL ANIMATION PAGE 27

28 IN-VESSEL COMPONENTS MAINTENANCE REMOTE HANDLING EQUIPMENT A crane system PAGE 28

29 IN-VESSEL COMPONENTS MAINTENANCE REMOTE HANDLING EQUIPMENT A manipulation system PAGE 29

30 IN-VESSEL COMPONENTS MAINTENANCE REMOTE HANDLING EQUIPMENT A top blanket handling system PAGE 30

31 IN-VESSEL COMPONENTS MAINTENANCE REMOTE HANDLING EQUIPMENT A lower Divertor and blanket handling system PAGE 31

32 IN-VESSEL COMPONENTS MAINTENANCE REMOTE HANDLING EQUIPMENT Lower Divertor and blanket handling system equipped with the blanket handling tool and the dexterous manipulators PAGE 32

33 PORT PLUG MAINTENANCE CFETR Exercice Problematics: Plug bodies are contaminated Plug rear side connections are clean Removal from inside hard to envisage Use of transfer casks to move the plugs to/from the vessel to the maintenance hot cell Corridors and pits are kept clean by a careful management of the contamination with double door interfaces PAGE 33

34 PORT PLUG MAINTENANCE CONTAMINATION PROTECTION MANAGEMENT PAGE 34

35 PORT PLUG MAINTENANCE CONTAMINATION PROTECTION MANAGEMENT Plug in «hot-cell» configuration Hydraulic actuation of the double-doors system PAGE 35

36 PORT PLUG MAINTENANCE CFETR Exercice Plug extraction process PAGE 36

37 PORT PLUG MAINTENANCE PORT PLUG REMOVAL ANIMATION PAGE 37

38 IN-CRYOSTAT MAINTENANCE CFETR Exercice Minimization of active components inside the bioshield Human access inside the cryostat possible Design to be compatible for easy access opening in case need PAGE 38

39 CONCLUSION CFETR Exercice From a preliminary design of CFETR a first round of remote maintenance analysis has provided innovative solutions with: Vertical extraction of blanket and divertor modules with direct transfer to the hot cells Reliable crane based carrier system Contamination free port plug management In-cryostat bioshielding proposal Further analysis is required to propose solutions for: Umbilicus management of all the remote maintenance equipment Maintenance of the thermal shielding in between coils and vacuum vessel In-cryostat bioshielding modularity Rescue of any maintenance operation Several iterations will be needed to optimize the tokamak design PAGE 39

40 INSPECTION DEMO tokamak is a nuclear facility Safety regulation will apply As a general rule, confinement barriers must be regularly inspected The vacuum vessel is the first barrier of confinement Inspection of the VV welds in presence of the in-vessel component has been identified as a major problematic PAGE 40

41 DISCUSSION? How far the trade off between: vertical port dimension / blanket module dimension / magnet system feasibility? Direct visibility of the blanket modules from the vertical port vs toroidal transfer of the modules inside the VV? Direct hot cell transfer vs cask transfer, for the blanket modules, for the divertor cassettes? Quantity, type and size of the in-vessel fluid connections? Inspectability, other in-vessel maintenance operations? Nuclear regulation requirements? Rescue systems? Ex-vessel maintenance? Maintenance of the thermal shielding? Hands-on / remote maintenance boundary?.. PAGE 41