# Presentation: 576432

## FIRE Vacuum Vessel and Remote Handling Overview

**B. Nelson, T. Burgess, T. Brown, D. Driemeyer, H-M Fan, K. Freudenberg, G. Jones, C. Kessel, P. Ryan, M. Sawan, M. Ulrickson, D. Strickler, **
**D. Williamson**
**FIRE Physics Validation Review**
**March 31, 2004**

## Presentation Outline 

**Vacuum Vessel**
- Design requirements
- Design concept and features
- Analysis to date
- Status and summary
**Remote Handling**
- Maintenance Approach & Component Classification
- In-Vessel Transporter
- Component Replacement Time Estimates
- Balance of RH Equipment
***Design and analysis are consistent with pre-conceptual phase, but demonstrate basic feasibility of concepts***

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## FIRE vacuum vessel

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vacuum vessel functions

**Plasma vacuum environment**
**Primary tritium confinement boundary**
**Support for in-vessel components**
**Radiation shielding**
**Aid in plasma stabilization**
- conducting shell
- internal control coils
**Maximum access for heating/diagnostics**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vacuum vessel parameters

**Configuration: ****	****	****	**Double wall torus
- Shielding 				water + steel with 60% packing factor
- Volume of torus interior		53 m^3
- Surface Area of torus interior		112 m^2
- Facesheet thickness			15 mm
- Rib thickness			15 - 30 mm
- Weight of structure, incl ports		 65 tonnes
- Weight of torus shielding		100 tonnes
**Coolant**
- Normal Operation			Water, < 100C, < 1 Mpa
- Bake-out				Water ~150C, < 1 Mpa
**Materials**
- Torus, ports and structure		316LN ss
- Shielding				304L ss (tentative)

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vessel port configuration

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vessel ports and major components

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Nuclear shielding concept

- Vessel shielding, port plugs and TF coils provide hands-on access to port flanges
- Port plugs weigh ~7 tonnes each as shown, assuming 60% steel out to TF boundary

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Active and passive stabilizing sys.

**Active control coils, segmented into octants**

**IB and OB passive stabilizing conductor**

**passive plates ~25 mm thick copper with integral cooling**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Passive conductor is also heat sink

**Copper layer required to prevent large temperature gradients in VV due to nuclear heating, PFCs**
**Passive plates are required in most locations anyway**
**PFCs are conduction cooled to copper layer**
- Reduces gradient in stainless skin
- Extends pulse length

- VV

- PFC Tile

- Cu Passive stabilizer

- Cu filler (can be removed to allow space for mag. diag.)

- Gasket

- VV splice plate

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## FIRE and ITER first wall concepts similar

- BE, Cu, SSt
- Detachable FW panel
- Cooling integral with FW panel (requires coolant connections to FW)

**ITER**

**FIRE**

- BE, Cu, SSt
- Detachable FW tiles
- Cooling integral with Cu bonded to VV

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## VV octant subassy w/passive structure 

**Vessel octant prior to welding outer skin between ribs**

**Outboard passive conductor**

**Inboard passive cond.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vessel octant subassembly fab. (2) 

- Vessel octant subassembly fab. (2)

- Octant-to-octant splice joint requires double wall weld
- All welding done from plasma side of vessel
- Splice plates used on plasma side only to take up tolerance and provide clearance
- Plasma side splice plate wide enough to accommodate welding the coil side joint

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vessel analysis

**Vessel subjected to numerous loading conditions**
- Normal operation (gravity, coolant pressure, thermal loads, etc.)
- Disruption (including induced and conductive (halo) loads
- Other loads (TF current ramp, seismic, etc.)
**Preliminary FEA analysis performed **
- Linear, static stress analysis
- Linear, transient and static thermal analyses
**Main issues are disruption loads, thermal stresses**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Vacuum vessel mechanical loads

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Disruption effects on VV

**Disruptions will cause high loads on the VV due to induced currents and conducting (halo) currents flowing in structures **
- Direct loads on vessel shell and ribs
- Direct loads on passive plates
- Reaction loads at supports for internal components
- Divertor assemblies and piping
- FW tiles
- Port plugs / in-port components (e.g. RF antennas)
**Dynamic effects should be considered, including:**
- Transient load application
- Shock loads due to gaps in load paths (gaps must be avoided)
**All loads should be considered in appropriate combinations**
**      **e.g. Gravity + coolant pressure + VDE + nuclear / PFC heating + Seismic + ...

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## TSC runs confirm induced currents will concentrate in passive structures

**Several TSC disruption simulations prepared by C. Kessel**

**VDE simulation used as basis for further analysis**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## VDE analysis based on TSC runs

**TSC output used to create drivers for Eddycuff model of VV**
**Peak loads applied to ANSYS model of VV**
**Halo loads from TSC mapped directly onto VV model**

- Copper
- Plates

- Inner
- Face
- Sheet

- Outer
- Face
- Sheet

- EDDYCUFF EM Model

- ANSYS Structural Model

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Plasma Evolution (TSC), from earlier data

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Typical Induced Eddy Currents 

- Constant Current Vectors

- Proportional Current Vectors

- Typical Induced Eddy Currents

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Current vs Time, Slow VDE (1 MA/ms)

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Typical EM loads due to Induced Current

-  Max force = -1 MN radial, +0.7 MN vertical per 1/16 sector (~11 MN tot)

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Total Force vs time, induced + halo currents

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Typ. EM Force distr. due to Halo Current

-  Mapped directly from TSC to ANSYS, Halo current = 12-25% Ip
-  Max force = +0.13 MN radial, +1.2 MN vert. per 1/16 sector

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Divertor loads from current loop

**Loads based on PC-Opera analysis  ****ref  Driemeyer, Ulrickson*

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Combined stress, with VDE

**Stresses due to gravity, coolant pressure, vacuum, VDE**
**VDE load includes direct EM loads on vessel (induced current and halo) and non-halo divertor loads**

- 1.5Sm = 28 ksi (195 Mpa)

- VV Torus

- Ports

**Stress is in psi**

**Stress is in psi**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Divertor attachment local stresses

**Global model not adequate for analysis**
**Detailed model indicates adequate design**

- Stress is in psi

- 1.5Sm = 28ksi (195 Mpa)

- Reinforced  pins near connection points

- Increased hole Diameter to 0.7”

- Modified rib thickness to correct values

- Extended pins through the ribs and attached them to the outer shell

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Nuclear heating and thermal effects

**Vacuum vessel is subject to two basic heat loads:**
- Direct nuclear heating from neutrons and gammas
- Heating by conduction from first wall tiles (which in turn are heated by direct nuclear heating and surface heat flux)
**A range of operating scenarios is possible, but the baseline cases for analysis assume:**
- 150 MW fusion power
- 100 W/cm^2 surface heat load assumed on first wall,
*45 W/cm^2 is current baseline* (H-mode)
- > 45 *W/cm^2  *for AT modes
- pulse length of 20 seconds (H-mode - 10T, 7.7 MA)
- Pulse length of 40-ish seconds (AT mode - 6.5T, 5 MA)
**Vessel is cooled by water**
- Flowing in copper first wall cladding
- Flowing between walls of double wall structure

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Heat loads on vessel and FEA model

**Fusion power of 150 MW**
**Surface heat flux is variable, 0, 50,100, and 150 W/cm****2 **** analyzed**

**D**

**C**

**B**

- Tile,    (36 mm)

- Cu cladding

- Double wall Vac Vessel

**A**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## 2-D temp distr (100W/cm2 surface flux)

**Inboard midplane****	****	****	****Outboard midplane**

**20 s pulse**

**40 s pulse**

**377 C**

**619 C**

**622 C**

**383 C**

**Be limit ~ 600C**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Peak Be temp vs heat flux, pulse length

- Be limit

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Nuclear heating distribution*

*** ****Ref M. Sawan**

**Neutron wall loading **
**Volumetric heating:**
**  ****plasma side, ss**
**  ****coil side, ss**
**  ****divertor**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Typical 3-D temp distribution in VV 

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## VV thermal deformation and stress

**High stress region localized**
**Stress < 3xSm ( 56 ksi)**

**Typical Deformation**

**Peak**

**Stress is in psi**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Combined stresses, 40 s pulse

**Nuclear heating, gravity, coolant pressure, vacuum**

**Max Stress = 23 ksi, < 3Sm (56ksi) ****	****Max Deflection = 0.041 in.**

**Stress is in psi**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Combined stress, 10T, 7.7MA, 20 s pulse, with VDE is worst loading condition

**Nuclear heating, gravity, coolant pressure, vacuum, slow VDE**

- Stress is in psi

**Stress is in psi**

**3xSm**

**Max Stress = 58 ksi, > 3Sm (56ksi), but very localized **

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Combined stress, 6.5T, 5 MA, 40 s pulse, with VDE – not as severe as high field case

**Nuclear heating, gravity, coolant pressure, vacuum, slow VDE**

**Stress is in psi**

**Max Stress = 46 ksi, < 3Sm (56ksi), also very localized **

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Preliminary VV stress summary (1)

**Normal, High field (10T, 7.7 MA), 20 s pulse operation – ****O.K.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Preliminary VV stress summary (2)

**High field (10T, 7.7 MA), 20 s pulse with VDE – *****a little high***

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Preliminary VV stress summary (3)

**Normal, Low field (6.5T, 5 MA), 40 s pulse operation – ****O.K.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Preliminary VV stress summary (4)

**Low field (6.5T, 5 MA), 40 s pulse with VDE – ****O.K.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Conclusions of vessel analysis

**Can vessel achieve normal operation?  YES**
**Can vessel achieve pulse length?  YES**
- 20 second pulse appears achievable
- 40 second pulse should be achievable but depends on surface heat flux distribution and Be temperature
**Can vessel take disruption loads?   ITS CLOSE**
- Some local stresses over limit, but local reinforcement is possible
- Additional load cases must be run

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## What analysis tasks are next?

**Optimized geometry and refined FEA models**
**Dynamic analysis with temporal distribution of VDE loads**
**Fatigue analysis, including plastic effects**
**Seismic analysis**
**Plastic analysis**
**Limit analysis**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Longer term issues for FIRE

**Refine design**
- Develop design of generic port plug
- Optimize divertor attachments for stress, remote handling
- Design internal plumbing and shielding
- Re-design / optimize gravity supports
**Perform needed R&D**
- Select/verify method for bonding of copper cladding to vessel skin
- Select/verify method for routing of cooling passages into and out of cladding
- Develop fabrication technique for in-wall active control coils
- Perform thermal and structural tests of prototype vessel wall, with cladding, tubes, tiles, etc. (need test facility)
- Verify assembly welding of octants and tooling for remote disassembly/reassembly (need test facility)

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Handling Overview

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Handling*

**Maintenance Approach & Component Classification**
**In-Vessel Transporter**
**Component Replacement Time Estimates**
**Balance of RH Equipment**
- *ref T. Burgess

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Maintenance Approach

**Hands-on maintenance employed to the fullest extent possible.  Activation levels outside vacuum vessel are low enough to permit hands-on maintenance.**
**In-vessel components removed as integral assemblies and transferred to the hot cell for repair or processing as waste.**
**In-vessel contamination contained by sealed transfer casks that dock to the VV ports.**
**Midplane ports provide access to divertor, FW and limiter modules.  Port mounted systems (heating and diagnostics) are housed in a shielded assembly that is removed at the port interface.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Maintenance Approach (2)

**Upper and lower auxiliary ports house diagnostic and cryopump assemblies that are also removable at the port interface.**
**Remote operations begin with disassembly of port assembly closure plate.**
**During extended in-vessel operations (e.g., divertor changeout), a shielded enclosure is installed at the open midplane port to allow human access to the ex-vessel region.**
**Remote maintenance drives in-vessel component design and interfaces.  Components are given a classification and preliminary requirements are being accommodated in the layout of facilities and the site.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Handling,Classification of Components

*** Activation levels acceptable for hands-on maintenance**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## In-Vessel Remote Handling Transporter

**	****Cantilevered Articulated Boom (± 45° coverage)**
**	**
**Complete in-vessel coverage from 4 midplane ports.**
**	**
**Local repair from any midplane port.**
**	**
**Handles divertor, FW modules, limiter (with component specific end-effector).**
**	**
**Transfer cask docks and seals to VV port and hot cell interfaces to prevent spread of contamination.**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Port plug designed for RH

**VV to Cryostat seal**

**VV port flange**

**Midplane port plug**

**Connecting plate**

**Cryostat panel**

**Plug uses ITER-style connection to vessel, accommodates transfer cask**

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## In-Vessel Remote Handling (2)

- Divertor and baffle handled as one unit

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Six (6) positioning degrees of freedom provided by boom (2 DOF) and end-effector (4 DOF)
 Module weight = 800 kg

** ****Module weight = 800 kg**

- Divertor Handling End-Effector

- Transport position

- Installation position

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Component Maintenance Frequency and Time Estimates

- * Includes active remote maintenance time only.  Actual machine shutdown period will be longer by ~ > 1 month.
- ** Based on single divertor module replacement time estimate.
- † Based on midplane port replacement time estimate.

| Component or Operation  | RH Class  | Expected Frequency  | Maintenance Time Estimate*  |
| --- | --- | --- | --- |
| Divertor Modules  | 1 | TBD replacements
> 2  | One module: 3.3 weeks |
| Limiter Modules  |  |  | All (32) modules: 5.9 months |
| Midplane Port Assemblies |  |  | One module: 3.3 weeks |
| In-vessel Inspection |  | Frequent deployment  | Bank (5?) modules: 3.5 weeks |
| FW Modules | 2 | TBD replacements
≤ 2  | One module: 3.3 weeks** |
| Combined FW and Divertor Modules |  |  | All (#TBD) modules: TBD |
| Auxiliary Port Assemblies † |  |  | 12 month time target |
| Vacuum Vessel Sector with TF Coil | 3 | Replacement not expected
 | TBD, replacement must be possible and would require extended shutdown |
| Passive Plates |  |  |  |
| In-Vessel Cooling Pipes |  |  |  |

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Handling Equipment Summary 

**In-Vessel Component Handling System**
- In-vessel transporter (boom), viewing system and end-effectors (3) for: divertor module, first wall / limiter module and general purpose manipulator
**In-Vessel Inspection System**
-  Vacuum compatible metrology and viewing system probes for inspecting PFC alignment, and erosion or general viewing of condition
-  One of each probe type (metrology and viewing) initially procured
**	**
**Port-Mounted Component Handling Systems**
-  Port assembly transporters (2) with viewing system and dexterous manipulator for handling port attachment and vacuum lip-seal tools
- Includes midplane and auxiliary port handling systems

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Remote Handling Equipment Summary (2)

**Component & Equipment Containment and Transfer Devices**
- Cask containment enclosures (3) for IVT, midplane and auxiliary port
- Double seal doors in casks with docking interfaces at ports and hot cell interfaces
-  Cask transport (overhead crane or air cushion vehicles TBD) and support systems
- Portable shielded enclosure (1) for midplane port extended opening
**Remote Tooling**
- Laser based cutting, welding and inspection (leak detection) tools for:
**vacuum lip-seal at vessel port assemblies (2 sets)**
**divertor and limiter coolant pipes (2 sets)**
-  Fastener torquing and runner tools (2 sets)
**	**
**Fire Site Mock-Up**
-  Prototype remote handling systems used for developing designs are ultimately used at FIRE site to test equipment modifications, procedures and train operators
- Consists of prototypes of all major remote handling systems and component mock-ups (provided by component design WBS)

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004

## Some generic issues for ITER/FIRE

**Develop ASME code for Fusion (Section III, Division 4) to avoid force fitting designs to Section III**
**Develop remote, in-vessel inspection systems**
- leak detection
- metrology
- Detection of incipient failure modes, like cracks
**Create a qualification / test facility for in-vessel and in-port components to quantify and improve RAM**
- Thermal environment
- Vacuum environment
- Mechanical loading, shock, fatigue
- Remote handling capability

- FIRE Physics Validation Review: Vacuum Vessel and Remote Handling

- 31 March 2004