EUTFPWI Meeting 29-31/10/07 C.Lowry ITER Design Review Decisions Taken 5 Major Issues Identified 1.Blanket Redesign 2.Vertical Stability and Shape Control.

EUTFPWI Meeting 29-31/10/07 C.Lowry

ITER Design Review

“Decisions Taken”

5 Major Issues Identified

1. Blanket Redesign

2. Vertical Stability and Shape Control

3. ELM and RWM Coils

4. Hot Cell and Test Requirements

5. Tritium and Dust

EUTFPWI Meeting 29-31/10/07 C.Lowry

Blanket Re-design

Main Issues with Blanket Design

• Refinement of Power Handling Requirements

• Installation and Remote Handling

Constraints

• Keep vacuum vessel interfaces fixed

• Minimise changes to the baseline design

EUTFPWI Meeting 29-31/10/07 C.Lowry

Steady State Wall Loads

Parallel (װ)

Perpendicular (┴)

~1°

Start-up & Ramp-down װ MW 15 15 8

Type of Interaction Units 2001 PID Latest Proposal

Outer Midplane

Radiation ┴ MWm-2 0.5 0.5 0.5

Power Conducted between ELMs

װ MWm-2 None None 3

Power Conducted by ELMs

װ MWm-2 None 0.93 2.5 (3.4)

Energy Conducted by ELMs

װ MJm-2 None 0.19 (0.93) 0.06 (1.7)

Near second X-point

Radiation ┴ MWm-2 0.5 0.5 0.5

Power Conducted between ELMs

װ MWm-2 None None 5

Power Conducted by ELMs

װ MWm-2 None 3.8 33

Energy Conducted by ELMs

װ MJm-2 None 0.77 (3.8) 0.8 (17)

Baffle Region

MARFE ┴ MWm-2 1.3 1.4 0.6

-5

-4

-3

-2

-1

0

1

2

3

4

5

3 4 5 6 7 8 9

Z, m

R, m

ITER-FEAT

q=1.5

q=2.0

q=2.5

q=3.0

Scenario #2

EUTFPWI Meeting 29-31/10/07 C.Lowry

Wall Loads due to Off-normal events

Parallel (װ)

Perpendicular (┴)

~1°

Type of Interaction Units 2001 PID Latest Proposal(In progress)

Plasma position perturbation

װ MWm-2 None None 150-250

Disruption TQ

General װ

┴

MJm-2 0.36 1.6-18+ 0.24-0.48

1.1-18

Near second X-point װ

┴

MJm-2 None 40-90+ 0.24-0.48

28-45

Disruption CQ ┴ MJm-2 0.72 2.5

VDE

Energy ┴ MJm-2 60 60 None

Energy װ MJm-2 None None 100-680

Power װ MWm-2 None None 600

EUTFPWI Meeting 29-31/10/07 C.Lowry

Design Philosophy

Shape first wall to shadow exposed edges

Improve the hydraulic connector by providing larger access hole

Details:

Ports

18 poloidal bands of advanced standard modules

~100mm

8% or less degradation in power handling at upper X-point

EUTFPWI Meeting 29-31/10/07 C.Lowry

Concept Under Construction

Wall start-up is being considered, and first indications are encouraging

An in-vessel detachable first wall has several advantages, and is being pursued

EUTFPWI Meeting 29-31/10/07 C.Lowry

0 2 4 6 8 10 12 14-6

-4

-2

0

2

4

6

Original Shape

Modified ShapeShifted inward by 9 cm

li=1.1 – SOF 15 MA – full kInward shift = 9cmReference VS (6kV)

Instability growth time goes from 71ms 37ms

Outside control range, the plasma is vertically unstable

Vertical Stabilisation and Plasma Position and Shape Control

G.Saibene

EUTFPWI Meeting 29-31/10/07 C.Lowry

Fast H-L transition ( loss in 1-2 s IW contact for up to ~ 5s) can lead to

large loads on the inner wall

0 5 10 15-0.10

-0.05

0.00

0.05

0.10

0.15

0.20 distance P

SOL

qII,wall

X Axis Title

Inn

er

Wa

ll/S

ep

ara

trix

Dis

tan

ce (

m)

0

50

100

150

200

250

300 PS

OL (M

W) q

II,wall (M

Wm

-2)

Vertical Stabilisation and Plasma Position and Shape Control

A.Loarte

EUTFPWI Meeting 29-31/10/07 C.Lowry

Vertical Stabilisation and Plasma Position and Shape Control

Stabilisation

• Increased Voltage Possibility was excluded on grounds of coil reliability

• Passive stabilisation being investigated, starting with assessment of forces

EUTFPWI Meeting 29-31/10/07 C.Lowry

ELM and RWM Coils

Wall Mounted Option

Picture frame Concept

Port Coil Concept

Port plugs to be designed to allow retro-fit

EUTFPWI Meeting 29-31/10/07 C.Lowry

Tritium and Dust

Design Change Requests were submitted regarding both the measurement and removal of tritium and dust, and accepted for study DCR’s 131 and 106

The importance of these issues was accepted, and C.Alejaldre, the DDG for Safety and Security has been charged to coordinate these activities and propose a workable solution.

ITER material strategy

Start ITER with carbon divertor and Be wall to allow a wide range of scoping studies

Change to a W divertor before the end of the non-active phase to allow characterisation of the divertor prior to the active phase

Watch This Space !

EUTFPWI Meeting 29-31/10/07 C.Lowry

EUTFPWI Meeting 29-31/10/07 C.Lowry