overview of the design and r&d of the iter blanket system

1ISFNT-10, Portland, OR, September 12-16, 2011

Overview of the Design and R&D of the ITER Blanket System

Presented by A. René RaffrayBlanket Section Leader

Blanket Integrated Product Team Leader ITER Organization, Cadarache, France

with contributions from M. Merola and members of the ITER Blanket Integrated Product Team

10th International Symposium on Fusion Nuclear Technology (ISFNT-10)Portland, OR, September 12-16, 2011

The views and opinions expressed herein do not necessarily reflect those of the ITER Organization

2

Blanket Effort Conducted within BIPT Blanket Integrated Product Team

ITER Organization

DA’s-

CN-

EU-

KO-

RF-

US

• Include resources from Domestic Agencies to help in major design and analysis effort.

• Direct involvement of procuring DA’s in design- Sense of design ownership- Would facilitate procurement

ISFNT-10, Portland, OR, September 12-16, 2011

3

Blanket System FunctionsMain functions of ITER Blanket System:

• Exhaust the majority of the plasma power.

• Contribute in providing neutron shielding to superconducting coils.

• Provide limiting surfaces that define the plasma boundary during startup and shutdown.


4

Mod

ules

1-6

Modules 7-10

Mod

ules

11-

18

~1240 – 2000 mm

~850

– 1

240

mm

Shield Block (semi-permanent) FW Panel (separable) Blanket Module50% 50% 50% 40%10%

Blanket System


http://www.iterkorea.org/

http://fusionforenergy.europa.eu/

http://www.iterrf.ru/

5

Blanket System Layout- The Blanket System

consists of Blanket Modules (BM) comprising two major components: a plasma facing First Wall (FW) panel and a Shield Block (SB).

- It covers ~600 m2.

- Cooling water (3 MPa and 70°C) is supplied to the BM by manifolds supported off the vacuum vessel behind or to the side of the SB.


6

Blanket Design• Major evolution since the ITER design review of 2007

- Need to account for large plasma heat fluxes to the first wall - Replacement of port limiter by first wall poloidal

limiters - Shaped first wall

- Need for efficient maintenance of first wall components. - Full replacement of FW at least once over ITER

lifetime - Remote Handling Class 1

• Design change presented at the Conceptual Design Review (CDR) in February 2010 and accepted in the ITER baseline in May 2010.

• Post-CDR effort focused on resolving key issues from CDR, particularly on improving the design of the first wall and shield block attachments to better accommodate the anticipated electromagnetic (EM) loads.


7

Blanket System in NumbersNumber of Blanket Modules: 440Max allowable mass per module: 4.5 tonsTotal Mass: 1530 tons

First Wall Coverage: ~600 m2

Materials:- Armor:Beryllium- Heat Sink:CuCrZr- Steel Structure: 316L(N)-IG

n-damage (Be / heat sink / steel): 1.6 / 5.3 / 3.4 (FW) 2.3 (SB) dpa

Max total thermal load: 736 MWISFNT-10, Portland, OR, September 12-16, 2011

I-shaped beam to accommodate poloidal torque

Design of First Wall Panel


First wall

Shield block

PlasmaToroidal direction

Toroidal gap : 16 mm on the inboard

Inboard wallHorizontal view

Why Shaping of First Wall is Needed?


• The heat load associated with charged particles along the field lines is a major component of heat flux to first wall.

First wall

Toroidal direction

5 mm

• The two situations are equally probable So chamfering on both sides is

necessary

First wall First wall

First wall

5 mm

First wall

Toroidal direction

Two Sides Need to be Considered


First wall

Toroidal direction

First wall

5 mm

16 mm

q


Shaping the First Wall

12

Plasma

RH access

Exaggerated shaping

- Allow good access for RH

- Shadow leading edges

Final Shaping of First Wall Panel• Heat load associated with charged particles is a major component of

heat flux to first wall.• The heat flux is oriented along the field lines.• Thus, the incident heat flux is strongly design-dependent (incidence angle of the field line on the component surface). • Shaping of FW to shadow leading edges and penetrations.


13

0 176 <= 1.3 MW/m² 40%1.4 MW/m² <= 42 <= 2.0 MW/m² 10%

3.0 MW/m² <= 162 <= 3.9 MW/m² 37%

4.0 MW/m² <= 60 <= 4.7 MW/m² 14%

Total 440 100%

First Wall Panels: Design Heat Flux

Poloidal Rows FWs distribution with design heat load

1 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 18

2 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 18

3 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 18

4 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 18

5 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 3.8 18

6 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 18

7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 18

8 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 18

9 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 18

10 1.0 Diag 1.0 Diag 1.0 EC 1.0 EC 1.0 Diag 1.0 EC 1.0 EC 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 1.0 Diag 18

11 1.0 1.0 1.0 1.0 2.0 1.0 2.0 1.0 2.0 1.0 2.0 1.0 2.0 1.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 36

12 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 36

13 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 36

14 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 0.5 3.6 0.5 3.6 0.5 3.6 0.5 3.6 3.6 3.6 22

15 4.0 4.0 4.0 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 0.5 3.6 3.6 0.5 3.6 0.5 3.6 0.5 3.6 3.6 22

16 4.0 3.6 4.0 3.6 4.0 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 36

17 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 36

18 1.3 1.3 1.3 3.6 1.3 1.3 1.3 1.3 3.6 1.3 1.3 1.3 1.3 1.3 1.3 3.6 1.3 1.3 1.3 1.3 3.6 1.3 1.3 1.3 1.3 1.3 1.3 3.6 1.3 1.3 1.3 1.3 3.6 1.3 1.3 1.3 36

S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C 440

Toroidal Index

Diag

Diag

Diag

Diag

Diag

TBM

Diag

port

IC ICTBM

portTBM

EC

9101112 123418 14151617 567813

DNB


14

First Wall Finger Design

SS Back Plate

CuCrZr AlloySS Pipes

Be tiles

Be tiles

Normal Heat Flux Finger:• q’’ = ~ 1-2 MW/m2 • Steel Cooling Pipes• HIP’ing

Enhanced Heat Flux Finger:• q’’ < ~ 5 MW/m2 • Hypervapotron• Explosion bonding (SS/CuCrZr) +

brazing (Be/CuCrZr)


15

First Wall Analysis• Detailed blanket design

activities on-going in parallel with supporting analyses in preparation for PDR.

• They address EM, thermal, thermo-hydraulic and structural aspects based on ITER Load Specifications and requirements.

• Design cases are categorized according to their probability of occurrence and allowable stress or temperature levels depend on the event category.

• The capability of the design to withstand the design number of cycles for each of the events must be demonstrated.

Schematic of EHF FW finger and Example Thermal Stress Results


More details on thermo-mechanical analysis of EHF FW from M. Sviridenko’s poster presentation on Wednesday

16

Shield Block Design

260

280

300

320

340

360

380

0.7 0.75 0.8 0.85 0.9 0.95 1Volume fraction of SS in blanket shield block

Inbo

ard

TF c

oil n

ucle

ar h

eat

(#1-

#14)

W/l

eg

New Mix, Water30%- 0.95g/ cc (fendl2.1)NAR,Water16%- 0.9g/ cc(fen1)Water16%- 0.9g/ cc(fen2)Water16%- 0.9g/ cc(fen2.1)

• Slits to reduce EM loads and minimize thermal expansion and bowing • Poloidal coolant arrangement.• Cooling holes are optimized for Water/SS ratio (Improving nuclear shielding

performance).• Cut-outs at the back to accommodate many interfaces (Manifold, Attachment,

In-Vessel Coils).• Basic fabrication method from either a single or multiple-forged steel blocks

and includes drilling of holes, welding of cover plates of water headers, and final machining of the interfaces.


More details on EM slit optimization study from J. Kotulski’s poster presentation on Wednesday

17

• Thermo-mechanical analysis indicates that the stress levels are acceptable and that the temperature level <~350°C , as illustrated by the example results for SB 1 shown here.

Shield Block Analysis


More details on cooling optimization from Duck-Hoi Kim’s poster presentation on Tuesday

18

Shield Block Attachment

• 4 flexible axial supports• Keys to take moments and forces• Electrical straps to conduct current to vacuum vessel• Coolant connections


19

Flexible Axial Support

• 4 flexible axial supports located at the rear of SB, where nuclear irradiation is lower.

• Compensate radial positioning of SB on VV wall by means of custom machining.

• Adjustment of up to 10 mm in the axial direction and 5 mm transversely (on key pads) built into design of the supports for custom-machining process.

• Cartridge and bolt made of high strength Inconel-718• Designed for 800 kN preload to take up to 600 kN

Category III load.ISFNT-10, Portland, OR, September 12-16, 2011

20

Example Analysis of Flexible Cartridge: Fatigue Assessment of M66 Main Thread for BM 18


Equivalent stress, Pa E132 tot

FQPP bLtot

]N[nV

1V

- SDC-IC 3322: Fatigue usage fraction- Total stress range- Elastic strain range (SDC-IC 3323.1.1)

Linearization of equivalent stress

Δσ, МPа T, oC2.Sy,

МPаΔε, % [N] n V

1904 150 1944 0.86 5111 400 0.078

Max. Von Mises stress 952 MPa

(m)

(Pa)

5111 cycles92.2%-margin

Elastic analysis – Design load for axial supports in Cat.II: 504 kN radial force, T = 1500C

The number of Cat.II events will be limited to 400 (cf. VV load specification)

Example Analysis of Flexible Cartridge: Collapse Load Assessment for BM 18 (immediate plastic collapse – SDC-IC 3211.2)

ISFNT-10, Portland, OR, September 12-16, 2011 21

Elastoplastic analysis

Reaction in pilot node from tensile force vs. displacement

Tension(Allowable (II) = 1.2 MN)

LF,collapseIII = 3.00 > LF,criteriaIII = 1.2 Margin 150%

LF,collapseII = 3.57 > LF, criteriaII = 1.5 Margin 138%

Symmetric assembly

Friction coefficients: 0.4(metal - metal)

0.6 (metal – ceramic)

Analysis model

Total strain (tension force 600 kN)

Max. total strain 0.43%

Collapse load: 1800 kN

1800 kN/600 kN

1800 kN/504 kN

22

Toroidal Forces

Poloidal Forces

Shear Keys Used to Accommodate Moments from EM Loads


23

Keys in Inboard and Outboard Modules

• Each inboard SB has two inter-modular keys and a centering key to react the toroidal forces.

• Each outboard SB has 4 stub keys concentric with the flexible supports.

• Bronze pads are attached to the SB and allow sliding of the module interfaces during relative thermal expansion.

• Key pads are custom-machined to recover manufacturing tolerances of the VV and SB.

• Electrical isolation of the pads through insulating ceramic coating on their internal surfaces.


24

Example Analysis of Inter-Modular Key

• Analysis of the inter-modular keys indicate stresses above yield (~172 MPa at 100°C) in the case of Category III load.

• Limit analysis then performed to check margin.


25

Limit Analysis of Inter-Modular Key• Reasonable load factors of 1.5 for

the pads and 1.9 for the neck of the key are obtained based on limit analysis under Category III loadwith 5% plastic strain.

Eddy Forces Applied

0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.40%

5%

10%

15%

20%

Neck Pad location

LoadFactor

Plas

tic st

rain

(%) 1.725 MN

1.725 MN


26

Analysis of Outboard Stub Key• Stub key for BM#11• Worst-case EM loads (from PDR Protocol):

- FMrII = 855 kN (cat. II)- FMrIII = 1014 kN (cat. III)


Plus (mainly taken by axial supports):- FMpII = 300 kN- FMpIII = 360 kN

Stub key

Pad

Reaction forces from forces due to radial moment, FMr

Stub key

Pad

27

Limit Analysis of Stub Key of BM #11


1.27 (Pa)

Stress redistribution at LFcollapseIII = 1.27

Plastic strain at LFcollapseIII = 1.27

Max. plastic strain: 5.01%

- LFcollapseIII = 1.27 > LFcriteria

III = 1 (Margin 27%)

- LFcollapseII = 1.510 > LFcriteria

II = 1.171 (Margin

29%)

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Electrical Straps• Each SB is electrically joined to the VV by two electrical straps, formed and

louvered from two sheets of CuCrZr alloy to achieve flexibility.• Each strap is bolted on to the rear of a SB using M8 bolts. The socket is

welded to the VV.• An M20 bolt inserted through the front face of the SB connects the straps to

the vessel socket via a compression block. • One electrical connection can handle up to 180 kA of electrical current.

Socket now welded on VV

Cu alloy strap

M8 bolt

M20 bolt

Blanket side

VV side


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Blanket Manifold


• A multi-pipe configuration has been chosen, with each pipe feeding one or two BM’s replacing the previous baseline with a large single pipe feeding several BM’s- Higher reliability due to drastic reduction of

number of welds and utilization of seamless pipes.

- Higher mechanical flexibility of pipes reduction of space reservation at back of BM.

- Superior leak localization capability due to larger segregation of cooling circuits.

- Elimination of drain.

- Reduction of cost: - Well established manifold technologies.- Simplification of Vacuum Vessel manufacturing due to

elimination of heavy anchoring plates.- Must be balanced with cost associated with higher

number of valves required for leak localization (2 valves per circuit).

Blanket Remote Handling

ISFNT-10, Portland, OR, September 12-16, 2011On-Rail Module Transporter

- Shield blocks designed for ITER lifetime (semi-permanent component)- First wall panels to be replaced at least once during ITER lifetime (designed

for 15,000 cycles).- Both are designed for remote handling replacement (FW: RH Class 1).- Blanket RH system procured by JA DA.- RH R&D underway.More details from S. Mori’s oral presentation on Monday and S. Shigematsu’s poster presentation on Thursday.

31

Supporting R&D• A detailed R&D program has been planned in support of the design, covering a range of key topics, including: - Critical heat flux (CHF) tests on FW mock-ups. - Experimental determination of the behavior of the attachment and insulating layer under prototypical conditions.- Material testing under irradiation. - Demonstration of the different remote handling procedures.

• A major goal of the R&D effort is to converge on a qualification program for the SB and FW panels. - Full-scale SB prototypes (KODA and CNDA). - FW semi-prototypes (EUDA for the NHF FW Panels, and RFDA and CNDA for the EHF First Wall Panels).- The primary objective of the qualification program is to demonstrate

that: - Supplying DA can provide FW and SB components of

acceptable quality.

- Components are capable of successfully passing the formal test

program including heat flux tests in the case of the FW panel.


32

Example R&D for Hypervapotron CHF (RFDA)• The R&D program in support of the EHF

hypervapotron CHF testing was conducted at the Efremov Institute, RF.

• The results confirm the CHF margin of 1.4 for the EHF FW under an incident heat flux of 5 MW/m2.


More details from I. Mazul’s oral presentation on Tuesday

– Each DA must demonstrate technical capability prior to start procurement.

– 2 phase approach:

I. Demonstration/validation joining of Be/CuCrZr and SS/CuCrZr joint (done)

II. Semi-prototype production/validation of large scale components (on-going)

FW Pre-Qualification Requirements

6 Fingers in 1 to 1 scale

2 slopes, 4 facets

NHF FW Pre-Qualification Program (EUDA, on-going)• Engineering support activity• Manufacturing Development activity

Standard NHF• 1 medium scale mock-up to study Be

tile sizes + checking end-of-finger configuration • 1 semi-prototype for 1 MW/m2 heat flux (S-NHF)

Upgraded NHF• 3 small-scale mock-ups for checking performance under Heat Flux• 1 semi-prototype for 2 MW/m2 heat flux (U-NHF)

CuCrZr heat sink

Be tiles

SS beam

35

Summary• The Blanket design is extremely challenging, having to

accommodate high heat fluxes from the plasma, large EM loads during off-normal events and demanding interfaces with many key components (in particular the VV and IVC) and the plasma.

• Substantial re-design following the ITER Design Review of 2007. The Blanket CDR in February 2009 has confirmed the correctness of this re-design.

• Effort now focused on finalizing the design work .

• Parallel R&D program and formal qualification process by the manufacturing and testing of full-scale or semi-prototypes.

• Key milestones:- Preliminary Design Review: Nov. 29 – Dec. 1, 2011

- Final Design Review in late 2012. - Procurement to start in early 2013 and should last till 2019. ISFNT-10, Portland, OR, September 12-16, 2011

overview of the design and r&d of the iter blanket system

Documents

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iter blanket systempresented

blanket systemisfnt

blanket modules bm

iter design review

major design

wall components

wall replacement