ARIES-DB Design Issuesand

Activation of Divertor W Alloys

ARIES-DB Design Issuesand

Activation of Divertor W Alloys

L. El-Guebaly, A. Robinson, D. HendersonFusion Technology Institute

UW - Madison

Contributors:Z. Dragojlovic, X. Wang, S. Malang (UCSD),

M. Rieth (FZK),G. Kulcinski (UW)

ARIES-Pathways Project MeetingAugust 26 - 27, 2009

Georgia TechAtlanta, GA

2

Contents

• ARIES-DB design issues:– Recirculating power– New TF magnet dimension/composition– Divertor activation.

• Radial builds for two cases: with andwithout radial manifolds (to be updated).

Z. Dragojlovic 7/19/2009

(72 mills/kWh for ARIES-AT)

Ave. Γ @ plasma = 3.4 MW/m2

ARIES-DB

3

ARIES-DB Recirculating Poweris Excessive

As defined by ASC, ARIES-DB generates > 4500 MWthwith:

~2000 MWe Pgross

1000 MWe Pe

680 MWe to pump helium (to be corrected)210 MWe to drive current and heat plasma

⇒ Inefficient machine

4

ARIES-DB Recirculating Poweris Excessive (Cont.)

0

200

400

600

800

1000

1 2 3 4 5

Rec

ircul

atin

g Po

wer

(MW

e)

I CSIVARIES- ST DB

247 238

518(325 for Cu mgnt)

253

940

He-cooled ARIES Designs

Need to reduce CD, heating, and He pumping powers

Stillhigh!

0

200

400

600

800

1000

ARIES-ATARIES-DBARIES-DB corrected

1 2 3 4 5 6 7

Pow

er (M

We)

Cryogenic Div

AuxiliaryPlasmaHeating

CurrentDrive

Blnkt

250

114

210

470

Breakdown of Recirculating Power

97

PumpingPower

Total

940

170

35~50374721

78

182

523

5

ARIES-DB TF Magnet

Win

ding

Pac

k503.2 5

Out

er C

oil C

ase

SS J

acke

t, In

sula

tor,

Coi

l Cas

e

Win

ding

Pac

k

32.8 cm

Out

er C

oil C

ase

(JK

2LB)

Inne

r C

oil C

ase

(JK

2LB)

ARIES-RS ARIES-DB

18.5% 316 SS48.2% Cu12.8% Nb3Sn10% GFF Polyimide10.5% LHe

7.8% Inconel48.8% Cu8.4% Nb3Sn10% Polyimide25% He

58 cm7.2

12.812.8

Too much He?

Too Thick?(shield will be reoptimized toaccount for thick coil case)

Too thin?

Why not JK2LB?

B/S/VV

Check magnet algorithm in new ASC

6

ARIES-DB-DCLL Divertor

Two-Heat-Flux-Zone concept(S. Malang and X. Wang)

6 cm

0.5 cm W Armor: 90% W10% void

5.5 cm Cooling Channel:31.3% W alloy1.7% W13.7% ODS-FS53.3% He

Concerns:• Activation• W decay heat and divertor temperature response during LOCA/LOFA. TBD• Survivability of W armor (lifetime could be weeks if bombarded with 1020 He atoms/cm2)

(UW could simulate ARIES-DB divertor conditions using UW-IEC experiment).

7

Candidate W Alloys for Divertor

– Pure W– W with impurities (99.99 / 0.01 wt%)– W-Re (74 / 26 wt%)– W-Ni-Cu (90 / 6 / 4 wt%)– W-Ni-Fe (90 / 7 / 3 wt%)– W-La2O3 (99 / 1 wt%) - for EU divertor, per Rieth (FZK).

• Key parameters for activation analysis:– 1 MW/m2 average NWL over divertor plates– 4 y irradiation period (3.4 FPY with 85% availability).

• Is divertor clearable? Recyclable? Disposable? Any high-level waste?

Structural W-alloyswith W impurities

3.4 MWy/m2

8

List of W Impurities(M. Rieth - FZK)

9

Specific Activity

10

Divertor is Not Clearable

• Even highly pure W cannot be cleared after 100 y cooling period.• Divertor should be recycled or disposed of.

11

W Can be Recycled(Cooling Channel)

AdvancedRH Limit

ConservativeRH Limit

Hands-onLimit

12

Candidate W Alloys Can be Recycled (Cooling Channel)

13

AdvancedRH Limit

ConservativeRH Limit

Hands-onLimit

Candidate W Alloys Can be Recycled (Cont.) (Cooling Channel)

• W-La2O3 alloy exhibits lowest recycling dose.• All four W alloys can be recycled with advanced equipment immediately after

divertor replacement• Conventional remote handling equipment can be used after 6-65 y cooling period.

14

Divertor Qualifies for Class C LLW

WDR* LLW

Pure W 0.02 Class A

W w/ imp. 0.34 Class C

W-Re 0.45 Class C

W-Ni-Cu 0.35 Class C

W-Ni-Fe 0.34 Class C

W-La2O3 0.34 Class C

* Evaluated at 100 y using NRC and/or Fetter’s limits.

W-Re generates highest WDR, but stillqualifies as LLW under ARIES-DBirradiation conditions (3.4 MWy/m2)

Cla

ss C

LLW

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6W

DR

Pure W W-Ni-FeW-ReWw/ Imp. W-Ni-Cu W-La

2O

3

15

ARIES-DB-DCLL Radial Builds• DCLL blanket and shield:

• 0.5 cm low-density Ultramel SiC inserts• Calculated overall TBR = 1.1 with 70% Li

enrichment• No stabilizing shells (to be added later)• Two cases:

– With radial LiPb/He manifolds– Without radial LiPb/He manifolds (reference).

• Radial builds defined for peak NWL @ IB, OB, Divof 3.4, 4.8, 2 MW/m2.

• Scaling laws for variation of shield with NWLprovided to ASC.

LiPb/HeManifolds

16

ARIES-DB-DCLL Radiation Limitsand Key Parameters

Calculated Overall TBR 1.1Net TBR (for T self-sufficiency) ~1.01

Damage to Structure 200 dpa - advanced FS (for structural integrity) ??? W structure*

Helium Production @ Manifolds & VV# 1 He appm (for reweldability of FS)

LT S/C Magnets (@ 4 K): Peak fast n fluence to Nb3Sn (En > 0.1 MeV) 1019 n/cm2

Peak nuclear heating 2 mW/cm3

Peak dpa to Cu stabilizer 6x10-3 dpa Peak dose to GFF polyimide insulator < 1011 rads

Plant Lifetime 40 FPY

Availability 85%

Operational Dose to Workers and Public < 2.5 mrem/h________________* For divertor plates, W stabilizing shells, and W shield blocks behind assembly gaps, if needed.# Reweldability not required near IB midplane. Only top/bottom interface between manifolds and shield needs to be reweldable for “without radial manifolds” case.

17

ARIES-DB-DCLL IB Radial Build(midplane cross section - to be updated)

Vac

uum

Ves

sel

(not

rew

elda

ble

near

mid

plan

e )G

ap

451531FW

/Bla

nket

( LiP

b/H

e/FS

)(r

epla

ceab

le e

very

3 F

PY)

2

HT

FS S

hiel

d(r

epla

ceab

le e

very

12

FPY

)

SOL

Plas

ma

5

Gap

+ T

h. In

sula

tion

148 cm

2

Skel

eton

Rin

g

20

BW

3.8

cm F

W5 40

withRadial Manifolds

Vac

uum

Ves

sel

Gap

4525 3027

FW/B

lank

et( L

iPb/

He/

FS)

(rep

lace

able

eve

ry 3

FPY

)

2

HT

FS S

hiel

d(r

epla

ceab

le e

very

12

FPY

)

SOL

Plas

ma

5 G

ap +

Th.

Insu

latio

n

Man

ifold

s(n

ot r

ewel

dabl

e @

Mid

plan

e)

164 cm

2

HT

FS S

hiel

d

15 15

Back

Wal

l

3.8

cm F

W

5 40

(reference)

without Radial Manifolds

32.8

Win

ding

Pac

k

Out

er C

oil C

ase

Inne

r C

oil C

ase

Win

ding

Pac

k

Out

er C

oil C

ase

Inne

r C

oil C

ase

32.8

Δ = 16 cm

18

ARIES-DB-DCLL OB Radial Build(Radial Xn Underneath Magnet - to be updated)

No Shells(to be added)

2635

198 cm

SOL

HT

FS S

hiel

d

Plas

ma

5 2080

FW/B

lank

et/B

W(L

iPb /

He/

FS)

(rep

lace

able

eve

ry 3

FPY

)

Vac

uum

Ves

sel

Gap

Gap

+ T

h. In

sula

tion

2 ≥2

LiPb

/He

Man

ifold

s

with Radial Manifolds

without RadialManifolds

30

≥ 167 cm

SOL

Skel

eton

Rin

g

Plas

ma

5 2080

FW/B

lank

et/B

W(L

iPb /

He/

FS)

(rep

lace

able

eve

ry 3

FPY

)

Vac

uum

Ves

sel

Gap

Gap

+ T

h. In

sula

tion

2 ≥2

(reference)

Δ = 31 cm

32.8

Win

ding

Pac

k

Out

er C

oil C

ase

Inne

r C

oil C

ase

32.8

Win

ding

Pac

k

Out

er C

oil C

ase

Inne

r C

oil C

ase

19

ARIES-DB-DCLL Upper/Lower Radial Build

Most challenging case due to: – Neutron streaming through large vacuum pumping ducts – High W decay heat (may require active cooling system during LOCA/LOFA).

ARIES-DB-DCLL Upper/Lower Radial Build

Most challenging case due to: – Neutron streaming through large vacuum pumping ducts – High W decay heat (may require active cooling system during LOCA/LOFA).

6 cm Thick DivertorTwo-Heat-Flux-Zone concept

(S. Malang and X. Wang)

20

ARIES-DB-DCLL Div Radial Build(to be updated)

147

cm w

/o g

aps

with Radial Manifolds without Radial Manifolds

132

cm w

/o g

aps Vacuum Vessel

Gap

Large Gap + Th. Insulation

Divertor

25

45Skeleton Ring

Gap

6

HT FS Shield(replaceable every ~5 FPY)

23

> 2

Reweldable(in absence ofn streaming)

(reference)

Winding Pack

Outer Coil Case

Inner Coil Case

Vacuum Vessel

Gap

Large Gap + Th. Insulation

Divertor

20

45HT FS Shield

Gap

6

> 2

HT FS Shield(replaceable every ~5 FPY)

23

> 2

He Manifolds 20

Winding Pack

Outer Coil Case

Inner Coil Case

32.8 32.8

Δ = 15 cm

21

CompositionsARIES-DB-DCLL ARIES-DB-DCLL* with Manifolds without Manifolds

Inboard:FW 34% FS, 66% HeBlanket 76% LiPb, 13% He/void,

7% FS, 4%SiCBack Wall 80% FS, 20% He

HT Shield / Skeleton Ring 15%FS, 10% He, 75% B-FS Filler

Manifolds 50% FS, 25% He, 24% LiPb, 1%SiC ---

VV 17% FS, 34% H2O, 49% WC 15% FS, 35% H2O, 50% WC_____________________________________________________________________________________________________________________________Outboard:

FW 34% FS, 66% HeBlanket 77% LiPb, 12% He/void,

7% FS, 4%SiC

Back Wall 80% FS, 20% He

HT Shield / Skeleton Ring 15%FS, 10% He, 75% B-FS Filler

Manifolds 50% FS, 25% He, 24% LiPb, 1%SiC ---

VV 30% FS, 50% H2O, 20% B-FS 28% FS, 52% H2O, 20% B-FS_____________________________________________________________________________________________________________________________Top/Bottom:

Divertor 29% W alloy, 9% W, 13% ODS-FS, 50% HeReplaceable HT Shield 15%FS, 10% He,

75% B-FS FillerPermanent HT Shield / Skeleton Ring 15%FS, 10% He,

75% B-FS FillerManifolds 50% FS, 25% He, 24% LiPb, 1%SiC ---

VV 22% FS, 48% H2O, 30% B-FS 19% FS, 50% H2O, 31% B-FS

22

Comparison BetweenARIES-AT and ARIES-DB

ARIES-AT ARIES-DB-DCLL Cost of (LiPb/SiC) (LiPb/He/FS) ARIES-DB-DCLL

Physics Several changes

IB, OB, Div radial standoff* 135, 160, 133 cm < 144, < 163, < 132 cmLimit on max. NWL (MW/m2) ~ 6 < 5.5Major radius 5.2 m 6.3 m ↑

Calculated overall TBR 1.1 ~1.1 w/o shellsw/ 90% 6Li enrichment w/ 70% 6Li enrichment

FW/blanket lifetime ~4 FPY ~2.8 FPY ↑⇒ 18 MWy/m2 ⇒ 13 MWy/m2

Overall energy multiplication 1.1 ~1.15 ↓

Structure unit cost# ~ 620 $/kg ~ 95 $/kg ↓

ηth ~ 60% ~ 40% ↑

Cost of heat transfer/transport system# ~ $200M ~ $700M ↑

He pumping power --- 680 MWe ↑

Level of Safety Assurance (LSA) factor 1 2 ↑

COE# 72 mills/kWh < 105 mills/kWh

________________* Excluding gaps.# in 2008$.

~260

23

Observations and RecommendationsObservations:

– ARIES-DB and ARIES-AT have comparable radial standoff– Four candidate W alloys have acceptable activation characteristics– Divertor pumping ducts will increase radiation level behind divertor shield where reweldability of coolant pipes is essential– Elements that tend to degrade TBR:

• Thick FW (to withstand disruption)• More structure within blanket• W armor on FW• Stabilizing shells.

Recommendations:– Check/confirm TF magnet composition/dimension– Reduce recirculating power– Segment OB blanket to reduce replacement cost and radwaste stream.

Qs and needs:– FW/Blanket composition and dimension (to assure TBR ≥ 1.1)

• Any W armor on FW?• Any change to FW materials? Any need for refractory alloys (W, Ti, Mo, or Nb) to handle high heat flux?

– Locations of kink shells, vertical stabilizing shells, and feedback coils. Impact on TBR?– Divertor pumping ducts: size and location.– VV design and FS content.

To be done/considered :– W decay heat and divertor temperature response during LOCA/LOFA– Change of SiC electric conductivity with neutron irradiation.– Change of electric conductivity of stabilizing shells with neutron irradiation.