Environmental Aspects of RecentTrend in Managing FusionRadwaste: Recycling and

Clearance, Avoiding Disposal

Environmental Aspects of RecentTrend in Managing FusionRadwaste: Recycling and

Clearance, Avoiding Disposal

L. El-GuebalyFusion Technology Institute

University of Wisconsin - Madisonhttp://fti.neep.wisc.edu/UWNeutronicsCenterOfExcellence

2nd IAEA TM onFirst Generation of Fusion Power Plants: Design & Technology

June 20 - 22, 2007Vienna, Austria

2

Handling Fusion Radioactive Materialsis Important to Future of Fusion Energy

• Background: Majority of fusion power plants designed to date focused on disposal ofactive materials in repositories, adopting fission waste management approach preferredin 1970’s.

• New Strategy: Develop new framework for fusion:– Minimal radwaste should be disposed of in ground– Recycle* and/or clear# all active materials, if technically and economically

feasible.

• Why?– Limited capacity of existing low-level waste repositories– Political difficulty of building new repositories– Tighter environmental controls– Minimize radwaste burden for future generations.

• Applications: Any fusion concept (MFE & IFE); power plants and experimental devices.

• Impact: Promote fusion as nuclear source of energy with minimal environmental impact._____________________* Reuse within nuclear industry.# Unconditional release to commercial market to fabricate as consumer products.

3

U.S. Repositories

• High-level waste (HLW) repositories:– Hanford facility in Washington:

• In operation since 1960.• 67,000 m3 capacity.

– Yucca Mountain repository in Nevada:• Planned to open in March 2017.• Total life cost $70B (originally estimated at $27B).• Capacity 70,000-120,000 tons (fission reactors generates 2,000 tons/y; 55,000 tons currently stored in 39 states).• Still needed even with fission spent fuel recycling program.• Not politically acceptable!

4

U.S. Repositories (Cont.)• Low-level waste (LLW) repositories:

– Barnwell facility in South Carolina:• 1971 – 2038.• Class A, B, C* LLW.• Supports east-coast reactors and hospitals.• Will severely curtail amount of LLW received in July 2008.• 36 states will lose access to Barnwell on 7/1/08, having no place to dispose 91% of

their Class B & C LLW.

– Richland facility in Washington:• Class C LLW.• 125,000 m3 capacity.• Supports 11 northwest states.

– Clive facility in Utah:• Class A LLW only.• Disposes 98% of U.S. Class A waste volume (does not accept sealed sources or biological tissue waste – a great concern for biotech industry).

_____________________* 0.1, 2, and 7 Ci/ft3 for Class A, B, and C waste, respectively.

5

U.S. Needs National Solution forLLW Problem

• LLW disposal is state responsibility, but no state would accept to be “nuclear dumpground” for the nation.

• Several states tried to developed disposal sites, then changed their mind because of strongopposition from public and environmentalists.

• Idaho state asked DOE to remove LLW stored at INL and ship it out of state.

• Utah state refused to open new Class C repository.

• Some utilities store LLW on site because of limited and expensive offsite disposal options.

• As near-term solution, DOE opened its disposal facilities to commercial LLW.

• Nuclear Regulatory Commission (NRC):– Favors permanent disposal instead of indefinite, onsite storage, but there is no

estimate of how long it would take to develop disposal facility.– Future availability of disposal capacity and disposal cost under current system

remain highly uncertain.

6

ARIES Designs(1988-2007)

ARIES-I ARIES-III ARIES-IV ARIES-RSSPPS

ARIES-ST

ARIES-AT

ARIES-CS

*

*LLNL

ARIES Team

UCSDUW

UCB

SNL

RPI

PPPL

NRLMITLBNL

LANL

INL

GT

GA

BoeingANL

7

Fusion Generates Large Amount of LLWthat Fills Repositories Rapidly

ITER

Economic Simplified Boiling Water Reactor(ESBWR) - Gen-III+

Reactor Vessel: 6.4 m ID, 21 m H

Fission

Fusion

20%LLW

80% Clearable

95% Clearable

5%LLW

1%HLW

8

Fusion Generates Large Amount of LLWthat Fills Repositories Rapidly (Cont.)

ARIES-ATAdvanced Tokamak

ARIES-ST Spherical Tokamak

Adv

ance

d Fi

ssio

n R

eact

orV

esse

l (ES

BWR

) (2

1 m

x 6

.4 m

)

Adv

ance

d Fi

ssio

n R

eact

orV

esse

l (ES

BWR

) (2

1 m

x 6

.4 m

)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Vo

lum

e (

10

3 m

3)

ARIES-ST

ARIES-AT

ESBWR

Class A & C LLW(active for 100s y)

HLW w/ TRU (active for 10,000 y)& Class C LLW

9

What We Suggest

• Business as usual is not environmentally attractive option.Something should be done.

• Fusion designs should adopt MRCB philosophy:

M – Minimize volume of active materials by design.

R – Recycle*, if economically and technologically feasible.

C – Clear# slightly-irradiated materials.B – Burn active byproducts, if any, in fusion devices@.

_____________________* Reuse within nuclear industry.# Unconditional release to commercial market to fabricate as consumer products.@ L. El-Guebaly, “Managing Fusion High Level Waste – a Strategy for Burning the Long-Lived Products in Fusion Devices,” Fusion Engineering and Design, 81 (2006) 1321-1326.

10

Radwaste MinimizationRadwaste Minimization

11

ARIES Project Committed toRadwaste Minimization

Tokamak waste volumehalved over 10 y study period

Stellarator waste volumedropped by 3-fold

over 25 y study period_____________________* Actual volumes of components (not compacted, no replacements).

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Bla

nke

t/S

hie

ld/V

acu

um

Ves

sel/M

agn

et/S

tru

ctu

re

Vo

lum

e (1

03 m3 )

ARIES – I1990

III1991

II1992

IV1992

RS1996

ST1999

AT2000

SiCSiC

SiC

V V

FS

FS(D-

3He)

Tokamaks*

0

1

2

3

4

5

6

7

8

Bla

nke

t/S

hie

ld/V

acu

um

Ves

sel/M

agn

et/S

tru

ctu

re

Vo

lum

e (1

03 m3 )

UWTOR-M24 m1982

SPPS14 m1994

ARIES-CS 8.25 m

2004

V FS

FS

ARIES-CS 7.75 m

2006

FS

FS

ASRA-6C20 m1987

Stellarators*

12

Disposal, Recycling,and Clearance

Disposal, Recycling,and Clearance

13

Disposal, Recycling, Clearance ApproachesApplied to Recent Fusion Studies

(red indicates preference)

Components Recycle? Clear? Dispose of @ EOL?

IFE:ARIES-IFE Targets# no yes / no yes

(for economic reasons) (as Class A)

Z-Pinch-IFE RTL* yes yes yes (carbon steel) (a must requirement) (as Class A)

MFE:ARIES-CS@ all yes yes / no yes

(as Class A & C)

______________________________# L. El-Guebaly, P. Wilson, D. Henderson, and A. Varuttamaseni, “Feasibility of Target Materials Recycling as Waste Management Alternative,”

Fusion Science & Technology, 46, No. 3, 506-518 (2004).* L. El-Guebaly, P. Wilson, and M. Sawan, “Activation and Waste Stream Analysis for RTL of Z-Pinch Power Plant,” To be published in Fusion

Science & Technology.@ L. El-Guebaly et al., “Designing ARIES-CS Compact Radial Build and Nuclear System: Neutronics, Shielding, and Activation,” To be published in

Fusion Science and Technology.

14

Economics Prevent Recycling ofARIES-IFE-HIB Hohlraum Wall

• Recycling of hohlraum walls doubles COE.• Hohlraum walls represent < 1% of waste

stream.• Once-through use generates Class A LLW.• Few materials (Au, Hg, Ta) have CI < 1.• Target factory designers prefer dealing

with non-radioactive hohlraum wallmaterials.

One-Shot Use RecyclingScenario Scenario

Cost per Target $ 0.4 $ 3.15Incremental Change to COE ~ 10 mills/kWh ~ 70 mills/kWhCost of Electricity (COE) ~ 70 mills/kWh ~ 130 mills/kWh

Hohlraum WallFoamsDT

Capsule(5 mm OD)

HIB

ARIES-IFE Target

2 cm

Preferred Option

15

Recycling is a “Must” Requirement for RTL of Z-Pinch toMinimize Radwaste Stream and Enhance Economics

Target

BreederJets

Breeder Foam

Recyclable Transmission LinesTop diameter = 1 m

Bottom diameter = 0.1 mLength = 2 m

Total thickness = 0.142 cm50 kg / RTL

100

101

102

103

104

105

106

107

108w/o RTL Recyclingw/ RTL Recycling

Was

te V

olu

me

(m3 )

ChamberWall

Building RTL Total

Chamber Wall

No recycling during 40 FPYTotal RTL volume = 7 M m3

With recycling1.1 day RTL inventoryTotal RTL volume = 0.0005 M m3

10-2

100

102

104

106

108

1010

103 104 105 106 107 108 109 1010 1011

Cle

aran

ce In

dex

Time After Shutdown (s)

Clearance Limit

100 y

IAEA

US

USw/o T

According to U.S. guidelines, RTL waste could be storedfor 50 y after plant decommissioning, then reused within

nuclear industry or released to commercial market

Z-Pinch Chamber

16

ARIES Compact Stellarator

2 m Bioshield

Cryostat

Blanket

Manifolds

Shield

VacuumVessel

Magnet

3 Field Periods.LiPb/He/FS System.7.75 m Major Radius.2.6 MW/m2 Average NWL.3 FPY Replaceable FW/Blanket.40 FPY Permanent Components.~78 mills/kWh COE ($2004).

ϕ = 0

ARIES-CS Cross Section @ ϕ = 0

17

ARIES-CS LLW Classificationfor Geological Disposal

All ARIES-CSComponents(~8,000 m3)

Class ARepository

Class CRepository

~ 8 m belowground surface> 8 m below

ground surface+

Thick ConcreteSlab

TemporaryStorage

(up to 100 y)

≈

Class C Class A Could beLLW LLW Cleared?

FW/Blkt/BW √ no

Shield/Manifolds √ no

Vacuum Vessel √ no

Magnet:Nb3Sn √ noCu Stabilizer √ √JK2LB Steel* √ √Insulator √ √

Cryostat √ √

Bioshield √ √

(~6,600 m3)(82%)

(~1,400 m3)(18%)

Least hazardoustype of waste

______* Preferred over Incoloy-908 for clearance considerations.

18

80% of ARIES-CS Active Materials can beCleared in < 100 y after Decommissioning

Recycle orDispose ofB/S/VV/M

(20%)

Clear Magnet w/o Nb

3Sn,

Cryostat & Bioshield(80%)

Cryostat

Blanket

Manifolds

ShieldVacuumVessel

Magnet

2 m Bioshield

Recycle orDispose of asClass A or C

Clear

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Not compacted, no replacementsFully compacted with replacements

Vo

lum

e (1

03 m3 )

FW/Blkt/BW

Shld/Mnfld

VV Magnets &Structure

Cryostat

10-2

100

102

104

106

108

1010

1012

100 102 104 106 108 1010 Pro

po

sed

U.S

. Cle

aran

ce In

dex

Time After Shutdown (s)

1d 1y

Inter-Coil Structure

Limit 100y

FW

Vacuum Vessel

Cryostat

Steel of Bldg

Concrete of Bldg

19

All ARIES-CS Components can be Recycled in < 1 yUsing Advanced RH Equipment

Cryostat

Blanket

Manifolds

ShieldVacuumVessel

Magnet

Bioshield

10-8

10-6

10-4

10-2

100

102

104

106

100 102 104 106 108 1010

Rec

yclin

g D

ose

Rat

e (S

v/h

)

Time After Shutdown (s)

Advanced RH Limit

Conservative RH Limit

Hands-onLimit1y1d

FW

Shield

Inter-Coil Structure

Steel of Bldg-IConc. of Bldg-I

VV

Cryostat

Development of more advanced RH equipment is foreseen to support fission GNEP initiative

20

Recycling & Clearance Flow Diagram

Original ComponentsReplaceableComponents

RecyclingFacility

TemporaryStorage

(~ 1 y)

Final Inspectionand Testing

Replaceable Components(@ 3 FPY)

Commercial Market(or Nuclear Industry)Commercial Market(or Nuclear Industry)

Blanket & DivertorFabrication and

Assembly

CI > 1

Fresh Supply(if needed)

MaterialsSegregation

NuclearIndustry

NuclearIndustry

Permanent Components @ EOL

CI < 1(SlightlyRadioactiveMaterials)

During OperationAfter Decommission

TemporaryStorage

Ore Mines& Mills

Ore Mines& Mills

21

General Observations

• Recycling and clearance options look promising and offer significantadvantage for radwaste minimization.

• They should be pursued despite lack of details at present.

• Fusion recycling technology will benefit from fission developments andaccomplishments in 50-100 y.

• Several critical issues still need further investigation for all three options:– Disposal– Recycling– Clearance

22

Disposal Issues

• Large volume to be disposed of (7,000 - 8,000 m3 per plant, includingbioshield).

• High disposal cost (for preparation, packaging, transportation, licensing,and disposal).

• Limited capacity of existing LLW repositories.

• Political difficulty of building new repositories.

• Tighter environmental controls.

• Radwaste burden for future generations.

23

Recycling Issues

• Development of radiation-hardened RH equipment (≥ 10,000 Sv/h).

• Energy demand and cost of recycling process.

• Radiochemical or isotopic separation processes, if needed.

• Any materials for disposal? Volume? Waste level?

• Properties of recycled materials? Reuse as filler? No structural role?

• Recycling plant capacity and support ratio.

• Acceptability of nuclear industry to recycled materials.

• Recycling infrastructure.

24

Clearance Issues

• Discrepancies between clearance standards*.

• Lack of consideration for numerous fusion radioisotopes*: (10Be, 26Al, 32Si, 91,92Nb, 98Tc, 113mCd, 121mSn, 150Eu, 157,158Tb,

163,166mHo, 178nHf, 186m,187Re, 193Pt, 208,210m,212Bi, and 209Po).

• Impact of missing radioisotopes on CI prediction.

• Need for fusion-specific clearance limits*.

• Clearance infrastructure.

• Availability of clearance market (none anywhere in the world, except inGermany and Spain. Currently, U.S. industries do not support unconditionalclearance claiming it could erode public confidence in their products and damagetheir markets).

______________________________* L. El-Guebaly, P. Wilson, and D. Paige, “Evolution of Clearance Standards and Implications for Radwaste Management of Fusion Power Plants,” Fusion Science & Technology, 49, 62-73 (2006).

10-5

10-3

10-1

101

103

0 50 100 150 200 250 300

Rat

io o

f P

rop

ose

d U

S t

o IA

EA

Cle

aran

ce L

imit

s fo

r C

on

cret

e

Atomic Mass of Radioisotopes

10-5

10-3

10-1

101

103

0 50 100 150 200 250 300Rat

io o

f P

rop

ose

d U

S t

o IA

EA

C

lear

ance

Lim

its

for

Ste

el

Atomic Mass of Radioisotopes

25

Q / A

General public and government agencies ask for energy source that:– is safe– generates little or no waste– does not deplete limited natural resources.

Question: Which option helps earn public acceptance? Disposal or recycling/clearance?

Disposal Recycling/Clearance

Generates little or no waste √

Does not deplete limited natural resources √

26

Recommendations

Fusion designers:– Continue developing low-activation materials.– Promote environmentally attractive scenarios such as recycling and clearance,

avoid geological burial, and minimize radwaste volume by design.– Identified critical issues should be investigated for all three options.– Technical and economic aspects must be addressed before selecting most

suitable radwaste management approach for any fusion component.

Nuclear industry and organizations:– Nuclear industry must accept recycled materials from dismantled nuclear

facilities.– National and international organizations (NRC, IAEA, etc.) should continue

their efforts to convince industrial and environmental groups that clearance canbe conducted safely with no risk to public health.