Satoshi Konishi Institute for Advanced Energy, Kyoto University

May.25, 2005

A critical review and comparison of power reactor blankets from nuclear

technology and socio-economic aspects

Contents - Broader “Externality” aspect - Tritium release to the environment - Waste strategy - Fuel supply - Deployment to hydrogen market

7th International Symposium on Fusion Nuclear Technology

Special Thanks to Kunihiko Okano, Yusuke Ichimasa and Kenji Tobita

・ Future energy will be evaluated by social preference.・ Such evaluation will consider all the possible impacts and effects to future society and environment.

Fusion

Other Energy

Outcome/benefit

Energy Supply

Damage/cost/”Externality”

Future Social

Demand

Government

funding

Institute of Advanced Energy, Kyoto UniversitySocio-Economic Aspect of Fusion

Public

Industry

Different outcome are expected for sponsors.

How fusion affects?How fusion affects?

Plasma

BlanketFacility

Environment,Society

Fuel, Material(D,Li-6,..)

Generation PlantHeat Transfer

Wastes (Solid nuclides, T,C-14)

Exhausts(T,heat)

(Recycle)Energy(Electricity)

　　 Fusion will be evaluated - what it consumes - what it exhausts - what it generates , and - what it leaves

Blanket is the keyFor Socio-economicFeature of fusion

Economy

　　－ Energy sales is not the only outcome of the research. →”Externality” ; economical effect out of the market

HowHow fusion will benefit public? fusion will benefit public?

　・ Impact by various pathways　　 -outside of energy market

- estimated with economical value (monetary term)　 environmental negative ： pollution, global warming　 environmental positive ： recycling, cleaning, reduced emission　 social negative ： nuclear proliferation, terrorism, fear of risk social positive ： security, backstop, technology

Energy

positive negative

benefitsecurity

riskcost

pollutionwarmingcleaning

recycle

・ All the risks and benefits・ evaluated from the viewpoint of sponsor・ market sales is only a part・ cost is not a good measure　　 but cost affects the market share

soci

alE

nviro

n.

・ various sponsors provide funding・ different purpose, different phase of development・ investment for research is a certain fraction of total sales →investment must yield benefit to sponsors

1960

transfer

６．２％For R&D

industry

utilityResearchinstitute

Basic research

Fission reactor casesales

Further competitivenessimprovements

commercialization

Researchinstitutes

Investment for nuclear technology

Temperature Thermal Efficiencycoolant

300

500

800

Light water Heavy water 、

Liquid metal

Molten salt

Helium

30%

40%

50%

NPD 1962

CalderHall1956

CO2

FERMI

1963（ 商用）

Obninsk(RBMK) 1954

Shippingport

PWR1957 VBWR

1957

EBR1

1951

AGR 1976

SGHWR

1968EL-4

1966

Variety of fission reactors developed

Generations of blankets fit different phases- Fusion has multiple generations with single plasma

1) Technically possible. (liquid metal)2) Governments policy and social preferences. (graphite, heavy water)3) Market selection. (light water reactor)

SHIELD

NEUTRON

USE

METAL

WATER

Q=10 500sec

β N=2.5

Q=30

STEADY

β N~3.5

GAS

INDUSTRIAL

HEAT

GENERATION

MARKET

SELECTION

EXPERIMENTAL REACTOR (ITER)

DEMO REACTOR

COMMERCIAL REACTOR

SiC/SiCVanadium

Ferritic Steel

PLASMA DEVICE

BLANKETS

MATERIALS

SUPER

CRITICAL

EFFICIENT

COOLANTSEFFICIENT

GENERATION

Strategies for blankets

Each generations has different purpose. -expected functions of blanket differs.

Learn from the history of fission.

2000 2010 2020 2030

PowerDemo

ITER

TBM

Tokamak

IFMIF

Const. BPP

Test

Generation

EPP

module1 module2

High beta, long pulse

KEP EVEDA Const. New line

10dpa/y 20dpa/y

RAF In pile irradiation Full irrad.1/2 irrad.

Fusion development strategy

Drawn from Fast track working group in Japan, 2002,Dec.

Evolution required In a same facility

Concept Design Const. Test

The 1st Blanket will aim at “earliest power generation”.Next target will be “deployment into the future society.

Energy Conversion Issue

Steam ~ 500 ℃ or high temperature He ~ 900 ℃

Technology temperature efficiency use of heat Fossil fire 　 Supercritical 600 ℃ 　　 47% +　 Combined 1200℃ 　 >60% +Fission LWRs 300 ℃ 33% - FBR 500 ℃ 40% +-Fusion　 Supercritical 500 ℃ 　　 39-41% +- High T gas 900 50%℃ +Renewables rt - -

Blanket heat transfer media will have to fit advanced energy.

mill

/kW

h

65

92

109125

0

25

50

75

100

125

150

2050 2060 2070 2080 2090 2100

year

Poss

ible

Intr

oduc

tion

pric

e

145

Target cost of electricity varies as a function of

Introduction time.

Introduction into the market

Possible introduction price of Fusion : increases with time as fossil price increases.

Current target of the development

year

pric

etechnology

resource

renewable

Emission dominated by normal detritiation

Tritium processing systems

TRITIUM RECOVERY

PRIMARY LOOPGENERATION

SYSTEM

SECONDARY LOOPS

BLANKET

reactor boundary

PLASMA

secondary confinementbuilding confinement

COOLANT PROCESS-ING

AIR DETRITIATION

tritium leak/permeation

TRITIUM THROUGHPUT (kg/day)

TOTAL THROUGHPUT (kg/day)

TRITIUM INVENTORY (kg)PRIMARY LOOP COOLANT PROCESS

1

3060

0.5

0.5500000

Water based heat transfer requires isotope separation.

TRITIUM FACILITY

DIFFUSIONWIND

SHALLOW SOIL

DEEP SOIL

DOSE EFFECT

INHALATION

SKIN ABSORPTION

INJESTION

F ISH

NORMAL/ ACCIDENTAL

TRITIUM REL EASE

PLU ME

ATMOSPHERE HT OATMOSPHERE HT

SURFACE SOILPLANT

OBTPLANT HTO GRAZING ANIMAL

HTOGRAZING ANIMAL

OBT

HUMA N BODY HTO

EFFECTIVE DOSE EQUIVALENT

DRINKING WATER

DRY DEPOSITION

WET DEPOSITION WASHOUT

HUMAN BODY OBT

SURFACE WATER

TRITIUM BEHAVIOR TO CAUSE HUMAN DOSE

Tritium is detectable far below the level that affects health.

Impact pathway of tritium

Distance from the source(m)

1E-10

1E-8

1E-6

Eff

ectiv

e do

se e

quiv

alen

t (S

v/g)

1E2 1E3 1E4 1E5

Col

lect

ive

dose

( pe

rson

Sv)

1E-6

1E-4

1E-2

Dose caused by normal tritium release of 1gAnd total “detriment”

1E2

1E4

1E6

popu

latio

n

Impact of radioactive emission

Tritium released fromthe facility diffusesbut not disappear.

According to the LNThypothesis by ICRP,detriment increaseswith distance.

Normal release accumulates in the environment.

Dose is negligible compared with natural radiation, but detectable in environment, foods and drinking water.Same thing happens with C-14 and worse.

EXHAUSTSEFFLUENTS

SOLID WASTEBLANKETREPLACEMENT

PRIMARY LOOPS

DISPOSAL RELEASE

RELEASE

EXHAUST DETRITIATION

DECONTAMINATIONOF SOLID WASTES

TURBINEGENERATOR

ISOTOPESEPARATION

FUELINGSTORAGE

TRITIUMEXTRACTION

PLASMA

BLANKET

EVACUATION PURIFICATION

PRIMARY LOOPS:Kg tritium

moderate conditionrobust containment

High temperature, pressureLarge processOut of primary enclosureEnvironmental release

SECONDARY LOOPS:100g tritium

BLANKETREPROCESSING

LOADINGIN/OUT

HX

WATER DETRITIATION

Waste Disposal Issue

TRITIUM containing medium will be confined :

expansion volume : He expansion pool : water (easy) : other liquids

IN CASE OF SPILL, TRITIUM IS RECOVERED BEFORE GOING

OUT TO THE NEXT BARRIER

DETRITIATIONSYSTEM