HIGH TEMPERATURE GAS-COOLED REACTOR FOR HEAT …€¦ · Fission fission product Diffusion Physical events to lose confinement function Sublimation Corrosion Containment Vessel Reactor

HIGH TEMPERATURE GAS-COOLED

REACTOR FOR HEAT SUPPLY AS A

NATURALLY SAFE AND INNOVATIVE

NUCLEAR SYSTEM

CIGS 3rd International Symposium on Global Warming

December 11, 2013

Masuro OGAWA

Nuclear Hydrogen and Heat Application Research Center Japan Atomic Energy Agency (JAEA)

CONTENTS

1. Outline of HTGR (High Temperature Gas-cooled Reactor)

2. Reduction CO2 with Heat

Supply from HTGR

3. Solutions for Social Issues

4. Perspective of HTGR

5. Concluding Remarks

1. OUTLINE OF HTGR

WHAT CAN HTGR DO?

( HTGR: High Temperature Gas-cooled Reactor)

3

HTGR can supply high-temperature heat

at 950oC

Heat supply to various

industry/transportation

fields

High thermal efficiency

due to high temperature

0 500 1000 1500

Reactor outlet temperature TH (℃)

0.5

0

1.0

TL : Low side temperature (25oC)

Td : Temperature with ⊿G = 0 (4436oC)

H2 production : η =TH - TL

TH

TH - TL

TH

Td

Td - TL

Td

Td - TL

Power generation

(Carnot cycle)

TH - TL

TH

TH - TL

TH

81%

950oC76%

66%

61%

52%

48%500oC

300oC

LWRHeat→Electricity→H2

33% 70-90%

23%

31%~

HTGR

Heat→H2

Theoreticalefficiencyof IS process

40%

~

67%

50%

η =

Th

eo

retica

l e

ffic

ien

cy η

0 200 400 600 800 1000 1200 1400 1600Temperature (oC)

Glass production

Cement production

Steel productionDirect reduced iron Blast furnace

High efficient GT power production

Thermochemical IS process

H2 production from naphthaH2 production from steam methane reforming

DME/Methanol synthesis

Ethylene production from naphtha

Ethylene production from ethane

Styrene production from ethyl benzene

City gas production

Oil refinery

Heavy oil desulfurization

Pulp, paper production

Urea synthesis

Desalination

District heating

HTGR

FBR

LWR

4

WHAT IS HTGR DIFFERENT

FROM EXISTING LWR?

5

Ceramic fuel-cladding, graphite-moderated

and helium gas-cooled HTGR

Typical specification

Coolant temperature : 950 oC

Thermal Output : Max. 600MW

Heat utilization ratio : 70-80%

Gas turbine

District heating

Seawater desalination

Hydrogen production

Process heat

Electricity generation

Agriculture, Aquatic product industry

950 oC

Reactor

500 oC

Waste heat

～200 oC

HTGR

6

HTGR LWR

Coolant Helium gas

• No phase change

• Chemically inert

• No activation

Light water

Fuel coating Ceramics • No melting Metal (Zirconium)

Moderator Graphite • No evaporation Light water

Reactor thermal power Compact (～600MW) • Collocation with demand site Large (～4500MW）

HOW DOES HTGR MAKE

PROGRESS IN TECHNOLOGY?

7

Previous abundant knowledge and experiences

GCR AGR HTGR VHTR

Fuel Natural

uranium

Enriched

uranium ← ←

Fuel coating Metallic

material ← Ceramics ←

Coolant

/Temperature CO2/400oC CO2/600oC～ He/700oC～ He/950oC～

Pressure

vessel Steel, PCRV PCRV

PCRV,

Steel (Small-size)

Steel

(Small-size)

Progress

Commercial

operation (UK, France, Italy,

Japan, etc.; 37 units)

Commercial

operation

(UK ;14 units)

Experimental reactor

(UK,US, Germany; 1 unit/country)

Prototype reactor

(US, Germany; 1 unit/country）

Test reactor (China; 1 unit),

Demonstration reactor (China; 2 units)

Experimental test

reactor HTTR

(Only exist

in Japan)

• Development of GCR starts from the first days of that of nuclear power, i.e. at the same

time as development of LWR.

• Direction of GCR commercialization with high coolant temperature is summarized to Gen-

IV VHTR as shown in the following table (Next generation LWR is classified to Gen-IV)

• Japan has constructed and been operating VHTR experimental test reactor, HTTR based

on extensive technical knowledge obtained in the developments of GCR, AGR, HTGR,

and accidents of TMI and Chernobyl.

8

0.92 mm

UO2

Ceramic

cladding of fuel

Isotropic

Graphite

Heat-resistant

Superalloy

Quartet coating technology for cladding to have heat resistance

Confinement of radioactive materials for about

three times longer than of LWR

Temperatures up to 1600 oC

Hot-pressurizing technology for graphite to have isotropy

High strength, thermal conductivity, and

radioactive-resistance

Temperatures up to 2400 oC

Fortifying technology for metal to have heat resistance

High-temp. structural technology for components

Helium-handling technology for coolant to reduce leakage

(Chemical, mechanical and nuclear-physical stability)

Utilization of heat at high temperature of 950 oC

Japan’s Cutting-edge Homegrown Technologies

IHX

Reactor

HTTR

(30MW, 950 oC)

HTGR test reactor of

JAEA at Oarai Japan

9

Prismatic HTTR reactor core and fuel

Reactor

Fuel

element

Primary

cooling pipe

Reactor pressure vessel

580mm

Fuel element Fuel rod

34mm

Graphite sleeve

Fuel compact

Plug

Fuel compact

26mm

39mm

Coated fuel

particle

Fuel kernel,600μm

920μm

Low density porous PyC

SiC

High density inner PyC

High density outer PyC

Fuel

rod

10

Remaining development issues in HTGR

11

Establishment of HTGR technologies - Demonstration for performance and reliability of key technologies

e.g. fuel, graphite moderator, Heat-resistant alloy, high

temperature structural design code, etc., using the HTTR

Construction of lead plant and commercial plant (Dec. 2010)

- Establishment of regulatory guidance for HTGR

Design guideline for high temperature component

Design guideline for graphite component

Safety design standards

- Development of material database including strength test and irradiation

test for life extension

Consensus-building toward the HTGR deployment in reactor site

PRESENT STATUS

IN THE WORLD?

12

National projects in the world

13

US; NGNP project 2012：Final design

started

Kazakhstan: KHTR project South Korea：NHDD project

750oC Cogeneration

発電

HTGR

Heat supply

Power generation

HTGR

H2 production

950oC H2 production

750oC

Power

generation

HTGR

H2 production

District heating

Power generation

2012：Concept study started

China: HTR-PM

750oC Power generation

2017：Construction of demonstration plant will be completed

2013：Feasibility study in preparation

US NGNP project

<Electric utility>

・Entergy

<Chemical company>

・Dow(The Dow Chemical Company)

<Petrochemical company>

・ConocoPhillips

・Petroleum Technology Alliance Canada (PTAC)

<Graphite manufacturer>

・GrafTech International Ltd.

・SGL Group ・Mersen

・Toyo Tanso Co., Ltd.

<Reactor vendors>

・AREVA ・Ultra Safe Nuclear

・Westinghouse

<Consulting company>

・Technology Insights ・SRS

・Advanced Research Center

South Korea NHDD project

<Electric utility>

・KHNP

・KEPCO

<Steel making company> <Petrochemical company>

・POSCO ・SK ENERGY

・GS Caltex

<Construction company> <Pump manufacturer>

・GS construction ・KNF

・Hyundai E&C

<Automobile company>

・Hyundai Motors

<Heavy Industry> <Electronics>

・Doosan Heavy Industry ・SUMSUNG

・STX Heavy Industry

<Research institute>

・KAERI

Industrial Alliances for HTGR in US and Korea

14

2. REDUCTION OF CO2 WITH

HEAT SUPPLY FROM HTGR

15

Concrete solution for reduction of CO2 emission

Vehicle 17%

Residential 13%

Steelmaking 13%

Chemical, petroleum

Others 23%

Power

generation 26%

Heat

57%

Elect

ricity

43%

Fossil

fuel

Nuclear

Issue： Reduction of

CO2 emissions in

heat utilization field

Solution: Heat supply from HTGR

Thermal power 600 MW

Outlet temp. 950℃

Coolant Helium

Cladding of fuel Ceramics

Moderator Graphite

1.19 billion ton CO2

(2010)

Natural energy

Natural

resources

Energy

Media

CO2 emissions

Heat demand in plants (MW) 27,000

Number of HTGRs 55

CO2 emissions reduction (%) 5

Chemical and petroleum plants

High temp. heat

Fuel cell vehicle

Number of vehicles (million) 75

Number of HTGRs 130

CO2 emissions reduction（%） 16

H2

Iron

ore

H2

Crude steel

(million t/y) 110

Number of

HTGRs 85

CO2 emissions

reduction (%) 9

Steelmaking Steam (c.a. 540oC) (~950oC)

Fuel

Heat

source

Reducing

substance

H2

30%

One HTGR (600MW) reduces

c.a. 0.1% of CO2 emissions

8%

16

3. SOLUTIONS FOR SOCIAL

ISSUES

WHAT WILL HAPPEN IN HTGR AT

THE FUKUSHIMA ACCIDENT?

17

Temp.

(oC)

Flow

rate

(%)

Time (hr)

Circulators trip

Coolant flow rate in the core

Reactor power

Fuel temperature

: Analysis: Experiment

Power

(%)

Temp. limit; 1600oC

Reactor inherently shut down

without control rod insertion

Decay heat removal

occurs naturally even if

normal heat transport

systems are not available

HTTR can intrinsically

shutdown reactor

• Initial reactor power

30%(9MW)

• Stop all circulators

• Without scram

• Operation of vessel

cooling system maintained

HTTR test result

TEPCO Fukushima

NPP accident

Earthquake

Control rod insertion

Reactor scram

Tsunami

Loss of offsite power

Loss of function for

decay heat removal,

core heat up,

core melt

H2 explosion

Release of

radioactive material

HTTR test condition (On December 12, 2010)

Vessel cooling system

Gas circulator Thermal

radiation

Natural convection

Control rod

Helium

Water

Dissipated to air

HTTR

－ HTTR Can Intrinsically Shutdown with the Case

Equivalent to TEPCO Fukushima Accident－

18

Issue: Obtain consent of risk concept from public who concerns the following

－ Even a small probability of occurrence such as once in 1 million reactor years, there is

no guarantee that it will not occur tomorrow.

－ For events that lead to very large consequence, the event shall be evaluated only the

impact of the consequence instead of evaluation in risk

(Risk) = (Occurrence probability) x (Consequence of the event)

Safety objective “Protect people and the environment from harmful effects of ionizing

radiation” must be met in the layer of consequence mitigation. The degree of attainment

would be evaluated by risk assessment (in review). “Probability of occurrence for the accident which results in Cs-137 release of 100 TBq or larger

should be reduced to the value lower than 10-6/reactor year”

Defense in depth: Having provisions responding to the event progression based on the

assumption of the failure in the former layer.

1. Prevention of accident (occurrence, progression), if failed,

2. Mitigation of consequences,

3. Emergency planning (Evacuation, etc.)

If mitigation of consequence failed, evacuation is required. What if evacuation failed ?

For that reasons, mitigation of consequence must accomplished successfully

(1) Safety

19

Reactor can intrinsically secure safety by mitigating physical events to lose confinement

function only with physical phenomena without reliance on backup systems

Issues accompanied by risk concept and evacuation can be solved

20

Solution: Consequence Mitigation

by Natural Phenomena

Fission

product

Diffusion

Physical events to lose

confinement function

Sublimation

Corrosion

Containment Vessel

Reactor

Pressure

Vessel

Cause events

Core

Heat-up

Cladding

oxidation

by air

Counter physical

phenomena

CO

explosion

Doppler effect

Thermal radiation,

Natural convection

and so on

Oxide layer

formation

CO oxidation

Cladding

Attain

stable

state

Retain

fission

products

within

cladding

Rupture Uranium

Confinement

Core

Reactor

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

Years

Ra

dio

toxi

city

[S

v]

102 104 106102

104

106

108

(pe

r 1

ton

of

fue

l)

LWR Spent Fuel

High Level Waste

After Transmutation

HTGR

Spent Fuel

High Level Waste

Issue：Reduction of Radiotoxicity in Radioactive Waste

Solution：Utilization of Thorium

Partitioning of U and Pu

Partitioning of MA

(2) Radioactive Waste Reduction

Fuel composition

・ LWR

U-235 ： 4.5%

U-238 ： 95.5%

・ HTGR

U-235 ： 10%

Th-232 ： 90%

Remarks

• Enrichment of uranium

and reprocessing of Th

are needed.

• LWR can also use Th.

U235: 4.5%

U238: 95.5%

U235 : 10%

Th232 : 90%

Elapsed

21

Operation and Maintenance

0

50

100

150

200

LWR HTTR

GBｑ/yr

≒0

175Liquid

0

5

10

15

20

LWR HTTR

ＧＢｑ/yr 12

≒0

Gaseous

Less Low-level

radioactive waste

Cooled by natural

circulation of air

Spent fuel

Easy management of spent fuel

Shallow ground disposal for spent graphite

Spent graphite quantity:

～3000m3/unit, 60 years

（1/500 of baseball dome volume

（1.58M m3）)

（http://www.sapporo-dome.co.jp）

Unit:[t-U(Enriched)/GWe]

Less spent fuel per unit power generation rate

(Depends on enrichment, efficiency)

1130

348

0

500

1000

1500

LWR GTHTR300

22

Low worker dose

10

5

0LWR

BWR（2005）PWR（2005）

HTTR

軽水炉の1/600

1～15.5

1～6.4

0.0016

被ばく線量

（人Sv/年）

1/600 of

LWR W

ork

er

dose (

man S

v/y

)

Power generation cost LWR : 5.3 Yen/kWh

HTGR : 4.2 Yen/kWh (HTGR 1 unit ( =4 modules) )

For 100MW electric power,

LWR : 9.7 Yen/kWh

HTGR : 5.3 Yen/kWh

In spite of

• High fuel enrichment,

• Multi-layer coating of fuel,

• Heat resistant alloy utilization,

compelling economics can be achieved

because of

• High electricity generation efficiency

• Simplified safety system

• Easy maintenance and operation

• Shop fabrication and preassembly

0

2

4

6

8

10

12

14

0 200 400 600 800 1000 1200 1400

HTGR

LWR

Po

wer

gen

era

tio

n c

ost

(Yen

/kW

h)

Electric power (MWe)

(3) Economy

Ref： M. Takei, et al., Economical Evaluation on Gas Turbine

High Temperature Reactor 300 (GTHTR300), Trans. At.

Energy Soc. Japan, 5(2), pp.109-117 (2006).

GTHTR300 Thermal/Electric Power

：600/275MW

Reactor outlet temp.

：850oC HX vessel

Recuperator PCS vessel

Compressor Generator

Turbine

Core

Reactor

Precooler

23

Issue: In general, as the power density becomes lower the plant economic get worse

Reactor and primary system

Reactor

(1.8)

Building (Reactor & turbine buildings, others)(25.6)

I&C, electric equipment(10.7)

Turbine, generator (11.5)

Reactor & station auxiliary system (13.0)

Primary system (9.2)

Condensate, feed water,

turbine auxiliary systems, Others

(13.1)

Others

(1.5)

Reactor

control system

(3.9)

Reactor protection

system

(4.0)

Construction cost*1 [Unit ％]

HTGR with low power density core can achieve compelling economics due to

the following reasons

• Reactor cost only responsible for 2% of plant cost

• Core power density of HTGR is 1/10 of that of LWR • Increase in portion of reactor cost from 2% to 20% (x10) results in increase in

plant cost only by 18%.

• The 18% cost increase can be canceled out by advantages in HTGR.

100%

0

118%

Reactor

cost

(ca.2%)

LWR HTGR

Construction cost

x 10

20%

Bird’s eye view of PWR (2 modules)

PWR 1 unit

Ref: *1 Private communication, *2 JAIF report, 1992;.

*3ORNL_sub_86-86004_7、Energy economic data base(EEBD) program phase VIII update(1986) BWR supplement 24

Rad waste

system,

Fuel

handling

(5.7)

Solution; HTGR can be economically competitive because of the superior

characteristics and the low ratio of reactor cost to plant cost

★Total building inventory: 674,000 m3

24 m

47 m

119 m

11 m

A

93.7 m

109.2 m

84.0 m

★Total building inventory：533,000 m3

80％ of LWR’s building inventory

Turbine building A-A cross section

The Foot Print of HTGR

Ref： X. Yan, et al., Nuclear Eng. Design., 226, p351-373 (2003) Ref： Figure cited from application for establishment permit of Kasiwazaki-

kariwa nuclear power plant unit No.3 of TEPCO

GTHTR300 (275MWe x 4 modules ) )

LWR (1100MWe )

45 m

68.5 m

80 m

53 m A 22 m

76 m

Reactor building Turbine building BWR-5

HTGR ( 1100MWe )

25

Equivalent power output

4. PERSPECTIVE OF HTGR

26

27

中間熱交換器

原子炉

ガスタービン

高温ガス炉

水素製造プラント熱化学法ISプロセス

Heat supply for industrial

demand

No core melt

Economically competitive

Reduce radio toxicity in radioactive waste on the

order of hundred years by utilizing Thorium

(Separation of spent fuel is required.

Residual fuel after separation will be recycled)

Maintain sustainability using uranium from

seawater

(Recycling for nuclear fuel supply is unnecessary)

Achievement of natural-safety

Green fuel；H2 production Corresponding to temporal storage by inert matrix fuel.

Reduce the amount of spent fuel per produced electricity by

1/3 due to high burnup.

Incinerate surplus plutonium.

HTTR

Lead plant

Commercial plant

Establishment of most of the HTGR technologies

Naturally Safe and Innovative HTGR

Toyo Tanso

Receive a contract for

core components

of HTR-PM in China

Mitsubishi Heavy Industry

Conduct conceptual study for

a commercial HTGR plant MHR.

Propose construction of

lead plant. Make a contribution

to promoting commercial

deployment of HTGR by own technology.

M. Toyama (MHI), et al., ,” Expectations to HTGR”, HTR2012, Tokyo Japan.

NFI

Developed coated fuel particle

fuel for higher burn-up condition

Fuel compacts are currently

under irradiation (100GWd/t)

Fuel compacts for irradiation test

JAEA Typical HTGR designs

(GTHTR300, GTHTR300H, and so on.)

Power : 600MW

Hydrogen : 51t/day

Electricity : 200MW

Temperature : 950oC

Burnup : 120GWd/t 250μm

IG-110

GTHTR300H

Present Status on National Activities

28

5. CONCLUDING REMARKS

HTGR is a Gen-IV and a small-sized reactor up to

600MW for heat supply such as hydrogen, process

heat, and steam.

HTGR technologies have been almost confirmed in

HTTR and lifetime verification remains. Technologies

of hydrogen production should be demonstrated.

HTGR can solve issues such as safety, reduction of

CO2 and radioactive waste in environmental

protection, economy and so on.

29

THANK YOU FOR YOUR ATTENTION!

HTTR

30