HTGR Plant Design

Hiroyuki Sato

Japan Atomic Energy Agency

Training Course on

High Temperature Gas-cooled Reactor Technology

October 19-23, Serpong, Indonesia

p.2

General features

• A Generation IV system

• Cooperative design of JAEA and domestic

industries (MHI, Fuji electric, KHI, etc.)

• Multiple applications, passive safety,

compelling economics, flexible plant siting

• Near-term deployable

Plant Design

• Plant is designed to minimize R&D and to

obtain compelling economics

• Original design features of conventional

steel pressure vessel, non-intercooled

direct cycle, horizontal gas turbine

• Water or air coolable

Reactor power plant H2 plant

Reactor

Helium gas

turbine

Thermal rating: 600 MW

Net electricity: up to 300MWe

Hydrogen rate: up to 5.2 t/hr

Non-intercooled,

horizontal gas turbine

Turbine Compressor

Inherent RPV

cooling scheme

140oC

0.5% of

main flow

Dry cooling configuration

Gas turbine

Reactor

Recuperator

Air cooler Precooler

GTHTR300: JAEA’s Commercial HTGR

p.3

GTHTR300 Outline

Reactor

Helium Gas Turbine

Recuperator

Precooler

Reactor power (max. output) 600 MWt

Reactor temperature 850-950oC

Reactor coolant pressure 7 MPa

Refueling interval/period 1.5-2 yrs/30 days

Plant load factor 90%

GTHTR300 (Gas Turbine High Temperature Reactor 300)

Sole Power Generation Plant

Cogeneration Plant

p.4

Design Philosophy

Simplicity, Economical Competitiveness and Originality (SECO)

1. Sharing of common technologies by all design variants

— a unified reactor primary circuit

— an aerodynamically and mechanically similar line of gas turbines

— the selected hydrogen production process, the IS process

2. Focused development that limits cost and risk

HTTR-type high burnup fuel, a baseline gas turbine, and IS process ation

3. Original design attributes

— Conventional material RPV, high burnup fuel cycle

— Horizontal gas turbine, non-intercooled power conversion cycle

— New IS process technologies

p.5

Design Features

K. Kunitomi, JAEA-Conference 2007-005 (2007).

p.6

System Configuration, Reactor

Turbine Compressor

Generator

Reactor

Recuperator

Precooler

588oC

136oC, 7.0 MPa

850oC

28oC, 3.5 MPa

22oC

Reactor bird’s eye view (GTHTR300)

Plant Layout (GTHTR300)

RPV

Standpipe

Core barrel

Hot plenum block

Control rod guide tube

Core support plate

Upper shroud

p.7

Core, Fuel Element

Permanent side reflector

Fuel block

Control rod guide block

Outer replaceable reflector

Control rod insertion hole

Reserve shut down channel

Inner replaceable reflector

Core horizontal cross section (GTHTR300)

Fuel block & fuel rod cross sections (GTHTR300)

Fuel block

Fuel compact

Coolant channel

Bottom plate

Upper plate

Center rod

Helium coolant

Spacerダウエル

A

Fuel channel

Dowel pin

Fuel brock handling hole

Fuel rod vertical cross section

Fuel brock horizontal cross section

p.8

Why Helium Gas Turbine ?

Most efficient and economical power generation possible by HTGR

Direct Brayton cycle helium turbine enables 50% efficiency at

least count of components

Wide range of heat application without drawbacks in efficiency

Cogeneration of desalination, which utilizes sensible waste heat

rejected of Brayton power generation cycle can attain overall energy

efficiency of 88%

Exclusion of water related safety events

High temperature waste heat rejection enables efficient dry cooling

which can eliminate core water ingress accident and

allow inland installation

1

2

3

p.9

Why Helium Gas Turbine ?

Aerodynamic Scaling from baseline design for

all other units: GTHTR300+, GTHTR300C and

GTHTR300H:

Baseline Design for GTHTR300: 6 turbine stages, 20 compressor stages, non-intercooled,

horizontal shaft, 3600 rpm synchronous, magnetic bearing, and 300 MWe class

X. Yan, JAEA-Conference 2007-005 (2007).

p.10

Helium Gas Turbine Outline

3. Helium compressor

aerodynamics R&D:

Program nearly

completed

2. Helium turbine

aerodynamics R&D:

Designed and

partially built

4. Magnetic bearing

design and control:

Test rig under

commissioning

1. Brayton cycle

helium gas loop:

Designed and

partially constructed

Only R&D on the baseline design is necessary (see design philosOnly R&D on the baseline design is necessary (see design philosophy)ophy)

JAEAJAEA’’ss R&D activities:R&D activities:

11

X. Yan, JAEA-Conference 2007-005 (2007).

p.11

Compressor Aerodynamics R&D

The R&D Goal

Development of high performance helium compressor for VHTR

The Results

1. Proposal of original design techniques

The Background

Neither successful helium compressor nor proven design existed, prior

to the present program !

2. 1/3 of full scale compressor tests

3. Establishment of performance evaluation methods

X. Yan, JAEA-Conference 2007-005 (2007).

p.12

R&D Results (1/3)

1. Proposal of original design techniques

1 High performance compressor flowpath: non-

intercooled, synchronous, and minimum number of

compressor stages

2 Tight blade tip clearance: 1.2 mm equivalent in full

scale, through a patented shaft-bearing system

3 3D blade airfoil: shown to eliminate boundary layer flow

separation on blade

11

Steaklines

TE Contour of Mach Number

1S 1C

CASE-1 0.539MPa

Steaklines

TE Contour of Mach Number

1S 1C

CASE-1 0.539MPa

Steaklines1S 1C

CASE-2 0.539MPa

TE Contour of Mach Number

Steaklines1S 1C

CASE-2 0.539MPa

TE Contour of Mach Number

Airfoil Case-A Airfoil Case-B

The Results (1/3)

streaklines streaklines

Rotor blade stator blade Rotor blade stator blade

Airfoil A Airfoil B

33

3322

X. Yan, JAEA-Conference 2007-005 (2007).

p.13

R&D Results (2/3)

2. 1/3 of full scale compressor tests

1) Internal flowpath boundary layer measurements

2) Airfoil performance measurements

3) Inlet/outlet casing geometry performance measurements

4) Compressor efficiency and surge margin

Helium compressor test rig

Detailed internal flowpath

measurement of aerodynamic variables

X. Yan, JAEA-Conference 2007-005 (2007).

Correlation of efficiency with

Reynolds number, Re-n, subject

to critical Reynolds number

Extensive test measurements

Viscous CFD analytical insights to

identify flow regimes

Efficiency vs. Reynolds Number Correlation

for Blade Section (from Case-1 all runs & Case-2 run1 measurement)

Reynolds number

Airfoil Case 1: Inlet A

Airfoil Case 1: Inlet B

Airfoil Case 2: Inlet B

Airfoil Case 2: Inlet C

1-ηp ~ Re-0.35

80

82

84

86

88

90

92

94

105

Re,critcal=1.2x106 for full scale

Re,critcal=4x105 for 1/3 scale

Re extrapolation

(full scale, 4 stages)

Throughflow prediction

(full scale, 20 stages)

Efficiency

pinch point

Po

lytr

op

ic E

ffic

ien

cy (

ηp,

%)

2 106

1074 6 8 2 4 6 8

Existing methods

New method

87%

92%

Efficiency vs. Reynolds Number Correlation

for Blade Section (from Case-1 all runs & Case-2 run1 measurement)

Reynolds number

Airfoil Case 1: Inlet A

Airfoil Case 1: Inlet B

Airfoil Case 2: Inlet B

Airfoil Case 2: Inlet C

1-ηp ~ Re-0.35

80

82

84

86

88

90

92

94

105

Re,critcal=1.2x106 for full scale

Re,critcal=4x105 for 1/3 scale

Re extrapolation

(full scale, 4 stages)

Throughflow prediction

(full scale, 20 stages)

Efficiency

pinch point

Po

lytr

op

ic E

ffic

ien

cy (

ηp,

%)

2 106

1074 6 8 2 4 6 8

Existing methodsExisting methods

New method

87%

92%3. Establishment of performance

evaluation methods

The Results (3/3 B)

B. Reynolds Correlation method

87%

92% 46.0%

43.5%

Compressor

efficiencyOverall plant

efficiency

Compressor performance

impact on plant efficiency

87%

92% 46.0%

43.5%

Compressor

efficiencyOverall plant

efficiency

Compressor performance

impact on plant efficiency

87%

92% 46.0%

43.5%

Compressor

efficiencyOverall plant

efficiency

Compressor performance

impact on plant efficiency

new method

existing method

p.14

R&D Results (3/3)

X. Yan, JAEA-Conference 2007-005 (2007).

Poly

tro

ph

ic e

ffic

ien

cyη

p, %

90

95

100

85

80105 106 107

92%

88%

n

p

Re1 ～

Critical Re in 1/3 scale test

Reynolds number

Correlation of efficiency based on test data

Efficiency pinch point for commercial GT

Efficiency pinch point for 1/3 scale test

Critical Re in commercial GT

Chord Re in commercial GT

p.15

Building Size Comparison

GTHTR300 (275MWe×4) BWR-5 (1100MWe)

★Building Capacity：674,000 m3

・Reactor + Affiliation：354,000 m3

・Turbine：320,000 m3

24 m

47 m

119 m

11 m

Turbine Building

45 m

68.5 m

80 m

53 m

76 m

A

A

Reactor Building Turbine Building

A-A断面

22 m

93.7 m

★建屋容積：485,000 m3

109.2 m

84.0 m

★Building capacity：533,000 m3

79 % of BWR-5

K. Kunitomi, JAEA-Conference 2007-005 (2007).

p.16

Safety Analysis (1/2)

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

200 400 600 800 1000 1200 1400 1600 1800 2000 2200Temperature (℃)

Axi

al d

ista

nce (

m)

0hr30hr70hr120hr200hr1000hr5000hr10000hr系列2系列3系列4系列5

Fuel region

Lower reflector

Upper reflector

Air inlet

Air outlet

Stack

Downward air flow(natural circulation)

Concrete biological shield

Insulator

Cooling panels

Reactorpressurevessel

Upward air flow(natural circulation)

Heat removal by radiation and natural circulation

Max. fuel temp. < Limit temp. (1600oC)

Decay heat is removed passively from the outside of RPV

Temperature distribution in GTHTR300 during DLOFC

K Katanishi et al., Nucl. Eng. Des.,237, 1372-1380 (2007).

p.17

Safety Analysis (2/2)

SiC (s) + O2 (g)→SiO (g) + CO (g) SiC (s) + 3/2O2 (g) →SiO2 (g) + CO (g)

The fuel remains intact during DLOFC accident

Fuel failure due to oxidation in GTHTR300

0

50

100

150

200

250

300

350

0 100 200 300 400

Natural circulation flow in GTHTR300

Time (Days)

Flo

w r

ate

(kg

/h)

K Katanishi et al., Nucl. Eng. Des.,237, 1372-1380 (2007).

p.18

Economics (1/2)

Analysis condition (plant specifications) GTHTR3001): Commercial HTGR designed by JAEA in cooperation with reactor vendors

- plant unit: 4 units/plant - plant power: thermal power 600MWt/unit

electric power ~275MWe/unit (gross) ~269MWe/unit (net)

- average burn-up: 120GWd/ton

Key assumption – Construct at current LWR site – Take into account standardization of design,

related codes & standards, operation & maintenance practices, components, regulatory, and project management

– equipment directly carried from an on-site exclusive port

– a reactor building and structures based on those of the HTTR – seismic condition same as that of the HTTR – including design and fabrication of facilities, plant construction cost and test operations

p.19

Economics (2/2)

19

a) Plant construction cost (NOAK)

b) Fuel cost (NOAK)

c) Power generation cost (NOAK)

0 10 20 30

LWR(PWR)

GTHTR300

Construction cost (10000 Yen/kWe)

Reactor

componentsPower conversion

systemAuxiliary system

Electric and

control systembuildings

0.0 1.0 2.0 3.0 4.0 5.0 6.0

LWR(PWR)

GTHTR300

Power generation cost (Yen/kWh)

capital cost

operating cost

fuel cost

0.0 0.5 1.0 1.5 2.0

LWR(PWR)

GTHTR300

Fuel cost (Yen/kWh)

U purchase, conversionenritchmentfabricationMOXstoragereprocessingwaste disposal

Ref) K. Kunitomi, et al., Proc. ICAPP2007, Nice, France, May 13-18, 2007, Paper 7375.

• Power production by HTGR has economical advantage against LWR fleet because of significant cost savings through simplified plant design, high efficiency power conversion, etc.

• Can expect further improvement by increasing turbine inlet temperature, and taking into account profit from waste heat usage such as desalination

p.20

Multi-purpose Small-sized HTGR

Reactor

IHX

Steam generator

Steam turbine

Isolation valve H2 plant

District heating

Project Scope: • Electricity and heat supply to Kurchatov in Republic of Kazakhstan at an early date • Establishment of exporting business & creation of new industries in the future

Status: 2010: System design1), Safety design2)

2011: Core design3), 4)

2012: Plant design5) , Safety Evaluation2)

Conceptual design completed

1) H. Ohashi, et al., JAEA-Technology 2011-013 (2011). 2) H. Ohashi, et al., JAEA-Technology 2013-017 (2013). 3) M. Goto, et al., JAEA-Technology 2012-017 (2012).

4) Y. Inaba, et al., JAEA-Technology 2012-019 (2012). 5) H. Ohashi, et al., JAEA-Technology 2013-016 (2013).

Design philosophy: • Utilize technologies based on the HTTR construction as much as possible • Simplification of engineered safety features actuation systems from the HTTR • Demonstrate

technologies required in commercial plant such as helium gas turbine, etc.

p.21

Core Design Approach for Small-sized HTGR

Result Criteria

Average power density [MW/m3] 3.5 > 3.5

Enrichment count 3 < 6

Effective Full Power Days 730 730

Maximum fuel temp. [oC] 1467 < 1495

Target

Approach • Optimization of power distribution by

enrichment arrangement - Follow optimized power distribution curve for axial direction - Flatten power distribution in radial direction • Preservation of optimized power distribution during

the whole operational time by BP arrangement - Maintain CR position in the first layer of fuel region

• Average power density: 3.5 MW/m3

• Enrichment count : Less than 6 • Effective Full Power Days: 730 days

Coolant flow

Results

3.4

8 m

34

80

mm

0

58

116

174

232

290

348

0 200 400 600

Core

heig

ht

(cm

)

Burn-up (EFPD)

Co

re d

ep

th [

m]

0

3.48

1.74

CR position

EFPD 0 730

0

58

116

174

232

290

348

0 2 4 6 8 10C

ore

heig

ht

(cm

)

Power density (W/cc)

Fuel region 1

Fuel region 2

Fuel region 3

Fuel region 4

400 200 Power density

[MW/m3]

0 10 8 6 4 2 600

Optimized curve

Ref) M. Goto, et al., Proc. ICAPP2012, Chicago, IL , USA, Oct. 9-13, 2012, Paper 12415.

p.22

Business Model for Small-sized HTGR (1/2)

Gas to liquids (GTL) is a refinery process to convert natural gas into liquid synthetic fuels such as gasoline or diesel fuel.

Manufacturing cost highly depends on raw material cost, i.e. natural gas price.

HTGR can contribute to reduce natural gas consumption by 30% by replacing its use for fuel with high temperature heat & steam from HTGR.

Air Separation Gas processing

Gas Synthesis

FT(Fischer-Tropsch) process

Upgrading Process

Natural Gas Air

Diesel Naphtha Parafin

High temperature heat

Steam

HTGR GTL process

850oC

200oC - 350oC

0

10

20

30

40

50

1.0 2.0 3.0 4.0 Natural gas price [$/MMBTu]

44% 61%

70% 76%

Man

ufa

ctu

rin

g co

st [

$/b

bl]

Plant size: 15,000 bbl/day Construction cost: 488 M$ Lifetime: 15 years

*Pertamania & JOGMEC, Feasibility study of Gas to Liquid technology (2003).

Natural gas Synthetic fuel

Fuel use / Loss

Material 70%

30% Replace by heat supplied from HTGR

Raw material cost

Operation cost

Capex

p.23

Business Model for Small-sized HTGR (2/2)

Analysis condition - Reactor thermal power: 200MW - Construction cost: $2B (Conservative

assumption) - Fuel & O&M cost: Based on literature*

- Heat utilization: 90%

*INL, TEV-1196 (2012)

0

20

40

60

80

100

120

140

HTGR+GTL general GTL Diesel

Natural gas export loss

Diesel

HTGR (Fuel)

HTGR (O&M)

HTGR (Capital)

GTL (Non gas O&M)

GTL (Capital)

GTL (Gas usage)HTGR+GTL GTL Diesel

Man

ufa

ctu

rin

g co

st [

$/b

bl]

0

20

40

60

80

100

120

140

Analysis results • Manufacturing cost of HTGR-GTL

combined process becomes low considering export loss of natural gas even the construction cost of HTGR becomes high.

• The break-even point of natural gas price is 8.8 USD/MMBtu considering export loss.

Natural gas price: 10 USD/MMBtu

HTGR-GTL combined process would be economically competitive against conventional oil refinery & general GTL process

Man

ufa

ctu

rin

g c

ost

[$

/bb

l]

0

50

100

150

200

250

2 4 6 8 10 12 14 16 18 20 Natural gas price [$/MMBTu]

HTGR+GTL

GTL w export loss

$8.8/MMBTu

p.24

Nuclear Renewable Hybrid System

Time

Short time-scale (seconds/minitues)

Adjust power generation rate by

coolant flow rate control corresponding

to renewable output variation.

Nuclear

Solar,

Wind

Nuclear renewable hybrid system with HTGR cogeneration system for electricity and hydrogen

Constant

power

＋ Constant power

Hydrogen

Ele

ctr

ic p

ow

er

H2 plant

Precooler

Recuperator

Power generation

rate control

Heat supply

rate control

Control flow

Coolant flow

IHX

Renewable energy power plant

Reactor

Core

Allowable core thermal capacitance: 850 MJ/oC

Power

synthesisConstant

power

Electric grid

Coolant inventory Bypass flow rate

Power

output

Power

output

Generator

Gas turbine