H2-MHR Conceptual Designs Basedon the SI Process and HTE

Matt Richards, Arkal Shenoy, Ken Schultz, Lloyd Brown – General AtomicsEd Harvego and Michael McKellar, Idaho National Laboratory

Jean-Phillippe Coupey and S.M. Moshin Reza, Texas A&M UniversityFutoshi Okamoto – Fuji Electric SystemsNorihiko Handa – Toshiba Corporation

Third Information Exchange on theNuclear Production of Hydrogen

andSecond HTTR Workshop on Hydrogen Production Technologies

Japan Atomic Energy AgencyOari, Japan

October 5 – 7, 2005

Presented by���������

General Atomics, San Diego, CA, USAMatt.Richards@gat.com

H2-MHR Conceptual Designs are Being Developed

• 3 year DOE NERI project with GA, INL, TAMU, & Entergy– Develop conceptual designs of “H2-MHR” hydrogen production plants– Initial focus on integration of MHR and Sulfur-Iodine-based hydrogen

production plant– Conceptual design also being developed for integration of MHR with High

Temperature Electrolysis– FY-05 is last year of project

• Participation in Related NERI/I-NERI Projects:– Centralized Hydrogen Production from Nuclear Power: Infrastructure Analysis

and Test Case Design Study (SRNL, GA, Entergy, ANL, Univ. S. Carolina)– High Efficiency Hydrogen Production from Nuclear Energy: Laboratory

Demonstration of S-I Water Splitting (SNL, CEA, GA)

• Additional Cooperation/Coordination with Various other Projects– UNLV High Temperature HX Project– Private collaborations with Fuji Electric / Toshiba– HTE Technology Development at INL

GT-MHR Provides Springboard to the H2-MHR• MHR coupled to a direct-

cycle Brayton power-conversion system

• 600 MW(t), 102 column, annular core, prismatic blocks

• Concept developed initially in the U.S.– Technology transferred to

Russia to further develop design for Pu disposition

– Similar concept being developed in Japan (JAEA GTHTR300)

ControlRods

PCS

Generator

Turbocompressor

Recuperator

Precooler

AnnularCore

Intercooler

MHR

The MHR is a Passively Safe Design

Passive Safety Features• Ceramic, coated-particle

fuel– Maintains integrity during loss-

of-coolant accident• Annular graphite core with

high heat capacity– Helps to limit temperature rise

during loss-of-coolant accident

• Low power density– Helps to maintain

acceptable temperatures during normal operation and accidents

• Inert Helium Coolant– Reduces circulating and

plateout activity

ControlRodDriveAssemblies

ReactorMetallic Internals

ReplaceableReflector

Core

Reactor Vessel

Shutdown Cooling System

Hot GasDuct

ControlRodDriveAssemblies

ReactorMetallic Internals

ReplaceableReflector

Core

Reactor Vessel

Shutdown Cooling System

Hot GasDuct

Ceramic Fuel Retains its Integrity Under Severe Accident Conditions and is an Ideal Waste Form for Permanent Disposal

Uranium OxycarbidePorous Carbon BufferSilicon CarbidePyrolytic Carbon

PARTICLES COMPACTS FUEL ELEMENTS

TRISO Coated fuel particles (left) are formed into fuel rods (center) and inserted into graphite fuel elements (right).

Reactor Design is Being Optimized for Higher Temperature Operation

• Optimize Power Distributions– Fuel placement or sandwich shuffling refueling schemes to reduce

“age” component of power peaking– Improved zoning of fissile/fertile fuel ratio and burnable poison– Use control rods in inner and outer reflector

• Reduce radial component of power peaking• Temperature limitations may require C-C clad rods

• Optimize Thermal Hydraulic Design– Reduce bypass flow

• Core restraint and sealing devices to minimize gaps• Reduce or eliminate flow in control-rod channels using C-C rods• Goal is to reduce bypass flow fraction from about 0.2 to about 0.1

– Alternative Inlet Flow Configurations• Reduce vessel temperature• Route flow through inner and/or outer reflector

• Use Higher-Temperature Metals, C-C Composites for Reactor Internal Components

Alternative Inlet Flow Configurations Can Reduce Vessel Temperatures

Reference GT-MHR(channel box)

(a) (b)

InnerReflector

Permanent SideReflector

ATHENA code used to assessalternative flow configurations

Inner reflector configuration removes significant heat capacity, resulting in higher fuel temperatures during accidents

H2-MHR Point Design Options Have Been Evaluated

GT-MHRH2-MHR

Orificed CoreH2-MHR

Optimized Core

Power Level (MWt)

600 600 600

Helium Inlet Temperature (°C)

490 490 590

Helium Outlet Temperature (°C)

850 1000 950

Coolant Flow Rate (kg/s)

320 226 320

Core Pressure Drop (kPa)

~50 ~50 >50

Orificed Core: Use of fixed orifices in upper/lower reflectorOptimized Core: Possible limited use of fixed orifices on “cold”

columns for additional design margin on fuel temperatures

Core Nuclear / Thermal Hydraulic Optimization – Scoping Studies

Fuel Temperatures

0.0 0.2 0.4 0.6 0.8 1.0

Volume Fraction

500

600

700

800

900

1000

1100

1200

Fuel

Tem

pera

ture

, °C

Reference GT-MHR491°C Coolant Inlet Temperature850°C Coolant OutletTemperature

H2-MHR491°C Coolant Inlet Temperature1000°C Coolant OutletTemperature

Irradiation Time, Effective Full Power Days0 100 200 300 400 500 600 700 800

SiC Layer Failure Probability

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

1350°C

1300°C

1250°C

Fuel Performance

Sulfur-Iodine CycleI-NERI Demonstration

Sandia

CEA

GA

MHR Coupled to S-I Thermochemical Water Splitting

H2O

SO2+H2O

H2SO4

HI

I2

BunsenReactor

High Temp HX -H2SO4 Decomposer

O2

High Temp HX -H2SO4 Decomposer

O2O2

H2Low Temp HX-HI Decomposer

H2Low Temp HX-HI Decomposer

H2Low Temp HX-HI Decomposer

565ºC

Inte

rmed

iate

HX

900ºC

950ºC590ºC

600MWthermalModularHelium Reactor

565ºC

Inte

rmed

iate

HX

900ºC

950ºC590ºC

600MWthermalModularHelium Reactor

Aspen flowsheet evaluations show efficiencies of about 45% based on HHV of H2

Conceptual IHX Design has Been Developed Based on HEATRIC Printed Circuit Heat Exchanger (PCHE)

Stacked Plates with Counterflow Diffusion Bonding Restores Properties of Base Metal

Shell and Tube: 100 tonnes

PCHE: 15 tonnes

High Temperature and High Pressure Capability

Compact, Lighter-Weight Design

PCHEs using higher temperature alloys are currently being developed by HEATRIC.600 MW(t) IHX would consist of 40 15-MW(t) modules.

MHR Coupled to High-Temperature Electrolysis

MHR 600 MW(t)

CIRC

Turbine

Separator

Gen

Electrolysis

Recuperator

Pre-Cooler

Helium

Helium

Helium

SteamGenerator

Steam

Hydrogen

Oxygen

Water

Electricity

Inter Cooler

IHX

HPComp

LPComp

CIRC

85%

15%

HTE-Based H2-MHR FlowsheetWater Supply System

Heat Transfer System

SecondaryHelium

H2 startuptank

Condensate

Primary Side Circulator

FLOWSHe primary (HOT)He secondary (cold)He primary in PCS

H2H2 mix

steam mixliquid waterwater steam

O2 with sweepO2 with negligible sweep

Brayton CyclePower Conversion System

(PCS)Secondary Side Circulator

H2 recirculator

Hydrogen Production System

Electric heater

H2 / waterknockout tank

Feedwater pump

O2 withsweepSweep steam

WaterPurification

System

H2 mix

steam mix

Inte

rcoo

ler

(Wat

er C

oole

d)

600C

112C

94C

582C

858C

444C

210C

22C

280C

858C

22C 141C

168C

27C

H2 product

IHX

950C 925C

351C637C

38.0 kg/s

2.6 kg/s

14.4 kg/s

23.6 kg/s 0.3 kg/s

26.4 kg/s

Prim

ary

Hel

ium

Sweep water fromwater storage

Generator

Bypa

ss V

alve

Pre

cool

er(W

ater

Coo

led)

Recuperator

Turbine

Low PressureCompressor

High PressureCompressor

Water tosweep system

Steam Generator

Super Heater

72C582C

Reactor System

Mod

ular

Hel

ium

Rea

ctor

600

MW

(t) 950C

26C

26C

590C

590C

642C

450C

832C

347C

827C

H2O / O 2knockout tank

Sweep condensate

27C

29C

27C

22.0 kg/s

17.0 kg/s

5.0 kg/s

827C

23.9 kg/s

water fromsweep condensate

Waterstorage

22C

14.4 kg/s 33.0 kg/s

Electricity fromPCS

Power Supply

Solid OxideElectrolyzer

Cathode

Ele

ctro

lyte

Anode

5.3 kg/s

2.4 kg/s

41.7 kg/s

321.1 kg/s

279.4 kg/s

160C

266C

257C

536C

41.7 kg/s 22.0 kg/s

925C

925C

21C 7.5 kg/s

02 / steam expander

POWER

210C

210C

6.6 kg/s

14.4 kg/s

2.7 kg/s27C

5.3 kg/s

27C

27C

O2 output21C

18.9 kg/s

Results of HTE Flowsheet Using HYSYS Process Simulation Software

MHR Module Thermal Power 600 MW(t) MHR Coolant Outlet Temperature 950°C

PCS Power Generation 312 MW(e)

PCS Thermal Efficiency 52%

Thermal Power Supplied for Hydrogen Production 68 MW(t)

SOE Process Temperature 827°C Power Supplied to SOE Modules 292 MW(e) Hydrogen Production Rate 2.36 kg/s Hydrogen Production Efficiency (based on HHV of H2) 55.5%

Auxiliary Power Generation 9.3 MW(e) Overall Process Efficiency 59.9%

Solid Oxide Electrolyzer Technology Has Been Successfully Tested

10-Cell Stack Tested at INL

4-MW(e) Trailer Module

Hydrogen Plant Will Not Impact Passive Safety

• Licensing issue of most concern is co-location of MHR and Hydrogen Plant– Passive safety of MHR allows

co-location– Earthen berm provides

defense-in-depth• Other reactors located in

close proximity to hazardous chemical plants and transportation routes– NRC allows risk-based

approach– INL recommends 60 to 100 m

separation distance

Economics for Nuclear Hydrogen Production are Competitive With Steam-Methane Reforming

SI-Based PlantHTE-Based

Plant

Capital Costs ($M)Reactor System

1030 1284

Hydrogen System

738 TBD – Depends on SOE unit

costsO&M Costs ($M/yr)Reactor System

27.8 34.6

Hydrogen System

70.9 TBD – Probably less than SI

plantHydrogen Cost ($/kg)

1.65 TBDNatural Gas Cost ($/MMBTU)

0.0 2.0 4.0 6.0 8.0 10.0 12.0

Hyd

roge

n C

ost (

$/kg

)0.50

1.00

1.50

2.00

2.50

Nuclear (SI Process)

Methane Reforming w/o CO2 Capture

Methane Reforming withCO2 Capture

Current Price

H2-MHR 4-Module Reference Design

• Standard MHR (850°C) or VHTR (950°C - 1000°C)reactor

• Intermediate Heat Exchanger (IHX) in adjacent cavity

• Intermediate heat transport loop

• MHR Passive Safety maintained

• H2 plant separation by berm• Non-nuclear H2 plant• 600 MWt ⇒ 200 tons/day

hydrogen production

4 MHR Modules, each with IHX

Earthen Berm

Hydrogen Production Plant

Cooling Towers

CONCLUSIONS• MHR is well suited for

hydrogen production– Passively safe reactor

design– Produces high

temperature heat needed for SI process and HTE

– Proof of principle for both SI process and HTE have been demonstrated

– Both SI process and HTE show potential for economical production of hydrogen without producing carbon dioxide

• MHR technology can be applied to other missions

LEUTRISOLEU

TRISO

LWRSpent Fuel

TRISO

LWRSpent Fuel

TRISO

WeaponsPlutonium

TRISO

WeaponsPlutonium

TRISO

TRISO Fuel in fuel blocks

Electricity

Hydrogen

One Reactor Design can be used for Multiple Applications

Er-167 burnable poisonPure W-Pu, small kernelTRISO coated 750,000 MWd/HMt burnup

Minor Actinides burnable controlLWR Actinides, small kernelTRISO coated 700,000 MWd/HMt burnup

Conventional burnable poisonLEU large kernel - fertile fuelTRISO coated 100,000 MWd/HMt burnup

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Thank you for your kind attention.

Solid Oxide Electrolyzer Technology Has Been Successfully Tested

Requirements for a 600 MW(t) MHR Module10-Cell Stack Tested at INL

Cell Area Individual Cell Width 10 cm Individual Cell Active Area 100 cm2

Total Number of Cells 12 x 106

Total Active Cell Area 120,000 m2

Cell Thickness Electrolyte 10 µm (Scandia Stabilized

Zirconia) Anode 1500 µm (Strontium Doped

Lathanum Manganite) Cathode 50 µm (Nickel Zirconia

Cermet) Bipolar Plate 2.5 mm (Stainless Steel) Total Cell Thickness 4.06 mm Stack Dimensions Cells per Stack 500 Stack Height 2.03 m Stack Volume 0.0203 m3

Stack Volume with Manifold 0.0812 m3 Number of Stacks 24,000