20 Years of German R&D on Nuclear Heat Applications

Mitg

lied

der H

elm

holtz

-Gem

eins

chaf

t

20 Years of German R&D on Nuclear Heat Applications

Werner von Lensa, Karl Verfondern

Research Centre Jülich, Germany

4th Int. Freiberg Conference on IGCC & XtL Technologies – IFC2010

May 3-6, 2010, Dresden, Germany

Coal Refinement

790 kWh electricity

360 kg coal dust

250 kg charcoal

280 l methanol

160 l gasoline

550 m3 synthesis gas

150 m3 SNG

Conversion of 1000 kg of lignite

Conventional vs. Nuclear Technologies

Hot flue gas -> Steam generation

BUT: CO2 Emission

Chemical Reactions ~ 5 eV

Closed CO2 or He Circuit -> GCR

No CO2 Emission !

Nuclear Reaction ~200 MeV

40 Million more energy per reaction !

Steam

Firing Chamber

High-Temperature Gas-Cooled Reactor: Fully Ceramic Fuel Element

Temperature Resistant up to 1600°C

No Release of Fission Products

Main

Innovation

Prismatic Block-type Fuel

Fuel-Compacts

Flexibility in Application & Fuel

LEUTRISO

LWR-Wastein TRISO c.p.

WeaponPlutonium

TRISO

TRISO Fuel in graphite blocks

(or pebbles)

Pure Weapon -Pu, small ParticlesTRISO Coating750,000 MWd/HMt burn-up

Minor Actinides from reprocessing ofLWR Fuel, small particlesTRISO - Coating700,000 MWd/HMt burn-up

LEU C.-PartikelTRISO coated 100-150 GWd/HMt burnup

Electricity

Hydrogen

Process heat

One Reactor Design for different Applications

Thorium

Temperature Ranges Provided and Required

Prototype Nuclear Process Heat (PNP) Project

Identify suitable coal gasification processes on lab scale

Test selected processes on semi-technical scale

Construct and operate pilot plants for selected processes

Design large-scale nuclear plant for process heat prod.

Construct and operate prototype nuclear coalgasification plant

Construct and operate commercial nuclear coalgasification plant

20 years Duration: 1970s – 1990s

Drivers for Nuclear Coal Gasification

Resource savings of up to 40 %

Respective reduction in CO2 and other coal-specificemissions

Reduction and diversification of dependency on oil importsif coal is converted to liquid hydrocarbons

Help to meet growth rates in energy consumption and substitute for expensive electricity production with fossil fuels (if cost of nuclear heat is sufficiently low)

Design of PNP-3000 Nuclear Process HeatPlant

Thermal Power: 3000 MW(th)Power Density: 5 MW/m3

He inlet/outlet: 300/950°COTTO fuel loading scheme6 main loops with SR+SG or IHX4 decay heat removal systemsPrestressed concrete pressure vesselor Prestressed Cast-Iron Reactor

Pressure Vessel

Prototype Plant PNP-500

50 t/h coal41,000 m3 SNG

166 t/h coal26,500 m3 SNG + 18.4 t/h charcoal

HTGR

Steam gasificationof hard coal

Hydro gasificationof lignite

Alternative: HTR-Modul

Principal Lines of Steam-Coal Gasification

counter-current co-current co-current10-30 mm 1-10 mm < 0.1 mm60-90 min 15-60 min < 0.02 min370-600°C 800-950°C 1400-1600°C

Coal Gasification with Nuclear Energy

with steam: C + H2O H2 + CO - HCO + H2O H2 + CO2

------------------CO + 3 H2 CH4 + H2O

with hydrogen: C + 2 H2 CH4 + H

------------------CH4 + H2O CO + 3 H2 - H

CO + H2O H2 + CO2

Nuclear Steam Coal Gasification

Steam Coal Gasifier Design forPrototype Plant

Thermal Power: 340 MWCoal throughput: 50 t/hEffective volume: 318 m3

Heat exchanging area: 4000 m2

Nuclear SimulatedSteam Coal Gasification

Lab scale testing:1973-1980 with 5.0 kg/h

Semi-technical scale testing: 1976-1984 with 0.5 t/h

Gasification: at 750-850°C and 2-4 MPa

Total coal gasified: 2413 tOperation time: ~26,600 h with

~13,600 h under gasification cond.

Allothermal Gas Generator (Pilot Plant)Parameter Value

Thermal power [MW] 1.2

Helium inlet temperature [°C] < 1000

Helium flow [kg/s] 1.1

Heat exchanging surface [m2] 33

Height [m] < 4

Cross section [m2] 0.8 * 0.9

Fluidized bed density [kg/m3] 344

Coal input [kg/h] 233

Coal particle size [mm] < 1

Steam velocity [m/s] 1.13

Gasification temperature [°C] 700 - 850

Pressure [MPa] 4

Raw gas production rate [Nm3/h] 816

Conversion rate [%] 83

FIG. 3. Schematic of allothermal

gas generator.

Gas Composition after Steam Coal Gasification

High pressure increases methane content good for SNG productionHigh temperature increases hydrogen content good for syngas production

9-Days Test RunTest run with highly volatile caking coal

Constant levels of product gas components reveal operationwith no problem

Catalytic and Non-Catalytic GasificationA number of tests with K2CO3to accelerate reaction rate

Modest effect for 2 or 3 %, but large one for 4 %

Fluidized bed temperaturedecreased (as was predicted)

Catalytic and Non-Catalytic Gasification

Parameter Non-Catalytic Catalytic

Pyrolysis Gasification Pyrolysis Gasification

Helium temperature [°C] 895 895

Gasification temperature [°C] 805 701

Reaction enthalpy [kJ/kg coal] 2192 5678 2058 5148

Coal throughput [t/h] 27.3 69.3

Raw gas production rate [Nm3/h] 234,000 659,500

Gas composition fractions [%] H2: CO: CO2: CH4:

44.2 11.1 19.2 23.7

53.5 12.7 25.8 7.4

57.6 1.1 25.9 14.5

57.2 2.4 32.7 7.3

10 MW(th) Helical IHX

Steinmüller

10 MW(th) U-Tube IHX

Balke-Dürr

10 MW(th) Component Test Loop (KVK)

Thermal Power: 10 MW(th)Helium flow: 3.2 kg/sMax. He temp. prim/sec: 950/900°CSystem pressure: 4 MPaOperation time: ~13,000 h

Hot gas duct

IHX Header and Hot-Gas Valve Tests

Nuclear Hydrogenating Coal Gasification

10 MW(th) Steam Reformer

EVA-II reformer tube bundleat the Research Center Jülich

Technical Data of EVA-II/ADAM-II

Power Input 10 MW(e)Cooling gas flow rate 4 kg/s of heliumPressure 4 MPaTemperature max/min 950/350 °CSG temperature/pressure 700 °C / 5.5 MPaMethane input 0.6 kg/sSteam reforming temp. max 820 °CMethanation temp. max 650 °CADAM-II heat release rate 5.3 MW(th)

_____________________________________________From 1981 - 1986: 13,000 hours of operation, of which

7750 h at 900 °C and 10,150 h as complete process

Pilot Plant forHydro Coal Gasification

Semi-technical scale testing: 1975-1982 with 0.2 t/h

Pilot plant scale testing:1983-1986 with 10.0 kg/h

Gasification: at 850-950°C and 6-12 MPa

Coal throughput: ~40,000 twith up to 6400 Nm3/h of SNG

Operation time: ~8000 h

Methanation(Long-Distance Energy Transport)

EVA-ADAM facility at FZJ

Hydrogen & Process Heat for Refineries

Increasing Demand for Cogeneration of Heat, Power & Hydrogen

Plus Heat !

Plus Heat !

Hydrogen Short-Term Option: Electrolysis

Electrolysis ideal for remoteand decentralized H2 production

Off-peak electricity from existingNPP (if share of nuclearamong power plants is large)

As fossil fuels become more expensive, the use of nuclear outside base load becomes more attractive

200 m3/h

Medium-Term Option: HT-Electrolysis

Increased efficiency

Reduced electricity needs

Capitalize from SOFC efforts

Next Step: Demonstration at HTTR

Containment

HTTR

Reactor(30 MW)

SteamReformer

Hot Gas Ducts

Control-CentreIHX (10 MW)

Heavy Oil RecoveryConventional: 2t OIP 1t Product + 2,5t CO2Nuclear: 2t OIP + 12 MWh 2t Product + no CO2

Methanol ProductionConventional: 300m3 Gas 1t Product + 1,5t CO2Nuclear: 300m3 Gas + 3MWh 2t Product + no CO2

Oil ShaleConventional: 12t Shale 1t Product + 2,5t CO2Nuclear: 12t Shale + 12 MWh 2t Product + no CO2

Biomass ConversionConventional: 12t Biomass 1t Product (CH3OH)Nuclear: 12t Biomass + 10 MWh 2t Product

Double Yield from Energy Resources by NPH !Important Contribution to SUSTAINABILITY !

CO2 Reduction & Gain in Resources

Potential Arrangement of 600 MW VHTR for H2 Production

H2storage

Reactor building

Heat exchangeThermo-chemical

Water splittingprocess

from CEA

Potential Hazards in CombinedNuclear/Chemical Plants

Tritium transportation from core to productgases and hydrogen in opposite direction;

Thermal turbulences induced by problemsin steam reforming system;

Fire and explosion of flammable mixtureswith process gases.

Tritium in German Legislation

According to German Preventive RadiationProtection Ordinance, specific radioactivitylimit for any fabricated product is500 mBq/g.

Exception from the rule:No licensing required for fossil products to berefined by nuclear process heat with tritiumcontent < 5 Bq/g.

Sources:- fission (51%)- lithium (34%)- helium (15%)

Problem Tritium

High mobility of both HT and H2 at high temperatures- radiation problem to consumer- corrosion problem in graphitic core structures

Measures of reducing HT and H2 transport- oxide layers (doping with O2)- gas purification system- intermediate circuit (doping with H2O)

Results from FZJ and JAEA calculations and tests- HT level in product gas deemed sufficiently low- permeability of oxide layer reduced by factor 100-1000

German BMI Guideline (1974)

Protection by means of design against pressure wave

German BMI Guideline (1974) for theProtection of NPP against External Explosions

R = 8 * M 1/3

TNT equivalent for explosives

100% for unsaturated HC and non-liquefied gases50% for gases liquefied under pressure10% for gases liquefied at low temperatures0.3% for combustible liquids

Minimum Distance: R ≥ 100 m

Protection by means of safety distance

German BMI Guideline (1976)

Guideline was the result of experts‘ opinion.

Guideline was confirmed by PNP gas cloud programthat gas mixtures typical for PNP cannot generatepressures beyond the design curve.

However, Guideline must not be applied to processheat HTGRs.

If applied to HTTR/SR:k = 3.7 R = 205 m for LNG storage tank(not considered: inventory in steam reformer)

LNG: 400 m3 169 t 1859 t TNTR = 2.2 km

(or show that attendant risk be sufficiently low)

US Regulatory Guide 1.91 (1975)

Flame Velocities of H2-CO-Air Mixtures

Danger of Deflagration to Detonation Transition

Results from Coal Gasification Activities

Coal conversion using nuclear energy can save up to 40 % of resources.

Various coal conversion processes were developedand successfully tested in a wide range of operationparameters and coal types.

Technical feasibility of an allothermal gas generator as (the only) new component was successfullydemonstrated.

Key problem remains the selection of appropriatematerials (HX, gas generator), also with regard to catalytic coal conversion

General Achievements of PNP Project

Confirmation of technical feasibility of allothermal, continuous coal gasification

Manufacture and successful operation of high temperature heat-exchanging components

Demonstration of licensing capability of a nuclearprocess heat HTGR by resp. safety research

Economics to be re-evaluatedCompatible to actual European Energy Policy(e.g. SET Plan)

Thank youfor your kind attention

Contact: k.verfondern@fz-juelich.dew.von.lensa@fz-juelich.de