Email: [email protected] JAEA`s Oarai R&D Center

2 Contents

1. Nuclear production (in general) 2. based on HTGR 3. R&D for hydrogen in JAEA

3 1. Nuclear hydrogen production – various pathways*

Fission Reactors

Energy conversion ->Electricity, Heat Powered by nuclear or hybrid systems * CRC Press, USA (2011)

Heat Electricity (75%) Heat (75%) Electricity (~50%) Energy input Electricity Fossil fuels Heat (25%) Electricity (25%) Heat (~50%

Hydro- Feed stocks Water Water Water Steam Steam Thermochemical Hybrid cycle Hydrogen Water reforming electrolysis water-splitting water-splitting processes electrolysis (500-850oC) (700~800oC) (850oC) (550~850oC)

H2, CO2 Hydrogen, , CO2-Free 4 Match nuclear reactors to H2 production processes Nuclear reactors and their coolant temperature ranges HTGR a.k.a. VHTR IV - Reactors Generation

Existing reactors Industrial process temperature range

Hybrid cycles Water electrolysis Steam electrolysis 5 2. Hydrogen production based on HTGR – Reactor general features

JAEA`s HTTR Graphite fuel block Moderator Graphite block (Temperature Limit) (2500 °C) fuel TRISO- ceramic coated particle (Temperature Limit) (1600 °C) Fuel rods & Fuel cladding Graphite fuel compact (Temperature Limit) (2500 °C) Ceramic coated particle fuel UO fuel kernel (0.6mm Dia.) Coolant Helium gas 2 1.Pyrolytic Carbon (inert, single-phase) 2.Silicon Carbite (max. temperature) ° Barrier Coating (950 C) 3. Inner Pyrolytic Carbon 4.Porous Carbon Buffer Neutron Spectrum Thermal neutrons 0.92 mm Fuel particle

6 JAEA`s HTGR Test Reactor – HTTR (high temperature engineering test reactor)

Main design parameters Reactor building Interior Thermal power 30 MWt Dry cooling Fuel SiC TRISO UO coated 2 tower particle fuel, pin in block Design type Prismatic core Coolant Helium Control room Temperature 850~950 °C Pressure 4 MPa

Refuel machine Intermediate heat exchanger

Containment Reactor core vessel 7 HTTR milestones : R&D, construction and operation

ITEM FY 1969 ・・・ 1987 ・・・・ 1990 1991 ・・・ 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 ・・・ 2010 ▼ ▼ ▼ ▼ R&Ds Construction start 950°C start ▼ 30 MW, 850°C (Apr 19) Milestone Construction decided ▼ (Dec 7) Long-term program for R&D and utilization of nuclear First criticality energy (Nov 10)

Construction Construction of reactor building & components

Fuel fabrication Fuel loading ▼ Safety Commissioning test test LOFC Test and ▼ Operation Criticality test Power-up test 950°C 50 days Rated power operation and safety demonstration tests operation

8 HTGR passive safety eases co-location to hydrogen processes : reduce heat transmission loss and cost

1. Ceramic (SiC) coated 3. Graphite core fuel particle Underground building Reactor Negative reactivity coefficient, o pressure high heat capacity and large Proven integrity at 1600 C Air vessel Air thermal conductivity of graphite core provide for safe removal of core decay heat to external VCS. Earth

Fuel kernel TRISO ceramic coatings 100 Fuel pin No failure of fuel coating 50 ° at < 1600 C Fuel block of (%) coating

Failure fraction Failure 0 3000 1600 3000 Core 1000 2000 C ) Temperature (oC) Heat o radiation Heat Experimental result Vessel cooling 2000 Fuel design limit 1600oC conduction system (VCS)

1000 2. Inert helium coolant Reactor is safely shutdown and Fuel temperature cooled by inherent design features ( Fuel temperature 0 No explosions of H2 and vapor due without reliance on any equipment 0 1 2 3 4 5 6 7 to chemical inertness and absence or operator action in the event of Elapsed time (day) of phase change of helium coolant loss of coolant or station blackout. Simulation of loss-of-coolant 9 GTHTR300 coupling to industrial cogeneration

Reactor primary system H2 cogeneration plant Reactor

Heat transmission piping: 50~200 m distance

MSF desalination Reactor cogeneration plant Production parameters Reactor thermal power 600 MWt Reactor temperature 850-950oC Production rates (not simultaneous) • Hydrogen production 120 t/d • Power generation 300 MWe Heat transmission • Desalination (cogenerated w/power) 55,000 m3/d piping • Steel (CO2 free steelmaking) 0.65 million t/yr 10 Hydrogen Production - Methane Steam Reforming

Steam reforming reaction (endothermic, ~850oC) Conventional Reforming: CH4 + H2O → CO + 3H2, ΔH=206 kJ/mol  widely practiced in the world Water gas shift reaction (exothermic)  35% methane is used as fuel CO + H2O → CO2 + H2, ΔH=−41 kJ/mol for endothermic reaction

HTGR HTGR coupled reforming:  save methane and reduce CO2 by 35% H2  deployable early because Methane reforming process is relatively Water developed

Steam reforming plant

11 Nuclear methane steam reforming developed in JAEA

Coupling to be built !

Existing

Helium heated steam reforming facility operated in 2005

12 Hydrogen production – iodine-sulfur (IS) thermochemical water-splitting process

o IS process consists of 3 chemical reactions o o It requires high temperature heat at 400-900 C o The process is free of CO2 emission

400~ Heat 800~ H 500oC 900oC O 2 (HTGR) 2

H2 1/2O2 + 2HI H2SO4 + I2 SO2 + H2O

Hydrogen iodide 2HI + H2SO4 Sulfuric acid SO (HI) I I2 + SO2 + 2H2O S 2 (H2SO4) decomposition + decomposition I2 reaction H2O reaction

H O Bunsen reaction 2 (HI and H2SO4 production) 13 IS process flowsheet for commercial plant* 3 o Heat and mass balance for 31,860 Nm /h-H2 (225 MWt) o Thermal efficiency 50.2%

16,050 Nm3/h 25.8 t/h 31,863 Nm3/h (1.2MPa) ½ O 2 H2O H2

SO3(g)→SO2(g)+0.5O2(g) SO2(g)+I2(L)+2H2O→ 2HI→H (g)+I (g) H2SO4+2HI 2 2 He SO o 3 SO , H O Bunsen I , H O I HI decomp. 726 C decomp. 2 2 2 2 2 He reactor 19.0 MWt 894oC (H O) 73.3MWt 1.2 MPa 2 0.3 MPa o 1.2 MPa o 100 C 850 C 435oC

H2SO4(L)→SO3(g)+H2O(g) SO3, H2O

Sulfuric Liq-liq Purifier & H2SO4 Purifier & H SO He 2 4 phase concentrate acid concentrate 610oC separator decomp. (H O) 1.2 MPa HI 53.0MWt 2 HIx 1.2 MPa 0.3 MPa 270oC 1.2 MPa o o 395 C 100oC 468 C (H2O)

Utilities electricity He 12.2MWe Electricity 486oC 15.3MWe 29.7MWt *S. Kasahara, et al., Conceptual design of the iodine–sulfur process flowsheet with more than 50% thermal efficiency for hydrogen production, Nuclear Engineering and Design 329 (2018) 213–222 14 JAEA development for IS-process hydrogen production

Development of industrial material components Commercial • Fluoroplastic lining Continuous H2 production test Bunsen reactor deployment • SiC (Silicon carbide) Technology transfer H2SO4 decomposer Present to private sector H2 production test facility HTTR-GT/H test • Ni base alloy HI （～0.1 Nm3/h scale） 2 decomposer Industrial material Establishment 1.3 m component test 2010～ of base technology R&D on elemental technologies H facility 2005～2009 2 HTTR Bench-scale test 1999～2004

• 1-week continuous H2 production by glass Helium gas turbine Lab-scale test apparatus power generation ~1997 3 (0.03 Nm /h-H2)

15 IS process facility operated in JAEA  Integrated IS process loop constructed of industrial materials  100 L/h H2 design capacity  Closed cycle operations are being carried at increased production rates and periods:  2016.2: 10 L/h, 8 hours,  2016.10: 20 L/h, 31 hours  2019.01: 30L/h, 150 hours (latest test)

800 水素製造量 H2 [NL] 700 Oct. 2016

2 酸素製造量 O2 600 Rate of H2 and O 500

2 (ca. 20 L/h) 400 decomp .

4 300 SO

decomp . 200 2 Bunsen H

HI 100

Production Production of H 0 0 5 10 15 20 25 30 35 Time [h]

16 Technical challenges for IS process

 Chemical engineering —Separating products from reactants, by-products —Purification to remove impurity  Process engineering —Process monitoring and automation —Thermal efficiency  Practical engineering — Reduce construction cost – developing new metals (to replace SiC) for corrosion resistance — Scale up to practical plants

17 Nuclear power/H2 + renewables for zero emission grid

o Supply 66% electricity demand (in Japan) while load following VRE for grid stability (GF/LFC) ＋ o HTGR produces hydrogen when HTGR+H2 Solar/Wind demand for electricity is low (EDC) Nuclear + VRE hybrid system Peak load • H2 Demand • H2 gas turbine HTGR power/H2 cogeneration Load Demand

Nuclear + VRE hybrid power Generation

nuclear power baseload

Hydro Daily hours 18 Zero emission grid simulation : Japan nationwide

20000 HTGR高温ガス炉 Solar太陽光 SFR高速炉 LNG水力 Wind風力 Demand需要 Generation mix % 15000 Solar 19 2018/3/24 Wind 7 10000

Hydro 8 5000

Biomass － [MW] Electricity 0 20000 LNG with CCS － 高温ガス炉 太陽光 高速炉 2018/7/17水力 風力 需要 HTGR 33 15000 SFR 33 10000

 Power generated：[email protected]¥/kWh 5000  H2 co-produced : 13.5Mt or 29% 3 Japan`s demand in 2050 (@25¥/Nm ) [MW] Electricity 0 24 hours 19 3. R&D for hydrogen in JAEA

(1) HTTR test reactor (2) BOP application technology HTTR  JAEA built and operated  R&D of nuclear the 30 MWt and 950oC helium gas turbine prismatic core HTGR test reactor (Operation He compressor from 1998 to present)  Developed technologies of fuel, graphite, superalloy and gained experience of operation,  R&D on IS process and maintenance. hydrogen production

(3) Commercial plant design (4) Connection technology  Develop GTHTR300 plant  Demonstration of design for power generation, nuclear hydrogen cogeneration of hydrogen, cogeneration on steelmaking, desalination, HTTR GTHTR300 HTTR-GT/H2 and for hybrid system with renewable energy   Establish safety standards for commercial Completed pre-licensing basic design plants. for an HTTR-GT/H2 test plant. 20 Nuclear hydrogen production – HTTR-GT/H2 test plan

 Objectives • To demonstrate nuclear hydrogen and electricity cogeneration system performance and cost • To license nuclear hydrogen production coupling to HTGR

1. Gas turbine power Dry cooling tower generator set H2SO4 decomposer HI decomposer

Coupling – high temperature heat transport loop with isolation valves Bunsen reactor HTTR Building （existing facility） 2. Hydrogen production Reactor (IS process) plant

PPWC 3. Heat exchanger for potential heat applications (steam supply, desalination, etc)

Containment vessel IHX Multiple cogeneration capabilities （New facility for demonstration) 21 Summary - Nuclear production of H2

1. It is practical today • Nuclear + water electrolysis 2. Current R&D goals are safer, more economical, more sustainable, flexible system, based on: • Advanced reactors • Advanced hydrogen producing processes • Cogeneration and hybrid systems 3. Deployment by 2050 • Demonstration - coupling of nuclear to industrial heat process plants • Establish regulatory requirements

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