Technology Session “Nuclear Power as a Power Source for Decarbonization”

H2 production with superior-safety nuclear reactor
Organization

Japan Atomic
Energy Agency(JAEA)

Overview

Launched time1998• HTGR (High-temperature gas-cooled reactor) shuts down and cools core in case of the blackout accident without any equipment or operator actions• HTGR can supply up to 950℃ of heat, witch can be used for various applications suchas H2 Production, high efficient power generation• IS process (thermochemical water-splitting H2 production) can directly harness the heat fromHTGR, which offers a large hydrogen supply and maximum energy security
HTGR technologies developed in Japan・Small particle fuels havehigh ability to trap
radioactive materials

HTGRCore・Potentially, hydrogenexplosion does notoccur because of nowater (hydrogen source)

Fuel kernel
Ceramics shell

Graphite stricture hasheat resistance of2,500℃

H2 400 C HTGRo

H2+I22HII

2HI + H2SO4

I2 + SO2 + 2H2O

I2900oCO2

H2SO41/2O2+
SO2 + H2O

SSO2+H 2O

H2OHeSource © JAEA (https://www.jaea.go.jp/english/)Each spherical shell traps
radioactive nuclear fueleven above 1,600℃
1 mm

・Core melting must notoccur due to its highheat resistancetemperature

Fuel

Carbon-free H2 production under development
in Japan Atomic Energy Agency

950℃

HeHelium gas coolant
・Chemically stable

・IS process can decomposes H2O using chemical
reactions suitable for HTGR・No CO2 is produced because heat is supplied byHTGR
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Technology Session “Nuclear Power as a Power Source for Decarbonization”

H2 production with superior-safety nuclear reactor
Barriers on developing the innovation• HTGR
Conforming to new regulatory withenhanced safety requirements forrestarting HTTR to contribute thecarbon neutrality

HTTR： A testing reactor to establish HTGR
technologies constructed by JAEA

• IS process
Developing chemical reactors that can withstand hightemperature corrosive process environments. Solving
corrosive fluid leakage due to equipment corrosion andpump malfunction caused by solidification of iodine

Success factors to overcome the above barriers• HTGR
Since Nuclear Regulation Authority of Japan concluded thatsignificant core degradation including core melting would notoccur, HTTR restarted without significant additional
reinforcements• IS process
Developed chemical reactors from various heat-resistantcorrosion-resistant materials. Improved quality control ofcorrosion resistant equipment manufacturing and the pump
to prevent the solidification. Hydrogen production (30 L/h,150 h) was successfully accomplishedSource © JAEA (https://www.jaea.go.jp/english/)

Future action plan

• Issue
Since CO2 emissions from the industrial sector such as steelmaking account for
about 25% of the total emissions in Japan, large-scale /economical hydrogen supply
are required* for the hydrogen-reduction steelmaking currently under development
Plans* for 2050 carbon neutrality in nuclear energy sector〜2030〜2040(a) Technology
development necessary
for carbon-freehydrogen

Demonstration of coupling
between carbon-free hydrogenproduction plant and HTGR(b) Establishment of carbon-free hydrogenproduction technology using high-temperature
heat

Demonstration necessary forpractical scale

Demonstration testsof inherent safecharacteristics using
HTTR

〜2050
Cost reduction byexpansion ofmarket and mass
production*Source: Website of METI

• JAEA’s efforts to solve the above issues(a) Developing connection technologies(b) Making the prospect ofwhich have heat source andtechnological feasibility of carbonhydrogen production facility secured
free hydrogen production methods
Conceptual drawing of HTTR-heat utilization test

Hydrogen production test apparatus of IS process

Hydrogen
Production Facility

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