Nuclear Production of Hydrogen, Fourth Information Exchange ...

PRESENT STATUS OF HTGR AND HYDROGEN PRODUCTION DEVELOPMENT IN JAEA
Figure 6: Development of IS process in JAEA
0.001 0.03 30 1000
H 2 (m 3 /h)
Electric heater
Glass
Electric heater
Glass
He gas
Industrial materials
Nuclear
demonstration
Lab-scale test
(~1997)
Bench-scale test
(~2004)
Process
engineering
HTTR-IS test
Verification
of closedcycle
watersplitting
Demonstration
of continuous
hydrogen
production for
one week
Figure 7: Main flow diagram of IS process
up to 500°C. JAEA proposed a concept of the sulphuric acid decomposer featuring multi-hole heat
exchanger blocks made of SiC ceramic (Figure 8). He gas flows through the inside channels of the SiC
ceramic blocks, and exchanges the heat with the counter-current H 2 SO 4 flow. The SiC ceramic blocks
of 0.25 m in outer diameter and 0.75 m in height are piled vertically. Pure gold, which exhibits excellent
corrosion resistance against high-temperature H 2 SO 4 , is used as the seal material between the SiC
ceramic blocks. The mock-up model of sulphuric acid decomposer was test-fabricated confirming the
fabricability and the structural integrity as shown in Figure 8 (Terada, 2006; Noguchi, 2006). Also, tests
have been carried out such as test fabrication of pump made of corrosion-resistant materials for the
transportation of high-temperature acidic solutions, and heat and corrosion resistance tests of
cost-effective glass lining materials. At the same time, development of a membrane technology is in
progress to improve the thermal efficiency of hydrogen production.
The reliability of component technologies and the controllability of hydrogen production system
will be examined in the next step. After completion of these tests on IS process, it is planned to
proceed to the nuclear hydrogen demonstration stage using HTTR (HTTR-IS), which will produce
hydrogen at a rate of up to 1 000 Nm 3 /h. The HTTR-IS test is the goal of HTTR project. Until, then,
necessary evaluation and component tests; safety evaluation against hydrogen explosion and
isolation valve tests will be completed.
52 NUCLEAR PRODUCTION OF HYDROGEN – © OECD/NEA 2010