High temperature gas-cooled reactors

Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.

High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02

https://doi.org/10.1016/C2018-0-05383-9

As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.

Study of container using hybrid technique for sulfuric acid decomposition of thermochemical water-splitting iodine-sulfur process

Ioka, Ikuo; Iwatsuki, Jin; Kuriki, Yoshiro*; Kawai, Daisuke*; Yokota, Hiroki*; Kubo, Shinji; Inagaki, Yoshiyuki; Sakaba, Nariaki

Mechanical Engineering Journal (Internet), 7(3), p.19-00377_1 - 19-00377_11, 2020/06

https://doi.org/10.1299/mej.19-00377

A thermochemical water-splitting iodine-sulfur processes (IS process) is one of candidates for the large-scale production of hydrogen with high cost performance. Severe corrosive environment which is thermal decomposition of sulfuric acid exists in the IS process. A hybrid material with the corrosion-resistance and the ductility was made by a plasma spraying and laser treatment. The specimen had excellent corrosion resistance in the condition of 95 mass% boiling sulfuric acid. This was attributed to the formation of SiO on the surface. To confirm the production characteristics of a container using the hybrid material, the container which has a welded part, a chamfer, a curved surface was experimentally made. There was no detachment in the plasma spraying and laser treated layer of the container after the laser treatment. It was confirmed that the construction of the container with high corrosion resistance in sulfuric acid was possible in the hybrid technique.

Development of strength evaluation method of ceramic reactor for iodine-sulfur process and hydrogen production test in Japan Atomic Energy Agency

Takegami, Hiroaki; Noguchi, Hiroki; Tanaka, Nobuyuki; Iwatsuki, Jin; Kamiji, Yu; Kasahara, Seiji; Imai, Yoshiyuki; Terada, Atsuhiko; Kubo, Shinji

Nuclear Engineering and Design, 360, p.110498_1 - 110498_6, 2020/04

https://doi.org/10.1016/j.nucengdes.2019.110498

Japan Atomic Energy Agency (JAEA) has been conducting R&D on the thermochemical iodine-sulfur (IS) process for nuclear-powered hydrogen production. The IS process is one of the promising candidates of heat application of the high-temperature gas-cooled reactors. JAEA fabricated main chemical reactors made of industrial structural materials and confirmed their integrity in practical corrosive environments in the IS process. Based on the results of these confirmation tests, JAEA have constructed a 100 NL/h-H-scale test facility made of industrial structural materials. In this report, we succeeded in extending the hydrogen production time from 8 hours to 31 hours by developing a stable hydrogen iodide solution transfer technology in a continuous hydrogen production test. In addition, using the fracture test data of the ceramic specimen, an equation for estimating the strength of the ceramic component was developed.

Development of new corrosion test equipment simulating sulfuric acid decomposition gas environment in a thermochemical hydrogen production process

Hirota, Noriaki; Kasahara, Seiji; Iwatsuki, Jin; Imai, Yoshiyuki; Ohashi, Hirofumi; Yan, X.; Tachibana, Yukio

Zairyo To Kankyo, 68(6), p.137 - 142, 2019/06

https://doi.org/10.3323/jcorr.68.137

New corrosion test equipment for high temperature gas of decomposed sulfuric acid was manufactured in order to ascertain flow rate of sulfuric acid in the piping, occurrence of sulfuric acid decomposition reaction in the equipment, and temperature distribution inside the furnace tube. The flow rate of the sulfuric acid solution was constantly measured using an ultrasonic flowmeter. The SO concentration at the inlet of the test equipment was almost the same as that at the inlet of the sulfuric acid decomposer in the hydrogen production plant assuming a high-temperature gas cooled reactor hydrogen-power cogeneration system (GTHTR300C). On the other hand, during a test, leakage of sulfuric acid occurred from the fitting part at the outlet side. Hence the temperature distribution of the fitting part at the outlet side was investigated using fluid analysis. As a result, it was found that the temperature at the fitting was low enough to use fluorine joint grease when the distance was 0.05 m or more away from the outlet side pipe. An improved furnace tube was manufactured and the temperature was measured again at fitting part of the outlet side. The temperature was lower that the temperature limit of the joint grease and almost the same as the temperature distribution in the fluid analysis, and leakage of sulfuric acid has not occurred to date.

Development of container using plasma sprayed and laser treated material for sulfuric acid decomposition of thermochemical water-splitting iodine-sulfur process

Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kubo, Shinji; Inagaki, Yoshiyuki; Sakaba, Nariaki

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 5 Pages, 2019/05

A thermochemical water-splitting iodine-sulfur processes (IS process) is one of candidates for the large-scale production of hydrogen using heat from solar power. Severe corrosive environment which is thermal decomposition of sulfuric acid exists in the IS process. A hybrid material with the corrosion-resistance and the ductility was made by a plasma spraying and laser treatment. The specimen had excellent corrosion resistance in the condition of 95 mass% boiling sulfuric acid. This was attributed to the formation of SiO on the surface. To confirm the production characteristics of a container using the hybrid material, the container which has a welded part, a chamfer, a curved surface was experimentally made. There was no detachment in the plasma spraying and laser treated layer of the container after the laser treatment.

Current R&D status of thermochemical water splitting hydrogen production iodine-sulfur process in Japan Atomic Energy Agency, 2; Reliability improvements of corrosion-resistant equipment

Kamiji, Yu; Noguchi, Hiroki; Takegami, Hiroaki; Tanaka, Nobuyuki; Iwatsuki, Jin; Kasahara, Seiji; Kubo, Shinji

Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 7 Pages, 2018/10

Japan Atomic Energy Agency (JAEA) has been conducting R&D on the thermochemical iodine-sulfur (IS) process for nuclear-powered hydrogen production. The IS process is one of the promising candidates of heat application of the HTGR. JAEA achieved continuous hydrogen production for one week with a hydrogen production rate of 30 NL/h by using a test apparatus made of glass and fluororesin material. Subsequently, JAEA fabricated main chemical reactors made of industrial materials and confirmed their integrity in corrosive environments in the IS process. Based on the results, JAEA has constructed a 100 NL/h-H-scale test facility made of industrial materials; one of the important materials is the glass-lined steel for corrosion resistant components such as vessels, pipes and protective sheaths of sensors. This report will present technical matters to improve reliability of the glass-lined protective sheaths of thermocouple. In addition, results of quality confirmation will be presented, which are stress analyses for the glass layer by FEM, tests for heat cycle, bending load and corrosion.

Conceptual design of the iodine-sulfur process flowsheet with more than 50% thermal efficiency for hydrogen production

Kasahara, Seiji; Imai, Yoshiyuki; Suzuki, Koichi*; Iwatsuki, Jin; Terada, Atsuhiko; Yan, X.

Nuclear Engineering and Design, 329, p.213 - 222, 2018/04

https://doi.org/10.1016/j.nucengdes.2017.11.046

A conceptual design of a practical large scale plant of the thermochemical water splitting iodine-sulfur (IS) process flowsheet was carried out as a heat application of JAEA's commercial high temperature gas cooled reactor GTHTR300C plant design. Innovative techniques proposed by JAEA were applied for improvement of hydrogen production thermal efficiency; depressurized flash concentration HSO using waste heat from Bunsen reaction, prevention of HSO vaporization from a distillation column by introduction of HSO solution from a flash bottom, and I condensation heat recovery in an HI distillation column. Hydrogen of about 31,900 Nm/h would be produced by 170 MW heat from the GTHTR300C. A thermal efficiency of 50.2% would be achievable with incorporation of the innovative techniques and high performance HI concentration and decomposition components and heat exchangers expected in future R&D.

Development plan of austenitic Fe and Ni based alloys with improved corrosion resistance to sulfuric acid and HI fluids of industrial processes

Hirota, Noriaki; Iwatsuki, Jin; Imai, Yoshiyuki; Yan, X.

JAEA-Technology 2017-027, 19 Pages, 2017/12

JAEA-Technology-2017-027.pdf:2.08MB

In this study, austenitic Fe-based alloys and Ni based alloys was developed as candidate structural materials for equipment operated in sulfuric acid and hydrogen iodide (HI) environment, which exists in various industrial processes including iodine-sulfur (IS) hydrogen production process and geothermal power generation process. The objectives of the study are to achieve the corrosion resistance performance sufficient under the working condition of these processes and to overcome the practical scale-up difficulty of the ceramic (SiC) material that is presently used in the processes due to the manufacturing size limitation of the ceramic. The chemical composition development plan for the austenitic Fe-based alloys is threefold: reinforcement of matrix by addition of Cu and Ta, strength compensation of the surface film by addition of Si and Ti, and prevention of peeling of surface oxide by addition of rare earth elements. Because addition of Cu and Si is known to reduce the ductility of the material and thus manufacturability of the component, it is important to determine the allowable amount of each element to be added. On the other hand, the chemical composition development plan for the Ni based alloys is reinforcement of matrix by addition of Mo, W and Ta, strength compensation of the surface film by addition of Ti, and prevention of peeling of surface oxide by addition of rare earth elements. In particular, the addition of Mo and W to the Ni based alloy is expected to be effective in preventing dimensional deviation of structures from increasing during heating and cooling of process equipment. Various material specimens will be fabricated based on the above chemical composition development plans and tests on these specimens will then be carried out to confirm the corrosion resistance performance under the fluid conditions simulating each industrial processes.

Current R&D status of thermochemical water splitting iodine-sulfur process in Japan Atomic Energy Agency

Kasahara, Seiji; Iwatsuki, Jin; Takegami, Hiroaki; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Onuki, Kaoru; Kubo, Shinji

International Journal of Hydrogen Energy, 42(19), p.13477 - 13485, 2017/05

https://doi.org/10.1016/j.ijhydene.2017.02.163

Current R&D on the thermochemical water splitting iodine-sulfur (IS) process in Japan Atomic Energy Agency is summarized. Reactors were fabricated with industrial materials and verified by test operations: a Bunsen reactor, a HSO decomposer, and a HI decomposer. Reactors of industrial materials showed corrosion stability. Demonstration of the test facility verified integrity of process components and stability of hydrogen production. An 8 hours continuous operation of the total IS process was performed in February 2016 with H production rate of 10 L/h.

IS process hydrogen production test for components and system made of industrial structural material, 2; HSO decomposition, HI distillation, and HI decomposition section

Noguchi, Hiroki; Takegami, Hiroaki; Kamiji, Yu; Tanaka, Nobuyuki; Iwatsuki, Jin; Kasahara, Seiji; Kubo, Shinji

Proceedings of 8th International Topical Meeting on High Temperature Reactor Technology (HTR 2016) (CD-ROM), p.1029 - 1038, 2016/11

JAEA has been conducting R&D on the IS process for nuclear-powered hydrogen production. We have constructed a 100 NL/h-H-scale test apparatus made of industrial materials. At first, we investigated performance of components in this apparatus. In this paper, the test results of HSO decomposition, HI distillation, and HI decomposition were shown. In the HSO section, O production rate is proportional to HSO feed rate and SO decomposition ratio was estimated about 80%. In HI distillation section, we confirmed to acquire a concentrated HI solution over azeotropic HI composition in the condenser. In HI decomposition section, H could be produced stably by HI decomposer and decomposition ratio was about 18%. The HSO decomposer, the HI distillation column, and the HI decomposer were workable. Based on the results added to that shown in Series I, we conducted a trial continuous operation and succeeded it for 8 hours.