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Journal Articles

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

 Times Cited Count:1 Percentile:24.17(Nuclear Science & Technology)

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$$_{2}$$-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.

Journal Articles

A $$Sigma p$$ scattering experiment at J-PARC and the analysis status

Nakada, Yoshiyuki*; Hasegawa, Shoichi; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Nanamura, Takuya*; Naruki, Megumi*; Sako, Hiroyuki; Sato, Susumu; et al.

JPS Conference Proceedings (Internet), 26, p.023024_1 - 023024_5, 2019/11

Journal Articles

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. L.; Tachibana, Yukio

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

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$$_{3}$$ 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.

Journal Articles

Current R&D status of thermochemical water splitting hydrogen production iodine-sulfur process in Japan Atomic Energy Agency, 1; Hydrogen production test and component development

Takegami, Hiroaki; Noguchi, Hiroki; Tanaka, Nobuyuki; Iwatsuki, Jin; Kamiji, Yu; Kasahara, Seiji; Imai, Yoshiyuki; Terada, Atsuhiko; 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 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$$_{2}$$-scale test facility made of industrial structural materials. This report will present an outline and results of hydrogen production tests and reliability improvements of operation stability and components, such as development of a strength estimation method for heat-resistant and corrosion-resistant ceramics components made of silicon carbide.

Journal Articles

RELAP5 modeling of the HTTR-GT/H$$_{2}$$ secondary system and turbomachinery

Humrickhouse, P. W.*; Sato, Hiroyuki; Imai, Yoshiyuki; Sumita, Junya; Yan, X. L.

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

This work describes the development of a RELAP5-3D model of the HTTR-GT/H$$_{2}$$ plant secondary system. The RELAP5-3D model presently includes detailed models of several of the heat exchangers in the secondary system as well as the turbomachinery, which includes two compressors and two gas turbines connected to a common shaft and motor. The predictions of the model agreed well to design parameters in both sole power generation and hydrogen co-generation modes in most instances. Both the turbomachinery and heat exchanger models rely on extensive customization via RELAP5-3D control variables, and these implementations are outlined in detail. Potential improvements to the RELAP5-3D turbine model are discussed.

Journal Articles

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

 Times Cited Count:4 Percentile:29.78(Nuclear Science & Technology)

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 H$$_{2}$$SO$$_{4}$$ using waste heat from Bunsen reaction, prevention of H$$_{2}$$SO$$_{4}$$ vaporization from a distillation column by introduction of H$$_{2}$$SO$$_{4}$$ solution from a flash bottom, and I$$_{2}$$ condensation heat recovery in an HI distillation column. Hydrogen of about 31,900 Nm$$^{3}$$/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.

Journal Articles

Design of HTTR-GT/H$$_{2}$$ test plant

Yan, X. L.; Sato, Hiroyuki; Sumita, Junya; Nomoto, Yasunobu*; Horii, Shoichi*; Imai, Yoshiyuki; Kasahara, Seiji; Suzuki, Koichi*; Iwatsuki, Jin; Terada, Atsuhiko; et al.

Nuclear Engineering and Design, 329, p.223 - 233, 2018/04

 Times Cited Count:6 Percentile:15.83(Nuclear Science & Technology)

The pre-licensing design of an HTGR cogeneration test plant to be coupled to JAEA's existing test reactor HTTR is presented. The plant is designed to demonstrate the system of JAEA commercial plant design GTHTR300C. With construction planned to be completed around 2025, the test plant is expected to be the first-of-a-kind nuclear system operating on two of the advanced energy conversion systems attractive for the HTGR closed cycle helium gas turbine for power generation and thermochemical iodine-sulfur water-splitting process for hydrogen production.

JAEA Reports

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.

JAEA Reports

Design database of helium gas turbine for HTTR-GT/H$$_{2}$$ test plant (Revised version)

Imai, Yoshiyuki; Sato, Hiroyuki; Yan, X.

JAEA-Data/Code 2017-011, 39 Pages, 2017/08

JAEA-Data-Code-2017-011.pdf:2.93MB

This report is the revised version of the report titled "Design Database of Helium Gas Turbine for High Temperature Gas-cooled Reactor, JAEA-Data/Code 2016-007" reflecting component design and experimental data analysis results for fission product isotope diffusion through the turbine blade alloy conducted in Fiscal Year 2016.

Journal Articles

Observation of $$Xi$$ bound states in the $$^{12}$$C$$(K^-,K^+)X$$ reaction at 1.8 GeV/$$c$$ in J-PARC

Nagae, Tomofumi*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; Tanida, Kiyoshi; et al.

Proceedings of Science (Internet), 7 Pages, 2017/05

Journal Articles

Study of the $$overline{K}$$-nucleus interaction by using the $$^{12}$$C(K$$^{-}$$, p) reaction at J-PARC

Ichikawa, Yudai; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Imai, Kenichi; Kimbara, Shinji; Nakada, Yoshiyuki; Sako, Hiroyuki; Sato, Susumu; et al.

JPS Conference Proceedings (Internet), 13, p.020007_1 - 020007_5, 2017/02

An interaction between K$$^{bar}$$ and nucleus is studied by using the X-ray from the kaonic atoms for a long time. However, it is difficult to determine the K$$^{bar}$$-nucleus interaction by using only kaonic-atoms data because the value of shift and width of the X-ray depend not only the potential depth but also the type of theoretical model. Thus, we study the $$overline{K}$$-nucleus interaction by comparing an observed missing-mass spectrum of the $$^{12}$$C(K$$^{-}$$, p) reaction with the DWIA calculation. Such a study has already reported from KEK-E548 experiment. However, their experiment is not enough to determine these interaction because they were pointed out about the experimental condition. Thus, we performed the further experiment to take the real spectrum of $$^{12}$$C(K$$^{-}$$, p) reaction at J-PARC.

Journal Articles

Conceptual design of 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.

Proceedings of 8th International Topical Meeting on High Temperature Reactor Technology (HTR 2016) (CD-ROM), p.491 - 500, 2016/11

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 Japan Atomic Energy Agency's commercial Gas Turbine High Temperature Reactor Cogeneration (GTHTR300C) plant design. Innovative techniques proposed by JAEA were applied for improvement of hydrogen production thermal efficiency; flash concentration of H$$_{2}$$SO$$_{4}$$ using waste heat from Bunsen reaction, prevention of H$$_{2}$$SO$$_{4}$$ vaporization from a distillation column by introduction of H$$_{2}$$SO$$_{4}$$ solution, and I$$_{2}$$ condensation heat recovery by direct contact heat exchange in the HI distillation column. A simulation of material and heat balance showed hydrogen of about 31,900 Nm$$^{3}$$/h was produced by 170 MW heat from the GTHTR300C. A process thermal efficiency of 50.2% was achievable with incorporation of the innovative techniques and several high performance components expected in future R&D.

Journal Articles

HTTR-GT/H$$_{2}$$ test plant; System design

Yan, X.; Sato, Hiroyuki; Sumita, Junya; Nomoto, Yasunobu; Horii, Shoichi; Imai, Yoshiyuki; Kasahara, Seiji; Suzuki, Koichi*; Iwatsuki, Jin; Terada, Atsuhiko; et al.

Proceedings of 8th International Topical Meeting on High Temperature Reactor Technology (HTR 2016) (CD-ROM), p.827 - 836, 2016/11

Pre-licensing basic design for a cogenerating HTGR test plant system is presented. The plant to be coupled to existing 30 MWt 950$$^{circ}$$C test reactor HTTR is intended as a system technology demonstrator for GTHTR300C plant design. More specifically the test plant of HTTR-GT/H$$_{2}$$ aims to (1)demonstrate the licensability of the GTHTR300C for electricity production by gas turbine and hydrogen cogeneration by thermochemical process and (2) confirm the operation control and safety of such cogeneration system. With construction and operation completion by 2025, the test plant is expected to be the first of a kind HTGR-powered cogeneration plant operating on the two advanced energy conversion systems of closed cycle helium gas turbine for power generation and thermochemical iodine-sulfur water-splitting process for hydrogen production.

Journal Articles

GTHTR300 cost reduction through design upgrade and cogeneration

Yan, X.; Sato, Hiroyuki; Kamiji, Yu; Imai, Yoshiyuki; Terada, Atsuhiko; Tachibana, Yukio; Kunitomi, Kazuhiko

Nuclear Engineering and Design, 306, p.215 - 220, 2016/09

 Times Cited Count:2 Percentile:69.72(Nuclear Science & Technology)

The latest design upgrade has incorporated several major technological advances made in the past ten years to both reactor and balance of plant in GTHTR300. As described in this paper, these advances have enabled raising the design basis reactor core outlet temperature to 950$$^{circ}$$C and increasing power generating efficiency by nearly 5% point. Further implementation of seawater desalination cogeneration is made through employing a newly-proposed multi-stage flash process. Through efficient waste heat recovery of the reactor gas turbine power conversion cycle, a large cost credit is obtained against the conventionally produced water prices. Together, the design upgrade and the cogeneration are shown to reduce the GTHTR300 cost of electricity to under 2.7 cent/kW h.

JAEA Reports

Design database of helium gas turbine for high temperature gas-cooled reactor

Imai, Yoshiyuki; Sato, Hiroyuki; Nomoto, Yasunobu; Yan, X.

JAEA-Data/Code 2016-007, 27 Pages, 2016/08

JAEA-Data-Code-2016-007.pdf:3.65MB

This report provides design database for helium gas turbine for HTGR. The design details for secondary helium cooling system and helium gas turbine in a heat application system to be coupled to the HTTR are described. In addition, experimental data for fission product isotope diffusion through turbine blade alloy is compiled.

Journal Articles

Observation of spin-dependent charge symmetry breaking in $$Lambda N$$ interaction; $$gamma$$-ray spectroscopy of $$^4_{Lambda}$$He

Yamamoto, T. O.*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji; Nakada, Yoshiyuki; Sako, Hiroyuki; et al.

Physical Review Letters, 115(22), p.222501_1 - 222501_5, 2015/11

AA2015-0707.pdf:0.5MB

 Times Cited Count:42 Percentile:7.69(Physics, Multidisciplinary)

Journal Articles

GTHTR300 cost reduction through design upgrade and cogeneration

Yan, X.; Sato, Hiroyuki; Kamiji, Yu; Imai, Yoshiyuki; Terada, Atsuhiko; Tachibana, Yukio; Kunitomi, Kazuhiko

Proceedings of 7th International Topical Meeting on High Temperature Reactor Technology (HTR 2014) (USB Flash Drive), 7 Pages, 2014/10

The latest design upgrade has incorporated several major technological advances made in the past 10 years to GTHTR300. These advances have enabled raising the design basis reactor outlet temperature to 950$$^{circ}$$C and increasing power generating efficiency by nearly 5% point. Further implementation of desalination cogeneration is made through employing a newly-proposed multi-stage flash process. Through efficient waste heat recovery of the reactor gas turbine cycle, a large cost credit is obtained against the conventionally produced water prices. Together, the design upgrade and the cogeneration result in reducing the GTHTR300 cost of electricity to under 2.7 US cent per KWh.

Journal Articles

Components development for sulfuric acid processing in the IS process

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

Nuclear Engineering and Design, 271, p.201 - 205, 2014/05

 Times Cited Count:6 Percentile:51.92(Nuclear Science & Technology)

The Japan Atomic Energy Agency has been conducting research and development on a thermochemical iodine-sulfur (IS) process. An examination is planned to verify the integrity of the components in the sulfuric acid decomposition section. A bayonet-type sulfuric acid decomposer made of SiC ceramics, a key component in the section, was test-fabricated. In parallel, a direct-contact heat exchanger (DCHX) is contemplated for use in the sulfuric acid decomposition section to simplify the process. Although the concept is very attractive, little is known about the heat and mass transfer behavior in the DCHX. Therefore, a test apparatus was constructed to measure the gas-phase mass transfer coefficients required for the optimal design of the DCHX. These coefficients of water were acquired and compared with an empirical correlation. The experimental data were in good agreement with those obtained from empirical correlation, and thus, the apparatus was confirmed to be reasonable.

JAEA Reports

Conceptual design of small-sized HTGR system, 5; Safety design and preliminary safety analysis

Ohashi, Hirofumi; Sato, Hiroyuki; Tazawa, Yujiro; Aihara, Jun; Nomoto, Yasunobu; Imai, Yoshiyuki; Goto, Minoru; Isaka, Kazuyoshi; Tachibana, Yukio; Kunitomi, Kazuhiko

JAEA-Technology 2013-017, 71 Pages, 2014/02

JAEA-Technology-2013-017.pdf:3.64MB

Japan Atomic Energy Agency (JAEA) has started a conceptual design of a 50 MWt small-sized high temperature gas cooled reactor (HTGR) for steam supply and electricity generation (HTR50S). Though the safety design of HTR50S was determined based on that of the High Temperature Engineering Test Reactor (HTTR) for the early deployment of HTR50S, the shutdown cooling system, which is the forced cooling heat removal system, was categorized as non-safety class to optimize the protection to provide the highest level of safety that can reasonably be achieved, and the vessel cooling system, which is categorized as the safety class system, was designed as a passive safety features. The preliminary safety analysis of HTR50S for the rupture of co-axial hot gas duct in primary cooling system and the tube rupture of steam generator was conducted to confirm the adequacy of the safety design. It was confirmed that the analysis results satisfied the acceptance criteria.

Journal Articles

Experimental study on the Bunsen reaction using an ionic liquid in thermochemical iodine-sulfur process for hydrogen production

Ohashi, Hirofumi; Imai, Yoshiyuki

Nippon Genshiryoku Gakkai Wabun Rombunshi, 12(4), p.295 - 303, 2013/12

The feasibility of the Bunsen reaction using ionic liquid containing iodine ion was experimentally examined to improve the thermal efficiency of the hydrogen production using the thermochemical water-splitting iodine-sulfur process by increasing of the hydrogen iodide concentration in the Bunsen reaction. The hydrogen iodide concentration in the hydriodic acid obtained by the Bunsen reaction using The 1-Butyl-3-methylimidazolium Iodide ([bimi][I]) was measured at room temperature, ambient pressure and reactant composition of ionic liquid : I$$_{2}$$ : H$$_{2}$$O = 0.25$$sim$$0.5 : 0.51$$sim$$2.1 : 1.0 (molar ratio). The maximum hydrogen iodide concentration was 24.5 mol% (= 69.8wt%), which was higher than that obtained by the conventional Bunsen reaction. The feasibility of the Bunsen reaction using ionic liquid was confirmed in terms of the increasing the hydrogen iodide concentration in the Bunsen reaction.

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