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Journal Articles

Development on ultrasonic hydrogen monitor; For the realization of a hydrogen society

Ara, Kuniaki; Hirabayashi, Masaru*

CROSS T&T, (71), p.10 - 14, 2022/07

Development of hydrogen concentration monitors based on the application of ultrasonic technology applicable to severe accidents in nuclear reactor facilities was conducted. This paper introduces the principle and features of the application of ultrasonic technology. This paper introduces the principles and features of the ultrasonic application, and describes the performance (measurement accuracy, time response, etc.) and environmental resistance of the prototype as development results. In addition, the application of the developed technology would be introduced.

Journal Articles

Development of hydrogen monitor; Applicability investigation of acoustic technique

Aizawa, Kosuke; Ara, Kuniaki; Hino, Ryutaro; Hirabayashi, Masaru*

Proceedings of OECD/NEA Specialist Workshop on Advanced Measurement Method and Instrumentation for enhancing Severe Accident Management in an NPP addressing Emergency, Stabilization and Long-term Recovery Phases (SAMMI 2020) (Internet), 4 Pages, 2020/12

Many functions of the instrumentation system did not work in the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant in the severe condition. The function of the hydrogen concentration measurement system was lost due to power supply loss and coolant loss because the system was based on the sampling method. Therefore, the development of an on-site installation type hydrogen monitor which is not based on the sampling method and has environment resistance characteristics is required. Thus, a new type of hydrogen monitor by using acoustic technique has been developed at JAEA. The measurement principle is to detect the changing of sound velocity with the hydrogen concentration in a mixed gas. In this paper, the basic performance and influence of environmental conditions are described.

Journal Articles

Experimental application of ultrasonic flowmeter for TEF-T LBE spallation target system

Obayashi, Hironari; Hirabayashi, Masaru; Wan, T.; Sasa, Toshinobu

Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 10 Pages, 2017/09

Journal Articles

Application of ultrasonic flowmeter for LBE flow

Obayashi, Hironari; Hirabayashi, Masaru; Sasa, Toshinobu; Ara, Kuniaki

NEA/CSNI/R(2017)2 (Internet), p.188 - 194, 2017/06

no abstracts in English

Journal Articles

Development of flow monitoring system for Pb-Bi by using ultrasonic

Obayashi, Hironari; Hirabayashi, Masaru

Kashika Joho Gakkai-Shi (USB Flash Drive), 36(Suppl.2), 2 Pages, 2016/10

no abstracts in English

Journal Articles

Development of plug-in type ultrasonic flowmeter for lead-bismuth spallation target system

Obayashi, Hironari; Hirabayashi, Masaru; Sasa, Toshinobu; Ara, Kuniaki

Proceedings of 11th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operation and Safety (NUTHOS-11) (USB Flash Drive), 10 Pages, 2016/10

Journal Articles

JAEA Reports

Review of JAEA activities on the IFMIF liquid lithium target in FY2006

Ida, Mizuho; Nakamura, Hiroo; Chida, Teruo*; Miyashita, Makoto; Furuya, Kazuyuki*; Yoshida, Eiichi; Hirakawa, Yasushi; Miyake, Osamu; Hirabayashi, Masaru; Ara, Kuniaki; et al.

JAEA-Review 2008-008, 38 Pages, 2008/03

JAEA-Review-2008-008.pdf:9.37MB

Engineering Validation Design and Engineering Design Activity (EVEDA) of the International Fusion Materials Irradiation Facility (IFMIF) is under going. IFMIF is an accelerator-based Deuterium-Lithium (D-Li) neutron source to produce intense high energy neutrons and a sufficient irradiation volume for testing candidate materials for fusion reactors. To realize such a condition, 40 MeV deuteron beam with a current of 250 mA is injected into high speed liquid Li flow with a speed of 20 m/s. In target system, nuclear heating due to neutron causes thermal stress especially on a back-wall of the target assembly. In addition, radioactive species such as beryllium-7, tritium and activated corrosion products are generated. In this report, thermal stress analyses of the back-wall, mechanical tests on weld specimen made of the back-wall material, estimations of beryllium-7 behavior and worker dose at the IFMIF Li loop and consideration on major EVEDA tasks are summarized.

Journal Articles

Reaction, transport and settling behavior of lead-bismuth eutectic in flowing liquid sodium

Miyahara, Shinya; Ohno, Shuji; Yamamoto, Nobuhiro; Saito, Junichi; Hirabayashi, Masaru

Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 7 Pages, 2006/07

The experimental study has been carried out to investigate reaction, transport and settling behavior of lead-bismuth eutectic (LBE) in flowing liquid sodium. In the test, 168 g of LBE were poured into flowing sodium from the top of a vertical-type sodium loop which contained 23.2 kg of sodium. The initial temperature of LBE and sodium was 673 K. The flow rate and the maximum velocity of sodium in the loop were controlled and measured at 20 dm$$^{3}$$/min and 1 m/sec, respectively, using an electro-magnetic pump and an electro-magnetic flow meter. The sodium loop has a settling chamber at the lower part to investigate the concentration decrease behavior of solid particle reaction products in the sodium due to the settling effect. The concentration was measured by sodium sampling from the 11 positions of the loop during the experiment and its post-test chemical analysis. The temperature changes at the various parts of the loop were also measured during the experiment by thermo-couples attached on the outer surface of the loop. Ultrasonic detectors were attached on the outer surface of the loop below the position of a LBE pour nozzle to demonstrate the utility as a leak detector.

Journal Articles

Feasibility study of in-sodium imaging technique employing $$gamma$$-ray emission

Otaka, Masahiko; Hirabayashi, Masaru; Ara, Kuniaki

Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), P. (50439), 2005/05

In order to enhance the maintenance performance of Sodium-Cooled Fast Reactor (SFR), a novel in-sodium imaging technique was proposed for monitoring a deformation or a displacement of in-sodium components or assemblies in primary cooling systems. This technique based on computed tomography using high-energy gamma photons emitted from radioisotopes of sodium (22Na, 24Na) in the primary coolant. Feasibility studies have been performed in order to explore the applicability to typical piping (or vessels). Preliminary analyses exploring measuring time and imaging capability were performed. The results showed that the proposed technique was feasible as a monitoring system of in-sodium components.

Journal Articles

Development of Ultrasonic Flow Meter for Liquid Lead-Bismuth Flow

Hirabayashi, Masaru; Kondo, Masatoshi*; Ara, Kuniaki; Takahashi, Minoru*

Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 0 Pages, 2005/05

In Pb-Bi Cooled Direct Contact Boiling Water Small Fast Reactor, PBWFR, a development of a primary loop flow meter is required. Since an electromagnetic flow meter is not better suited to an annular channel geometry such as the primary loop of PBWFR, an ultrasonic flow meter to measure the velocity of Pb-Bi has been developed.An ultrasonic transit-time method is applied to the flow velocity measurement. To evaluate the flow velocity in this method, the sound velocity in Pb-Bi is required. Therefore the sound velocity in Pb-Bi was measured at the temperature range from 187 to 407$$^{circ}$$C and the experimental correlation equation of the sound velocity was derived. An ultrasonic flow meter which consisted of the high-temperature sensors and the signal processor was developed and manufactured on trial. The piezoelectric element of the sensor was lithium niobate. The sensor was heated up to 500$$^{circ}$$C and the heat resistance was confirmed. The shoe, i.e. the material wetted by Pb-Bi, of the sensor was made from high-chrome steel. The in-water and the in-Pb-Bi tests were performed and the applicability of the ultrasonic flow meter was verified.

JAEA Reports

Study on In-vessel ISI for JOYO; Ultrasound propagation characteristic in the core support plate

Ariyoshi, Masahiko; Ara, Kuniaki; Hirabayashi, Masaru

JNC TN9400 2005-020, 44 Pages, 2005/03

JNC-TN9400-2005-020.pdf:6.5MB

This report describes the feasibility study on the in-vessel inspection technique to be applied for the experimental fast reactor JOTO. The object of this examination is to comfirm the integration of reactor structure under sodium environment by an immediate means. The core support plate which is an important structure supprts the weight of the core assembly is selected to an object of the inspection.In the examination until last year, the core support plate inspection equipment concept which combined ulutrasound sensor with manipulator was constructed.In this conceprt, the ulutrasound sensor is accessed to a low-pressere plenum sidewall and integrity of the core suppot plate weld is inspected.

JAEA Reports

Study on sodium viewing technique applying sodium gamma-rays emission tomography; Verification of basic principle by analytical investigation

Hirabayashi, Masaru; Otaka, Masahiko; Hayashida, Hitoshi; Ara, Kuniaki

JNC TN9400 2003-016, 35 Pages, 2003/04

JNC-TN9400-2003-016.pdf:1.45MB

To confirm structural integrity of a primary cooling system and in-vessel components in a sodium-cooled fast breeder reactor, monitoring and inspection technique applying Gamma-rays emitted from sodium are proposed. The basic principle is as follows. As radioisotope $$^{24}$$Na decays, photons are emitted and a fraction of these photons penetrate materials. If the number of these photons is counted by radiation detectors, an image of gamma-rays source is reconstructed by a computed tomography technique. In this report, Applicability and problems concerned with the technique are investigated. Main results are as follows: (1)To verify applicability, the technique was analytically investigated based on gamma-rays emitted from sodium coolant in a typical pipe of a primary cooling system. As a result, it was confirmed that the image of gamma-rays source could be reconstructed. (2)A required time to measure in a spatial resolution of about 1mm was investigated in the detection efficiency of 20%. The time was about 4 minutes per section by a thousand detectors in the typical pipe of a primary cooling system. And in a typical steam generator, the time was about 2 days per section by ten thousand detectors. (3)To realize a fluoroscopic inspection system, it is necessary that the principle should be verified by experimental researches. Main equipments of the system are a collimator, radiation detector, scanner, signal processing device and image processing device. As a spatial resolution is decide by the collimator, the shape must be evaluated by experimental researches and analytical investigation.

JAEA Reports

Development of ultrasound Doppler velocimetry technique applying cross-correlation processing

Hirabayashi, Masaru; ;

JNC TN9400 2002-016, 72 Pages, 2002/05

JNC-TN9400-2002-016.pdf:1.54MB

Utrasound Doppler Velocimetry technique (UDV) applying Doppler effect has been developed for measuring velocity distributions of sodium flow. As Doppler shift frequency is proportional to velocity of microparticles carried by flowing liquid, it is possible to evaluate velocity distributions of flowing liquid from Doppler shift frequency. In this report, a technique applying cross-correlation processing is proposed to derive Doppler shift frequency from the echoes of ultrasonic pulses. Verification studies of the proposed technique are conducted based on simulated echoes and actual echoes in water tests. Mahl results are as follows: (1)As the result of verification studies conducted based on the simulated echoes, relative error estimated by the proposed technique is about 1 percent. (2)The proposed technique is an effective measures fbr the reduction of noise signals. (3)The velocity distributions of water flowing in a pipe are evaluated in the experiments. The velocity distributions evaluated by the proposed technique is almost equivalent to that of turbulent flow evaluated by 1/7th power law.

JAEA Reports

Sodium leakage and combustion tests; Measurement and distribution of droplet size using various spray nozzles

; Hirabayashi, Masaru; ; Oki, Shigeo; ;

JNC TN9400 99-030, 123 Pages, 1999/04

JNC-TN9400-99-030.pdf:5.33MB

In order to develop a numerical code simulating sodium fires initiated frame dispersion of droplets, measured data of droplet diameter as well as its distribution are needed. In the present experiment the distribution of droplet diameter was measured using water, oil and sodium. The tests elucidated the influential factors with respect to the droplet diameter. In addition, we sought to develop a similarity law between water and sodium. The droplet size distribution of sodium using the large diameter droplet (Elnozzle) was predicted. The results are as follows. (1)Verification of existing method to determine droplet size distribution. Using a phase Doppler system the droplet size distribution to water spray from a binary fluid nozzle was measured. We found that there was not a large difference between the measured distribution and Nukiyama-Tanasawa distribution function. (2)Characterization of inferential parameters with respect to droplet size distribution. Here we note that the droplet size distribution using a nozzle with binary fluid was different from the one using a compression nozzle was used. It was clarified that the viscosity and surface tensjon are the primary factors which influence the volumetric average diameter. The correlation equation between droplet diameter containing viscosity and surface tension terms, was derived. (3)Evaluation on the droplet size distribution to sodium spray from the El nozzle. A relationship between the volumetric average diameter and the pressure was studied and the volumetric average diameter was formulated as a function of the physical properties (viscosity, surface tension) in the case of the E1 nozzle. Finally, the droplet size distribution to sodium spray from the E1 nozzle was estimated using the developed correlation equation.

JAEA Reports

A Study on a velocity distribution measurement system applying the ultrasonic technique

Hirabayashi, Masaru; Kobayashi, Jun; Tokuhiro, Akira; Oki, Yoshihisa; ;

PNC TN9430 98-002, 29 Pages, 1998/01

PNC-TN9430-98-002.pdf:1.25MB

no abstracts in English

JAEA Reports

The development of liquid surface visualization and void detection system for sodium; Imaging characteristic examination of sound propagation simulation and underwater basic test

Hayashida, Hitoshi; Hirabayashi, Masaru

PNC TN9410 97-053, 29 Pages, 1997/05

PNC-TN9410-97-053.pdf:1.72MB

On the FBR plant, it is necessary that cover gas would not involve in the primary coolant, and especially the measures is very important in order to compact the reactor on the design of DFBR. Thus the behavior of free liquid surface must be evaluated in sodium pool tests at the design phase. And also from the viewpoint of safety analyses, the void detection system which measure the void in the reactor vessel inlet piping is also developed as a measurement system for confirming that the void has not been entrapped in the coolant. Then on the liquid surface visualization system which image the behavior of liquid sodium surface and the void detection system which image the detected void using the ultrasonic wave, the sound propagation simulations and the underwater basic tests were carried out to obtain a knowledge on the basic imaging characteristics. As a first step, the sound propagation simulations were carried out to evaluate the imaging characteristics of the vortex model. As the next step, the measurement system was produced tentatively in order to image the fluctuating liquid surface and the rising void in the underwater basic tests. The signals from some ultrasonic transducers to image them were processed by the cross correlation method and the aperture synthesis method. However the imaging processed in off-line because of the limitation of thc signal processing ability. As the results, it was confirmed that the vortex model could be imaged by the sound propagation simulations. And the fluctuating liquid surface and the rising void could be also imaged by the measurement system in the underwater basic tests. However since the slope of vortex can't be imaged well, the most suitable arrangement of the transducers will be examined to image the slope. And it will be necessary for the measurement system to confirm that the size and shape of void can be imaged accurately.

Oral presentation

Study on ultrasonic measurement technique for liquid metal

Hirabayashi, Masaru; Saito, Junichi; Miyahara, Shinya; Ara, Kuniaki

no journal, , 

no abstracts in English

Oral presentation

Experiment on reaction and transfer behavior of lead-bismuth in sodium

Ohno, Shuji; Saito, Junichi; Hirabayashi, Masaru; Miyahara, Shinya

no journal, , 

Two series of experiment were carried out to investigate the reaction and transfer behavior of lead-bismuth in liquid sodium. As the test results, fundamental data were obtained on the sodium-lead-bismuth reaction, transfer of reaction products, and on the leak detection method.

Oral presentation

Study on acoustic instrumentation technique for high-temperature liquid metal

Hirabayashi, Masaru; Ara, Kuniaki

no journal, , 

no abstracts in English

32 (Records 1-20 displayed on this page)