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Sato, Hiroyuki; Terada, Atsuhiko; Hayashida, Hitoshi; Kamiji, Yu; Kobayashi, Jun; Yamagishi, Isao; Morita, Keisuke; Kato, Chiaki
JAEA-Research 2013-042, 25 Pages, 2014/03
JAEA-Research-2013-042.pdf:5.13MB
Spent zeolite adsorption vessels in the Fukushima No.1 nuclear power plant are kept for long-term with washing out with fresh water for prevention of corrosion remaining salt component in vessel. However, corrosion result is concerned by residual concentration of salt component, washing out experiment is carried out using actual and unspent adsorption vessel (KURION). KURION adsorption vessel is filled with 1,650 ppm of sodium chloride (1,000 ppm of chloride ion) and washed out with pure water for estimating washing effect in this experiment. Pure water is streamed with volume flow rate 4.5 m
/h, chloride concentration in vessel is measured with drainage sample water. 1,000 ppm of chloride concentration is decreased till 0.5 ppm and below by washing out with about double pure water volume of adsorbing material filling volume in vessel, washing out is more effective in KURION adsorption vessel.
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 
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.
Kisohara, Naoyuki; Uchita, Masato; Konomura, Mamoru; Kasai, Shigeo; Soman, Yoshindo; Shimakawa, Yoshio; Hori, Toru; Chikazawa, Yoshitaka; Miyahara, Shinya; Hamada, Hirotsugu; et al.
JNC TN9400 2003-002, 109 Pages, 2002/12
JNC-TN9400-2003-002.pdf:8.12MB
Sodium is the most promising candidate of an FBR coolant because of its excellent properties such as high thermal conductivity. Whereas, sodium reacts with water/air and its opaqueness makes it difficult to inspect sodium components. These weaknesses of sodium affect not only plant safety but also plant availability (economy). To overcome these sodium weak points, the appropriate countermeasure must be adopted to commercialized FBR plants. This report describes the working group activities for sodium/water reaction of steam generators (SG), in-service inspection for sodium components and sodium leak due to sodium components boundary failure. The prospect of each countermeasure is discussed in the viewpoint of the commercialized FBR plants. (1)Sodium/water reaction. The principle of the countermeasure for sodium/water reaction accidents was organized in the viewpoint of economy (the investment of SG and the plant availability). The countermeasures to restrain failure propagation were investigated for a large-sized SG. Preliminary analysis revealed the possibility of minimizing tubes failure propagation by improving the leak detection system and the blow down system. Detailed failure propagation analysis will be required and the early water leak detection system and rapid blow down system must be evaluated to realize its performance. (2)In-service inspection (ISI&R). The viewpoint of the commercialized plant's ISI&R was organized by comparing with the prototype reactor's ISI&R method. We also investigated short-term ISI&R methods without sodium draining to prevent the degrading of the plant availability, however, it is difficult to realize them with the present technology. Hereafter, the ISI&R of the commercialized plants must be defined by considering its characteristics. (3)Sodium leak from the components. This report organized the basic countermeasure policy for primary and secondary sodium leak accidents. Double-wall structure of sodium piping was ...
; ; ; ;
JNC TN9410 2002-005, 74 Pages, 2002/05
JNC-TN9410-2002-005.pdf:4.95MB
In order to evaluate the manufacturability of the triple wall tubes for the steam generators (SGs), which are designed for the simplified secondary sodium loop, various specifications of the triple wall tubes were constructed. We used SUS316 steel and evaluated the manufacturability of the 12Cr tubes, since it was estimated to be difficult to fabricate the ribs even on the SUS316 thin tubes. The following results were obtained from these results; (1)It was estimated that a thin wall tube made from 12Cr steel could be manufactured for the practical plant design, (2)The two kinds of the separate tubes, which had the spiral ribs and the straight ones and were installed between the inner and the outer tubes, were manufactured by the drawing-tube method. Those with ringed ribs were also manufactured by welding of ringed spacers, (3)It was estimated that 0.4mm height for the spiral ribs and the straight ones was almost limiting height in case of 1mm tube thickness, and the drawing-tube process did not affect the tube strength and the tube tolerances, and (4)The assembling loads of the inner tubes, the separate ones and outer ones were estimated to become the reasonable loads for the practical size of triple wall SG tubes. Triple wall SG tubes for vibration tests were designed and manufactured.They were made up of four kinds of ribes (spiral rib, straight rib, ringed rib and straight rib with narrow gap). In this study, the vibration tests were also planned for examining the actual behaviour of the triple wall SG tubes.
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.
Yamamoto, Kazuhiro; ; ; Kamide, Hideki; *; Maeda, Yukimoto*
JNC TN9410 2001-010, 56 Pages, 2001/03
JNC-TN9410-2001-010.pdf:1.44MB
Flow distribution in the core is planned to measure in the Experimental LMFBR, Joyo. Flow rate in a subassembly will be measured by permanent magnet type electromagnetic flow meter (EMF) which is set at the top of the subassembly by fuel handling machine. In-sodium calibration tests of the EMF were carried out in the Core Component Thermal Hydraulics Test Loop (CCTL). Tests were performed under such various conditions that sodium and permanent magnet temperature were 200, 225, 250, 275
C, and sodium flow rates ranged o to 640 l/min. Tests results are as follows: (1)Calibration curves were obtained at under each temperature condition. The eorrelations were linear and the maximum deviation between the calibration curve and the experimental data was within 
0.4%. (2)The sensitivity of the EMF output (
) at 250C was 29.48 (
V/[l/min]). The uncertainty was l.5% under the nominal flow rate condition (570 l/min). (3) depended on the sodium temperature (T) as follows: = 21.39+1.16
10
T-5.0210
T
+6.7110
T (4)Initial change of the after the sodium charge was examined, during few days. The was constant and stable. (5)There was no dependency of impurity concentration (plugging temperature) for the . The calibration curves and temperature dependency are applied to the flow distribution measurement and the evaluation in the Joyo core.
;
JNC TN9400 2001-045, 54 Pages, 2000/12
JNC-TN9400-2001-045.pdf:2.74MB
A Laser-induced breakdown spectroscopy Leak Detection technique (abbreviated LLD) of sodium is accomplished by plasmafying the sodium aerosol and then selectively detecting the sodium specific optical spectrum. This method is potentially more reliable as a means of detecting of sodium small leakage. This report describes test results of detection characteristics of LLD using sodium aerosol. The test was carried out following LLD detection sensitivity evaluation test in last year. The main results are as follows: (1)The LLD signal appeared insensitive to the effect of carbon dioxide concentration in the examined range. (2)With the rise in the atmosphere (sampling gas) temperature, the sodium detection sensitivity of LLD tended to be lower. However, it seems to be a peculiar problem of this LLD system, because of decrease of breakdown reaction rate in higher temperature condition of sampling gas (atmosphere temperature). Further evaluation will be needed for this point. (3)LLD showed the fast-response for the aerosol which arose with the sodium combustion as well as for the aerosol which was created on the basis of the sodium vapor. According to the test result, detection property of LLD for very small quantity sodium aerosol was clarified.
Nakayama, Oukatsu;
JNC TN9400 2000-087, 74 Pages, 2000/07
JNC-TN9400-2000-087.pdf:3.25MB
We have been developing an Ultrasound Doppler Velocimetry technique (UDV), in order to apply thermo-hydraulic measurement in sodium. A feasibility study had been conducted to identify development subjects of sensor and signal processing. Thus, high temperature ultrasonic transducers were manufactured to use in water and sodium tests, which will be scheduled to optimize an algorism of signal processing and to improve the characteristic of the transducer. ln this report, we described the results of an experiment on the acoustic characteristic of transducer in water. The results are as follows : (1)The ultrasound beam profile of the transducer relating to the characteristic of velocity profile measurement using scattering ultrasound wave was obtained. The estimation of ultrasound beam profile in liquid and an ultrasound near-field region were introduced from these experimental data, (2)lt was confirmed that the frequency's spectrum of transducers are adequate for the design requirement of flow velocity range. The specifications of a transmitter and receiver for a transducer were identified, such as the amplitude gain for scattered ultrasound signal and the frequency resolution for Doppler sift signal. (3)The spatial resolution of the ultrasound beam was estimated to evaluate the accuracy of now profile measurement on UDV system.
Kimura, Nobuyuki; ; ; ; Kamide, Hideki; Tokuhiro, Akira; Hishida, Koichi
JNC TN9400 2000-057, 60 Pages, 2000/05
JNC-TN9400-2000-057.pdf:2.11MB
ln experimental study for the thermohydraulics of fast reactor, a simple experiment with fine measurement has been desired for understanding of phenomena and for verification of computer code rather than mockup experiments of large scale. For such purposes quality of experimental data must be improved. ln the velocity measurement, instantaneous velocity profile will have great advances for the understanding of phenomena and for the verification of computer code. ln this report two methods of the velocity profile measurement are discussed; one is ultrasound Doppler velocimetry (UDV) and the other is particle image velocimetry (PIV). These methods were applied to water experiments. The UDV was applied to pipe flow, planer jet, and the inter-wrapper flow which is seen in the gap region between subassemblies of fast reactor core. Cross check with laser Doppler velocimetly showed proper measurement of the UDV. Problems including the application to sodium experiments are also discussed. The PIV was also applied to the inter-wrapper flow. For the application to complex flow geometry, noise reduction method was developed to improve the measurement accuracy.
; Tokuhiro, Akira; ;
Proceedings of 8th International Conference on Nuclear Engineering (ICONE-8) (CD-ROM), 0 Pages, 2000/00
None
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JNC TN9400 2000-020, 54 Pages, 1999/11
JNC-TN9400-2000-020.pdf:2.36MB
A Laser-induced breakdown spectroscopy Leak Detection technique (abbreviated LLD) of sodium is accomplished by plasmafying the sodium aerosol, and then selectively detecting the sodium specific optical spectrum. This method is potentially more reliable as a means of detecting of sodium small leakage. This report, describes test results of detection characteristics using sodium aerosol, carried out to verify the principle of LLD in addition to evaluating the response under various conditions. 0ur main objective is to examine the applicability of LLD for small sodium leakage. The main results are as follows; (1)We confirmed the principle of LLD, specifically detecting the sodium optical spectru.m. (2)The relation between LLD fluorescence intensity and sodium aerosol concentration is nearly proportional within a relatively Na concentration ranges 10
10
g/cm. (3)The LLD signal appeared insensitive to the effect of sampling gas flow rate, oxygen concentration, and humidity in the examined range. ln fact, a high S/N ratio is obtained for small sodium leakage, and the reliability of the leakage detection is high, because LLD showed sensitive to sodium concentration. From these results and others discussed in this report, LLD appears to be an applicable technique in small leakage detection both in terms of response and reliabilily in the leakage phase.
; Kokaki, Nobuhisa; ; ;
JNC TN9400 99-014, 51 Pages, 1999/01
An ultrasonic thermometer based on the temperature dependence of the velocity of sound in a medium is being developed to measure the temperature of sodium non-intrusively. The principle of the device is based on the propagation time of an acoustic pulse wave, and the back calculation of the sodium temperature. As the part of the development a test was conducted in sodium pipe-flow in order to evaluate various aspects of implementing the ultrasonic thermometer. This report describes sodium test results of the ultrasonic thermometers using acoustic guide rods and a heat-resistant, but low temperature (the 80C design use temperature) ultrasonic transducer. The results and conclusions to date are as follows: (1)The ultrasonic thermometer appears relatively insensitive to flow velocity of sodium, pressure of the cover gas and the impurity concentration in sodium. The calculated error of the measured thermometry in the experiment was approximately 2 C, a smaller value than the expected 4C of the system. (2)The ultrasonic thermometer using vertical acoustic guide rods for pipeflow has been used wherein the thermal expansion coefficient was known and with 200C as the reference temperatures. For the entire temperature range tested the difference between this and a two-point calibration approach, over the temperature range is only expected to be about 2 C. (3)The number of transmit and receive cycles from which a mean value was calculated was determined. 4)(4)The in-sodium test period was about 2 months. No noticeable change in measurement characteristics of the ultrasonic thermometer were observed. Therefore, there is growing confidence in the device and the technique as a means of thermometry for sodium pipe flow is promising.
Hayashida, Hitoshi; Kokaki, Nobuhisa; Ueda, Masashi; Isozaki, Tadashi; Ara, Kuniaki
JNC TN9400 98-001, 54 Pages, 1998/10
Based on the temperature dependence of the velocity of sound in sodium, an ultrasonic thermometer that measures the temperature of sodium non-intrusively is being developed. The principle of the device is based on the propagation time of an acoustic pulse wave, and the back calculation of the sodium temperature. As the part of the development a test was actually carried out in sodium pipe-flow in order to evaluate various aspects of realizing the ultrasonic wave thermometer. The results and conclusions to date are as follows: (1)Within the present test range, the ultrasonic wave thermometer appears relatively insensitive to flow velocity of sodium, pressure of the cover gas and the impurity concentration in sodium. The calculated error of the measured thermometry was in the experiment about 1 C, a smaller value than the expected 2.5C of the system. (2)The ultrasonic thermometer has only been used wherein the thermal expansion coefficient was known and with 200 C as the reference temperatures. For the entire temperature range tested the difference between this approach and a two-point calibration over a temperature range is only expected to be about 1 C. (3)By using the mean value of multiple ultrasonic wave transmit and receive measurements, a value whereby the ultrasonic propagation time was stabilized is obtained. (4)As acoustic coupling material between the ultrasonic transducer and piping, a copper plate was found to be more suitable than a specialized acoustic bonding material. A weight equivalent, area distributed force of 2.0kg/mm was used to press the test copper plate to the pipe. A slightly smaller force appears more than sufficient as well. (5)We found that mounting the ultrasonic transducer to the exterior surface of the pipe by a clamping method is sufficient such that no welding is needed. (6)The in-sodium test period was about 2 months. No noticeable change in measurement characteristics of the ...
Hirabayashi, Masaru; Kobayashi, Jun; Tokuhiro, Akira; Oki, Yoshihisa; ;
PNC TN9430 98-002, 29 Pages, 1998/01
no abstracts in English
Hayashida, Hitoshi; Hirabayashi, Masaru
PNC TN9410 97-053, 29 Pages, 1997/05
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.
PNC TN9420 97-004, 19 Pages, 1997/04
A study on an improvement of the small sodium leakage detection system of the FBR plant was carried out. At first, the item which should be improved were examined and focused to S/N, responsibility and exclusive detectability for sodium aerosol. Next, the feature of the new detection techniques which could be feasible was studied. Then, the laser breakdown spectroscopy was selected as an advanced system. Finally, development subjects were picked up, and the direction of the research and developmet program was proposed.
Kamide, Hideki; Hayashi, Kenji; Gunji, Minoru; Hayashida, Hitoshi; Nishimura, Motohiko; Iitsuka, Toru; Kimura, Nobuyuki; Tanaka, Masaaki; Nakai, Satoru; Mochizuki, Hiroyasu; et al.
PNC TN9410 96-279, 51 Pages, 1996/08
Large-scaled thermohydraulic tests are planned for some new key technologies in the heat transport systems of demonstration fast reactors, in which the reactor vessel, the primary system, the secondary system, water-steam system, and the decay heat removal systems are modeled. Thermohydraulic issues and structural integrity issues were discussed for the top entry piping systems with satellite pools of the intermediate heat exchangers and the pumps, the natural circulation decay heat removal using direct heat exchangers in a reactor hot pool, the reactor vessel wall cooling system, and the new type of steam generators in the demonstration reactor. Concepts of the experimental model for the reactor vessel and the primary system were created and compared with each other for the sodium test facility which enables to answer the thermohydraulic and structural integrity issues. Following items were considered in the creation and in the selection of the models; (1)solution of the issues for Demonstration First Reactor on total system characteristics, the reactor vessel wall cooling system, the decay heat removal system, and the steam generator, (2)balance between the thermohydraulic issues and the structural integrity issues, (3)simulations of compound phenomena and interactions between the components and the heat transport systems. Total system of test facility was specified based on the selected test model.
