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Journal Articles

The Project for grouting development for high level radioactive waste repository, 3; Study of allowable seepage water quantity by permiability test though contact face of buffer material blocks

Sekine, Ichiro*; Yamada, Tsutomu*; Sekiguchi, Takashi*; Fujita, Tomoo; Nakanishi, Tatsuro

Doboku Gakkai Heisei-23-Nendo Zenkoku Taikai Dai-66-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.69 - 70, 2011/09

no abstracts in English

JAEA Reports

Parallel processing for the simulation of electromagnetic terahertz wave emission

Higuchi, Kenji; Hiratsuka, Atsushi*; Endo, Tatsuro; Ota, Yukihiro; Machida, Masahiko

JAEA-Data/Code 2010-025, 84 Pages, 2011/02

JAEA-Data-Code-2010-025.pdf:1.94MB

We describe the parallelization and performance evaluation of the simulation program for emission of terahertz electromagnetic wave from high-Tc cuprate superconductors, where high performance was achieved as a result of tuning on multi-core system. Firstly the simulation space was divided for parallel processing, where MPI communication was implemented. The divided simulation space was further assigned to processes on multi-processors. Secondly parallel performance on each processor was accelerated by multi-threads implemented by OpenMP with a ratio at the number of core's. We have evaluated the parallelized program on HA8000 cluster system at Information Technology Center of the University of Tokyo, and, thus, achieved high performance in the analysis of terahertz electromagnetic wave emission from superconductors.

Journal Articles

$$mu$$SR study of organic antiferromagnet $$beta$$'-(BEDT-TTF)$$_2$$ICl$$_2$$ under high pressure

Sato, Kazuhiko*; Sato, Koichi*; Yoshida, Tetsushige*; Taniguchi, Hiromi*; Goko, Tatsuro*; Ito, Takashi; Oishi, Kazuki*; Higemoto, Wataru

Physica B; Condensed Matter, 404(5-7), p.600 - 602, 2009/04

 Times Cited Count:3 Percentile:16.82(Physics, Condensed Matter)

Zero-field muon spin relaxation was measured for organic antiferromagnet $$beta$$'-(BEDT-TTF)$$_2$$ICl$$_2$$ under high pressure of up to 1.37 GPa. Neel temperature, which is 22 K at ambient pressure, increases with increasing pressure and becomes approximately 48 K at 1.37 GPa. Muon precession frequency at 1.37 GPa, becomes about 5 times larger than that at ambient pressure.

JAEA Reports

Sodium flow and endurance test of "MONJU" dummy fuel; Subassembly of 6th test production

*; *; *; Iguchi, Tatsuro*

PNC TN941 84-74, 103 Pages, 1984/05

PNC-TN941-84-74.pdf:6.24MB

Sodium flow and endurance test for "MONJU" dummy fuel subassembly of the 6th test production (abbreviated name ,M6CWP) was carried out in Sodium Flow Test Loop. This test was performed for 2,384 hours with the inlet sodium temperature of 397$$^{circ}$$C, the flow rate of 17.36 kg/sec and the cold trap temperature of 120$$^{circ}$$C. The results of this test showed that; (1)The initial average pressure loss coefficient C$$_{D}$$ of M6CWP was given by following equation. C$$_{D}$$ = 113.58 $$times$$ Re$$_{B}$$$$_{-0.10775}$$$$_{B}$$. (2)In the measurement of total pressure, the increase of pressure loss became, to saturation at about 300 hours after the beginning of the test and finally approached to 3% larger than the initial value. (3)AS a result of the sodium draining conducted in accordance with the design condition for "MONJU" EVST (Ex-vessel Storage Tank), it was found that the sodium of about 90g remained in the subassembly. (4)The eye inspection of the subassembly after the test showed that the subassembly was intact without separation of fuel pins from knock bars. Since this was the final test for "MONJU" dummy fuel subassembly of test production, this report summarized the total pressure liss increase and various points concerning endurance found in the test series until now.

JAEA Reports

Flow induced vibration of a deformed fuel pin bundle (2); Effect of porosity/ring on pin vibration

*; Abe, Sadayoshi*; Iguchi, Tatsuro*

PNC TN941 84-69, 39 Pages, 1984/04

PNC-TN941-84-69.pdf:1.31MB

The flow induced vibration of a fuel pin bundle is considered to be one of the major factors causing wear marks observed on "JOYO" MK-I fuel claddings. This experiment was performed by using a fuel pin bundle having porosity/ring of twice as large as that of "JOYO" MK-I fuel assembly, in order to study the effect of porosity/ring on the flow induced vibration of pins. The following was clarified from the comparison between the results of this experiment and the previous one using the test bundle of porosity/ring equal to that of "JOYO" MK-I fuel assembly. Any significant fuel pin vibration was not observed in the deformed bundle test in which the deformed pins were lined up on the outermost row simulating thermal bowing of the fuel assembly irradiated in reactor, because the restrain effect of the deformed peripheral pins was larger than that of porosity/ring. The similar result ,had been obtained in the previous experiment. In the test of normal bundle without any deformed pin, the fuel pin vibration was much larger in this experiment than the previous one. This experimental result showed that the effect of porosity/ring on the vibration was significant in the normal bundle.

JAEA Reports

Pressure loss characteristics of deformed fuel assembly

Abe, Sadayoshi*; *; Iguchi, Tatsuro*

PNC TN941 84-67, 30 Pages, 1984/04

PNC-TN941-84-67.pdf:0.86MB

The objective of this experimental study is to obtain the data on pressure loss characteristics of the fuel assembly which must be deformed during hypothetical core disruptive accident (HCDA). Three of deformed bundle and one of normal shaped bundle were used in the experiment. These bundles had the same geometry as the fuel bundle part of "Monju" blanket assembly. The main conclusions are as follows: The pressure loss ($$Delta$$P) of deformed bundle at the same Reynolds numbers as normal bundle can approximately predicted by using the ratio of cross sectional flow area(A), as shown below. ($$Delta$$P(deformed))/($$Delta$$(normal)) = (A(normal)/A(deformed))$$^{2}$$. This equation is applicable with the following limitations. (1)Reynolds numbers defined at bundle area is 10$$^{3}$$ to 3$$times$$10$$^{4}$$. (2)Reduction of flow area is within 17% of flow area of normal bundle. Prediction area of the equation is less than 8% and 3% for the range of Reynolds number of 10$$^{3}$$ to 8$$times$$10$$^{3}$$ and 8$$times$$10$$^{3}$$ to 3$$times$$10$$^{4}$$, respectively.

JAEA Reports

Application analysis of SSC-L(1); Analysis of MONJU primary loop natural circulation

Yoshikawa, Shinji*; Iguchi, Tatsuro*

PNC TN941 84-26, 110 Pages, 1984/02

PNC-TN941-84-26.pdf:3.54MB

SSC-L(Super System Code - Loop version) is a thermo-hydraulic transients analysis code in LMFBRs, developed at Brookhaven National Laboratory in USA. This code is capable of both analyses of normal operation and accident. It allows free allocation of the components in heat transport systems, and arbitrary representation of the heat transport systems. Since the introduction of this code in June 1980, a large effort has been devoted to facilitate and validate the use of the SSC code for MONJU plant transient analysis. This report describes analysis of reactor shutdown transient in MONJU plant from full-power operation to natural circulation with simultaneous all pumps trip. In this transient a pressure loss characteristics of the primary loop and a frictional characteristics of the primary pump dominate coolant thermohydraulic behavior. In order to investigate the sensitivity of the loop and pump characteristics for the transient, following two cases were analized. (1)Characteristics of the loop pressure loss and the pump frictional torque based on the physical theory and experimental data. (2)Under the natural circulation, pressure losses of core, check valves, and stopped pumps have great effect on flow rate. Results are summarized as follows: (1)Flow coastdown transient up to natural circulation is characterized by the pump speed. In the range of flow rate under 50% of the rated value, the pump frictional torque plays a important role in the determining the flow rate. (2)Under the natural circulation, pressure losses of core, Check valves, and stopped pumps have great effect on flow rate. (3)The maximum coolant temperature at the top of the core during the transient is determined by the degree of mismatch of thermal power and flow rate. In this analysis, the maximum coolant temperature, is higher than both in full power operation and in natural circulation.

JAEA Reports

Experimental study of heat transfer through cover gas in LMFBR

*; *; *; Iguchi, Tatsuro*

PNC TN941 84-06, 8 Pages, 1984/01

PNC-TN941-84-06.pdf:0.38MB

Experimental investigation were performed on the combined radiation and natural convection heat transfer through the cover gas space over the sodium pool. The amount of heat transmitted from the hot sodium to the cold wall through the gas space folled with sodium mist was measured. The thermophysical properties such as the thermal emissivities of liquid sodiim and mist-deposited stainless steel and the radiative characteristics of mist-filled space were also measureed using especially devised anparatus. The amount of heat transmitted through the space, measured by experiments, was compared with the analytical results based on the measureed thermophysical properties. The agreement was comparatively good between the experiment and analysis.

Journal Articles

Experimental Study of Heat Transfer Through Cover Gas in LMFBR

*; Iguchi, Tatsuro*; ;

Proceedings of 3rd International Conference on Liquid Metal Engineering and Technology in Emergy Production, 0 Pages, 1984/00

None

JAEA Reports

Hydraulic characteristics and sodium flow tests on "JOYO" MK-II irradiation test assemblies; Pressure loss measurement and sodium steeping of CMIR and SMIR

*; Abe, Sadayoshi*; *; Iguchi, Tatsuro*

PNC TN941 84-42, 29 Pages, 1983/03

PNC-TN941-84-42.pdf:0.64MB

Hydraulic test and sodium soaking were carried out for "JOYO" MK-II Core Materials Irradiation Test Assembly (CMIR) and Structual Materials Irradiation Test Assembly (SMIR). The results were as follows. (1)The pressure loss coefficient of CMIR was 75.6 at Reynolds number of 1.58 $$times$$ 10$$^{4}$$. This result agreed well with its design value. (2)The total pressure loss of SMIR was 0.5806 kg/cm$$^{2}$$ at 0.5 kg/sec. And the pressure loss of the orifice of SMIR was 0.5194 kg/cm$$^{2}$$ at 0.5 kg/sec. (3)Sodium soaking, sedoum draining and preheating tests of CMIR and SMIR were performed under simulated plant conditions. The test result obtained will be reflected to the actual post irradiation examinations together with the cleaning test and disassembling test to be conducted by other sections.

JAEA Reports

Sodium flow endurance test on "JOYO" special type dummy fuel assembly(3); Durability and pressure drop of trial product type A

*; *; *; Iguchi, Tatsuro*

PNC TN941 83-33, 35 Pages, 1983/03

PNC-TN941-83-33.pdf:1.38MB

Sodium flow endurance and cleaning tests were carried out for special A-type dummy fuel assembly. The endurance test was performed for 1278 hours with the sodium temperature of 600$$^{circ}$$C, the flow rate of 10kg/sec, and the cold trap temperature of 120$$^{circ}$$C. The sodium cleaning for the assembly was performed by using water and alcohol. The results of this test are as follows. (1)The pressure loss coefficient was 6.56 at Reynolds number of l.7$$times$$10$$^{6}$$. This result agreed well with that of measured water flow test. (2)Any time-depending change of the pressure loss coefficient was not observed during the sodium flow endurance test. (3)The weight of remaining sodium in the assembly after the tests was about 48 grams. Neither deformation nor defect were found by visual inspection of the assembly after the tests. Therefore, it is concluded that the assembly does not have any difficulty in the flow characteristics, the durability and the cleaning characteristics. The test results obtained will be reflected to the actual design and fabrication of A-type fuel assembly.

JAEA Reports

Hydraulic characteristics of "Joyo" irradiation test assembly(V); Flow distribution in A-Type fuel assembly

*; *; Abe, Sadayoshi*; Iguchi, Tatsuro*

PNC TN941 83-32, 64 Pages, 1983/03

PNC-TN941-83-32.pdf:0.97MB

The A-type fuel assembly has two kinds of irradiation ducts which contain "Monju" and "Joyo" MK-II fuel pin arrays. In this experiment, measurement test of pressure loss coefficient and electrolyte injection test were conducted for both individual elements and assembly. The experimental data can be used to calculate the coolant flow distribution in the A-type fuel assembly. The main conclutions from this experiment are as follows. (1)A wide gap is formed around the irradiation duct when the "Joyo" MKII type irradiation duct is used. The gap should be narrowed by some design improvement to decrease leakage flow. (2)The size of the orifice at the entrance region of the "Monju" type irradiation duct can be determined by using the pressure loss coefficients led from experimental results. (3)The experimental results for flow distribution rates in the irradiation ducts have rather big experimental errors because of the test method to know the rates in the small ducts from the pressure drop in the large driver bundle. Therefore, it is desirable to know correctly thermal-hydraulic characteristics of the assembly by using TED (Temperature Difference) thermometers at the first irradiation.

JAEA Reports

Aerosol release rate from sodium pool into nitrogen gas; Effects of oxygen and water impurities in Nitrogen gas

Himeno, Yoshiaki; *; *; Iguchi, Tatsuro*

PNC TN941 82-268, 14 Pages, 1982/12

PNC-TN941-82-268.pdf:0.72MB

Sodium leak detection system is now under development for quick detection of a small leak from Monju primary systems. In this development, aerosol release rate from leaked sodium is requied to evaluate the delay time for the detection as well as to determine the lower limit of the detectable aerosol concentration. To meet that requirement, the test under the following conditions was made. This was to determine the aerosol release rate from sodium into innert nitrogen enviroment under the primary cell simulated conditions. [sodium temperature : 200 to 550$$^{circ}$$C] [H$$_{2}$$O content in N$$_{2}$$ : 0.04 to 1.0%] [O$$_{2}$$ content in N$$_{2}$$ : 0, 1.5, and 3.0%] [surface area of sodium : 20 and 80 cm$$^{2}$$] The test results revealed that the aerosol release rate is sensitive to the oxygen concentration, but not to the water concentration, and has the same temperature coefficient as the sodium evaporation rate into argon gas.

JAEA Reports

Development of aerosol counter

Himeno, Yoshiaki; *; *; Iguchi, Tatsuro*

PNC TN941 82-197, 32 Pages, 1982/09

PNC-TN941-82-197.pdf:1.13MB

To develop in-situ aerosol particle counter, the method to utilize laser beam was selected, and its feasibility test has been carried out. The principle of the method is to measure the gravitational settling velocity of a particle and to calculate a particle size from the settling velocity by using Stokes equation. The particle being measured is sodium mist that is familiar to be handled by the present authors. The test is divided into two steps. In the first step, particle size distribution of mist was measured by a cascade impactor. The ABS code was modified for sodium mist, and numerical study was performed with this code to check reliability of the measured data. In the latter step, the laser counter was used to measure particle size distribution of mist. In this event, the particle size distribution previously obtained in the first step was used as reference data. The results of the present test revealed that the minimum particle size to be detected by the laser counter was about 1.0 $$mu$$m. To meet the requirement as the aerosol counter, particles as small as 0.5 $$mu$$m have to be detected. Hence, it was recognized that the data processing method of the present counter have to be modified.

JAEA Reports

Thermal and Hydraulic Experiments of JOYO Fuel Subassembly

Miyaguchi, Kimihide*; Sato, Kazujiro; Iguchi, Tatsuro*

PNC TG033 82-01(5), 16 Pages, 1982/01

PNC-TG033-82-01(5).pdf:0.25MB

Several series of thermal and hydraulic experiments have been conducted using full mock-ups of JOYO fuel subassemblies. This paper describes the test results of cross-flow mixing and pressure loss in wire-wrapped pin bundles. It also presents the comparison between cross-flow mixing experiments and calculations by SWIRL code.

JAEA Reports

Physical properties for sodium technology; Na, Ar, He, 304SS, 316SS, 2.25Cr-Mo

*; *; Himeno, Yoshiaki; Iguchi, Tatsuro*

PNC TN941 81-73, 270 Pages, 1981/04

PNC-TN941-81-73.pdf:20.62MB

In R&D of FBR, various kinds of physical properties are used for designing of test loop and analysis of test data. In this report, tables and figures, which are frequently used, are presented for convenience of their easy reference. Physical properties of sodium, argon, helium, 304 stainless steel, 316 stainless steel, and 2.25Cr-1Mo steels are listed up to 800 $$^{circ}$$C. The report is a supplement and revise edition of PNC-report, No. N941 75-19, "Practical use method of Thermophysical properties of Sodium", Published in 1975.

JAEA Reports

Behavior of particulate impurities in sodium system; Tests by mesh-type and magnetic-type filters

Sasaki, Shuichi; *; Himeno, Yoshiaki; *; Iguchi, Tatsuro*

PNC TN941 81-06, 75 Pages, 1981/01

PNC-TN941-81-06.pdf:4.9MB

In an sodium test facility, particulate impurities are accumulated with time progresses when it has been operated for long period of times at elevated temperatures. Similar event may also be happen in coolant systems of LMFBR. In particular, deposition of radioactive corrosion products in sodium components and in pipings of a primary coolant system of the reactor may causes in high radiation background around them. But, the fact is that behavior of particulate corrosion products in sodium system is not well understood. No information is available, except few experimental findings. To meet the requirement, a series of tests have been conducted placing their emphasis on determinations of particle sizes, elements compositions, and concentration of particulate in flowing sodium system. Mesh-type and magnetic-type filters were used for these purposes. Results here obtained are summerized as follows. (1)Particulate concentrations of the present sodium loop ranged from 1$$sim$$5 ppb depending strongly upon flow velocity in main sodium curculation piping. This suggests that concentration is being controlled by settling of particles. (2)Particle sizes determined ranged from sub-micron to 50 $$mu$$m, while their mean radius was 2-3 $$mu$$m. (3)Main compositional elements of particulates were Fe (18-48%), Cr (4.4-18%), Mn (4-9%), Ni(2-3%), and Si(3-4%). (4)Both the present mesh-type and magnetic-type filters worked effectively for collecting and trapping particulates in the loop sodium.

Journal Articles

None

Ninokata, Hisashi; Iguchi, Tatsuro*

11th LIQUID METAL BOILING GROUP MEETING, , 

None

Oral presentation

Development of exposure reduction technologies by digitalization of environment and radioactive source distribution, 6; Computational method validation and effectiveness evaluation of an estimation system of radiation sources and dose rates

Aoki, Yuto; Ito, Rintaro; Kitamura, Akihiro; Omori, Takazumi; Taniguchi, Tatsuro; Ide, Hiroshi

no journal, , 

In this report, we present the validation results of the radiation source inverse estimation computation method and the effectiveness evaluation method of the "estimation system of radiation sources and dose rates" developed by JAEA. As for the validation test, the JMTR was used as the evaluation site, and the results of radiation source inverse estimation computations were compared with measured data. As a result, it was confirmed that the hot spot could be estimated approximately well. As for the effectiveness evaluation, the test field to be established at the NARREC and at the JMTR were used as the evaluation sites, and the effectiveness evaluation items such as the functions of each tool and the process of the system were summarized.

Oral presentation

LASSO reconstruction scheme to predict radioactive source distributions inside reactor building rooms; Evaluation activities

Aoki, Yuto; Ito, Rintaro; Kitamura, Akihiro; Machida, Masahiko; Suzuki, Masahiro; Omori, Takazumi; Taniguchi, Tatsuro; Ide, Hiroshi

no journal, , 

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