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JAEA Reports

Theoretical background and user's manual for the computer code on groundwater flow and radionuclide transport calculation in porous rock

*;

JNC-TN8400 2001-027, 131 Pages, 2001/11

JNC-TN8400-2001-027.pdf:0.8MB

In order to document a basic manual about input data, output data, execution of computer code on groundwater flow and radionuclide transport calculation in heterogeneous porous rock, we investigated the theoretical background about geostastical computer codes and the user's manual for the computer code on groundwater flow and radionuclide transport which calculates water flow in three dimension, the path of moving radionuclide, and one dimensional radionuclide migration. In this report, based on above investigation we describe the geostastical background about simulating heterogeneous permeability field. And we describe construction of files, input and output data, a example of calculating of the programs which simulates heterogeneous permeability field, and calculates groundwater flow and radionuclide transport. Therefore, we can document a manual by investigating the theoretical background about geostastical computer codes and the user's manual for the computer code on groundwater flow and radionuclide transport calculation. And we can model heterogeneous porous rock and analyze groundwater flow and radionuclide transport by utilizing the information from this report.

JAEA Reports

The data analysis of the single well injection-withdraw tracer experiment using the MACRO II

*; *;

JNC-TN8400 2001-012, 69 Pages, 2001/04

JNC-TN8400-2001-012.pdf:8.43MB

On understanding the radionuclide transport in natural barrier in radioactive waste isolation research, the macroscopic dispersion in heterogeneous permeability field in the underground rock is regarded as an important process. Therefore, we have conducted lots of tracer experiments by the MACRO II facility with an artificially constructed heterogeneous permeability field. In order to study the scale dependence of dispersion coefficients in case of laboratory experiments, we placed the flow cell horizontally, and conducted injection-withdraw tracer experiment with a single well. We have conducted I5 cases experiments. These cases were prepared by changing a position of single well and the injection-withdraw time. At each position we have conducted 9 cases and 6 cases experiments. In this report, we evaluated the macroscopic dispersion coefficients by the fitting of analytical solution to breakthrough curve measured by the 15 cases pumping tracer experiment. Consequently, we could evaluate the dispersion coefficients for 12 cases of 15 cases. Then, we discussed the relation between a injection-withdraw flow rate and a property of heterogeneous media and dispersion coefficient. The conclusions obtained from the results of the evaluation are summarized as follows, (1)It was found that the macroscopic dispersion coefficients tend to be increased with increase of the average radius of tracer front spread around a single well. (2)We have conducted any experiments with s single well settled at two positions. In case of that there is low permeability around a single well, we found dispersion coefficients are large. In case of that there is high permeability around a single well, we found dispersion coefficients are small. (3)In three cases that we could not evaluate because of incorrect accuracy of fitting, we have found it possible that there is some points that dispersion coefficients were strikingly small in tracer front.

JAEA Reports

Reliability evaluation of simulation models for nearfield groundwater flow and radionuclide transport computation

*; *; *; *

JNC-TJ8400 2000-006, 232 Pages, 2000/05

JNC-TJ8400-2000-006.pdf:7.75MB

In this research, simulations with some parameters which characterize ground water flow and the reliability evaluation for the expansion of the calculation method of groundwater flow were carried out by using the radionuclide transport computations in nearfield heterogeneous porous media. Concretely contents are follows: (1)With the series of calculation method for three-dimensional saturated/unsaturated groundwater flow and one-dimensional radionuclide transport. the computational analyses with the parameters used in JNC report in 2000 was carried out and the influence of the different input flux was evaluated. (2)The examination of the application for the different ways of inverse laplace transformation which is used in one-dimensional radionuclide tansport analysis code "MATRICS" was carried out. (3)The examination of the application of multi-element "MATRICS" (m-MATRICS) for radionuclide transport computations in nearfield heterogeneous porous media was carried out. (4)The series of calculation methods from three-dimensional saturated/unsaturated ground water flow simulation code to one-dimensional radionuclide transport simulation code was integrated.

JAEA Reports

Reliability evaluation of simulation models for nearfield groundwater flow and radionuclide transport computation

*; *; *; *

JNC-TJ8400 2000-005, 71 Pages, 2000/05

JNC-TJ8400-2000-005.pdf:4.0MB

In this research, simulations with some parameters which characterize ground water flow and the reliability evaluation for the expansion of the calculation method of groundwater flow were carried out by using the radionuclide transport computations in nearfield heterogeneous porous media. Concretely contents are follows: (1)With the series of calculation method for three-dimensional saturated/unsaturated groundwater flow and one-dimensional radionuclide transport, the computational analyses with the parameters used in JNC report in 2000 was carried out and the influence of the different input flux was evaluated. (2)The examination of the application for the different ways of inverse laplace transformation which is used in one-dimensional radionuclide transport analysis code "MATRICS" was carried out. (3)The examination of the application of multi-element "MATRICS" (m-MATRICS) for radionuclide transport computations in nearfield heterogeneous porous media was carried out. (4)The series of calculation methods from three-dimensional saturated/unsaturated ground water flow simulation code to one-dimensional radionuclide transport simulation code was integrated.

JAEA Reports

Fundamental water experiment on subassembly porous blockage studies in 4 sub-channeI geometry (III); Flow visualization around the Porous Blockage

; ; Kamide, Hideki

JNC-TN9400 2000-026, 70 Pages, 1999/11

JNC-TN9400-2000-026.pdf:10.93MB

The phenomena on a thermal-hydraulic field inside/outside the porous blockage has been investigated by the experiment employed the 4-subchamlel geometry water test facility. From existing experimental and numerical studies, it was shown that the now field around the blockage had significant effect on the temperature distribution inside the blockage. Therefore, We conducted the experiment of flow visualization with 4-subchannel geometry water test facility. The flow visualization showed that the recirculation flow and a lateral flow existed at the side of the porous blockage. The region of recirculation flow extended to the downstream side with increasing of the flow rate. The mixing due to the convection was dominant in the region of recirculation flow, and was getting effective as increasing of the flow rate. ln the wake region, the flow was unstable due to the interaction between the flows in the unplugged and plugged subchannels. The coolant was provided from the unplugged subchannels and also through the inside of porous blockage. These results obtained from the flow visualization gathering with the numerical simulation will be reflect to the evaluation of the local blockage issue of large scale Fast Breeder Reactor.

JAEA Reports

Study on temperature field in porous blockage in a fuel subassembly; 37-pin bundle sodium experiment

; ; ; ; Kamide, Hideki

JNC-TN9400 2000-025, 78 Pages, 1999/11

JNC-TN9400-2000-025.pdf:2.24MB

Local blockage issue in a fuel subassembly is one of initiation of local fault in a fast reactor core. ln existing studies, it is shown that blockage in a wire-spacer type pin bundle will consist of small particles coming through the bundle and will be porous. ln order to evaluate the integrity of fuel pins covered by the porous blockage, we have to predict thermohydraulics in the blockage and also in the pin bundle. ln this study sodium experiments were carried out using a 37-pin bundle test section with a porous blockage. The fueI pins are modeled by electric heater pins of 8.5 mm in diameter (full scale). The blockage is formed by stainless steel spheres of 0.3 mm in diameter. The blockage is set in the two rows of subchannels along one side of hexagonal wrapper tube. The length of blockage in axial direction is 35 mm and corresponds to 1/6th of wire wrapping pitch. The experimental parameters were power of the heater pins. The heater power was varied from 14% to 43% of the maximum linear heat rate of a real reactor ($$sim$$420W/cm). The flow rate in the subassembly was set at 430 l/min corresponding to 93% of the Reynolds number in a fuel subassembly of real reactor under full power condition. The experimental results showed that the highest temperature was measured on the pin surface covered by the blockage and faced to the subchannel which was surrounded by the blockage. The height of peak temperature point was nearly top of the blockage. lt means that the temperature field in the blockage is influenced by flow filed in the blockage significantly. The non-dimensional temperature profile in the blockage and in the pin bundle is independent on heater power.

JAEA Reports

Radionuclide migration analysis in porous rock

Ijiri, Yuji; ; *; Watari, Shingo; K.E.Web*; *; *

JNC-TN8400 99-092, 91 Pages, 1999/11

JNC-TN8400-99-092.pdf:6.62MB

JNC has been developed the performance assessment approaches for both fractured rock and porous rock. An equivalent continuum model is incorporated for solving the radionuclide migration in porous rock, while a discrete fracture network model is incorporated for solving the radionuclide migration in fractured rock (see more detail in Sawada et al. [1999]). This report describes the methodology, the data and the results of the performance assessment of porous rock. From the results of radionuclide migration analyses that were based on the hydrogeological properties obtained from the Neogene sedimentaly rock at the Tono mine, it was found that the release rate of selenium-79 and cesium-135 are dominant in porous rock. The sensitivity analyses using one-dimensional porous model revealed that hydraulic conductivity has more influences on the results than porosity does. In addition, it was found that smaller distribution coefficients of sandstone yield higher release rate than mudstone and tuff, and smaller distribution coefficients of saline water conditions yield higher release rate than fresh water conditions. The radionuclide migration in Neogene sedimentaly rock, where flow in rock matrix as well as in fractures are significant, was evaluated by superposing the results of porous model and fracture model. Since fracture model tends to yield more conservative results than porous model, it is obvious that the performance of Neogene sedimentary rock can be conservatively assessed by fracture model alone. The nuclide migration analyses performed in this report were based on the hydrogeological properties obtained at the depth between 20 meters and 200 meters frrom the ground surface. Therefore, it should be noted that the release rate at the depth of a future repository in Neogene sedimentary rock, 500 m, will be smaller than that shown in this report due to peemeability decrease from 200 m to 500 m.

JAEA Reports

None

*

JNC-TJ1400 99-016, 24 Pages, 1999/02

JNC-TJ1400-99-016.pdf:0.86MB

no abstracts in English

JAEA Reports

None

Jinno, Kenji*; *; *; *; Ijiri, Yuji*; *; Watari, Shingo

PNC-TY1606 98-001, 52 Pages, 1998/03

PNC-TY1606-98-001.pdf:4.2MB

no abstracts in English

Journal Articles

Generation of vapor stream using porous rod in an electron beam evaporation process

Oba, Hironori; Shibata, Takemasa

J. Vac. Sci. Technol., A, 16(3), p.1247 - 1250, 1998/00

no abstracts in English

Journal Articles

Production of stable atomic beam in an electron beam evaporation process

Oba, Hironori; Shibata, Takemasa

Proc. of 6th Workshop on Separation Phenomena in Liquids and Gases (SPG'98), p.241 - 245, 1998/00

no abstracts in English

JAEA Reports

None

PNC-TN1430 97-004, 85 Pages, 1997/08

PNC-TN1430-97-004.pdf:3.44MB

no abstracts in English

JAEA Reports

None

Jinno, Kenji*; *; *; *; Ijiri, Yuji*; Watari, Shingo; WEBB E*

PNC-TY1606 97-001, 44 Pages, 1997/03

PNC-TY1606-97-001.pdf:2.76MB

no abstracts in English

JAEA Reports

Experimental studies on colloid flow rate in geologic media; Colloid transport through columns packed with glass beads

*; Yui, Mikazu

PNC-TN8410 97-125, 20 Pages, 1997/03

PNC-TN8410-97-125.pdf:1.02MB

To evaluate migration behavior of radionuclides in geologic media is one of the most significant issues for the performance assessment of geological disposal system for high level radioactive waste. For performance analysis, effects of micro particles such as colloids on the radionuclides migration should be considered; whether colloids enhance tansport of radionuclides in a geologic formation. Based on the theory of Hydrodynamic Chromatography(HDC), the average flow rate of colloids could be faster than that of the bulk water under the condition that the flow profile of bulk water is parabolic. Transport of radionuclides through geologic media could be accelerated when the radionuclides are sorbed on colloids. In order to investigate the transport behavior of colloids in geologic media, we used a column packed with glass beads as simulated porous geologic media and two types of colloid tracers of gold colloid and latex particle as simulated natural colloids. We compared the flow rate of colloids based on the HDC theory with the results of the column experiments. By this comparison, it is suggested that the flow rate of the colloid in porous geologic media is significantly slower than that predicted based on the HDC. The differences between them was explained by colloid retardation processes due to its sorption on the glass beads, that it is not strictly described in the HDC theory.

JAEA Reports

None

Sugihara, Yoichiro*; Mukai, Katsuyuki*; Nunomiya, Ichiro*

PNC-TJ6357 97-001, 40 Pages, 1997/03

PNC-TJ6357-97-001.pdf:1.52MB

None

JAEA Reports

Angular distributions of atomic vapor stream produced by electron beam heating

Oba, Hironori; ; Shibata, Takemasa

JAERI-Tech 97-020, 30 Pages, 1997/03

JAERI-Tech-97-020.pdf:0.96MB

no abstracts in English

JAEA Reports

None

PNC-TJ1281 95-002, 257 Pages, 1995/02

PNC-TJ1281-95-002.pdf:27.26MB

None

JAEA Reports

None

Takase, Hiroyasu*; *

PNC-TJ1281 95-001, 67 Pages, 1995/02

PNC-TJ1281-95-001.pdf:6.49MB

None

JAEA Reports

None

*

PNC-TJ1281 94-004, 181 Pages, 1994/02

PNC-TJ1281-94-004.pdf:10.28MB

None

JAEA Reports

None

Takase, Hiroyasu*

PNC-TJ1281 94-003, 24 Pages, 1994/02

PNC-TJ1281-94-003.pdf:1.31MB

None

25 (Records 1-20 displayed on this page)