Comparison of particle confinement in the high confinement mode plasmas with the edge localized mode of the Japan Atomic Energy Research Institute Tokamak-60 Upgrade and DIII-D tokamak

Takenaga, Hidenobu; Mahdavi, M. A.*; Baker, D. R.*

Physics of Plasmas, 8(5), p.1607 - 1611, 2001/05

https://doi.org/10.1063/1.1362295

no abstracts in English

Coupled thermo-hydro-mechanical experiment at Kamaishi mine technical note 14-99-01; Verification of the buffer material emplacement technique

Sugita, Yutaka; Chijimatsu, Masakazu*; Fujita, Tomoo; Tranduc, P.*

JNC TN8430 99-009, 45 Pages, 1999/06

JNC-TN8430-99-009.pdf:2.58MB

It is an important part of the near field performance assessment of nuclear waste disposal to evaluate coupled thermo-hydro-mechanical (T-H-M) phenomena, e.g., thermal effects on groundwater flow through rock matrix and water seepage into the buffer material, the generation of swelling pressure of the buffer material, and thermal stresses potentially affecting porosity and fracture apertures of the rock. An in-situ T-H-M experiment named "Engineered Barrier Experiment" was conducted at the Kamaishi Mine, in which the host rock is granodiorite, in order to establish conceptual models of the coupled T-H-M processes and to build confidence in mathematical models and computer codes. This report summarizes the results of the in-situ direct compaction technique to evaluate the appropriate conditions for this technique. The in-situ direct compaction technique is one of the major candidate emplacement techniques for the buffer material. This experiment consisted of the mock-up tests and the in-situ test. The mock-up tests showed the appropriate conditions for the in-situ direct compaction technique. For the in-situ experiment, the manufactured OT-9607 achieved dry density averaged 1.65 g/cm, which matched the demand for the thermo-hydro-mechanical experiment.

Geostatistical Analysis of Groundwater Chemistry in Japan; Evaluation of the Base Case Groundwater Data Set

PATRICIA F SALTE*; Sasamoto, Hiroshi; Apted, M. J.*; Yui, Mikazu

JNC TN8400 99-023, 231 Pages, 1999/05

JNC-TN8400-99-023.pdf:63.86MB

The groundwater chemistry is one of important geological environment for performance assessment of high level radioactive disposal system. This report describes the results of geostatistical analysis of groundwater chemistry in Japan. Over 15,000 separate groundwater analyses have been collected of deep Japanese groundwaters for the purpose of evaluating the range of geochemical conditions for geological radioactive waste repositories in Japan. The significance to issues such as radioelement solubility limits, sorption, corrosion of overpack, behavior of compacted clay buffers, and many other factors involved in safety assessment. It is important therefore, that a small, but representative set of groundwater types be identified so that defensible models and data for generic repository performance assessment can be established. Principal component analysis (PCA) is used to categorize representative deep groundwater types from this extensive data set. PCA is a multi-variate statistical analysis technique, similar to factor analysis or eigenvector analysis, designed to provide the best possible resolution of the variability within multi-variate data sets. PCA allows the graphical inspection of the most important similarities (clustering) and differences among samples, based on simultaneous consideration of all variables in the dataset, in a low dimensionality plot. It also allows the analyst to determine the reasons behind any pattern that is observed. In this study, PCA has been aided by hierarchical cluster analysis (HCA), in which statistical indices of similarity among multiple samples are used to distinguish distinct clusters of samples. HCA allows the natural, a priori, grouping of data into clusters showing similar attributes and is graphically represented in a dendrogram Pirouette is the multivariate statistical software package used to conduct the PCA and HCA for the Japanese groundwater dataset. An audit of the initial 15,000 sample dataset on the ...

Thermal Conductivity of beginning-of-life uranium-plutonium mixed oxide fuel for fast reactor

; ;

PNC TN9410 98-014, 46 Pages, 1997/11

PNC-TN9410-98-014.pdf:2.16MB

Thermal conductivity of uranium-plutonium mixed oxide fuel for fast reactor at beginning-of-life was correlated based on the recent results in order to apply to the fuel design and the fuel performance analysis. A number of experimental results of unirradiated fuel speimens were corrected from open literatures and PNC internal reports and examined for the database. Thermal conductivity of acutual fuel with porosity (), that of fully dense fuel ( 100%TD) and porosity correction factor (F) had theoretically the following correlation : = F 100%TD. The following correlation was developed for fully dense fuel by the results of high density fuel pellets which the effect of porosity was relatively small. The data base ranged from 17 to 30% for plutonium content in heavy metal atoms, from 1.90 to 2.00 for oxygen to metal ratio, from 90 to 98% of theoretical density and from 400 to 2090 degree C for temperature. = (1/(-0.03237+0.8606+2.48310T))+75.2710T where 100%TD: Thermal Conductivity (W/mK) T: Temperature (K) O/Z: Oxygen-to-metal ratio (-) In this work two porosity correction factors were needed for high density fuel and low density fuel (around the current Monju specification). For high density fuel (as-fabricated fuel density : 90%TD) F = 1-2.95P(P:Porosity volume Fraction (-)) For low density fuel (as-fabricated fuel density: around 85%TD) F = 1-1.4P (P: Porosity volume Fraction (-)) The universal porosity correction factor was not determined in this work. In the next step, theoretical and analytical considerations should be taken into account.

H mode transition threshold power scaling and its relation to the edge neutrals in JT-60U

Fukuda, Takeshi; Takizuka, Tomonori; ; Kamada, Yutaka; Nagashima, Keisuke; Sato, Masayasu; Takenaga, Hidenobu; Ishida, Shinichi; Konoshima, Shigeru; Higashijima, Satoru; et al.

Nuclear Fusion, 37(9), p.1199 - 1213, 1997/00

https://doi.org/10.1088/0029-5515/37/9/I02

no abstracts in English