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Sato, Haruo; ; ; ; ; Yui, Mikazu
PNC TN8410 97-127, 57 Pages, 1997/08
Retardation of key nuclides is one of the most important mechanisms to be examined specifically and modelled for the performance assessment of geological disposal of radioactive waste. We have been studing diffusion of nuclides into the pore spaces of the rock matrix, sorption of nuclides on the rock pore surfaces and pore properties to quantify the degree of nuclide retardation in fractured crystalline rock. The work has concentrated on predominant water conducting fracture system in the host granodiorite in the Kamaishi In Situ Test Site, which consists of fracture fillings and altered granodiorite. Through-diffusion experiements to obtain effective and apparent diffusion coefficients (Da and De, respectively) for Na, Cs, HTO, Cl and Se as a function of ionic charge at 22 25C and batch sorption experiments for Cs, Sr, Se, U and Pu were conducted on fracture fillings, altered and intact granodiorite. The experiments only for Se, a redox sensitive element, were done in an N2-atmospheric glove box (O 1 ppm) to keep the chemical species. In situ groundwater (pH8.79.5) sampled from the same place as rock samples was used for the experiments. Porosity and density of cach rock sample were determined by both water saturation method and mercury porosimetry, and pore-size distribution and specific surface area of pores were measured by mercury porosimetry. The porosity is in the order; fracture fillings (5.6%) altered rock (3.2%) intact rock (2.3%). The pore-size distribution of the intact and altered granodiorite is ranging from 10 nm to 0.2 mm, and the fracture fillings have that of 50 nm to 0.2 mm, but a lot of pores were found around 100 nm and 0.2 mm in the fracture fillings. The effective diffusion coefficients for all species (Na, Cs, HTO, Cl, Se0) are in the order of fracture fillings altered rock intact rock in proportion to these porosities. Effective diffusion ...
G.F.Matthews*; Asakura, Nobuyuki; J.Goetz*; Guo, H.*; A.Kallenbach*; B.Lipshultz*; K.McCormick*; M.Stamp*; S.Allen*; U.Samm*; et al.
Journal of Nuclear Materials, 241-243, p.450 - 455, 1997/00
Times Cited Count:59 Percentile:95.78(Materials Science, Multidisciplinary)no abstracts in English
Yamanishi, Toshihiko; Okuno, Kenji
Journal of Nuclear Science and Technology, 31(6), p.562 - 571, 1994/06
Times Cited Count:7 Percentile:56.51(Nuclear Science & Technology)no abstracts in English
Nemoto, Shinichi; Sakai, Toshiyuki*; Sanyoshi, Hirotaka; Kikuchi, Kenji; Iwasaki, Isao*; Kuribayashi, Masakazu*; Matsushima, Kazumi*
PNC TN8410 93-283, 86 Pages, 1993/11
None
;
Journal of Nuclear Science and Technology, 23(9), p.794 - 801, 1986/00
Times Cited Count:9 Percentile:69.97(Nuclear Science & Technology)no abstracts in English
; ; ; ; ; ; ; ; ; Araki, Kunio
JAERI-M 9191, 18 Pages, 1980/11
no abstracts in English
Sengoku, Seio;
Journal of Nuclear Materials, 93-94, p.75 - 85, 1980/00
Times Cited Count:21 Percentile:86.09(Materials Science, Multidisciplinary)no abstracts in English
Shiba, Koreyuki; ;
JAERI-M 8207, 29 Pages, 1979/04
no abstracts in English
; Iwamoto, K.
JAERI-M 5937, 30 Pages, 1974/12
no abstracts in English
; Kuriyama, Isamu;
Seni Gakkai-Shi, 30(3), p.184 - 188, 1974/03
no abstracts in English
Yamaguchi, Koichi; Takehisa, Masaaki
JAERI-M 5524, 32 Pages, 1974/01
no abstracts in English
; Takehisa, Masaaki; Machi, Sueo
JAERI-M 5451, 9 Pages, 1973/11
no abstracts in English
Igarashi, Hiroshi
no journal, ,
The literature overseas was reviewed on the increase in the surface area of HLLW vitrified products due to cooling during glass pouring process and mechanical impact, from the perspective of a parameter of modeling the radionuclide release rate from glass in performance assessment of geological isolation. The investigation was focused on the experimental work to evaluate an increase in surface area, and how the parameters on surface area were set based on those experimental results. The surface area obtained from the experiments executed in Japan were also discussed in comparison with the overseas studies. While surface area increase factor and the management on its uncertainty in the modeling varied according to the country, the factor set in the modeling reported from Japan was within the range from overseas. The surface area increase factors from the experiment in Japan which were evaluated in the same manner as overseas, were comparable with those overseas.
Fujiwara, Kenso; Kuwata, Haruka*; Terashima, Motoki; Akata, Naofumi*
no journal, ,
The analysis method for organically bound tritium is summarized in the radioactivity measurement method series managed by the regulatory agency, but the pretreatment takes time. So far, joint research has investigated shortening the pretreatment, but the pretreatment still takes about a week, and speeding up is expected. This time, we investigated the relationship between the shape and weight of the sample and the time to reach a constant weight during freeze-drying. In the freeze-drying process, by increasing the surface area of the sample, the process that used to take about two days was shortened to about one day. In addition, with the aim of promoting efficient combustion, we attempted to accumulate data that would contribute to the control of combustion temperature by suggestive thermal analysis of organic matter samples.