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Miyahara, Naoya; Suzuki, Eriko; Uesawa, Shinichiro; Sato, Isamu*; Matsuura, Haruaki*; Hagura, Naoto*; Koshigoe, Koki*; Osaka, Masahiko
no journal, ,
We have started the fundamental research on detailed aerosol deposition phenomena at the walls of containment vessel and reactor building to develop a reasonable evaluation model of aerosol deposition amount which have a large influence on release amount to the environment. In this study, an aerosol deposition test onto various materials was conducted to investigate the physical and chemical phenomena related to aerosol deposition. As a result, important phenomena such as aerosol penetration into concrete pore were observed, which should be considered in the aerosol deposition model.
Koshigoe, Koki*; Sato, Isamu*; Miyahara, Naoya*; Suzuki, Eriko; Osaka, Masahiko; Matsuura, Haruaki*
no journal, ,
To elucidate cesium (Cs) penetration behaviour in concrete structural materials under Fukushima Daiichi Nuclear Power Station accident condition, penetration tests of CsCl and CsI into concrete were performed. The depth profile and chemical state of Cs in penetrated concrete were investigated by using XRF and EXAFS. As a result, it was found that the chemical state of Cs could be affected by volume ratio of coarse aggregates, whereas the depth profile of Cs could not be affected.
Yoneyama, Kai*; Sato, Isamu*; Matsuura, Haruaki*; Koshigoe, Koki*; Miyahara, Naoya*; Kurihara, Norihiko*; Suzuki, Eriko; Osaka, Masahiko
no journal, ,
For the safety and rational management of radioactive concrete waste generated in the decommissioning of Fukushima-Daiichi Nuclear Power Station, we have developed the estimation technology for Cs penetration into concrete, considering the fraction/distribution of mortar and aggregate. In this work, the Cs distribution and diffusion coefficients of mortar, aggregate and concrete were evaluated by the Cs penetration tests to identify the influencing factor on Cs penetration behavior. While the distribution and diffusion coefficients of aggregate were smaller than that of mortar, the diffusion coefficient of concrete, which contained aggregates, was smaller than that of mortar. This result suggests that the existence of aggregate could significantly affect the Cs penetration behavior.
Koshigoe, Koki*; Sato, Isamu*; Miyahara, Naoya*; Suzuki, Eriko; Osaka, Masahiko; Matsuura, Haruaki*
no journal, ,
For the waste management of radioactive concrete in the Fukushima Daiichi Nuclear Power Station, the Cs penetration behavior into concrete focused on the effects of aggregates was investigated by small-scale leaching tests of concrete with various contents of aggregates into CsI or CsCl dissolved water solution. The distribution in depth direction and chemical state of Cs were measured by using XRF and EXAFS, respectively. It was found that the Cs concentration and coordination number of O with Cs changed according to the content of aggregates. These results suggested importance of the effect of content of aggregates.
Koshigoe, Koki*; Sato, Isamu*; Hagura, Naoto*; Miyahara, Naoya*; Suzuki, Eriko; Osaka, Masahiko; Matsuura, Haruaki*
no journal, ,
For the waste management of radioactive concrete in the Fukushima Daiichi Nuclear Power Station, the analysis technology of Cs penetration behavior into concrete was developed. In this study, samples of small-scale leaching tests into CsI or CsCl dissolved water solution were subjected to the PIXE. The results of PIXE show that the Cs penetration depth and the change of Cs concentration with the content of aggregates can be obtained, which indicates that the PIXE measurement was useful for the samples with dilute concentration.
Koshigoe, Koki*; Sato, Isamu*; Hagura, Naoto*; Miyahara, Naoya*; Suzuki, Eriko; Osaka, Masahiko; Matsuura, Haruaki*
no journal, ,
For the waste management of radioactive concrete in the Fukushima Daiichi Nuclear Power Station, the Cs penetration behavior into concrete focused on the effects of aggregates was investigated by small-scale leaching tests into CsI or CsCl dissolved water solution. The Cs chemical state was investigated by using EXAFS. As a result, the coordination number of O with Cs was decreased with increase of the content of aggregates. This suggests that the content of aggregates can affect the Cs penetration behavior into concrete.
Yoneyama, Kai*; Sato, Isamu*; Matsuura, Haruaki*; Koshigoe, Koki*; Miyahara, Naoya*; Kurihara, Norihiko*; Suzuki, Eriko; Osaka, Masahiko
no journal, ,
For the rational management of radioactive concrete waste generated in the decommissioning of LWR severe accident, the influence of mortar and aggregate on Cs penetration behavior based on the Cs penetration test using mortar, aggregate and concrete. While the distribution and diffusion coefficients of aggregate were smaller than that of mortar, the diffusion coefficient of concrete, which contained aggregates, was smaller than that of mortar. This result suggests that the boundary surfaces between aggregate and mortar could affect the Cs penetration behavior.
Yoneyama, Kai*; Sato, Isamu*; Matsuura, Haruaki*; Koshigoe, Koki*; Miyahara, Naoya*; Kurihara, Norihiko*; Suzuki, Eriko; Osaka, Masahiko
no journal, ,
For the management of radioactive concrete waste generated in a severe accident of light water reactor, the cesium (Cs) penetration tests into the mortar, aggregate and concrete were performed in order to evaluate the influence of aggregate on Cs penetration behavior. While the diffusion coefficient of aggregate was very smaller than that of mortar, the diffusion coefficient of concrete, which contained the aggregate, was larger than that of mortar. This result suggests that the interface between mortar and aggregate promoted the Cs penetration.
Uchiyama, Shogo*; Matsushima, Ryotatsu; Koshigoe, Koki; Sato, Fuminori; Arai, Tsuyoshi*
no journal, ,
no abstracts in English