Evaluation of the cryogenic tensile properties for aramid fiber rod

Saito, Toru; Okubo, Toshikazu*; Izumi, Keisuke*; Okawa, Yoshinao*; Kobayashi, Norihiro*; Yamazaki, Toru; Kawano, Katsumi; Isono, Takaaki

Teion Kogaku, 50(8), p.400 - 408, 2015/08

https://doi.org/10.2221/jcsj.50.400

Aramid fiber-reinforced plastic (AFRP) has been developed as a structural material that has the advantages of light weight and high strength. In this study, tensile tests were carried out to measure the tensile properties of AFRP rod on the market for reinforcement of concrete at room temperature, 77 K and 4.2 K. Especially at cryogenic temperatures, it is difficult to perform a tensile test of the bar because the specimen slips through the jig grip. To prevent the rod from slipping, tensile tests were carried out with some filling conditions. The applicable and appropriate tensile test conditions were established by modifying the jig grip, treating the surface of the rod and using cryogenic epoxy infill to grip the rod. They were more than 1100 MPa. Additionally, the AFRP rod included a temperature dependence in which the Young's modulus increased as the test temperature decreased. It was confirmed that the Young's modulus increased because aramid fiber was more dominant than epoxy.

The Computational Design of Geological Disposal Technology Integration Syatem(II)

Ishihara, Yoshinao*; Neyama, Atsushi*; Kobayashi, Shigeki*; Iwamoto, Hiroshi*

JNC TJ8440 2003-006, 250 Pages, 2003/02

JNC-TJ8440-2003-006.pdf:4.06MB

In order to develop "Geological Disposal Technology Integration System" that is intended to systematize as knowledge base for fundamental study of geologixal environment, repository design and safety assessment, the computational design of an indispensable database and main function of "Geolodical Disposal Technology Integrated System" was done. The prototype was made in order to verify the system function.

Cs Adsorption behavior evaluation on the surface of nuclear reactor structure materials under high temperature and high pressure steam

Sumita, Takehiro*; Yonekawa, Kazuo*; Sekio, Yoshihiro; Sato, Isamu*; Kobayashi, Yoshinao*; Osaka, Masahiko; Maeda, Koji; Akasaka, Naoaki

no journal, , 

During Fukushima Daiichi Nuclear Power Plant (1F) accident, high radionuclides such as Cs and I were mainly released as fission products (FPs) due to fuel melting in units 1 to 3, and it increased radiation dose in reactor buildings. With the aim of 1F decommissioning, it is necessary to establish methods to retrieve fuel and an adequate access route, which requires knowledge of Cs adsorption behavior on the surface of structural materials during Severe Accidents (SA). However, there are no Cs adsorption behavior evaluations under the simulated SA condition with high pressure in the previous studies. In this study, CsI adsorption behavior on SUS304L under the condition was evaluated using newly designed apparatus which can control temperature, pressure, moisture and gas atmosphere. The findings from microstructural observation and elemental analysis after the adsorption test suggested that the adsorption of CsI was influenced by especially pressure.

Investigation of in-reactor cesium chemical behavior in TEPCO's Fukushima Daiichi Nuclear Power Station accident, 9; Thermodynamics of evaporation of silicon compounds at high temperatures

Kobayashi, Yoshinao*; Ueda, Shigeru*; Sato, Isamu*; Osaka, Masahiko

no journal, , 

SiO and Si(OH) can be Si source for Cs-bearing particle and other in-reactor compounds during Fukushima-Daiichi NPS accident. Dependencies of vapor pressure of those species on oxygen partial pressure and tenperature were evaluated thermodunamically. And experimental condition by chemical equilibrium method was determined in focusing CsO-SiO system.