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JNC TN9400 2000-060, 168 Pages, 2000/05
JNC-TN9400-2000-060.pdf:4.09MB
Optimal vertical isolation characteristics were studied for the structural concept of vertical seismic isolation system, which uses a common deck and a set of large coned dish springs. Four kinds of earthquake wave and three kinds of artificial seismic wave were used. The earthquake response analysis of a base isolated building was carried out considering some ground conditions and some vertical vibration characteristics of the building isolator. Floor response and acceleration time history at the vertical isolation level were arranged. Using the acceleration time history as a seismic input, the earthquake response analysis of the vertical isolation system according to single degree of freedom model was carried out. Linear analysis and non-linear analysis were made. ln the linear analysis, vertical isolation frequency was examined within 0.8 to 2.5 Hz, and damping ratio was examined within 2 to 60%. ln the non-linear analysis, it was examined within vertical isolation frequency 0.5 to 5Hz, which depended only on the rigidity of the coned disk spring, rigidity ratio of the damping devise 1 to 20 and yield seismic intensity of the damping devise 0.01 to 0.2. As the optimal vertical isolation characteristics of the system, the criterion of largest relative displacement, maximum acceleration and maximum value of the floor response acceleration between 5 to 12Hz was set, the combination region of the appropriate parameter were examined. ln case of largest relative displacement 50mm, acceleration response magnification of 0.75, floor response magnification of 0.33 were used as a criterion, from the result of the linear analysis, vertical frequency was set at 0.8 to l.2 Hz, and by combining the damping ratio over 20 %, it was proven that appropriate vertical isolation characteristics were obtained. The result of the non-linear analysis showed that the combination of the coned disk spring of vertical frequency 0.8 to 1.0 Hz and the damping element of rigidity ...
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JNC TJ7400 2000-001, 79 Pages, 2000/02
JNC-TJ7400-2000-001.pdf:3.07MB
no abstracts in English
Isozaki, Kazunori;
PNC TN9410 97-069, 134 Pages, 1997/07
Hyougo-ken southern earthquake broke out in 1997/01/17. The Atomic Energy Safety Co㎜ission considered reasonable of the design guide for seismic design. And the Science and Technology Agency(STA) required reevaluation of atomic power facilities built by old design guide according to the new seismic design guide. JOYO obtained the construction license in 1970/02. Heat transport system and buildings of JOYO was reevaluated by the new seismic design guide for the MK-III project. So, JOYO was not required reevaluation by STA. But, this evaluation of MK-III was limited to reconstruction area, and the seismic design was reevaluated extensively to confirm earthquake proof characteristics. The structural integrity of buildings and equipments was confirmed by the result of reevaluation by the new seismic design guide. The analysis model conditions were established according to the 1987 and 1991 version of JEAG. This was done by ground investigation result and buildings vaibration test. It was made clear that the analysis model conditions were reasonable and conservative from a technical view point.
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PNC TN7410 90-004, 41 Pages, 1989/12
The Second Phase of the Stripa Project included the continued development of methods and techniques for repository site investigations. The crosshole investigations demonstrated that it is possible to characterize fractures in crystaline rock with a reliability and realism not obtained before. At the investigated site at Stripa, it was shown that groundwater flow is concentrated within a few major fractures that were identified by geophysical methods. The main features were considered to be broadly planar, containing patches of high and low hydraulic conductivity. Detailed investigations of the fracture hydrology at Stripa and of the migration of tracers in the groundwater, together with additional information of the groundwater composition, resulted in an improved knowledge of groundwater flow in fractured crystalline rock. The work at Stripa has shown that it is possible to collect and analyze data that enable one to determine the type of distribution its parameters for each of the essential geometrical and hydraulic properties of the fracture system, and hence compare one site with another as part of experience building in safety assessment studies. The migration experiment demonstrated that the groundwater flow could be very unevenly distributed in the rock. Together with the tritium measurements it also gave strong support to the notion that a non-negligible portion of the flow takes place in channels which have little contact with other main channels. A further research effort has to be devoted to development of appropriate numerical models for the description of flow in fractured crystalline rock. The hydrogeochemical investigations at Stripa also indicated that a new type of solute source must be considered - fluid inclusions in the host rock. The age of the solutes may be entirely different from the age of the groundwater. At Stripa, the age of the solutes is likely to be hundreds of millions of years older than the groundwaters. Furthermore, this ...
Choi, B.; Nishida, Akemi; Guo, Z.; Muramatsu, Ken; Takada, Tsuyoshi*
no journal, ,
This study focuses on uncertainty quantification of seismic response analysis to improve the reliability of Seismic Probabilistic Risk Assessment (SPRA) for nuclear facilities. In this paper, the uncertainty evaluation of seismic responses of a nuclear plant building against various earthquake waves is shown.
Choi, B.; Nishida, Akemi; Takada, Tsuyoshi*
no journal, ,
In this paper, in order to clarify the influence of difference due to modeling methods on the results of seismic response analysis for a nuclear facility, seismic response analysis using various earthquake events was conducted and the findings obtained from the uncertainty assessment of the response result due to the difference in modeling methods are reported.