The Arrangement of the seismic design method of the underground facility

Tanai, Kenji; Horita, M.*; Dewa, Katsuyuki*; Goke, Mitsuo*

JNC TN8410 2001-026, 116 Pages, 2002/03

JNC-TN8410-2001-026.pdf:9.19MB

Earthquake resistance for the underground structure is higher than the ground structure. Therefore, the case of examining the earthquake resistance of underground structure was little. However, it carries out the research on the aseismic designing method of underground structure, since the tunnel was struck by Hyogo-ken Nanbu Earthquake, and it has obtained a much knowledge. However, an object of the most study was behavior at earthquake of the comparatively shallow underground structure in the alluvial plain board, and it not carry out the examination on behavior at earthquake of underground structure in the deep rock mass. In the meantime, underground disposal facility of the high level radioactive waste constructs in the deep underground, and it carries out the operation in these tunnels. In addition, it has made almost the general process of including from the construction start to the backfilling to be about 60 years (Japan Nuclear Fuel Cycle Development Institute, 1999). During these periods, it is necessary to also consider the earthquake resistance as underground structure from the viewpoint of the safety of facilities. Then, it extracted future problem as one of the improvement of the basis information for the decision of the safety standard and guideline of the country on earthquake-resistant design of the underground disposal facility, while it carried out investigation and arrangement of earthquake-resistant design cases, guidelines and analysis method on existing underground structure, etc.. And, the research item for the earthquake resistance assessment of underground structure as case study of the underground research laboratory.

Study on optimaI vertical isolation characteristics

;

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 ...

Development of a subcritical benchmark method using the indirect estimation method for calculation error; Noise analysis method

Yamamoto, Toshihiro; Sakurai, Kiyoshi; Naito, Yoshitaka; Arakawa, Takuya*

Proc. of Topical Meeting on Criticality Safety Challenges in the Next Decade, 0, p.365 - 370, 1997/00

no abstracts in English

On-line measurement of subcriticality using pulsed spallation neutron source method

Iwamoto, Hiroki; Nishihara, Kenji; Yagi, Takahiro*; Pyeon, C. H.*

no journal, , 

no abstracts in English

Convergence acceleration of eigenvalue calculation of prompt neutron decay constant alpha using dynamic mode decomposition

Yamaguchi, Hibiki*; Endo, Tomohiro*; Yamamoto, Akio*; Tada, Kenichi

no journal, , 

The numerical solution of the alpha eigenvalue is obtained by the inverse power iteration method. This method requires a large number of iterations to calculate the alpha eigenvalue. This study developed the acceleration method using the DMD method to reduce the calculation time of the alpha eigenvalue calculation and validated the developed method.

Reduction of uncertainty due to thermal neutron scattering law for light water by data assimilation using prompt neutron decay constant

Harada, Yoshinari*; Yamaguchi, Hibiki*; Endo, Tomohiro*; Yamamoto, Akio*; Tada, Kenichi

no journal, , 

The data assimilation using the prompt neutron decay constant was performed to reduce the uncertainty in nuclear calculations due to the thermal neutron scattering law (TSL) for light water. The uncertainty in the effective multiplication factor due to TSL for light water can be reduced using the bias factor method based on the deterministic sampling method when there is a strong correlation between nuclear properties through TSL for light water.