Modelling heterogeneous hydration behaviour of bentonite by a FracMan-Thames coupling method for the Bentonite Rock Interaction Experiment (BRIE) at sp HRL

Sawada, Atsushi; Sakamoto, Kazuhiko*; Watahiki, Takanori*; Imai, Hisashi*

SKB P-17-06, 154 Pages, 2023/08

Epistemic Uncertainty Quantification of Floor Responses for a Nuclear Reactor Building

Choi, B.; Nishida, Akemi; Li, Y.; Muramatsu, Ken*; Takada, Tsuyoshi*

Proceedings of 26th International Conference on Nuclear Engineering (ICONE-26) (Internet), 9 Pages, 2018/07

After the 2011 Fukushima accident, nuclear power plants are required to take countermeasures against accidents beyond design basis conditions. In seismic probabilistic risk assessment (SPRA), uncertainty can be classified as either aleatory uncertainty, which cannot be reduced, or epistemic uncertainty, which can be reduced with additional knowledge and/or information. To improve the reliability of SPRA, efforts should be made to identify and reduce the epistemic uncertainty caused by the lack of knowledge. In this study, we focused on the difference in seismic response by modeling methods, which is related epistemic uncertainty. We conducted a seismic response analysis with two kinds of modeling methods; a three-dimensional finite-element model and a conventional sway-rocking stick model, by using simulated various input ground motions, which is related to aleatory uncertainty. And then we quantified the seismic floor response results of the various input ground motions of each modeling methods. For the uncertainty quantification related to different modeling methods, we further perform a statistical analysis of the floor response results of the nuclear reactor building. Finally, we discussed how to utilize the results from these calculations for the quantification of uncertainty in fragility analysis for SPRA.

OSCAAR development and applications

Homma, Toshimitsu

Proceedings of 4th International MACCS Users Group Meeting, p.57 - 66, 2002/10

no abstracts in English

Effects of model complexity on uncertainty estimates

M.Elert*; A.Butler*; J.Chen*; C.Dovlete*; A.Konoplev*; A.Golubenkov*; M.Sheppard*; Togawa, Orihiko; T.Zeevaert*

Journal of Environmental Radioactivity, 42, p.255 - 270, 1999/00

https://doi.org/10.1016/S0265-931X(98)00058-7

no abstracts in English

Validation of biospheric transfer models; Results and prospects of the BIOMOVS study

Togawa, Orihiko

Hoken Butsuri, 29, p.55 - 64, 1994/00

https://doi.org/10.5453/jhps.29.55

no abstracts in English

LISA package user guide, Part 1: PREP(Statistical PRE Processor) preparation of input sample for Monte Carlo simulations program description and user guide

Homma, Toshimitsu; A.Saltelli*

EUR-13922, 33 Pages, 1992/00

no abstracts in English

Identification of important parameters for source term analysis; Expectation of outcomes from fuel safety research

Zheng, X.; Sugiyama, Tomoyuki

no journal, ,