Development of hydrogen behavior simulation code system

Terada, Atsuhiko; Matsumoto, Masaaki*; Sugiyama, Hitoshi*; Kamiji, Yu; Hino, Ryutaro

Proceedings of 6th International Conference on Hydrogen Safety (ICHS 2015) (CD-ROM), 11 Pages, 2015/10

To improve the safety performance of the Nuclear Power Station, especially on the hydrogen safety under severe accident conditions, a simulation code system has been developed to analyze hydrogen behavior including diffusion, combustion, explosion and structural integrity evaluation. This developing system consists of CFD and FEM tools in order to support various hydrogen user groups consisting of students, researchers and engineers. Preliminary analytical results obtained with above mentioned tools, especially with open source codes including buoyancy turbulent model and condensation model, agreed well with the existing test data.

Reliability evaluation of simulation models for nearfield groundwater flow and radionuclide transport computation

*; *; *; *

JNC TJ8400 2000-006, 232 Pages, 2000/05

JNC-TJ8400-2000-006.pdf:7.75MB

In this research, simulations with some parameters which characterize ground water flow and the reliability evaluation for the expansion of the calculation method of groundwater flow were carried out by using the radionuclide transport computations in nearfield heterogeneous porous media. Concretely contents are follows: (1)With the series of calculation method for three-dimensional saturated/unsaturated groundwater flow and one-dimensional radionuclide transport. the computational analyses with the parameters used in JNC report in 2000 was carried out and the influence of the different input flux was evaluated. (2)The examination of the application for the different ways of inverse laplace transformation which is used in one-dimensional radionuclide tansport analysis code "MATRICS" was carried out. (3)The examination of the application of multi-element "MATRICS" (m-MATRICS) for radionuclide transport computations in nearfield heterogeneous porous media was carried out. (4)The series of calculation methods from three-dimensional saturated/unsaturated ground water flow simulation code to one-dimensional radionuclide transport simulation code was integrated.

Reliability evaluation for radionuclide transport analysis code MATRICS

*; Ijiri, Yuji*; *; *

JNC TN8400 2000-021, 66 Pages, 2000/04

JNC-TN8400-2000-021.pdf:4.38MB

A reliability evaluation for radionuclide transport analysis code, MATRICS, used in radionuclide transport analysis in the natural barrier system PA in H12 report has been carried out. Sensitivity analysis to radionuclide transport parameter in MATRICS and analytical solution has been performed, and the results of each analysis have been compared. Additionally sensitivity analysis using Talbot Method, Crump method and Hosono method has been carried out, and the results of each inverse Laplace transform method has been compared. The conclusions obtained from the results of the evaluation are summarized as follows, (1)In case of the infinite matrix diffusion distance, an error among the results of each calculation is maximum about 0.4% in the range of Pe number from 1.0 to 100. And, an error among the results of each calculation is maximum about 5.5% in the range of transmissivity from 1.010 to 1.010(m/s). (2)In case of the finite matrix diffusion distance (0.031.0(m)), an error among the results of each calculation is maximum about 0.7% in the range of Pe number from 1.0 to 100. And, an error among the results of each calculation is maximum about 2.4% in the range of transmissivity from 1.010 to 1.010(m/s). 3)By comparing Talbot method with other inverse Laplace transform method, Talbot method is confirmed to give similar results with other inverse Laplace transform method in the range of Pe number from 5.010 to 2.010, and that of transmissivity below 1.010(m/s). Therefore, it is concluded that the reliability of MATRICS are confirmed by conducting sensitivity analysis in the range of Pe number and transmissivity coefficient used in H12 report.

Study on the advanced performance assessment methods concerning nuclide migration through heterogeneous media

Okubo, Hiroo*; Nakajima, Kengo*; Matsumoto, Masaaki*

JNC TJ1400 2005-015, 388 Pages, 1999/02

JNC-TJ1400-2005-015.pdf:27.73MB

no abstracts in English

Development of hydrogen behavior simulation code system; Code system with open source code and validation

Matsumoto, Masaaki*; Ashida, Takaki*; Kawai, Masaki*; Terada, Atsuhiko; Hino, Ryutaro

no journal, , 

In the Fukushima Daiichi Nuclear Power Station (NPS) accident, hydrogen was generated by oxidation reaction of the cladding and water etc, then leaked into the NPS building, and finally led to occurrence of hydrogen explosion in the building. This resulted in serious damage to the environment. To improve the safety performance of the NPS, especially on the hydrogen safety under severe accident conditions, a simulation code system has been developed to analyze hydrogen behaviors including diffusion, combustion. This developing system consists of open source code in order to support various hydrogen user groups of students, researchers and engineers. Preliminary calculated results obtained with above mentioned tools, agreed well with ISP47 TOSQAN test-data.

Development status of hydrogen behavior simulation for NPP containment; Hydrogen combustion simulation

Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Sugiyama, Hitoshi*; Matsumoto, Masaaki*; Kadowaki, Satoshi*

no journal, , 

no abstracts in English

For discussions with the public for the safety of nuclear power; Their trust on safety

Miyano, Hiroshi*; Muramatsu, Ken*; Noguchi, Kazuhiko*; Narumiya, Yoshiyuki*; Takata, Takashi; Muta, Hitoshi*; Itoi, Tatsuya*; Matsumoto, Masaaki*; Matsunaga, Yoko*; Sugiyama, Kenichiro*

no journal, , 

In considering nuclear safety, it is an important task to clarify the relationship with "peace of mind" that is the heart of people. What is the state that scientific safety is something that people feel safe? We considered the relationship between quantified risk and safety, and ways to acquire peace of mind. We analyzed the thresholds of safety risks as a social common, showed a safe condition, and showed the importance of forming a consensus to obtain peace of mind.

For discussions with the public for the safety of nuclear power; Discussion with the public

Matsunaga, Yoko*; Miyano, Hiroshi*; Noguchi, Kazuhiko*; Muramatsu, Ken*; Narumiya, Yoshiyuki*; Takata, Takashi; Muta, Hitoshi*; Itoi, Tatsuya*; Matsumoto, Masaaki*; Sugiyama, Kenichiro*

no journal, , 

After Fukushima Daiichi nuclear accident, it becomes more important risk communication with the public. In discussions with the public in nuclear safety, communication and discussions on risks that not only nuclear risks also social risks are important. Differences in viewpoints, understanding, and thought about risks become communication difficult. We need to discuss risks fairly, appropriately with the public and reduce total social risks.

For discussions with the public for the safety of nuclear power; Applying risk information to prevention/mitigation of SA

Narumiya, Yoshiyuki*; Miyano, Hiroshi*; Noguchi, Kazuhiko*; Muramatsu, Ken*; Takata, Takashi; Muta, Hitoshi*; Itoi, Tatsuya*; Matsumoto, Masaaki*; Matsunaga, Yoko*

no journal, , 

In order to grasp efficiency of risk information, we tried to apply an insight of PRA to considering of severe accidents; TMI, Chernobyl, and Fukushima Dai-ichi. Based on this analysis, three points are disclosed. At first, PRA can product adequate countermeasures for low-likelihood events; huge earthquake or Tsunami. Next, PRA can prove weak points in design or operation reasonably. Third point is safety culture. PRA and safety culture are seemed to be connected deeply. These analyses revealed PRA is one of the most efficient and systematic risk analysis methods to prevent/mitigate severe accidents.