Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shimada, Kazumasa; Sakurahara, Tatsuya*; Farshadmanesh, P.*; Reihani, S.*; Mohagehgh, Z.*
Annals of Nuclear Energy, 197, p.110243_1 - 110243_12, 2024/03
Times Cited Count：6 Percentile：63.53(Nuclear Science & Technology)This research improves the realism of Level 3 probabilistic risk assessment (PRA) for nuclear power plants (NPP) to avoid subjective expert judgment when setting evacuation behavior for residents. Therefore, the evacuation speed output by the traffic simulation code MATSim was input to the level 3 PRA code MACCS. Furthermore, to set the priority of the places where road closure is to be considered, a method to evaluate the road closure risk due to the earthquake using the natural disaster risk assessment code HAZUS was developed. Then, the relationship between the evacuation routes and the radiation dose was evaluated for the case study of the Sequoyah NPP adopted in the SOARCA study conducted by the US NRC. As a result, the present study found an evacuation route with low closure risk but causing high radiation dose of residents when it is closed. This showed effectiveness of the proposed Level 3 PRA methodology for supporting decision-makers to enhance evacuation routes.
Shimada, Kazumasa; Sakurahara, Tatsuya*; Reihani, S.*; Mohagehgh, Z.*
Proceedings of Asian Symposium on Risk Assessment and Management 2020 (ASRAM 2020) (Internet), 12 Pages, 2020/11
Level 3 Probabilistic Risk Assessment (Level 3 PRA) and Traffic simulation were integrated to evaluate the effects of evacuation more realistically on radiation exposure to residents in the offsite consequence analysis. In this study, WinMACCS was used as the Level 3 PRA code. As a test case, the Sequoyah Nuclear Power Plant(NPP) site, which was targeted by the State-of-the-Art Reactor Consequence Analyzes (SOARCA) issued by U.S. Nuclear Regulatory Commission in 2017, was adopted. The MultiAgent Transport Simulation (MATSim) was used to simulate the evacuation of a Sequoyah NPP's 10-mile Emergency Planning Zone. For the transportation route choice, the route where each vehicle chooses the shortest distance and the route where the total evacuation time is shortened by iterative calculation were chosen. In the calculation of MACCS, the source term with the shortest release start time in the SOARCA report was adopted. As an example of the results, the radiation dose of the residents when the evacuation time was optimized was reduced by about 30% from the dose when the shortest distance was selected. Furthermore, a sensitivity analysis was conducted, and it was shown that the evacuation preparation time was the largest factor that contributed to the radiation dose to residents.
Sakurahara, Tatsuya; Tanaka, Satoru*; Kato, Masato; Uchida, Teppei; Uno, Hiroki*
no journal, ,
Elastic constants of 20% Pu-containing MOX sintered pellet were measured by ultrasonic pulse echo method as a function of porosity and O/M ratio. In addition, the effects of O/M ratio on elastic constants and its atomic scale mechanism were investigated based on the modeling by first-principle calculation which was performed on Ce-O system as a surrogate material of MOX. Measured Young's and shear moduli decreased linearly as the porosity increased in the range from 5% to 15%, where as poison's ratio remained almost constant. Young's and shear moduli of non-stoichiometric samples (O/M = 1.973 and 1.963) decreased slightly from stoichiometric sample (O/M = 2) by less than 5%, which was in a fairly good agreement with first-principle calculation on Ce-O system. Computational results by first-principle calculation indicated that O/M ratio effect on Young's modulus was dominated by the contribution of chemical lattice expansion.
Uchida, Teppei; Kato, Masato; Konashi, Kenji*; Yato, Tadao*; Sakurahara, Tatsuya*; Tanaka, Satoru*
no journal, ,
no abstracts in English
