"Completion of Multiple Reciprocity Boundary Element Method for Liquid Criticality System Having Irregular Geometry"
Project/Area Number |
10558074
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Research Category |
Grant-in-Aid for Scientific Research (B).
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Allocation Type | Single-year Grants |
Section | 展開研究 |
Research Field |
Nuclear engineering
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Research Institution | HOKKAIDO UNIVERSITY |
Principal Investigator |
ITAGAKI Masafumi Hokkaido Univ., Grad.School of Eng., Prof., 大学院・工学研究科, 教授 (30281786)
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Co-Investigator(Kenkyū-buntansha) |
NARITA Masakuni Akita Univ., Faculty of Engineering and Resource Science, Prof., 工学資源学部, 教授 (00001313)
ENOTO Takeaki Hokkaido Univ, , Grad.School of Eng., Prof., 大学院・工学研究科, 教授 (10001992)
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Project Period (FY) |
1998 – 2000
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Project Status |
Completed (Fiscal Year 2000)
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Budget Amount *help |
¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥2,600,000 (Direct Cost: ¥2,600,000)
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Keywords | reprocessing process / earthquake / liquid nuclear material / criticality safety / irregular geometry / multiple reciprocity method / boundary element data / preprocessor / 規則幾何形状 |
Research Abstract |
The aim of the research is to finalize the development of the criticality safety analyzing system based on the multiple reciprocity boundary element method (MRBEM). The main part of the system solves the three-dimensional, two-group neutron diffusion equation in order to analyze the nuclear criticality of liquid nuclear material systems in a reprocessing plant. In such analyses one often meets problems of irregular geometry, e.g., a listing or sloshing of liquid surface arising from an earthquake. The MRBEM is well suited for the analysis of such an irregular geometry since the method requires the discretization of the surface only rather than of the volume. Subdivision of a domain into mesh points or finite elements is not required since the critical eigenvalue itself is also calculated using only boundary integrals. In addition to this, the "preprocessor", which was introduced in the first year of the project to make boundary element data efficiently, has expanded the flexibility of analysis of complicated geometry. The MRBEM has been now reformulated to analyze the modified Helmholtz flux mode in a strong neutron absorber domain, as well as the ordinary Helmholtz one. Mathematical quantities that play an important role in the formulations are the zero-order and the higher order matrix-type fundamental solutions for the two-group neutron diffusion equation. Test calculations demonstrate the validity of the present reformulation and the usefulness when applied to the analysis of multi-domain criticality system The above research results were reported at the international conferences of boundary element research : BEM21 (1999) and BEM22 (2000). Further, results of analyses for actual sloshing experiments indicate the fact that the reactivity increases when a pan-cake shaped liquid suffers sloshing motion. As the product of the project, the whole computer system has been highly optimized and completed as a powerful tool for wide criticality analyses. (<300 words)
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Report
(4 results)
Research Products
(6 results)