Use of CAD generated geometry data in Monte Carlo transport calculations for ITER

ITERモンテカルロ輸送計算におけるCADデータから作成した形状データの利用

Fischer, U.*; 飯田 浩正; Li, Y.*; Loughlin, M.*; 佐藤 聡; Serikov, A.*; Tsige-Tamirat, H.*; Tautges, T.*; Wilson, P. P.*; Wu, Y.*

Fischer, U.*; Iida, Hiromasa; Li, Y.*; Loughlin, M.*; Sato, Satoshi; Serikov, A.*; Tsige-Tamirat, H.*; Tautges, T.*; Wilson, P. P.*; Wu, Y.*

CAD形状データからモンテカルロ計算コードMCNP入力データを作成するための研究開発が行われている。変換システムとして、中国によりMCAM、ドイツによりMcCAD、日本によりGEOMIT、米国によりDAG-MCNPXコードの開発が進められている。2005年から2007年におけるITERの活動において、各国が各々のコードを用いてITERのベンチマークCADデータをMCNP入力データに変換し、ITERのさまざまな核的応答を計算し、各国で開発したコード間の結果を比較,検証した。本論文では、各国で開発した変換システム,各コードでのITERベンチマーク計算の結果,CADデータへの要求事項等をレビューする。

Several approaches have been recently developed to make available CAD geometry data for Monte Carlo calculations with the MCNP code. Among these are conversion tools for the automatic generation of geometry models in MCNP representation such as MCAM of China, McCad of Germany, and GEOMIT of JAEA, as well as the direct DAG-MCNPX approach developed by USA. An extensive benchmark exercise has been conducted on ITER between 2005 and 2007 with the objective to test and validate the different approaches and thereby check the maturity level for ITER design applications. The exercise encompassed the generation of a dedicated neutronics CATIA model based on available engineering CAD design data, the conversion into MCNP geometry, the verification of the converted models, and a number of calculations to compare the different approaches with regard to the performance and the validity of the results obtained. The paper briefly reviews the different approaches and provides a detailed description of the ITER benchmark effort, its results and conclusions. As a key issue, the recommendations are discussed that need to be followed when generating a neutronics CAD model for ITER design calculations. This is considered essential since the ITER quality assurance requirements will request the consistency of the analysis models and the underlying engineering CAD models.