移行パラメータ信頼性評価手法の確立(II)

A Study about the Certainty Evaluation of Nuclear Transport Parameter II

吉野 尚人; 野本 康介*; 松井 幹雄*; 梨本 裕*

Yoshino, Naoto; Nomoto, Kosuke*; Matsui, Mikio*; Nashimoto, Yutaka*

地層処分の安全評価では様々な不確実要因が内在し,これらを完全に排除することは困難である。そのため,安全評価の不確実性を定量的に評価する手法に関する検討が必要となる。サイクル機構殿は地下水流動解析に着目し,調査試験データや解析で求められる値の空間的なバラツキの定量化を目的として,2003年度に,透水係数設定方法の整理と分散の定量化手法の検討,確率論による浸透流解析に基づく評価項目のバラツキの定量化手法の開発,二次元鉛直断面における事例検討,を行った。本業務では2003年度の検討結果を踏まえ,1)任意点からの地下水流れの到達点のバラツキ評価の検証,2)2次元プログラムの3次元化,3)3次元プログラムによる事例検討,の検討および作業を行った。

There are various uncertainty factors in the safety assessment for the geological disposal of High Level Nuclear Waste. And it is difficult to eliminate these uncertainty factors completely. Then it is important to evaluate the various uncertainty factors quantitatively for the safety assessment of the geological disposal. Japan Nuclear Cycle Development Institute focused on the groundwater flow analysis and studied about following issues in 2003 in order to quantify the variance of values which obtained by field investigation or numerical analysis. (1)The method to estimate the hydraulic conductivity and quantify the variability of estimated hydraulic conductivity. (2)The quantification of the key parameter's variability based on probability flow rate analysis. (3)Case study by the vertical two dimensional field. Two-dimensional numerical simulation program in which the uncertainty of the reach point in the ground water flow can be estimated was developed in above subjects. In this study, following three issues are studied (1)verification about the variance of the reach point estimated by 2-dimensional simulation program (2)development of 3-dimensional simulation program (3)Case study by 3-dimensional simulation program