Problems of lead nuclear data in fusion blanket design

In an irradiation experiment using a LiAl/Pb assembly, we found out that the neutron flux inside the assembly calculated with JENDL-3.3 underestimates an experimental value in the 10–16 MeV region by around 30% and that in the 0.5–5 MeV region by around 15%, while the calculated flux with JEFF-3.1 overestimates the measurement in the 5–10 MeV region by around 20%. In order to reveal a reason of the discrepancy, problems of the nuclear data libraries for lead were investigated. As a result, the following problems of the evaluated libraries were pointed out: the cross-sections of the (n,2n) reaction in JENDL-3.3 for lead isotopes are too large and cause a significant underestimation of the neutron flux above 10 MeV, which appeared in the analysis of the above experiment. Inelastic scattering data for ²⁰⁸Pb in JENDL-3.3 reproduce previous experimental double-differential cross-section data most well. However, those for the other lead isotopes have some problems and cause a large underestimation of the neutron flux from 0.5 to 5 MeV. The reason of the overestimation in the energy region of 5–10 MeV with JEFF-3.1 is still unclear.     

多功能网络化核数据获取和处理系统

应用网络技术将多个功能不同、相互独立的以PC微机为基础组成的核数据获取和处理子系统有机互联,组成了一种新型的多功能网络化核数据获取和处理系统,探讨了系统的最佳组成模式、工作原理及实现方法,给出了系统在2．5MeV静电加速器上进行团簇特性研究的初步结果。     

A nuclear data oriented interface code for processing applications

A new user interface code developed to facilitate the processing of evaluated nuclear data is presented. The CadTui package proposes an easy-to-use interface with the widely use processing and nuclear data codes. It was especially designed to simplify the complex relationships between an evaluation and its processing. In response to requests from users involved in reactor development programs, intuitive Unix commands relying on Monte Carlo techniques were implemented to propagate the uncertainty of the model parameters to integral calculations at a given dilution cross section.     

用数据处理标定核数据采集系统

利用计算机程序拟合数据采集系统获取的数据,改变拟合参数,找出最佳拟合值,从而标定该数据采集系统,所得标定值的系统误差最小。     

Development and verification of a new nuclear data processing system FRENDY

Japan Atomic Energy Agency developed the new nuclear data processing system FRom Evaluated Nuclear Data librarY to any application (FRENDY) in order to solve the problems of the current widely used nuclear data processing systems and process the new evaluated nuclear data file. Verification of FRENDY was carried out by three steps, i.e. verification of each function, comparison of the results, and comparison of the k_eff values for the 79 benchmark experiments in the ICSBEP handbook using cross section data library processed by FRENDY with those by NJOY99. These results verified that FRENDY generates the ACE (A Compact ENDF) file correctly.     

微型化双参数核谱数据获取与处理系统

本文叙述了一个以微型计算机为基础的双参数核谱数据获取与处理系统。主要特点是造价低,使用方便、谱形显示立体感较强。文中对数据获取通道和立体谱形显示作了较详细的描述,给出了应用实例。     

基于核电四极矩共振技术的爆炸物检测系统的数据处理及信号识别算法

分析了核电四极矩共振(NQR)信号的特点,利用傅里叶频谱分析对NQR信号进行处理的信噪比及其随测量时间的变化曲线,在此基础上,针对NQR信号提出一种具有更高信噪比的频谱分析方法(加权傅里叶频谱分析),同时提出一种可以有效区分NQR信号和正弦干扰信号的频谱差值分析方法。     

Challenge of nuclear data for innovative nuclear energy

The article devoted to assessment of present-day demand to nuclear data for transmutation problem, including the discussion of required accuracies, status and perspectives of nuclear data evaluation and development of nuclear models. The effect of nuclear data uncertainties on radiation damage of structural materials is discussed. An analysis of ISTC projects related to nuclear data measurement and evaluation is presented. The recommendations for differential, integral experiments and recommendations on the evaluated data preparation are presented.     

Small and Medium Power Reactors in developing countries — Present status

Introduction of Small and Medium Power Reactors (SMPRs) in the electrical grids of developing Member States is a long standing programme for the International Atomic Energy Agency. This presentation describes the activities of the Agency in this area for the last few years and discusses the advantages of SMPRs for developing countries with small grids. Constraints which hinder the introduction of SMPRs are also described as are suggested ways to overcome the constraints.