加速器驱动次临界堆大跨度能谱下多群数据库及其共振自屏效应研究

The accelerator driven subcritical system has been proposed to solve the problems of fuel breeding and waste transmutation during the development of nuclear power. The nuclear data libraries are the basis of nuclear analysis for the design of ADS system..The ADS system has the characteristics of resonance self-shielding effects and great neutron energy spans..At present, the nuclear data libraries during the world can’t fully meet the.Needs of nuclear analysis in ADS system with complex energy spectrum structures and.resonance self-shielding effects.If these characteristics are ignored in the.design of nuclear libraries for ADS, neutronics calculations and analysis may not be precise.And this will cause nuclear security in the design of ADS system..In this project, resonance self-shielding effects and great neutron energy spans.in accelerator driven subcritical system are analyzed and studied by nuclear reaction theoretical models and numerical methods..The optimization background cross section method will be developed to do the correction for resonance self-shielding effects in the design of nuclear data libraries of ADS system..On the basis of the analysis and studies, a nuclear data library for ADS system.Will be developed for accelerator driven subcritical system. To validate and qualify.The reliability of the ADS data library, the evaluated benchmark experiments of the.international handbook of evaluated criticality safety benchmark experiments and.neutronics integral experiments will be performed..These benchmark results will provide optimization advices to improve the precision.of ADS data library..The project research can provide necessary basis for physical design of ADS system.

加速器驱动次临界堆ADS目前被认为是一种理想的长寿命放射性废物嬗变装置，核数据研究是开展核设计分析的基础与必要前提。ADS次临界堆中子能量跨度大，能谱复杂，共振自屏效应强烈，如果多群计算中忽略大跨度能谱特征及共振自屏效应影响，会造成屏蔽、结构及堆芯设计精度难以保证，引发核设计安全问题。国内外针对ADS次临界堆多群核数据库设计中能谱确定难、共振自屏复杂等问题，通常采用忽略高能中子反应等近似处理方法，未能充分解决多群核数据库设计中关键问题。本项目拟基于核反应理论模型及数值计算方法，从数据库能群结构、权重函数、自屏效应修正等方面对ADS次临界堆核数据库关键问题展开研究，探索能群结构、权重函数确定及自屏效应修正方法，在此基础上设计出多群核数据库。本项目研究成果可以为ADS堆芯及屏蔽的计算提供有效核数据支持，可以在一定程度上解决现有应用核数据在20MeV以上数据缺乏的问题，具有很强的应用价值。

加速器驱动次临界堆ADS目前在国际上被认为是一种理想的长寿命放射性废物嬗变装置，核数据库研究是开展ADS次临界堆设计分析的基础与必要前提。ADS次临界堆中子能量跨度大，能谱复杂，共振自屏效应强烈，如果多群核数据库设计中忽略大跨度能谱特征及共振自屏效应影响，会造成ADS次临界堆的屏蔽、结构及堆芯设计的精度难以保证，引发核设计的安全性问题。本项目从20 MeV以上中高能中子与次临界堆包层材料相互作用的理论模型分析入手，研究20MeV以上中子核反应截面特性，并从数据库能群结构、权重函数、自屏效应修正等理论分析方面对ADS次临界堆核数据库关键问题展开研究，探索ADS核数据库设计中能群结构、权重函数确定及自屏效应修正的方法，在此基础上设计出了适用于ADS次临界堆核分析的数据库。本项目的研究成果可以为ADS次临界堆的堆芯物理计算、屏蔽计算等提供有效核数据支持，可以在一定程度上解决现有应用核数据在20MeV以上数据缺乏的问题。