10 MeV工业辐照电子加速器GEANT4计算和工艺界面软件开发

利用GEANT4蒙特卡罗软件程序包,建立了10 MeV工业辐照电子加速器数学模型,并模拟计算了不同密度下均质产品剂量分布数据。结合Qt界面设计开发平台,对模拟数据进行C++编程计算,获得了各种产品密度、不同厚度单双面辐照剂量分布图及辐照不均匀度等参数。同时,利用Qt将产品辐照剂量与束下装置传送速度计算、日常工艺管理和剂量场分布数据绘图等功能界面化,研制了辐照工艺界面软件。经过产品剂量分布测试实验和对行业研究结果比较,验证了GEANT4模拟计算结果和工艺软件准确性。实验表明：计算和测试结果具有很好的吻合性。辐照工艺界面软件可以快速显示产品辐照效果及计算传送速度等主要工艺参数,为产品辐照工艺设计提供了有力工具。     

辐射屏蔽专用蒙特卡罗软件RShieldMC开发与验证

辐射屏蔽计算是核电厂辐射防护设计和审评的重要内容之一。国际屏蔽计算软件对中国实行"出口封锁",制约了我国核电辐射屏蔽审核计算能力,因此,研发了具有自主知识产权的基于蒙特卡罗方法的辐射屏蔽专用蒙特卡罗软件RShieldMC(Radiation Shielding Monte Carlo)。为了验证RShieldMC程序,进行中子注量率计算的准确性和适用性,利用秦山一期反应堆结构与辐照监督管相关参数,通过RShieldMC可视化前处理模块建立辐照监督管屏蔽计算模型,计算秦山一期反应堆辐照监督管堆芯中平面和上焊缝处的中子注量率。RShieldMC程序计算结果与辐照监督管实验测量值以及MCNP(Monte Carlo N-Particle)、JMCT-S(J Monte Carlo Transport)、TORT(Three-dimensional Neutron/Photon Transport)程序计算结果符合较好,验证了RShieldMC软件在中子注量率计算中的可用性及正确性。     

CPR1000超温超功率保护通道精度计算及软件实现

确定反应堆保护系统参数整定值时,需考虑参数测量和处理的精确度。本文首先结合超温超功率ΔT保护计算原理及保护通道精度计算方法,对超温和超功率保护通道误差进行分析,给出系统功能设计和类结构设计,最后通过C＋＋进行软件实现精度计算的界面化操作。计算方法和软件已应用于CPR1000及相关改进项目中。     

用于辐照监督数据处理的TransTemp程序开发

开发了用于压水堆核电站反应堆压力容器辐照监督数据处理的TransTemp程序软件,程序使用Matlab语言编写.该程序采用双曲正切模型描述压力容器韧脆温度转变曲线,根据辐照监督数据,计算得出韧脆温度转变曲线,并给出韧脆转变温度(T41J)及误差估计.     

上海辐射中心钴源装置剂量场计算

本文用γ辐照装置剂量场计算简化模型计算了上海辐射中心γ辐照装置剂量场分布,并与实测值进行了比较。计算和测量了辐照产品箱内累积最大和最小吸收剂量、均匀性等参数,介质为空气时符合较好,辐照产品为马铃薯时在10％以内符合。同时也给出了辐照产品为马铃薯时的产量和源利用率的计算值和实测值。     

弥散核燃料等效辐照肿胀计算模拟

本文将弥散核燃料芯体看作一种特殊的颗粒复合材料,利用细观计算力学的方法,假设燃料颗粒在芯体中周期性分布,建立了对芯体等效辐照肿胀进行计算模拟的有限元模型。考虑颗粒的辐照肿胀和基体材料的辐照硬化效应,分别建立了燃料颗粒和基体材料的应力更新算法,编制了用户材料子程序,在Abaqus软件中实现了芯体等效辐照肿胀的有限元模拟。计算分析了颗粒大小和体积含量对芯体等效辐照肿胀的影响,并得到了等效辐照肿胀的拟合公式。研究结果表明,影响芯体等效辐照肿胀的主要因素是颗粒的辐照肿胀和体积含量。     

严重事故下安全壳内水池pH值分析模型开发与验证

为解决事故后核电厂安全壳内水池pH值计算工具缺失的问题，研究开发了可直接建模和实时模拟的pH值计算模型。基于牛顿拉夫森方法，通过建立关键物项物性及反应数据库，构建气-液两相化学平衡计算模型，开发了数据库完整、具备高辐照反应计算能力和事故进程耦合能力的pH值计算软件CalcpH。针对不同计算功能，CalcpH软件计算结果分别与事故分析软件ASTEC和化学平衡计算软件PHREEQC计算结果进行了对比。结果表明，对于非辐照反应，CalcpH软件计算结果与PHREEQC软件计算结果差距在1.3%以内；对于辐照反应，CalcpH软件计算结果与ASTEC软件计算结果差距在2.7%以内。同时，CalcpH软件计算结果与实验对比，其误差在1%以内。通过软件对比与实验对比2种方式充分证明了计算结果的可靠性。因此，CalcpH软件建立的数值计算模型可用于事故后安全壳内水池pH值的预测。     

电子束辐照降解二氯苯废水的研究

二氯苯是重要的有机污染物,采用常规处理方法难以降解.利用束流为1 mA、电子束能量为1.5 MeV的高能电子束辐照处理邻,间,对-二氯苯的模拟废水.辐照剂量分别为35 kGy、70 kGy、105 kGy、140 kGy、210 kGy.实验表明电子束能够降解氯苯类废水且效果很好,邻二氯苯、间二氯苯、对二氯苯的降解率为50%时所需剂量分别为:38 kGy、35 kGy、46 kGy.辐照降解过程中氯离子的质量浓度增加,辐照后溶液呈强酸性,pH在2-3.根据实验结果,本文给出了二氯苯的辐照降解机理并初步探讨了辐解中间产物的类型.     

3号辐照场剂量的微机管理

本文针对四川省原子核应用技术研究所３号辐照场的基本特点和辐照加工情况，论述了３号辐照场源排列，空场实场剂量计算，分布曲线和辐照工艺评价软件的主要内容。     

三维燃料棒精细化模拟软件FUPAC3D与FUPAC的对比验证研究

为验证基于三维有限元分析平台建立的三维燃料棒精细化模拟软件FUPAC3D在分析评价压水堆燃料棒辐照-热-力耦合行为方面的能力和精度,本文给出了三维FUPAC3D软件采用的热学模型、燃料棒力学模型、裂变气体释放模型以及腐蚀模型,以华龙一号典型燃料棒参数和运行工况作为输入参数,分别使用三维FUPAC3D软件和已工程化应用的1.5维FUPAC软件进行建模分析,并针对2种软件在芯块和包壳温度、包壳应力与应变、芯块与包壳间间隙宽度的计算结果进行对比研究。研究结果表明,FUPAC3D软件与FUPAC软件具有相当的精度,FUPAC3D软件具备压水堆燃料棒辐照-热-力耦合行为的精细化模拟能力。      

靶件内中子注量率分布计算方法研究

选择ANISN作为实验靶件内中子注量率分布计算的程序，编制辅助程序输入混合材料截面。计算得到延时水箱附近的中子注量率，与测量数据作对比。计算得到靶片自屏因子，并与2000年实验数据对比。确认计算方法可行后，计算得到实验靶件内热中子注量率分布数据。     

A Time-Optimal,On-Off,Program for the NRU Reactor Digital Computer Control Experiment

Methods by which we can control flux tilts and maintain constant overall power of a high flux research reactor (NRU) using digital computer control are described. From coolant water temperature signals, the digital computers detect overall power deviation caused by flux tilts and control the reference setting to the analog neutron flux control system.

First, according to sampled-data control theory and with linear approximation, a control program which is repeated regularly with fixed period is obtained mainly from time domain synthesis.

Second, methods for computer time saving are studied, since the computers are time-shared amongst various tasks. One method is to change the constant period of control calculation to being dependent on system error. Actually an On-Off sampling scheme is used for this purpose. The other method is, in addition to the former, to change control calculation itself. A Time Optimal Control is applied to our control program.

These control programs were designed, programmed, and then tested for the NRU simulator system. The results showed that considerable computer time was saved by the proposed methods.     

Series Solution for Magnetic Flux Density of Circular Current Loop and a Relevant Application

The series solution to the magnetic flux density of a circular current loop is presented in the paper. The convergences of these series are assessed. Comparing the result with elliptic integral method, the validity and feasibility of series solution were verified. A computer program has been developed by the method to calculate the magnetic flux density of a multi-coil magnet and its uniformity successfully.     

NPDMC中子和光子耦合输运孔道计算三维蒙特卡罗程序

ＮＰＤＭＣ是一个我国研制的多群中子和光子耦合输运的三维孔道计算蒙特卡罗程序。该程序配备了国内制作的８７群中子和２５群光子截面数据库,在程序设计中,采用了一些独特的方法和技巧,成功地解决了蒙特卡罗方法应有和到辐射屏蔽计算中所遇到的“深穿透”和“小概率”等难题。ＮＰＤＭＣ程序可以计算各种类型的研究性反应堆和动力堆中的管道,束孔和缝隙的中子能量,能谱,剂量率和γ光子通量及剂量率等。     

A new trial function for hexagons

A new trial function is proposed for approximating the neutron flux in hexagons. Its properties are compared with those of the trial functions usually applied. The new trial function has been successfully applied in the framework of the finite-element diffusion program .     

测量氡析出率的驻极体收集法

本文描述了测量氡析出率的驻极体收集被动采样法。给出了对铀尾矿堆或建筑材料的部分测量结果。测量结果的可靠性由刻度程序保证,并在比对测量中得到检验。     

Spherical harmonics method for neutron transport equation based on unstructured-meshes

Based on a new second-order neutron transport equation, self-adjoint angular flux (SAAF) equation, the spherical harmonics (PN) method for neutron transport equation on unstructured-meshes is derived. The spherical harmonics function is used to expand the angular flux. A set of differential equations about the spatial variable, which are coupled with each other, can be obtained. They are solved iteratively by using the finite element method on unstructured-meshes. A two-dimension transport calculation program is coded according to the model. The numerical results of some benchmark problems demonstrate that this method can give high precision results and avoid the ray effect very well.     

Comparisons of the RETRAN two-phase flow model with experimental data

The RETRAN computer program was designed for thermal-hydraulic analysis of nuclear steam supply systems at steady-state and off-normal conditions. A homogeneous equilibrium mixture model (HEMM) of two-phase flow is used in the program. The constitutive models for wall friction, two-phase friction multiplier, heat transfer coefficient, and critical heat flux are compared with steady-state experimental data in this report. The void fraction predicted by the HEMM is also compared with data. The results of the data comparisons indicate that the constitutive models are accurate representations and that the RETRAN numerical scheme provides an excellent framework for data comparisons.     

Simulation of momentum flux ratios in the cascade in the sputtering of Mo---Mo

Momentum flux ratios ⁹²Mo/¹⁰⁰Mo towards the surface and the bulk through marker planes have been studied by a static Monte Carlo simulation program for an isotopic mixture ⁹²Mo_0.5¹⁰⁰Mo_0.5 bombarded with 5 keV Xe ions. The calculations show that the momentum flux ratios in the cascade deviate far from one at different surface depths. The calculations also show that the zero-fluence isotopic ratio in the near-normal direction and its difference between small and large polar emission angles are positive.     

Bubble Dynamic Behavior Study on Pool Boiling with Downward Facing Heated Surface

Based on the Matlab software, a program for automatic identification of vapor liquid two-phase flow interface was developed. The program can obtain such characteristics as vapor liquid interface change, vapor film thickness, vapor film departure period and normal velocity. The dynamic data of bubbles on the downward facing heated grooved surface with different inclination angles and heat fluxes were processed and analyzed by this program. The results show that when the downward facing heated surface under the nucleate boiling, the vapor film thickness increases with the heat flux, and the bubble departure period decreases with the increase of the heat flux firstly and then maintains a stable value. The vapor film departure period decreases with the increase of inclination angle, and is about 0.27 s when the inclination angle is 5°. When the boiling crisis occurs, the vapor film thickness decreases rapidly, which can be used as the basis for dynamically monitoring the boiling state of heated surface.