8×8单元CsI(Tl)探测阵列研制

描述了1个8×8单元CsI(Tl)探测阵列的结构和工作原理。探测阵列的每个单元是由1块前表面21 mm×21 mm、后表面23.1 mm×23.1 mm、高50 mm的CsI(Tl)棱台、1块光导和光电倍增管组成。在兰州放射性次级束流线(RIBLL)上对探测阵列进行测试,得到探测阵列对30 MeV质子的能量分辨可达2.7%,对170 MeV7Be可达1.5%,可很好地用于放射性束物理实验中带电粒子的鉴别。     

Development of drift-flux model based on 8 × 8 BWR rod bundle geometry experiments under prototypic temperature and pressure conditions

The drift-flux model is one of the imperative concepts used to consider the effects of phase coupling on two-phase flow dynamics. Several drift-flux models are available that apply to rod bundle geometries and some of these are implemented in several nuclear safety analysis codes. However, these models are not validated by well-designed prototypic full bundle test data, and therefore, the scalability of these models has not necessarily been verified. The Nuclear Power Engineering Corporation (NUPEC) conducted void fraction measurement tests in Japan with prototypic 8 × 8 BWR (boiling water reactor) rod bundles under prototypic temperature and pressure conditions. Based on these NUPEC data, a new drift-flux model applicable to predicting the void fraction in a rod bundle geometry has been developed. The newly developed drift-flux model is compared with the other existing data such as the two-phase flow test facility (TPTF) data taken at the Japan Atomic Energy Research Institute (JAERI) [currently, Japan Atomic Energy Agency (JAEA)] and low pressure adiabatic 8 × 8 bundle test data taken at Purdue University in the United States. The results of these comparisons show good agreement between the test data and the predictions. The effects of power distribution, spacer grids, and the bundle geometry on the newly developed drift-flux model have been discussed using the NUPEC data.     

3×3-2回堆考验组件辐照后检验

文章涉及3×3-2可拆卸组件和相应热室检验装置的设计及热室内组件的远距离再组装和拆卸;组件检验及平均燃耗(以金属铀计,全文同)为30.9 GW*d/t和6.5 GW*d/t燃料棒的非破坏性检验和破坏性检验;室温和高温下的燃料棒检漏.主要结果是可拆卸组件及相应热室检验装置的设计合理,热室内远距离操作可行;经堆内考验后组件结构完整,但格架辐照弹簧松弛量较大;燃料棒性能完好,环脊明显,棒径减小显著;采用多种方法检漏,未发现破损的燃料棒.     

Lattice physics analysis of measured isotopic compositions of irradiated BWR 9 × 9 UO2 fuel

As part of a validation study of burnup calculations of BWR cores, lattice physics analyses were performed on burnups and isotopic compositions of U, Pu and fission product nuclides measured on five samples taken from 9 × 9 BWR fuel assemblies. Burnup calculations in infinite assembly geometry were carried out using MVP-BURN and SRAC codes coupled with major nuclear data libraries. The burnups determined based on the Nd-148 method were from 27.9 to 64.2 GWd/t. The typical relative differences in isotopic compositions (atom/Total-U) between the burnup calculations and measurements were ?2 ～ 19% for ²³⁴U, ?20 ～ 3% for ²³⁵U, ?1.5 ～ 0.1% for ²³⁶U, ?0.04 ～ 0.02% for ²³⁸U, ?4 ～ 11% for ²³⁸Pu, ?11 ～ ?2% for ²³⁹Pu, ?3 ～ 0% for ²⁴⁰Pu, ?12 ～ ?2% for ²⁴¹Pu and ?2 ～ 3% for ²⁴²Pu. They were ?2 ～ 2% for Nd isotopes, ?15 ～ 7% for Eu isotopes, ?13 ～ 1% for Cs isotopes, ?13 ～ 8% for Sm isotopes, 0 ～ 7% for ¹⁴⁷Pm, ?7 ～ ?2% for ⁹⁵Mo, ?2 ～ ?1% for¹⁰¹Ru and 0 ～ 4% for ¹⁰³Rh.     

γ辐照对AG1-×8树脂吸附Mo(Ⅵ)的性能研究

为评价γ辐照对AG1-×8树脂吸附⁹⁹Mo的影响,选择吸收剂量分别为37.5、275、825 kGy的AG1-×8树脂,通过静态和动态实验,研究AG1-×8树脂对Mo(Ⅵ)的吸附性能。结果表明,经γ辐照后,AG1-×8树脂表面形态未发生变化及破损;AG1-×8树脂对Mo(Ⅵ)的静态分配系数随吸收剂量的增加而减小;AG1-×8树脂辐照前后对Mo(Ⅵ)的静态分配系数在NH₄OH介质中不随介质浓度变化,而在硝酸、氢氧化钠、碳酸铵介质中随浓度的增加而减小;在1 mol/L氨水介质中,AG1-×8树脂辐照前后对Mo(Ⅵ)吸附行为符合Langmuir等温模型,吸附过程为自发、吸热过程,饱和吸附容量分别为74.07、71.02、70.97、57.57 mg/g;Mo(Ⅵ)在NH4OH中吸附、用1 mol/L 碳酸铵溶液解吸,Mo(Ⅵ)回收率随吸收剂量的增大而降低。     

3×3-2小组件加深燃耗考验元件的金相检验

对3×3-2小组件加深燃耗考验元件进行了金相检验,元件最高燃耗(以金属U计,全文同)为30 917 MW*d/t.检验结果表明锆包壳外表面氧化膜剥落较为严重,内表面氧化膜最大厚度为19.46 μm;芯块与包壳平均间隙为24.93 μm;包壳最大吸氢量达到190 μg/g;芯块平均晶粒尺寸约为15.65 μm,部分晶粒有所长大,但无柱状晶出现;芯块气孔率约为5.52%,尺寸小于5 μm气孔的体积份额约占总气孔度的29.86%.在该燃耗下,元件仍具有一定的安全裕度.     

Colorimetric Determination of Ruthenium With 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

The chemical behavior of ruthenium in the nuclear fule reprocessing is much complicated, and it mostly exists as the form of RuNO complexes. Presently, the analysis of RuNO complexes is adopted by radiometric determination, but the non-radiometer is not s…     

Investigation of the PuO2F2 - HF - H2O system (20°C isotherm)

The PuO₂F₂ — HF — H₂O system was investigated by using the method of isomermic solubility at 20 °C. It was established that there are three phases in the sytem: plutonyl fluoride dihydrate PuO₂F₂ · 2H₂O, tetrafluoroxyplutonic acid H₂PuO₂F₄ · 4H₂O, and plutonium oxyfluoride PuO₂F₂, the composition of which was determined by chemical analysis and by using the Schreinmacher method. The chemical individuality of the phases was confirmed by electron absorption spectra. The existence of the H₂PuO₂ F₄ · 4H₂O acid was proved by using the electromigration and the potentiometric titration methods.     

2×2棒束内超临界水传热特性实验研究

以中国超临界水冷堆（CSR1000）燃料组件研发为研究背景，采用实验辅以理论分析的方法，开展2×2棒束结构内超临界水工质的传热特性研究。实验工况范围为:压力（P）23~25 MPa；质量流速（G）680~1400 kg/(m2?s)；热流密度（q）174~968 kW/m2。实验结果表明，随着q的增加、G的减小，2×2棒束的传热性能减弱；随着P从23 MPa变化到25 MPa，2×2棒束的传热性能变化微弱； 2×2棒束内超临界水的传热特性既与边界层和主流的物性差异程度有关，又受流道各子通道之间的流动传热不均匀性影响；基于实验数据进行多元线性回归分析，获得2×2棒束内超临界水换热关系式，约88.9%的实验数据与该换热关系式的计算值偏差范围在±25%内。      

2×2棒束内超临界水传热特性数值研究

复杂通道是介于典型通道和典型栅元之间的几何结构,在通道形状、加热方式等方面更接近于原型组件。本文以小棒束2×2结构为分析对象,采用计算流体力学(CFD)工具分析组件内的温场特征,并讨论热流密度、质量流速等热工参数对通道平均换热系数的影响。结果表明,减小热流密度、增加质量流速都会增强换热。棒束结构的壁面温度分布存在明显的周向不均匀性,固体壁面导热会有效抑制这种周向不均匀性,进而增强通道的换热能力。     

锆-2合金和18-8奧氏体不锈钢冶金结合层的研究

应用金相、显微硬度,电子探针及X射线衍射等方法研究了锆-2合金和18-8奥氏体不锈钢之间的扩散结合层和爆炸结合层。确定了结合层中各种相的成分和晶体结构。扩散结合层中可分为四层,其中存在α-Fe、Zr(Fe5/8Gr3/8)_2、Zr_2(F3/4Ni4/4)和α-zr等相,而爆炸结合层中只发现zr(FeCrNi)_2相。并讨论了扩散结合层中各组织的形成规律。     

300×300mm~2二维多丝室

本文报道了灵敏面积为300×300mm~2的二维多丝室的结构、工艺以及性能。位置读出是采用扁平延迟线。用~(55)Fe源测得阳极位置线谱半宽度为1.5mm、阴极位置线谱半宽度为2.5mm,并给出了较为清晰的二维成象照片。     

含绕丝2×2棒束内超临界水传热特性数值研究

超临界水冷堆燃料组件多采用稠密栅格布置,用绕丝进行定位,绕丝可增强通道间的交混能力,对通道的换热特征会产生明显影响。以含绕丝的小棒束2×2组件为分析对象,采用计算流体动力学(CFD)方法分析超临界条件下绕丝对换热特征的影响。分析结果表明:绕丝会改善通道的换热能力,抑制周向不均匀分布,但也可能在局部产生壁温峰值。在数值计算中发现壁温峰值的成因有两类,并对二者的成因进一步叙述,分析绕丝结构参数对换热特性的影响。     

基于MPS算法的2×2棒束结构熔化行为数值模拟

以典型压水堆燃料组件2×2棒束结构为研究对象,建立了含定位格架和不含定位格架的棒束三维模型,基于半隐式运动粒子（MPS）算法对严重事故背景下棒束结构的熔化行为进行了数值模拟,分析了定位格架对棒束熔化过程中流道堵塞进程的影响。结果表明:MPS算法能够较好地模拟棒束结构熔化行为,定位格架会加快堆芯的熔化进程和冷却流道的堵塞速度,本文研究结果有利于严重事故下堆芯熔化模型的优化改进。      

2×2MV串列静电加速器周围照射量率分布的测量

中国科学院近代物理研究所的2×2MV 串列静电加速器于1986年研制成功,本文介绍对该加速器周围工作场所的照射量率分布的测量结果。     

Analysis of products of thymine irradiated by ^18O^8＋ ion beam in N2O saturated aqueous solution

Some methods of capillary gas chromatography,such as GC,GC-mS,GC-FT-IR,are used to analyze the products of thymine irradiated by ^18O^8 ion beam in N2O saturated aqueous solution.From the results of GC-MS the molecular weight of products can be determined,and from the results of GC-FT-IR some molecular structure information of products can be obtained.By this way the products,5,6-Dihydrothymine,5-Hydroxyl-5-Methylhydantoin,5-Hydroxyl-6-Hydrothymine,5-Hydro-6-Hydroxylthymine,5-Hydroxymethyluracil,Trans-Thymine glycol,Cis-Thymine glycol and dimers are dtermined without separation of them from sam,ples.Though these products are as same as those products of thymine irraduiated by γ rays in N2O saturated aqueous solution,the mechanism of thymine irradiated by heavy ion beam in aqueous solution is differrent from that by γ rays.The main products of thymine irradiated by ^18O^8 ion beam in N2O saturated aqueous solution are hydroxyl adducts at 5-6 band of thymine,while the main products of thymine irradiated by γ ray in N2O staurated aqueous solution are dimers of thymine.     

放射损伤时血浆与红细胞膜8-表氧-前列腺素F_(2α)的改变

8-表氧-前列腺素(PG)F_(2α)是氧自由基催化的脂质过氧化的一个产物,不依赖于环氧化酶。犬经~(60)Co γ射线照射(总剂量3Gy)期间及照射后血浆与红细胞膜8-表氧-PGF_(2α)含量明显增加,超氧化物歧化酶可抑制这个反应。血浆与红细胞膜丙二醛含量无显著改变。结果提     

放射损伤时血浆与红细胞膜8-表氧-前列腺素F_(2α)的改变

8-表氧-前列腺素(PG)F_(2α)是氧自由基催化的脂质过氧化的一个产物,不依赖于环氧化酶。犬经~(60)Coγ射线照射(总剂量3Gy)期间及照射后血浆与红细胞膜8-表氧-PGF_(2α)含量明显增加,超氧化物歧化酶可抑制这个反应。血浆与红细胞膜丙二醛含量无显著改变。结果提示8-表氧-PGF_(2α)可作为观察放射损伤时过氧化反应的一个新的敏感的指标。     

Production of ~8Li Secondary Nuclear Beam

8Liisatypicalneutron-skinnucleuswithahalf-lifeof838msandaneutronseparatioenergyof2.033MeV.Usinga8Libeam,onecanstudythereactionsrelevanttonuclearhalostructure,aswellastheimportantprimordialastrophysicsreactionssuchasd(8Li,9Li)p.Tomakethosemeasurementsfeasi…