钚量热计的研制

设计研制了1台结构简单、操作方便、样品池内径185 mm和高200 mm用于钚热功率测量的量热计.性能测试表明钚量热计的样品热功率测量下限为4 mW、测量上限高于9 W,灵敏度约为202 mV*W-1,线性范围为4 mW～9 W.使用该量热计测量了钚样品的热功率,并与用分析化学和称量法测得的样品热功率进行了比较,结果表明该量热计测量钚样品热功率具有较高的测量精度,当样品热功率不小于200 mW时,精密度优于0.5%.     

电解还原制备U(Ⅳ)过程中的阳极材料腐蚀研究

用间歇电解还原法研究了在有机玻璃电解槽中阳极镀铂钛网在ＵＯ２（ＮＯ３）２－ＨＮＯ３－Ｎ２Ｈ５ＮＯ３－Ｈ２Ｏ体系中的耐腐蚀情况。研究结果表明：在无隔膜电解还原时，镀铂钛网上的Ｐｔ的腐蚀速率极低（＜２．５×１０－２μｍ／ａ），而在以阳离子交换膜作隔膜的电解还原中，镀铂钛网上的Ｐｔ有明显的腐蚀，其腐蚀速率为５．７μｍ／ａ。对这两种情况下Ｐｔ的腐蚀速率明显差别的原因进行了分析讨论。     

~(210)Po量热测量结果偏差原因分析

~(210)Po是~(210)Po-Be中子源的原料。~(210)Po活度数据是计算中子产额的关键依据。我们在~(210)Po-Be中子源研制和生产过程中,是用量热计测量~(210)Po原料的放射性活度。但是,在秦山核电站启动中子源的中子产额测量中,发现中子源的~(210)Po投料量热测量数据与做成中子源后,其中~(210)Po量热测量数据有比较大的差异。表1是用同一台量热计在投料和做成源条件下的测量     

~(210)Po量热测量结果偏差原因分析

~(210)Po是~(210)Po-Be中子源的原料。~(210)Po活度数据是计算中子产额的关键依据。我们在~(210)Po-Be中子源研制和生产过程中,是用量热计测量~(210)Po原料的放射性活度。但是,在秦山核电站启动中子源的中子产额测量中,发现中子源的~(210)Po投料量热测量数据与做成中子源后,其中~(210)Po量热测量数据有比较大的差异。表1是用同一台量热计在投料和做成源条件下的测量     

γ量热计及HFETR中γ释热率的测量

本文介绍了适用于高 γ 释热率测定的量热计设计及在高通量工程试验反应堆(HFETR)的G_7,辐照孔道中的 γ 释热率测量,其测量误差在±4.5%以内.     

大功率α、β量热计的研制

研制了一台用于α、β核素测量的大功率量热计,量热计样品池尺寸空间为直径75mm、高120mm.性能测试表明,该量热计功率测量范围为1～300 W,当样品热功率不小于10 W时,测量精度优于1.0%.     

UO_2(NO_3)_2-HNO_3-N_2H_5NO_3(H_2O)/30%TBP(煤油)体系中组分浓度对U(Ⅵ)电解还原速率影响的研究

本文在振动搅拌槽中,研究了UO_2(NO_3)_2-HNO_3-N_2H_5NO_3(H_2O)/30％TBP(煤油)体系的水相电解液组分浓度对U(Ⅵ)电解还原速率的影响。根据实验所得数据,经回归分析得到反应动力学微分方程 式中速度常数k一般说是温度的函数。25℃时,k=0.00187。在实验浓度范围内,U(Ⅵ)还原速率随U(Ⅵ)浓度升高而增大,表观反应级数为0.75级;而[N_2H_5~+]及[HNO_3]影响不大,反应级数近于0。     

新型硅吸收剂量量热计的电校准

叙述了新型硅吸收剂量量热计的结构及电校准原理;给出了量热计在0—35℃工作温区的电加热校准因子,拟合出硅比热随温度变化关系式,并对实验误差进行了讨论。     

用于中子吸收剂量测量的量热计

本文介绍我们研制的中子吸收剂量量热计的原理、结构及其测量系统。测量了池式研究用反应堆的中子吸收剂量并得到满意的结果。该量热计轻便、简单、测量迅速而准确。已精确知道比热数值的其它吸收材料均可采用本设计。     

Calorimetric measurements on electrochemical cells with Pd-D cathodes

Two series of experiments were performed to determine the conditions of cell operation that produce sufficient excess heat to be useful for the production of energy. In the first series, the results from a differential temperature analysis of identical light- and heavy-water electrochemical cells were too ambiguous and, thus, not suitable for evaluating excess heat effects. In the second series, two Pd-D/LiOD-saturated D₂O/Pt cells were operated at current densities between 12.5–500 mA/cm² in a constant-heatloss-rate twin calorimeter for 460 hours. Water loss measurements during the experiments indicated that the recombination reaction (2D₂ + O₂ 2D₂O) did not occur. The D/Pd ratio was determined gravimetrically during the experiments. No excess heat was found within the sensitivity (0.13 W, 0.082 W/cm³ of Pd, 0.013 W/cm² of Pd) and precision (±0.3 W) of the calorimeter.     

电解法制备高纯度墙^18O2

采用自行设计制造的石英玻璃电解装置，以重氧重水为原料，通过碱性介质电解法进行了^18O气体的制备，在原料重氧重水^18O的摩尔分数〉80％条件下，最终制得^18O气体中^18O2摩尔分数达63．66％，表明整个电解系统气密性良好。此外，制得的气体能够满足电子回旋共振离子源提供^18O重离子束的实验要求。     

Preliminary investigation of possible low-temperature fusion

Preliminary tests have been made with electrolytic cells utilizing 0.2N LiOD in D₂O as the electrolyte and a palladium cathode surrounded by a wire-wound platinum anode operating at cathode current densities of 100–400 mA/cm². The cathodes were swaged to diameters of 2.8 or 5.5 mm with 8.5 cm of active length. The electrolyte temperature was controlled, heat was removed by flowing water in a cooling jacket, and the cell was insulated. Cooling water and electrolyte temperatures were measured by thermocouples, and neutron and gamma-ray spectra were recorded. The electrolyte level was periodically monitored and replenished with D₂O. Tests up to 2 weeks in duration were made with no sustained release of energy in excess of the electrical power input, although there was one period of 12 h when an unaccountable heat excess was observed. In another test, an anomalous neutron flux was measured during the first few hours that was 3.5 standard deviations above the background.     

High precision calorimetric search for evidence of cold fusion usingin situ catalytic recombination of evolved gases

We have developed a calorimeter suitable for testing cold fusion electrolytic cells that achieves better than 0.3% accuracy in absolute energy balance. It uses self-sustained catalytic recombination of the evolved gases and so operates in a completely closed fashion, and also it has demonstrated insensitivity to temperature gradients in the electrolytic cell. We work with 0.1M LiOD in D₂O solutions and with vacuum degassed 99.9% Pd bars whose electrochemical charging curves have been carefully studied prior to use. The charging rates show a discontinuity betweenx=0.6 andx=0.7 (close to the expected onset of the β phase) whereupon the rates slow considerably andx saturates at about 0.80–0.84 after half a day. Calorimetric studies on these samples have so far shown no excess heat generation to the 0.3% level for input powers in the 4–18 watt range.     

低压低流速条件下的过冷沸腾换热特性

为探究低压低流速条件下的过冷沸腾换热特性,开展本实验研究。通过分析实验中采集的热工参数和可视化图像,探究了沸腾滞后现象、沸腾失稳现象以及沸腾换热特性。实验发现沸腾起始点壁面过热度较高,而沸腾的发生大幅提高了换热系数,因此出现了显著的沸腾滞后现象。实验中较为光滑的加热面可达到较高的过热度,而低压下快速产生的气泡尺寸较大,在较低的热流密度下气液界面发生剧烈变化,使气泡破裂为多个小气泡并成为核化点。在过冷沸腾换热系数的预测中,Dittus-Boelter对流换热关系式不再适用,采用Hallman关系式和Gnielinski关系式计算对流换热系数,并引入壁面过热度对池式沸腾换热系数进行修正,可使过冷沸腾换热系数的预测精度大幅提高。     

Film Boiling Characteristics of Potassium Droplets on Heated Plate

For providing background information on the possible vapor explosion in the event of a core disruptive accident of LMFBRs, an experiment was conducted on the film boiling characteristics of liquid metal potassium in association with the Leidenfrost phenomenon. In a steel container filled with Ar gas, K droplets were put on a joule-heated plate of 316-SS or Ta. The behaviors of droplet were observed by a camera and a color VTR through viewports. The experimental conditions were the Ar pressure 1 bar, the initial K temperature 350~760°C, and the plate temperature 900~1,250°C for 316-SS and 1,100~1,600°C for Ta.

Stable film boiling known as Leidenfrost phenomenon was observed for a high temperature condition of the plate, whereas an instantaneous break-up of droplet with extensive vaporization occurred for a low temperature. The heat transfer characteristics of film and transition boiling regions were obtained by estimating the heat flux from the volumetric reducing rate of droplet due to vaporization. The results in the film boiling region showed an appreciably good agreement with the prediction based on Bromley's expression combined with the theory of Baumeister et al. The minimum film boiling temperature and heat flux were found to be about 1,300°C and 15 W/cm², respectively, for a droplet size of 0.15 cm³.     

联合电解催化交换系统的动态模型及理论计算

为探求联合电解催化交换系统各单元中氚浓度空间分布和动态变化的内在规律，建立了D／T体系的气-液两元模型。根据不同的催化剂传质性能，计算了为达到特定脱氚率和电解池浓缩倍数所要求的交换床总高度和进液位置。理论计算得到的氚在交换床上的空间分布趋势与文献报道的中试结果一致，电解池中的氚浓度随时间呈线性增长。     

螺旋管中汽-水两相流强制对流沸腾传热研究

对螺旋管中两相强制对流沸腾传热特性进行了试验研究。试验是在高压水回路上进行的 ,试验参数为系统压力 6 0～ 1 1MPa ,质量流速 40 0～ 1 2 0 0kg/(m2 ·s) ,热流密度 0～ 45 0kW /m2 ,螺旋直径1 3 7m ,螺旋上升角 3 94°。用修正L M关系式整理了两相强制对流放热系数。同时也得到了螺旋管单相水和单相蒸汽的强制对流放热系数 ,并与文献进行了比较     

Terminal Solid Solubility of Hydrogen in Hafnium

The terminal solid solubility (TSS) of hydrogen during hydride dissolution/precipitation is determined by differential scanning calorimetry technique for nonirradiated hafnium (Hf) that is used as control rods of light water reactors. The hydrogen concentration in hydrogenated Hf samples ranged from 27 to 300 wt ppm. The reliability of the TSS data obtained for Hf was confirmed using those for Zircaloy-2 (Zry-2) obtained in this study with the literature data, and best-fit equations for the obtained TSS curves for Hf are derived. The TSS for Hf at 573 K, which corresponds to an operational temperature of control rods in boiling water reactors, is in the range of 10–15 wt ppm, and is found to be 1/5–1/7 of the TSS for Zry-2.