Energy Options for the Future

This paper summarizes the presentations and discussion at the Energy Options for the Future meeting held at the Naval Research Laboratory in March of 2004. The presentations covered the present status and future potential for coal, oil, natural gas, nuclear, wind, solar, geothermal, and biomass energy sources and the effect of measures for energy conservation. The longevity of current major energy sources, means for resolving or mitigating environmental issues, and the role to be played by yet to be deployed sources, like fusion, were major topics of presentation and discussion.Summary of the Meeting held at the U.S. Naval Research Laboratory, March 11–12, 2004     

Thorium Molten-Salt Nuclear Energy Synergetics

In the next century, the “fission breeder” concept will not be practical to solve the global energy problems, including environmental and North-South problems. As a new measure, a simple rational Th molten salt breeding fuel cycle system, named “Thorium Molten-Salt Nuclear Energy Synergetics [THORIMS-NES]”, which composed of simple power stations and fissile producers, is proposed. This is effective to establish the essential improvement in issues of resources, safety, power-size flexibility, anti-nuclear proliferation and terrorism, radiowaste, economy, etc. securing the simple operation, maintenance, chemical processing, and rational breeding fuel cycle. As examples, 155 MWe fuel self-sustaining power station “FUJI-II”, 7 MWe pilot-plant “miniFUJI-II”, 1 GeV-300 mA proton Accelerator Molten-Salt Breeder “AMSB”, and their combined fuel cycle system are explained.     

β粒子痔疮治疗仪的开发

开发了一种近距β粒子痔疮治疗仪（或称β粒子痔疮敷贴器）。该仪器由照射器、定位器、升降器、屏蔽套和控制器等部件组成，可用于治疗内痔、外痔、混合痔、肛裂、肛窦炎等多种肛肠疾病。初步临床试验表明，与其他痔疮治疗术相比，β粒子腔内放疗术具有安全、有效、方便、无痛苦和无创伤等优点。     

Radiation synthesis and characterization of polyacrylic acid hydrogels

The pH-sensitive polyacrylic acid （PAA） hydrogels were synthesized by gamma-ray irradiation at an ambient temperature. The influences of dose, monomer concentration, cross-linking agent content, pH, and ionic strength on the swelling ratio （SR） of the PAA hydrogels were investigated in detail. The results show that the SR of the hydrogel decreases with an increase in the dose, monomer concentration, and cross-linking agent content. In alkaline solution, the SR of the hydrogels is much higher than that in acid solution. Also, the ionic strength can influence the SR of the hydrogels. The more the concentration, the lower the SR.     

外泌体检测在肿瘤放化疗中的应用

本文就外泌体的提取、富集、追踪及其在放化疗中的应用进展进行综述。目前外泌体提取与富集的主要方法包括超速离心法,层析法和色谱法等,外泌体可通过荧光素酶标记进行追踪。由于外泌体具有特异的表面标志物及其在体液中广泛存在的特点,使其成为潜在的肿瘤标志物之一。此外,外泌体在肿瘤的辐射敏感性与辐射损伤、肿瘤的靶向治疗和多重耐药等放化疗中的作用也日益受到关注。     

碳、氮、氧稳定同位素生产技术现状及发展趋势

碳、氮、氧稳定同位素从分离成功至今已经走过了半个多世纪的历程;生产能力实现了从百克级实验室规模到数公斤级批量生产,以及百公斤级大规模生产三个阶段的跨越;而分离技术方面也实现了从热扩散法、色谱法、离子交换法为代表的第一代分离技术,以化学交换法、精馏法为代表的第二代分离技术,以及以物料循环利用、能源耦合、节能减排等技术创新为特点的第三代大规模生产技术的提升。当前,¹³C的生产全部是低温精馏法,¹⁵N的生产方法是NO/HNO₃化学交换法及NO低温精馏法,¹⁸O的生产方法是水精馏法、NO低温精馏法及O₂低温精馏法。这些分离方法共同的特点是在工艺上实现能源高度耦合、物料循环利用、达到了规模化生产,并实现了节能减排。今后,继续通过科技创新,开发环境友好、原料价廉易得、低能耗、低成本、大规模生产的分离技术将是稳定同位素分离产业不断发展的主旋律。     

程控中子管老炼台的研制

程控中子管老炼台采用计算机控制技术,以中子管内的真空度和高压击穿情况为判据,决定高压脉冲电压幅度和限流电阻的增加或减少,对老炼工艺过程、高压脉冲 " /-"极性和限流电阻的转换进行自动控制,实时记录老炼过程的数据及相关信息.     

Changes in trace elements of cerebrospinal fluid after subarachnoid hemorrhage, and effects of trace elements on vasospasm

Various causal factors have been proposed for cerebral vasospasm after subarachnoid hemorrhage (SAH), such as serotonin, acetylcholine, angiotensin, thrombin and thromboxane A2. However, none of them explain the whole pathomechanism of vasospasm. To evaluate the role of trace elements on vasospasm, we have examined these sequential changes in the cerebrospinal fluid (CSF) after SAH by PIXE, and have investigated the relation between trace elements and vasospasm. We obtained the CSF samples from cisternal drainage in patients with SAH who underwent radical surgery within 48 h from the onset. The drainage was placed into basal cisterns at the end of the operation. Three sampling times (3–5, 7–9 and 12–14 days from the onset) has been scheduled because vasospasm is likely to occur from day 4 to day 14 after the onset. In this study, we focused on the levels of Mg, Ca, Mn, Al, Zn, P, Pb, Sr, Br, Co, Cu, Si, Ti, Mn,Co, Cu, Zn, Br, Sr, Mo and Pb, and we found a significantly lower level of Mg in the CSF of patients with vasospasm on days 7–9 after the onset. These results suggest that Mg in the CSF may ameliorate vasoconstriction due to Ca in the pathomechanism of vasospasm.     

Wavelengths,transition probabilities,and oscillator strengths for M-shell transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions. The fully relativistic multiconfiguration Dirac–Fock method, taking quantum electrodynamical effects and the Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states for Cu-, Zn-, Ga-, Ge-, and Se-like Au ions from the method were compared with available theoretical and experimental results, and good agreement with them was achieved.     

Inherent Prevention and Mitigation of Severe Accident Consequences in Sodium-Cooled Fast Reactors

Safety challenges for sodium-cooled fast reactors include maintaining core temperatures within design limits and assuring the geometry and integrity of the reactor core. Due to the high power density in the reactor core, heat removal requirements encourage the use of high-heat-transfer coolants such as liquid sodium. The variation of power across the core requires ducted assemblies to control fuel and coolant temperatures, which are also used to constrain core geometry. In a fast reactor, the fuel is not in the most neutronically reactive configuration during normal operation. Accidents leading to fuel melting, fuel pin failure, and fuel relocation can result in positive reactivity, increasing power, and possibly resulting in severe accident consequences including recriticalities that could threaten reactor and containment integrity. Inherent safety concepts, including favorable reactivity feedback, natural circulation cooling, and design choices resulting in favorable dispersive characteristics for failed fuel, can be used to increase the level of safety to the point where it is highly unlikely, or perhaps even not credible, for such severe accident consequences to occur.     

设备失效根本原因分析技术和方法及其在广东核电的应用

系统地介绍了设备失效根本原因分析(RCA)的技术和方法,其中较详细地介绍了设备失效根本原因分析的9个步骤,并以具体的实例说明了设备失效分析的过程,指出了RCA工作中应注意的6个问题。具体地介绍了大亚湾核电站RCA工作在组织目标、分析人、分析技术、外部技术支持体系、纠正措施制定和纠正措施跟踪体系等7个方面的做法和尝试。     

动力堆模拟高放废液的甲醛脱硝及脱硝过程中的沉淀行为北大核心CSCD

两步法玻璃固化工艺中,高放废液可通过化学脱硝达到降低酸度的目的,常用的化学脱硝剂有甲酸、甲醛、蔗糖等。以甲醛为化学脱硝剂,对动力堆模拟高放废液进行脱硝及脱硝过程中沉淀行为进行研究。模拟高放废液在90℃、脱硝比例为1.0~2.0范围内进行脱硝,对脱硝后各物质运用电感耦合等离子发射光谱(ICP-OES)、X射线荧光光谱(XRF)、扫描电镜-能谱分析(SEM-EDS)、Raman光谱、X射线衍射(XRD)、热重分析仪(TG)进行分析。结果表明:脱硝后废液中NO_(3)^(-)含量明显降低,随脱硝比例增大,NO_(3)^(-)的含量逐渐降低,甲醛含量增加。脱硝过程中出现由Zr、Mo、La、Ce、Nd、Fe、Te、Pr、Cs、Sm、Cr、Sr、Y、Co、Ni组成的沉淀,沉淀的形成有两个过程:一个过程为形成颗粒状的结晶物Ln_(2)Zr_(3)(MoO_(4))_(9)(Ln=La、Ce、Nd、Pr、Eu、Sm)和MoO_(2);另外一个过程为形成由O、Fe、Zr、Mo、Te构成的无定形粉末物质;脱硝产物的热分解主要发生在约360℃以下。     

Effects of cold plasma treatment on alfalfa seed growth under simulated drought stress

The effect of different cold plasma treatments on the germination and seedling growth of alfalfa(Medicago sativa L.) seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000(PEG 6000)with the mass fraction of 0%(purified water), 5%, 10%,and 15% were applied to simulate the drought environment. The alfalfa seeds were treated with15 different power levels ranged between 0–280 W for 15 s. The germination potential,germination rate, germination index, seedling root length, seedling height, and vigor index were investigated. Results indicated significant differences between treated with proper power and untreated alfalfa seeds. With the increase of treatment power, these indexes mentioned above almost presented bimodal curves. Under the different mass fractions of PEG 6000, results showed that the lower power led to increased germination, and the seedlings presented good adaptability to different drought conditions. Meanwhile, higher power levels resulted in a decreased germination rate. Seeds treated with 40 W resulted in higher germination potential,germination rate, seedling height, root length, and vigor index. Vigor indexes of the treated seeds under different PEG 6000 stresses increased by 38.68%, 43.91%, 74.34%, and 39.20%respectively compared to CK_(0-0), CK_(5-0), CK_(10-0), and CK_(15-0)(the control sample under 0%, 5%,10%, and 15% PEG 6000). Therefore, 40 W was regarded as the best treatment in this research.Although the trend indexes of alfalfa seeds treated with the same power were statistically the same under different PEG 6000 stresses, the cold plasma treatment had a significant effect on the adaptability of alfalfa seeds in different drought environments. Thus, this kind of treatment is worth implementing to promote seed growth under drought situations.     

Simulations of W7-X magnet system fault scenarios involving short circuits

The stellarator Wendelstein 7-X (W7-X) which is presently under construction at the Max-Planck-Institut für Plasmaphysik in Greifswald [(C. Beidler, G. Grieger, F. Herrnegger, E. Harmeyer, J. Kißlinger, W. Lotz, H. Maassberg, P. Merkel, J. Nührenberg, F. Rau, J. Sapper, F. Sardei, R. Scardovelli, A. Schlüter and H. Wobig., Physics and engineering design for Wendelstein 7-X, Fusion Technol., 17 (1990)148–168)], uses 70 superconducting coils, arranged in 7 groups to create the magnetic confinement for the plasma. A wide variety of tests and investigations are performed in order to ensure the later safe operation of the device. Much attention is also paid to the proper insulation of all the parts. These measures are costly and time consuming but are necessary in order to avoid the severe consequences of faults–—especially short circuits–—during operation. If a short circuit would happen during an emergency switch-off, the discharge of any shorted inductance would be delayed, and the coupled magnetic flux of the discharging system would induce additional currents into this shorted part. The currents and forces developing in such a case depend not only on the short circuit resistance and the critical current of the superconductor, but also on the shorted inductance itself, its magnetic coupling to other inductances, and its position within the system. The paper describes the influences of these factors and presents simulation results for different fault scenarios involving short circuits across a coil group, a single coil, different double layers, and a single turn. Maximum currents result from a shorted outer double layer, maximum forces from a shorted coil group, depending on its position in the magnet system.     

8省1系统实施常见职业性放射性疾病诊断标准的调查

为评估常见放射性疾病诊断标准在职业性放射性疾病诊断医师、放射工作人员、放射卫生监督人员中的贯彻落实情况,了解诊断标准技术性内容及实施过程中存在的问题,采用调查问卷方式,抽调四川、江苏、内蒙、山东、河南、天津、安徽、浙江8省(市、自治区)和核工业系统进行调研,调查问卷分为A、B、C卷,分别对应职业性放射性疾病诊断医师、放射工作人员、放射卫生监督人员。调查结果表明:(1)A卷140人次,B卷2 815人次,C卷310人次,标准掌握及知晓率由高到低依次为职业性放射性疾病诊断医师、放射卫生监督人员、放射工作人员;(2)设定五项标准的综合评分满分为100,职业性放射性白内障的诊断、职业性外照射急性放射病诊断、职业性外照射慢性放射病诊断、职业性放射性皮肤损伤诊断和职业性放射性肿瘤判断规范5项标准的满意评分分别为68.8、74.8、73.5、74.1和72.4。调查结果认为,8省1系统实施五项职业性放射性疾病诊断标准情况较好。     

Calculation and evaluation of cross-sections for p+Fe reactions up to 250 MeV

All cross-sections of proton-induced reactions, angular distributions and the energy spectra of neutron, proton, deuteron, triton, helium and alpha-particle emission are consistent calculated and analyzed for p+^{54,56,57,58,nat}Fe at incident proton energies below 250 MeV by using nuclear theoretical models which integrate the optical model, the intra-nuclear cascade model, direct, preequilibrium and equilibrium reaction theories. Especially, the cross-sections of the light composite particle (d, t, ³He and α) emissions are improved based on the exciton model including the pick-up mechanism. Theoretical calculated results are compared with existing experimental data.     

Calculation of Gamma-Ray Production Cross Sections at Neutron Energies of 1–20 MeV

In order to prepare the p-ray data library requested in a design of fission and fusion reactors, γ-ray production cross sections and spectra of Al, Si, Ca, Fe, Ni, Cu, Nb, Ta, Au and Pb have been obtained at the neutron energies of 1–20 MeV, using a spin-dependent multi-step evaporation model. Calculations include dipole and quadrupole transition without the distinction between electric and magnetic process, and take explicit account of the role of yrast levels. The effects of the yrast levels and γ-ray strength function upon γ-ray production are also investigated in relation to particle emission. At the incident neutron energies where (n,n^γ ) and/or (n,2^nγ ) reactions are dominant, the present model is shown to be able to predict the production of secondary γ-rays (<9.0 MeV) from medium-heavy to heavy nuclei with reasonable accuracy.     

废离子交换树脂的优化处理

核设施产生的废树脂的安全处理、整备和处置是热点问题。本文论述了废树脂的特殊性 ,解析了各种废树脂处理、整备技术 ,包括脱水干燥后装入高整体性容器、洗脱、热压、生物降解、焚烧、湿法氧化、沥青固化、聚合物固化、玻璃固化和水泥固化等。重点分析了废树脂水泥固化 ,讨论了树脂溶胀作用破坏固化体的机理 ,介绍了克服树脂溶胀作用的方法。强调指出必须重视水泥固化的配方 ,关键是必须满足处置要求。最后 ,对优化处理废树脂提出了建议     

Assessment of the weathering effects on cellulose based materials through a multianalytical approach

Paper and papyrus endurance depends on their intrinsic properties that are related to the manufacture processes and to the environmental conditions (temperature, humidity, presence of micro-organisms, etc.). During the time, paper and papyrus undergo unavoidable ageing processes causing mainly the degradation of the cellulose. In the framework of the European Project “PAPERTECH” a multi-analytical approach was selected to carefully study the behaviour, properties, and the quality of different samples of paper with different provenience, before and after artificial ageing. This work was focused to understand and explain the degradation processes occurring in paper during the time. Portable EDXRF, NMR, Raman, FTIR, ATR, mechanical properties, colour measurement and XRD analyses were performed before and after the accelerated weathering. The light and the chemical oxidation were found to cause the most aggressive ageing processes.     

广东省放射性地质环境监测数据管理信息系统建设及应用

采用C#开发语言,以Oracle 11G为数据存储库,用ArcSDE 10.2进行空间数据交换,建立了包括陆地γ辐射剂量率、就地γ能谱,水体、底泥、土壤、岩石等样品子库,通过系统集成,建成了广东省放射性地质环境监测数据管理信息系统。该系统具有功能齐全、通用性强、系统稳定、运行效率高、制图智能化、界面友好美观等优点,为广东省辐射环境监督管理提供可靠的技术支撑。