放射性废油焚烧处理的可行性研究

本文介绍了放射性废油焚烧处理的可行性研究试验 ,试验主要包括废油的物性测定、预处理及喷雾焚烧实验。对于可能混有汽油等低闪点成分的放射性废油 ,推荐采用添加煤油来降低粘度的预处理方法。喷雾焚烧试验表明 ,对于粘度小于 30 m Pa· s的废油 ,在燃烧炉容积热强度低于 1.6× 10 6k J/ (m3 ·h)时 ,可以实现完全燃烧。在很宽的空气过量系数范围内 ,烟气中 CO浓度均低于 0 .1%。     

放射性废石墨的焚烧处理

石墨用作燃料套管、慢化剂和反射层的反应堆退役后产生大量的放射性废石墨,面临处理。焚烧作为研究较为深入的处理技术之一,可实现其大幅度减容,且产物具有较高的安全性和稳定性。本文介绍了目前典型的焚烧技术有固定床焚烧法、流化床焚烧法、激光焚烧法等,其中流化床焚烧技术在燃烧效率和技术成熟度上具有优势。     

固定床燃烧系统概念设计——钍-铀循环燃料后处理首端过程研究

讨论了高温气冷堆元件球后处理首端过程用固定床燃烧法去除石墨的可行性。确定了燃烧过程工艺参数和概念流程,并且改进了固定床燃烧器的结构设计。     

固定床燃烧系统概念设计——钍-铀循环燃料后处理首端过程研究

讨论了高温气冷堆元件球后处理首端过程用固定床燃烧法去除石墨的可行性。确定了燃烧过程工艺参数和概念流程,并且改进了固定床燃烧器的结构设计。     

HTGR石墨燃料元件球固定床燃烧实验研究

用改进的固定床燃烧器进行了台架规模石墨球燃烧实验,测定了燃烧速率、热功率、氧利用率、温度轴向分布和尾气组成。比较了分批燃烧和移动床式连续燃烧两种操作方式。由于移动床式连续燃烧功率释放平稳,易于控制,推荐采用这一操作方式。     

HTGR石墨燃料元件球固定床燃烧实验研究

用改进的固定床燃烧器进行了台架规模石墨球燃烧实验,测定了燃烧速率,热功率,氧利用率,温度轴向分布和尾气组成。比较了分批燃烧和移动床式连续燃烧两种操作方式。由于移动床式连续燃烧功率释放平稳,易于控制,推荐采用这一操作方式。     

"可燃核废物焚烧装置"的建立及试车

本文介绍了我国某核工厂“可燃核废物焚烧装置”的建立及试车情况,主要包括焚烧装置的工艺流程简介和系统冷热态试车及试运行结果。根据该厂可燃核废物性状,确定以固体废物热解焚烧为主,兼顾进行废油喷雾焚烧和废石墨固定床式焚烧及干湿法烟气净化相结合的工艺路线。非放模拟物料和实际放射性废物焚烧的冷热态试车及试运行结果表明：工艺方案可行、装置运行平稳、安全可靠,各项技术指标均达到合同书及国家有关焚烧及污染物排放控制标准的要求。     

紧凑式低放固体废物焚烧工艺装置设计及验证

焚烧作为处理放射性废物的主要技术之一,在世界范围内广泛应用。为满足部队、科研及核技术应用等废物产生量较少的单位的放射性废物焚烧处理需求,中国辐射防护研究院针对性开发了紧凑式低放可燃固体废物焚烧装置,并实现了工程应用。经试验验证,该装置技术指标能够满足设计目标和国家标准规范的要求。在处理能力相当的情况下,紧凑式焚烧设施占用的建筑面积减少为常规焚烧设施的1/30,人员减少为原1/6,能耗减少为原1/8,建造成本降为原1/8,并且可实现8 h/d间歇运行,大幅降低了建造和运行成本。     

氢化海绵钛粉末制备

介绍了氢化海绵钛粉末制备的工艺流程,即海绵钛块经过渗氢,得到的氢化海绵钛块在高纯氩气保护的手套箱中用鄂式破碎机破成小于10mm的颗粒,再用高速破碎机破碎成粉末,用自行研制的机械筛分机对粉末进行筛分,并对粉末的粒度和杂质氧、氮含量进行分析,最后得到合格的粉末,其氢-钛原子比达到1.8～2.1,粉末粒度在74μm以下占98.9%,氧、氮含量分别低于2500μg/g、150μg/g,年生产能力达到3t.     

焚烧灰玻璃固化处理工艺条件初探

在对国内外玻璃固化体配方进行调研和分析的基础上,结合具体的处理对象和处理要求,将模拟焚烧灰与一定种类以及质量比的添加剂进行混合后高温熔融,形成了玻璃固化体。固化体表观坚硬、光滑且致密,密度在2.6 g/cm³以上。经X射线衍射法(XRD)检测,样品为均匀的玻璃态物质。证明焚烧灰利用高温熔融方法,得到玻璃固化体的处理工艺可行。同时,焚烧灰的熔融温度随着玻璃添加剂中硼砂含量的增加而降低,熔融态的流动性和成型效果也明显改善。最终,实验初步得到焚烧灰熔融处理的工艺条件为:当B₂O₃和Na₂O的添加量在30%～35%之间时,处理温度应至少保持在1 100 ℃以上;当B₂O₃和Na₂O的添加量达到40%时,处理温度可以降低至1 000 ℃或更低。最后,以真实焚烧灰在相同处理条件下进行实验,得到了相似的结果。     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

The preclinical pharmacological study of dopamine transporter imaging agent 18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β- carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444,0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum,striatum/frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

Web Services interface of SSRF archive data analysis system

Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.     

Investigations on landmine detection by BF3 detector

Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 16(2014)

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Radioactivity levels in soil of salt field area,Kelambakkam,Tamilnadu,India

Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ~(232)Th,~(238)U and ~(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ~(232)Th in the present study is 1.19 times higher than world median value while the activity of ~(238)U and ~(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ~(232)Th,~(238)U and ~(40)K in soil samples is 36.99 nGy·h~(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area.