热解燃烧废TBP／OK料液配制

针对在乏燃料后处理过程中积存的大量放射性废TBP/OK溶剂,热解燃烧是目前世界上公认的行之有效的处理方法。热解燃烧工艺的优点在于解决了磷酸腐蚀的难题。为此,需在TBP/OK溶剂中加入固磷剂、表面活性剂,配成均匀、稳定的料液。     

2 应用新型聚合物吸附材料固化液体放射性废物

中国原子能科学研究院与美国太平洋贸易公司开始讨论应用新型聚合物吸附材料来处理液体放射性废物，特别是含^3H的有机废油和来自后处理厂的溶剂，诸如真空泵油、润滑剂、闪烁液、废TBP／OK溶剂等。双方决定推进合作，并于2005年4月和10月先后两次在实验室进行模拟试验。模拟的液体废物流有真空泵油、废树脂泥浆、30％TBP／OK、闪烁液、无机酸、碱、盐等。模拟试验的目的是：应用聚合物吸附剂固化上述模拟废液，以确定废物与吸附剂的最佳比例.     

热解焚烧废TBP—煤油的料液配方研究

采用热解焚烧法处理放射性废磷酸三丁酯／煤油（ＴＢＰ／ＯＫ），为了避免热解产生的Ｐ２Ｏ５或Ｈ３ＰＯ４等腐蚀性物质对设备的腐蚀，在料液中加入Ｃａ（ＯＨ）２固体粉末使热解产生的含磷化合物转变成极难溶的磷酸盐或焦磷酸盐并以固体形式分离出反应器。同时加入适当的乳化剂或表面活性剂使ＴＢＰ／ＯＫ－Ｈ２Ｏ乳浊液与Ｃａ（ＯＨ）２固体粉末形成稳定、均匀的混合料液，稳定时间可达７２ｈ。克服了因固体Ｃａ（ＯＨ）２的难溶性致使料液容易沉降的困难，料液的稳定性、流动性（粘度）等可根据不同的工艺要求进行配方，达到使ＴＢＰ／ＯＫ稳定热解并焚烧的目的     

磷酸加合水解法分离TBP和煤油的研究

在Purex流程中,由于射线和化学试剂的作用,溶剂(TBP 煤油)产生降解现象,因而妨碍了萃取过程的正常进行。为了消除降解产物的影响,国内外已经做了大量研究工作。但许多方法均不能令人十分满意,这主要是因萃取剂TBP和稀释剂煤油性质相差很大,混在一起处理较困难。因而目前有些研究者趋向于将萃取剂和稀释剂分开后再分别处理的手段。根据磷酸可以和TBP形成加合物的性质,采用浓磷酸萃取煤油中的TBP,从而达到使TBP与煤油分离的目的。为辐照后溶剂的再生提供了一种新的可能性。     

废TBP-溶剂的固化研究

李文研究苯乙烯固化处理废TBP溶剂的工艺条件。用模拟的废TBP溶剂和联邦德国WAK后处理厂的真实废TBP溶剂制备了固化样品,测定了它们的抗浸出性能、耐辐照性、热稳定性和贮存耐久性。此法能包容高达70％(W)的废TBP溶剂。测定结果表明,固化物满足贮存和处置的要求。     

放射性废TBP处理技术

介绍了热解焚烧、蒸汽重组、超临界水氧化三种放射性废TBP高温处理技术。因蒸汽重组技术具有设备体积小、成本较低、二次废物简单、减重率高等优点,被视为一种具有优势的TBP高温处理技术,建议我国积极开展该技术的研究。     

热解焚烧处理放射性废有机溶剂台架试验中料液的配制与输送技术

本文介绍了热解焚烧处理放射性废有机溶剂台架试验中料液配制与输送技术的研究结果，试验结果表明，加入适当分散剂可促进石灰粉的分散，防止分散开的小粒子重新凝集，从而减小了粒子的沉降速度，提高了悬浮液的稳定程度，用这种介稳悬浮液进行了６００多ｈ的试验，进料情况正常，稳定，说明介稳悬浮液可满足废有机溶剂热解焚烧台架试验的需要。     

废TBP／煤油热解焚烧冷台架试验装置的设计与运行

本文介绍了废ＴＢＰ／煤油热解焚烧冷台架试验装置的设计,运行情况,本装置主要由配料系统,热解燃烧系统和烟气净化系统三部分组成。通过试验,确定了料液配方,工艺流程和主要工艺条件。在给定工艺条件下,ＴＢＰ热解率达到９９．９％以上,固磷率也达９９．９％,对Ｕ,Ｓｒ,Ｃｓ的净化系数达１０＾６以上;装置设计符合规范要求,安全措施合理,累计安全运行达３４５ｈ。     

废TBP/煤油中Pu和总α的测定

为了准确测定乏燃料后处理废TBP／煤油中Pu和总α活度,在蒸馏出废TBP／煤油中的煤油后,采用碳化氧化法消解TBP,阴离子交换法分离^238U和^237Np等核素,最后在洗脱Pu后,用大面积屏栅电离室-α谱仪测量总Pu。在对样品作初步处理后,测量总α的活度,并对此值作校正(以分离后总Pu中的^239,240Pu的a活度为标准)。样品分析结果表明,α核素在废TBP／煤油样品中分布不均匀。     

二氧六环基闪烁液的回收

一、引言随着液体闪烁计数器的广泛应用而产生大量的废闪烁液。对这些放射性有机废液的处理,有人提出把它封在密闭的容器里扔入大海中;也有人提出其他处理方法。其次,闪烁液价格昂贵,仅以二氧六环基闪烁液为例(包括二氧六环溶剂),第一溶质2,5-二苯基噁唑(PPO),第二溶质1,4-双-[5苯基噁唑基-2]-苯(POPOP)和反射体萘,按我们的配方(0.3克的POPOP,5克的PPO和100克萘溶于二氧六环后,稀释到1升)每升闪烁液成本约90元,扔弃是个很大的浪费。S.R.Sachan等人提出了闪烁液回收方法,我们在此基础上进一步做了一些条件实验,并初步用于废闪烁液回收。     

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。     

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.     

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.     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

Linear accelerators equipped with multileaf collimators （MLC） are becoming more common and are widely used in the intensity-modulated radiotherapy （IMRT）. There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance （QA） and quality control （QC）. This paper is aimed to investigate the role of AGFA high-energy CR （Computed Radiography） in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.     

Gamma radiation levels in the ambient environment of the QNPP Base

Monitoring results of gamma dose rate level in 1992～2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84～113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.