核电站放射性废物水泥固化处理

概述了放射性废物水泥固化处理技术和处理对象,介绍了国内各核电站采用的水泥固化处理工艺（包括桶内搅拌工艺和桶外搅拌工艺）及其特点;简要介绍了国外水泥固化技术及其进展;总结了国内在水泥固化配方研究和固化体性能研究的最新成果和动态。按照不同配方固化的水泥固化体应满足国家现行标准《低、中水平放射性废物固化体性能要求水泥固化体》及《放射性废物固化体长期浸出试验》的相关要求。     

研究堆放射性湿废物处理系统湿废物桶内处理工艺设计方案研究

通过对核电站放射性湿废物处理系统湿废物桶内处理工艺参数的比较，介绍了研究堆放射性湿废物处理系统废物桶内处理工艺设计方案以及在湿废物桶内处理工艺设计中遇到的重点、难点，并对这些重点、难点的解决方案进行了探讨。该方案在保证工作人员人身安全的前提下，更能适合研究堆的湿度物处理。     

阳江核电站废物暂存库(QT)的优化设计

阳江核电站规划建设6台机组,其废物处理工艺各机组有所不同,产生的废物形式具有多样性。除了阳江1、2号机组采用传统的水泥固化桶外,阳江3~6号机组采用了新型高整体性容器HIC桶贮存废物。因此,阳江核电站的废物暂存厂房(QT)需要进行重新设计。本文从工艺和布置的角度,分别介绍了设计过程中所做的优化和改进工作。     

CPR1000机组固体废物处理系统及其调试

CPR1000核电机组固体废物处理系统负责电站运行期间产生的各类固体放射性废物的收集、贮存及处理,系统涉及水泥固化、混凝土固定、超级压缩处理等废物处理工艺。本文就系统处理源项、系统工艺流程、系统调试启动进行介绍,并着重就CPR1000机组固体废物处理系统与目前国内其它电站的差异性进行论述,对其存在的不足及后续系统改进优化提出合理化提议。     

放射性废物水泥固化桶外混合技术分析

对放射性废物水泥固化的两种桶外混合工艺——连续供料混合工艺和批次混合工艺——的技术特点及其在国内核电厂的应用情况进行了详细介绍;分析了它们的优缺点,连续供料混合器结构小巧,但因受水泥及树脂进料流量不稳定的影响,以及混合时间不足的影响,得到的水泥浆的均匀性较差;批次混合器能将废物与水泥充分混匀,但在工程应用中必须解决水泥浆从混合器中顺利排卸出来的问题;这两种桶外混合工艺都具备废物装桶率较高的优势,但需要解决对混合器清洗以及由此而产生的二次废物的处理问题。针对这两种桶外混合工艺存在的问题,给出了相应的改进建议。     

秦山核电基地放射性废物最小化技术实践与探讨

介绍了秦山核电基地在放射性废物最小化方面的实践。包括建立了蒸汽发生器排污树脂和通风过滤器金属框架清洁解控工作流程;改进了水泥固化线工艺,水泥固化包装容器采用金属桶代替水泥桶;开发了废过滤器芯子暂存衰变法分类处理及一桶装多芯方案;开发了技术废物“三明治”式废物装桶和超级压实提高外包装容器效率等最小化实践。对废液、废树脂、技术废物、有机废液等处理技术进行了比较分析,建议采用废液蒸干压实技术、废树脂蒸汽重整技术、可燃废物和有机废液焚烧技术,预计秦山核电基地废物产生量可由541 m³/a减至约94 m³/a。     

福塔普混凝土的α辐解

【美国《核学会汇刊》1981年第39卷第355页报道】低放和中放废物的水泥固化已经使用了近30年。最近的实验室研究指出,适当制备的热压混凝土对于军事和民间产生的废物以及超铀废物的处理都是有效的。这种称为福塔普(FUETAP)的混凝土是在升温升压条件下成形,然后部分脱水而制成的,以保证以后的热稳定性和辐解稳定性。     

硼饱和模拟废活性炭的桶外水泥固化

核电站在运行过程中会产生含硼废水浸泡且硼饱和的废活性炭,需要对其进行固化处理。采用2.5‰(质量分数)的硼酸溶液对活性炭进行浸泡直至含硼量达到稳定来模拟实际废物源项,然后脱去硼饱和后活性炭中的游离水,并采用桶外水泥固化工艺对其进行水泥固化。结果表明,试验过程稳定可靠。另外通过试验验证可知,华龙一号新增废物源项废活性炭能够利用现有桶外水泥固化技术进行废物的处理,对硼饱和模拟废活性炭采用桶外工艺固化后,养护形成的水泥固化体按照标准GB 14569.1-2011进行游离液体、机械性能、抗水性、抗冻融性以及耐γ辐照性试验测试,结果均满足要求,且活性炭颗粒在固化体中分布均匀,未出现上浮现象,其搅拌完成以及30min后自由流动度均大于200mm,完全满足桶外水泥固化工艺稳定可靠的运行要求。     

AP1000核电机组离堆废物处理方案探讨

根据废物最小化原则和我国核电国产化的总体政策,分析了AP1000核电机组离堆废物的整备处理形式。通过对不同废物处理工艺进行比较并优化组合,提出了AP1000核电机组离堆废物处理的初步工艺方案。该方案可将单堆废物货包体积控制在50 m3/a以下,符合废物最小化原则。     

低水平放射性废物和混合废物的商用处理技术（六）

4.1 0固化 /稳定化本节中描述的技术是将化学或放射性有害物固化成一种固体废物体 ,限制废物可浸出的表面积 ,限制废物的溶解性或消除废物中的有毒组分。所有这些工艺过程都使用无机或有机添加剂 ,其作用是作为化学粘接剂、废物体或工艺性能的增强剂、或防止放射性扩散。一种固化技术的应用和选择通常应考虑到 EPA有害废物处理标准、废物管理问题、或者处置场的废物接收标准。以下讨论的是几个典型的固化 /稳定化工艺技术及其对特殊种类废物的适用性。4.1 0 .1波特兰水泥固化系统采用波特兰水泥作为固化 /稳定剂来固化废物。在这类系统中 …     

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.     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

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.