放射源安全和保安的新进展

本文介绍了放射源安全和保安的最新进展.放射源安全和保安不仅是核与辐射安全和保安的重要组成部份,也是防止辐射恐怖事件的最重要的手段.国际原子能机构在最近发布了“放射源安全和保安行为准则（Code of Conduct on the Safety and Security of Radioactive Sources）”和“放射源的进口和出口导则（Guidance on the Import and export of Radioactive Sources）”.放射源的全寿期连续控制以及失控源的搜寻和重新控制取得了较大的进展.前苏联生产的放射性同位素电池的安全和保安引起了国际上的关注.近年来,我国放射源安全和保安取得了较大进展,但仍然有许多工作有待进一步开展.有必要加强和积极推动失控源搜寻和废放射源最终处置等工作.     

高活度废放射源整备装置可行性验证

为使高活度废放射源满足长期贮存安全要求,在研制的高活度废放射源整备装置上进行了可行性试验研究。结果表明装置满足整备活度超过3.7×1013 Bq（1 000 Ci）的废放射源的要求,操作位的剂量率为8.5～16.5μSv/h,该装置用于高活度废放射源的整备是可行的也是安全的。     

废放射源长期贮存现状

简单介绍了国际上对对废放射源的长期贮存方法一直接贮存、加外包装贮存和整备后贮存,分别介绍了英国、奥地利、白俄罗斯、捷克、比利时等国废放射源的贮存现状;介绍了我国对废放射源的贮存方法及北京城市放射性废物库、中国辐射防护研究院废放射源贮存库、核工业废放射源集中贮存库、国家废放射源集中贮存库对废放射源的贮存情况,以期对我国废放射源的长期贮存研究有所帮助。     

多放射源3D搜寻定位系统设计与模拟

为实现对多个放射源的搜寻定位,设计了用于确定放射源坐标的探测系统。探测系统基于方位角测量,用Na I探测器辨别γ放射源的方向。利用MCNP软件进行多放射源搜寻定位模拟实验,结果表明探测系统能够在多个放射源形成的辐射场中实现对放射源的搜寻并确定其空间坐标,且坐标偏差较小。探测系统可用于搜寻丢失的γ放射源并尽快确定其空间坐标。     

我国核工业废放射源安全管理

废放射源易于在管理上失去控制，从而酿成事故，对人类和环境造成危害。本文分析了我国废放射源产生的原因，介绍了我国核工业废放射源的现状与安全管理的技术路线和策略，提出了当前所面临的主要问题。     

基于角度测量信息的移动寻源方法

随着放射源在各领域的广泛应用，放射源丢失事件时有发生。针对单个放射源的搜寻问题，提出基于到达角度的粒子滤波寻源方法来提升计算效率，通过粒子集描述放射源位置和强度，把到达角度引入粒子更新过程，根据粒子相对角选择更新粒子，并完成归一化、重采样和自适应更新。建立观测向量集合，每测量1个新的环境观测数据，即可得到当前所有观测向量反映的放射源最优估计位置，并引导搜寻路径向放射源位置靠近，当粒子滤波满足收敛条件时，对粒子进行加权求和，得到放射源最终的估计位置。仿真实验表明，本方法可应用于移动式寻源，相比于已有粒子滤波方法具有更高的工作效率，其探测区域也显著增加。     

预估带法搜寻丢失放射源模拟研究

为了能快速高效的搜寻丢失的放射源,本文提出了一种预估带法丢失放射源搜寻方案,该方案具有操作简单,定位准确性高,实用性强,用时短,搜寻人员所受剂量低的优点。实验模拟了226Ra丢失情况下,采用BH3013B环境辐射剂量率仪进行搜寻,验证了该方案在无遮挡、单面遮挡和掩埋三种情况下搜寻丢失放射源的效率与定位准确性。实验结果表明,此搜寻方案能有效、快速、准确的确定丢失放射源的位置,为搜寻人员提供了依据,从而尽可能的减少损失。     

长寿命废密封放射源整备装置冷实验验证

开发长寿命废密封放射源整备装置,使整备后废放射源满足长期贮存要求是废放射源管理的重要组成部分。研制并建立了废241Am-Be中子源的整备装置,开展了废放射源整备冷实验,实验结果表明,该整备装置满足长寿命废密封放射源整备要求。     

改革密封放射源安全和保安监管的几点建议

本文对改革密封放射源安全和保安监管提出了如下几点建议：（1）对源实施“全链式”通报和盘查;（2）促使和鼓励将废源返回源的生产单位或出口国;（3）对源按其潜在危险进行分类并实行分级监管;（4）抓紧制定我国的放射源安全和保安规定。文中还简要阐述了提出这些改革建议的理由或考虑。     

移动式低活度废放射源整备装置设计与研制

在研究了低活度废放射源整备工艺流程及废放射源封装方案和封装容器方案的基础上,研制了移动式低活度废放射源整备装置以及与其配套的低活度放射源封装容器、混凝土包装容器和贮存容器。使用60Co和137Cs废放射源示范整备实验表明:装置布置合理,操作方便,整备装置各系统和设备运行稳定,能顺利开展整备操作。     

放射性废源的安全管理与处置

本文阐述了放射性废源的产生和安全问题;讨论了加强管理的必要性和国务院笫449号令提出的相关措施;给出了国际原子能机构和我国发布的有关密封源管理的法规和标准;介绍了放射性废源的安全处理和整备技术,重点介绍了现在国外废镭源的整备技术.     

甘肃城市放射性废物库在线监测管理系统

从设备选型、数据采集与传输系统、辐射剂量监控系统、放射性废物信息管理系统、视频监控系统等方面介绍了甘肃城市放射性废物库在线监测管理系统,以及系统的运行情况。     

Salvaging the Lepse tender

The basic problems of salvaging the Lepse tender of the Murmansk Shipping Company are examined. The main sources of nuclear and radiation danger are determined, the characteristics of their structural features which prevent the appearance of a spontaneous reaction are given, the consequences of long-time storage of spent fuel assemblies are described, and different variants of their removal from storage are proposed. A computational validation of the required degree of subcriticality of the spent nculear fuel and an assessment of possible accidents, including accidents accompanying sinking of the vessel at its permanent base, are given. The salvaging steps are described, the bottlenecks are determined, schemes for handling the vessel are validated, and the radiation load on the workers is estimated. __________ Translated from Atomnaya énergiya, Vol. 101, No. 1, pp. 65–69, July, 2006.     

VVER机组一回路硫酸根升高原因分析

针对核电厂大修期间一回路硫酸根异常升高的问题,首先对一回路和乏燃料水池可能产生硫酸根的物项成分进行分析,排除了给水、硼酸、氢氧化钾等添加试剂是造成硫酸根的主要来源。在对大修期间一回路硫酸根的变化趋势分析时发现,一回路硫酸根的变化和净化系统有关。通过试验确认乏燃料水池中的硼酸溶液在放射性和富氧条件下生成了氧化物质,当乏燃料水池和硼箱净化系统在净化乏燃料水池时,阳树脂中的磺酸基被氧化脱落进而分解生成硫酸根是导致一回路硫酸根升高的主要原因。根据研究成果通过减少阳床的运行时间有效解决了VVER机组中普遍存在的问题。     

山西省城市放射性废物库周围辐射环境监测(2016—2019)

山西省核技术利用项目产生的放射性固体废物(源)暂存于山西省城市放射性废物库。2016—2019年,废物库废旧放射源存量增加近千枚。2016—2019年,对废物库库区周围辐射环境(包括:库区周围γ辐射剂量率,库区α、β表面污染水平,气溶胶总β水平,库区及周围水中总α、总β水平,库区及周围居民点土壤中γ核素水平等项目)的监测结果显示,废物库周边辐射水平处于天然辐射水平范围内,未见可察觉的改变。     

Development of a direction finding gamma-ray detector

This paper describes a direction finding gamma-ray detector, which consists of three different scintillators; NaI (Tl), CsI (Tl) and BGO. The detector positively increases directional sensitivity to incident gamma-rays, and can measure direction, energy and number of gamma-rays. This detector will be useful to carry out monitoring of nuclear power plants or radiation facilities in emergencies. It will be also effective in searching for radiation sources such as radioisotopes and radioactive contaminations. Experimental results have shown the proposed directional detector has a potential for practical use in real fields and will contribute to radiation emergency preparedness.     

可移动式高活度废放射源整备装置的示范性验证

在高活度废放射源、整备场地、整备装置、监测仪器、人员和文件准备的基础上,利用自行研制的国内第1套可移动式高活度废放射源整备装置,顺利完成了活度为3.71×1013Bq的60Co废放射源的示范整备和回取作业。整备方案考虑了废放射源整备后的安全、可回取和体积最小化等原则,以及国内废放射源地坑式贮存现状。在整备过程中,将29枚高活度60Co废放射源从原始容器中取出后封装在螺纹封装管中,再将多根封装管放入薄壁盛装容器中,最后将盛装容器放入长期贮存容器中。在回取过程中,将已整备的多枚高活度60Co废放射源恢复原状,放入原始容器。在整备过程中,整备装置外表面剂量率1.56μGy/h~4.48μGy/h,装置顶盖外表面剂量率4.23μGy/h～14.8μGy/h;距整备装置外墙10 m处的剂量率1.20μGy/h~1.84μGy/h;整备操作人员最大个人受照剂量5.4μSv,平均个人受照剂量3.0μSv。在废放射源整备和回取作业过程中,以及作业以后,整备装置工况良好。     

废放射源整备用封装管的设计与检测

研制废放射源整备封装管,使整备后废放射源满足处置或者长期贮存要求,是废放射源管理的重要组成部分。本文针对不同活度、不同核素的废放射源,设计制造了不同的封装管,并对其中的螺纹封装管进行了跌落性、抗冲击性、耐热性等一系列检测。检测结果表明,本研究设计的封装管,满足封装废放射源的要求。     

Advancing US public acceptance of spent fuel storage and transport: proposed outreach services for ionising radiation education support

Abstract

Expansion of commercial nuclear energy could be one of the future US sources for clean, safe, reliable and economic electricity. However, no federal policy has effectively achieved wide acceptance of nuclear energy, with such policies having fallen victim to the politics of public radiation fears from nuclear energy usage and from spent fuel storage and transport. Many experts have described the foundation of public fear as not so much nuclear technology, but the ionising radiation to which people fear they might be exposed, and this issue has been talked and written about, yet gone substantially unaddressed with respect to public education for more than three decades. In the USA, the Blue Ribbon Commission Final Report is just the latest of clear statements where such an educational need is firmly asserted. The lamentable fact is that no one has made that substantive and concerted effort to do anything about it. Indeed, the only effort seems to have been talk about ‘better communication’, with a focus on risk based communication. Any rejuvenation of public acceptance of commercial nuclear energy in the USA, including spent fuel storage and transport, can only be sustained using a different strategy from that of earlier decades. This paper highlights professional opinion on the radiation fear issue and why current industry efforts in risk based information for and communication with the public have not achieved the desired success. Education to expand the public’s understanding of comparative radiation sources and exposures while ameliorating concern about radiation from nuclear energy is the proposed alternative. In addition, here, the clear linkage between education supporting nuclear energy and facilitating necessary spent fuel storage and transport is unmistakable. The paper summarises a concept for outreach services for ionising radiation education support for application in the US, as well as key elements of such a process: its basis for success, its education content and potential implementation approaches. Comparative radiation education of the public can prove effective using current research, which has been effective in other industries. Additionally, while this discussion addresses the US situation, much of the content is likely applicable to many of the world’s nuclear energy producing countries.     

Investigations on Inconel 718 irradiated with 800 MeV protons

In spallation sources, the neutrons (utilized as probes for condensed matter research or for inducing nuclear transmutations) are generated by protons of around 1 GeV energy which cause spallation of the nuclei in a heavy metal target. The beam powers of the proposed future facilities are in the range of 1 to several 10 MW and the corresponding high particle fluxes make radiation damage the crucial effect for the lifetime of target structural materials in or close to the proton beam. In order to establish a database on spallation-relevant radiation effects, post-irradiation investigations of components of spent targets from operating medium power sources are being performed. Here we report first results on Inconel 718 irradiated in LAMPF up to a fluence of 3 × 10²⁵ p/m². Microhardness and bending tests together with SEM and TEM investigations show a considerable degradation of the mechanical properties of the material requiring additional highly controlled tests, now underway, to determine fracture toughness and tensile properties as a function of dose.