新疆伊犁铀矿冶退役场所辐射环境影响现状调查

以新疆伊犁4个铀矿冶退役场所为研究对象,调查其辐射环境影响,包括退役场所的γ吸收剂量率、土壤表面氡析出率以及土壤及水体中的天然放射性核素含量。结果表明,部分退役场所超标情况严重,亟需进一步治理。     

日本对降水引发的环境γ辐射随时间的变化的分析

由于换气效应,大气中的氡子体伴随降雨或降雪而到达地面。这就会使地表环境的γ辐射比正常水平高百分之几十,乃至比100％还多。这种变化给核工厂释放的放射性气体监测带来一系列严重问题。 降水中的氡子体量和环境γ辐射随时间的变化是同步测量的。前者采用井型NaI(TI)闪烁计数器——自动测量氡子体,该氡子体量是在假设降水中RaB和RaC处于放射性平衡的前提下的量;而对后者是采用普通的NaI(TI)闪烁型环境γ辐射测量系统进行的。由于降水引发的氡子体累积在地表,而γ辐射剂量率是根     

某铀矿区退役后环境辐射水平调查

对某铀矿区退役后辐射环境进行了调查监测。监测结果表明,某铀矿退役场所部分点位土样中核素226Ra含量超出限值要求,急需采取措施进行治理。     

驻极体法在铀尾矿库氡析出率调查中的应用研究北大核心CSCD

氡析出率的测量对于我国铀矿冶设施退役治理具有重要意义,是评价铀尾矿库防氡覆盖治理效果的关键环节。针对我国铀尾矿库氡析出率调查工作量大、仪器测量周期长的问题,本研究提出基于驻极体的氡析出率技术方法,缩短氡析出率测量时间,以此增加每日布置测量点位的频次,实现对广域铀矿冶场所氡析出率的快速调查。实验室校准和现场应用结果表明,该方法装置可靠、方法可行、结果可信,在氡析出率测量点位数量相同条件下,驻极体法测量耗时是RAD7测量耗时的2/9。     

用炭过滤器测量~(222)Rn通量的方法

本文介绍一种测定地表~(222)Rn(氡)射气率的新方法。将美国陆军改进的装有活性炭的气体防毒面具的过滤器封闭在地表几小时至几天(视预计的氡通量大小而定)。活性炭过滤器所吸附的氡量,通过记录与氡平衡的子体放出的伽玛辐射来测定,本文还详细叙述了活性炭过滤器的标定方法及其影响测定氡通量的参数。     

铀矿山废石堆与尾矿库覆盖抑氡实验效果对比研究

覆土抑氡是铀矿冶场址退役重要手段,覆土实验研究结果可为退役治理工程的设计与环境影响评价等工作提供科学依据。研究针对废石堆与尾矿库两种典型铀矿冶退役覆盖场地,设计覆土试验,确定了覆盖介质、覆土场地尺寸、压实度、监测方法等。根据覆土实验结果对比讨论两种场地氡析出率、覆土厚度、介质扩散系数之间的关系,建立了相应的函数关系表达式。结果表明,两种覆盖场地覆土厚度与氡抑制效果显著相关,但废石堆与尾矿库在覆盖过程中覆土厚度与氡抑制效果在不同的覆土层表现不同。研究结果可应用于指导覆土施工现场工作。     

某铀矿冶设施退役前后氡浓度调查及剂量评价

采用RAD7电子测氡仪对某铀矿冶设施退役前、过程中及退役后氡水平进行了调查,并估算了氡子体所致成年人有效剂量。结果表明,退役前、过程中和退役后该铀矿冶设施厂区氡浓度平均值分别为（35.5±3.8）Bq/m3～（38.7±4.1）Bq/m3、（14.8±2.2）Bq/m3～（84.9±6.8）Bq/m3和（10.6±1.6）Bq/m3～（11.4±1.7）Bq/m3。厂区内氡浓度退役前接近本底水平上限且数值稳定;退役过程中呈先增后减趋势,高于本底水平;退役后达到本底水平且数值稳定。该设施场所退役前、中、后氡子体照射所致成年人平均年有效剂量分别为0.97 mSv、1.34 mSv和0.27 mSv。     

Wismut公司铀矿山退役和地表复原的进展

本刊1992年第1期介绍过德国东部Saxony州和Thuringia州的铀矿区铀生产所带来的一些环境问题。本文继续报道德国统一后对该地区进行地下矿井治理和地表复原的进展情况。这项耗资130亿马克的庞大治理计划将延续10～15年。几个已完成治理工作的废石堆已能继续在地表进行农业耕作,或将辟为公园,或将在其上建设居民区。监测区的氡测量结果表明,低于德国联邦辐射防护委员会推荐的居民区室外氡浓度限值80Bq·m~(-3)。     

一铀矿山废石堆场退役治理后环境放射性监测

对某退役治理后的铀矿山废石堆场按20m×20m网格均匀布点进行贯穿辐射剂量率监测和地表222Rn析出率监测,报道了监测结果,并对仪器的宇宙射线响应值扣除方法、γ辐射剂量率与222Rn析出率关系、覆盖土中添加阻滞剂CaO对覆土掩埋治理效果的影响进行了探讨,对铀矿山环境治理具有参考价值。     

一种适于湿热环境的防氡涂层

利用自制的防氡涂料,在释氡模块氡提供的辐射环境下,对防氡涂层的防氡性能和防氡稳定性进行了研究。结果表明：在1^#释氡模块氡辐射环境下,涂覆0.8 mm厚的防氡涂层,消泡剂的较佳添加量为0.3%（质量分数,下同）。在消泡剂添加量为0.3%时,随着涂覆厚度的增加,防氡效率提高,当涂覆厚度大于2.0 mm后,防氡效率趋于稳定。在分别添加灰钙、白水泥、石膏和沉淀硫酸钡4种快干助剂的防氡涂层中,仅添加沉淀硫酸钡的防氡涂层的防氡效率明显下降,而添加其他3种快干助剂对防氡涂层的防氡效率基本无影响。在防氡稳定性中,白水泥和石膏的加入在一定程度上降低了防氡涂层的防氡稳定性,而添加灰钙对防氡涂层的防氡稳定性几乎无影响。在湿热和2^#释氡模块氡辐射环境下,防氡涂层仍具有良好的耐湿热老化和防氡性能。     

A study of the decommissioning procedure of an activated structure through an evaluation of the decommissioning cost for a research reactor

As decommissioning of a research reactor and a nuclear installation requires a long period of time from the decommissioning preparation work to the site remediation, the management of the data generated during the entire period of decommissioning is one of the most important tasks. In particular, the data obtained from research reactor decontamination and decommissioning activities can be important resources securing the safety and economic feasibility for other research reactor decommissioning. The owner of the research reactor and nuclear power plant need to submit decommissioning plan to the regulatory body at the starting stage of the research reactor and nuclear installation decommissioning project. The cost plan for decommissioning and the method for assessing the amount of exposure to protect workers must be stated in the decommissioning plan.This paper introduces the DES (Decommissioning Engineering System) that can be able to manage the data generated in the process of decommissioning of the TRIGA research reactor, to calculate an amount of waste, to evaluate decommissioning cost after deriving unit work productivity factor, and to predict the decommissioning process in advance. To verify the usability of this system and data integrity through connections among the unit systems, it describes the process to calculate the decommissioning cost using the data generated in dismantling an activated bio-shielding concrete in the TRIGA research reactor.As a result of the experiment to calculate the decommissioning cost with the TRIGA research reactor structure, it was found that the calculations were done precisely without flaw as the purpose of the experiment. Therefore, the DES can not only be used for other research reactors decommissioning, but also it is expected to be applied to other research reactors in the future. As a decommissioning cost between an activated concrete and a non-activated concrete according to the method of the dismantling procedure was significantly different, a study regarding the dismantling procedure needs more research.     

关于我国核电厂退役工作的思考

随着我国核电机组的数量和运行时间的增加，核电厂退役工作越来越重要。如何安全、经济、环保地退役，关系着核工业持续发展，以及生态环境安全和子孙后代的健康。本文从国际核电退役经验反馈和市场发展的角度出发，结合我国核退役规划要求，提出我国未来核电厂退役应开展的重点工作，包括:完善退役相关法规、标准；坚持自主化、企业化、市场化、专业化道路，合作共赢；落实全生命周期对于退役的要求；加快退役关键技术和设备研发；保障退役费用。      

Algorithmisation of nuclear installations equipment dismantling

The standardised structure of cost items for decommissioning was issues jointly by OECD/NEA, IAEA and European Commission in 1999 for promoting of harmonisation in decommissioning costing. The computer code OMEGA, developed recently by the company DECOM, a.s. in Slovakia, implements this standardised structure of cost items as the base of an universal cost calculation structure for evaluation and optimisation of cost, exposure and other parameters for decommissioning options. The paper focuses on selected modules of the code which were developed for modelling of dismantling of systems, decontamination of building surfaces and demolition of structures. Evaluation of these activities is one of the most important tasks to be done prior to performance of decommissioning activities. Selection of proper techniques for these activities depends on category of the item to be dismantled, decontaminated or demolished (material composition, construction, type of building surface, etc.), local radiological conditions (dose rate, contamination), local working conditions (constraints), and other factors. Local radiological conditions and pre-defined limits of dose rate determine the selection of manual or remote techniques. Dismantling, decontamination of building surfaces and demolition activities include also set of preparatory and finishing activities. Extent of these auxiliary activities varies when performed within or outside of the controlled area and/or when performed manually or remote. Paper presents the approach for selection of the techniques for decommissioning activities and extent of auxiliary activities which was implemented in the OMEGA code, using the standardised cost structure as the cost calculation structure.     

核设施退役信息数据库的结构与功能设计

核设施退役工程是一项不仅需要考虑拆除（毁）设备、建筑物,还要考虑辐射影响和核废物处理的复杂工程,其拆除（毁）工作具有高危险、高污染的特点,因此建立针对核设施退役项目的信息系统辅助退役工程很有意义。本文通过收集退役活动数据(设备物资数据、源项数据、辐射剂量数据等)设计退役信息数据库,开发了基于退役数据库的信息管理系统,该系统可对数据库中各类信息数据（照片、图纸、辐射数据、时间等）进行录入、删除、修改、查询等基本操作,并根据各类数据处理流程的特点分功能模块进行相应数据信息的管理,并对不同数据信息进行分析。该系统可提升退役过程中的管理能力,优化工程安排,减少作业人员所受辐射剂量,是顺利进行退役活动的必要基础。     

清洁解控和退役若干动向与新发展

对国际辐射防护协会第 1 0届大会 ( IRPA-1 0 )涉及的清洁解控和退役问题作了论述 ,包括排除、豁免、清洁解控和废物最少化 ;退役工程技术的发展 ,包括去污技术、切割解体技术、探测技术 ;介绍了一个研究堆退役例子和加速器退役 ;最后 ,还论及了退役中受关注的一些问题 ,如 :石墨废物、混凝土废物、重水堆退役的氚防护、退役时间和退役废物量等。     

核电厂初步退役计划

文章在目前国家对核电厂安全要求不断提高的背景下,对核电厂在设计阶段就应考虑便于退役的措施,并编制初步退役计划的要求,提出该计划应从便于退役的考虑、退役经费、退役活动等几个主要方面进行考虑开展编制工作,并以ACP1000堆型为例,给出了该设施从安全关闭到拆除的整个过程所涉及的活动内容。     

Identification and evaluation of facilitation techniques for decommissioning light water power reactors

This paper describes a study sponsored by the US Nuclear Regulatory Commission to identify practical techniques to facilitate the decommissioning of nuclear power generating facilities. The objectives of these “facilitation techniques” are to reduce public/occupational exposure and/or reduce volumes of radioactive waste generated during the decommissioning process.The paper presents the possible facilitation techniques identified during the study and discusses the corresponding facilitation of the decommissioning process. Techniques are categorized by their applicability of being implemented during the three stages of power reactor life: design/construction, operation, or decommissioning. Detailed cost-benefit analyses were performed for each technique to determine the anticipated exposure and/or radioactive waste reduction; the estimated cost for implementing each technique was then calculated. Finally, these techniques were ranked by their effectiveness to facilitate the decommissioning process.This study is a portion of the NRC's evaluation of decommissioning policy and supports the modification of regulations pertaining to the decommissioning process. The findings can be used by the utilities in the planning and establishment of the activities to ensure all objectives of decommissioning will be achieved.     

核设施退役辐射检测及其仪器仪表应用

核设施退役辐射场检测技术在核设施退役的整个过程中起着非常重要的作用.较系统论述了核设施退役辐射检测的质量保证,最后从满足核设施退役工作的需要出发,评述了退役过程辐射检测仪器仪表的选择及其应用.指出国内辐射监测仪器仪表在满足核设施退役的需求上的较大差距,值得各有关方面关注.     

核电厂退役资金管理

核电厂退役资金问题是核电政策、核电管理、退役管理方面的重要问题之一。文章介绍了国外核电厂退役现状,对国外在核电厂退役费用估算、资金提取和管理、保证资金充分性等方面的实践进行了阐述;在简要分析我国核电厂退役资金管理现状的基础上,提出了当前在退役资金方面需要开展的工作。     

A qualitative identification and analysis of hazards,risks and operating procedures for a decommissioning safety assessment of a nuclear research reactor

Korea Research Reactor-1(KRR-1, TRIGA Mark-II type reactor), the first nuclear research reactor in Korea, is being prepared for a decommissioning. The decommissioning methods and procedures of KRR-1 ought to be based on its structural conditions and radiological characteristics. Also, a systematic approach to the decommissioning tasks must be followed by reviews and assessments of the decommissioning workers’ safety.