铀同位素浓缩试验装置的退役处理

1985年9月至1986年12月完成了一套铀同位素浓缩试验设施的退役.本次退役属第三类退役形式,要求设施全部拆除迁离,厂房改作其它用途.退役活动包括:设施拆除、部件拆卸解体、包装、运输、去污、辐射监测、废物管理及物资处理.依靠以化学方法为主,辅以机械的和熔炼方法的去污手段,使1300吨金属部件表面污染水平降至允许限值以下.退役废物总量约50吨.监测结果表明,退役活动未造成对人员、环境明显影响.     

反应堆工程退役简介

本文介绍了反应堆工程退役的基本概念、过程和国际原子能机构(IAEA)规定的三级退役。反应堆工程退役的主要工作有:①退役文件和技术的准备;②退役工程现场准备;③设备、系统和设施的拆除工作;④系统去污和拆除后的去污;⑤运行废物和退役废物的处理和处置工作等。     

核设施退役中的去污和废物最小化技术

已关闭核设施的退役需要进行去污，去污可降低放射性水平，并可使拆除设施时产生的放射性废物体积降至最低。许多去污方法（例如研磨和高压水射流）是有效的。去污方法应根据自身情况进行选择。本文从正反两方面描述了各种去污方法，给出了英国原子能管理委员会一些成功去污的项目实例，同时讨论了一些还不太成功的新方法的运用以及可从中吸取的经验教训。     

浅谈回旋加速器退役拆解过程中实现放射性废物最小化的方法

本文主要针对陕西某三甲医院回旋加速器实施退役过程中,放射性废物最小化处理方法的分析和总结,旨在为今后类似回旋加速器退役治理过程中放射性废物处理提供良好的实践经验。本文中的回旋加速器主要用于生产医用放射性同位素,因设备老旧无法满足生产要求,故对其实施退役,以达到场所和设备清洁解控的目的。本次退役范围主要包括回旋加速器主体及主机房、药物合成室及其配套用房,需要进行清洁治理的为回旋加速器主体及主机房。在对回旋加速器进行拆解和大块部件切割之前和切割过程中,进行现场监测和实验室采样分析,通过现场监测结果和产生的放射性废物源项分析,按照废物最小化原则,对低放射性废物和极低放射性废物进行分类收集整备并送贮,对达到清洁解控水平的部件进行清洁解控与资源回收利用。本次退役共产生放射性废物约25吨,依据本文论述方法分拣出的可解控废物约12吨,实现了废物最小化。     

我国放射性废物处理与处置技术十年进展

本文概要介绍了我国低、中放废物处理,高放废液处理、放射性废物最终处置,退役去污及有关标准法规制订等方面十年来研究开发活动和进展。     

反应堆退役放射性废金属的熔炼处理

反应堆退役将产生大量放射性废物金属,熔炼处理可使其减容、再循环再利用,以大量减少放射性废物处置量,回用绝大部分金属。熔炼处理有减容、整备、包容放射性核素、降低比活度、便于放射性监测等优点,但会产生二次废物、对一些放射性核素的去污效果不理想等缺点。因此采用这项工艺要预先用其他去污工艺去污,预计去污效果和落实再循环再利用的去向,还必须有效控制二次废物。     

某研究所临时废物库退役改造项目辐射监测

本工作根据某研究所临时废物库源项调查报告,制定临时废物库退役改造项目的过程监测计划,对整个退役拆除项目进行了全过程跟踪测量。     

哈德姆内克核电站的退役去污工作

【英国《国际核工程》 1998年 12月报道】　康涅狄格扬基原子动力公司 (CY)的哈德姆内克 (Haddam Neck)核电厂已经进入退役阶段。在退役的准备过程中 ,该厂选择了西门子公司 (Simens) HP CDRD D UV工艺进行全系统去污。CY开发了一种独特的应用方法 ,它应用主要的电厂设备进行去污 ,而不是用外部去污设备进行去污。CY于 1996年 12月宣布进入退役运行阶段 ,在按 AL ARA(尽可能低地排放放射性废物 )进行了一次仔细的评估后 ,管理人员决定在移走任何主要部件前进行全系统去污工作 (FSD)。其目的是将最初系统的剂量率减少到原来的 1/ …     

商业核电站退役前拆除前去污技术的开发

本文介绍了作为商业核电站退役的各种技术之一的商业核电站退役拆除前的去污技术的开发,考查研究了系统（如管道）的化学去污和研磨去污。以及大型设备和槽罐的凝胶喷射去污技术。在基本实验中,用冷模拟样品进行了去污试验,得到了最佳的去污条件。从已取得的结果来看,把它们用于商业核电站退役拆除前的去污有较好的前景。     

去污和退役是90年代美放射性废物方面的一个关键问题

【美国《核废物新闻》1991年第11卷第41期第407页报道】美国能源部(DOE)废物管理局局长 Jill Lytle 在 DOE 于1991年10月14日田纳西州橡树岭举行的一次会议上说,去污和退役是90年代关键性的放射性废物管理问题。能源部核场地的去污和退役     

Final Status of the Decommissioning of Research Reactors in Korea

A decommissioning project for the Korean Research Reactors KRR-1 and KRR-2 was started in 1997 and had been carried out with the goal of completion by the end of 2008. All the facilities were dismantled and the building surfaces decontaminated. The radioactive waste was packed into 200 liter drums and 4m³ containers and temporarily stored on site until their final disposal at the national repository facility. Some of the releasable waste was freely released and utilized for non-nuclear industries. The assessment of the residual radioactivity was carried out according to the Multi Agency Radiation Site Survey and Investigation Manual (MARSSIM), and accordingly, the safety of the site release was verified. The site and buildings will be cleared for reuse for non-nuclear purposes after a review of the assessment. In this paper, the final status of the decommissioning of research reactors in Korea including dismantlement processes, waste management, and a final assessment for unrestricted use of the site and buildings as the final goal of the decommissioning project will be described.     

重水研究堆退役废物再利用研究

实现废物再利用是废物最小化的重要措施之一,从废物流中将有潜在利用价值的物料分离出来实现再利用可大幅减少对环境的影响。本文以中国原子能科学研究院重水研究堆退役为实例研究了放射性废物再利用问题。通过全面分析和计算重水研究堆在退役期间产生的各类废物,得出具有一定数量的物料有潜在的利用价值,可直接或经适当处理后再利用在其他行业领域中。研究表明,通过采取废物最小化控制措施（如废物分类和废物流分离等）,采用适当的去污技术和执行清洁解控要求,至少可使重水研究堆退役过程中产生的几十吨钢铁、10 t铝材和5 t重水实现再利用。     

Working plan for decommissioning of the Lovisa Atomic Power Plant

Conclusion The option with dismantling of radioactive parts immediately after completion of power operation was adopted for the decommissioning of the Lovisa Atomic Power Plant. If the engineering life of the power units is 30 yr, the decommissioning of the first power unit will begin in 2008 and that of the second power unit in 2012. The entire period of decommissioning of the atomic power plant from the time of shutdown of the first power unit until the burial facilities are sealed and license obligations are discharged will last more than 12 yr.Careful analyses showed that the dismantling of radioactive parts of the power units is possible through the use of methods that have already been developed.According to estimates and calculations, decommissioning operations for the power units of the atomic power plant will require approximately 3000 man-yr.Waste from dismantling can be buried safely in facilities built in the bedrock at the plant site. The irradiation doses to the public due to the burial of such waste remain low.The collective irradiation dose to personnel engaged in dismantling is estimated to be 23 man-Sv.The costs for decommissioning the power units of the atomic power plant, as calculated from the data compiled, are 800 million Finnish marks.Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 83–88, August, 1989.     

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。     

Treatment and geological disposal of waste from NET pre-design

Within the European Fusion Technology programs Studsvik RadWaste AB has performed studies on fusion waste treatment and disposal for several years. This paper deals with the treatment and geological disposal of radioactive waste from NET operation and decommissioning. Results from calculations on radioactive waste fluxes for the operation and decommissioning of NET are reported. The calculations are based on the NET predesign report published 1993 and include results for the exchangeable in-vessel and external parts of the machine as well as permanent reactor components. Different aspects of treatment, packaging, transportation, and interim storage of the waste are discussed. The volumes of waste conditioned for final disposal are preliminarily quantified, according to German and Swedish scenarios for radioactive waste disposal. A total repository volume of approximately 45,000 m³ is required in the German Scenario and 35,000 m³ is required in the Swedish Scenario. Results from dose rate calculations for NET waste in final repositories are presented for the Swedish Scenario. This work was financially supported by the Swedish Natural Science Research Council (NFR) and the European Atomic Energy Community, under an association contract between Euratom and Sweden.     

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.     

Dismantling design for the loop rooms on the MR reactor

The recently completed international co-operation project was aimed at planning for decommissioning the MR reactor identified as a pilot plant for the decommissioning of the other shutdown reactors on the site. The MR reactor was a pool-type, materials testing reactor with the total thermal power of 50 MW which incorporated pressure tubes containing fuel under test. The MR facility includes the reactor with its nine loop rig rooms containing pumps, heat exchangers and experimental equipment as well as systems and equipment located in other buildings in the complex. The objective of the MR reactor decommissioning project was to identify dismantling equipment and the decommissioning methodology for the reactor, loop rooms and redundant services to permit the refit and re-use of the building for a different nuclear related purpose. The dismantling design comprises two separate, but combined, tasks, namely, the dismantling of reactor installation itself and dismantling of experimental loops. The techniques proposed to undertake the dismantling operations within the loop rooms are described. Two options have been developed for removing contaminated equipment from the high radiation field loop rooms and packaging the waste into approved waste containers. The benefits and detriments of both methods have been identified, which allows implementing the safe, timely and cost-effective decommissioning.     

Improved analytical methodology for calculation assessment of material parameters in the nuclear installation decommissioning process

The process of nuclear installation decommissioning is, besides other features, characterized by production of large amount of various radioactive and non-radioactive materials or waste that have to be managed, taking into account its physical, chemical, toxic and radiological characteristics. Waste management is considered to be one of the key issues within the frame of the decommissioning process from the technological and also financial point of view. Because of that mentioned fact, the evaluation of costs and other parameters is necessary to be done as precise as possible in the decommissioning planning period. The calculation code OMEGA with its implemented module of integrated material flow, is suitable for the assessment and further optimization of the various decommissioning waste management scenarios considering the different input parameters.In the paper, the improved analytical methodology based on the identification of decommissioning materials, definition of detailed material streams, development of scenarios, calculation of output parameters and final optimization, is presented. The process of implementation of such methodology to the existing OMEGA material flow system, including the new or perspective technologies and methods for the waste managing, is also discussed more in details.Finally, the summarizing conclusions and recommendations resulting from the model calculation results, done for the verifying the suggested methodology and functionality of new improved material flow system of the OMEGA code, are presented.     

核设施退役中几种"问题"废物的管理

核设施退役产生的废物不同于运行或日常维护过程中产生的废物,由于其中某些废物的特殊性质被认为是有“问题”的废物,需进行特殊的管理。本文介绍了几种含有危险性材料或有毒物质类的“问题”废物的管理。     

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.