极低放废物的填埋处置

极低放废物所含放射性水平很低,可以采用简易和经济的填埋方法处置。本文概述了区分极低放废物的意义,极低放废物的定义和限值,介绍了国外极低放废物的处置方法,并对我国的极低放废物处置提出了建议意见。     

极低放废物处置研究进展

极低放废物是国际上近年来新提出的一种放射性废物,目前尚未形成公认的定义和处置方式。本文介绍了研究极低放废物比较早的几个国家对极低放废物的定义,概述了国际原子能机构(1AEA)和一些国家的极低放废物处置政策与方法,综述了极低放废物处置场的安全评价方法,比较了这些国家极低放废物的处置状况,指出了我国研究极低放废物的迫切性和研究方向。     

西班牙第二个低放废物处置室获准投运

正【世界核新闻网站2016年7月7日报道】西班牙国家核安全委员会(CSN)近日批准位于科尔多巴省的埃尔·卡博里(El Cabril)处置设施将第二个极低放废物处置室投入运行。2006年,能源政策和矿业总局批准西班牙国家放射性废物公司(Enresa)在埃尔·卡博里建设一座由4个处置室组成、用于处置极低放废物和中低放废物的设施。第一个极低放废物处置室即29号处置室2007年完成建设,并于2008年开始处置     

匈牙利废物管理公司近期主要工作

<正>【普氏《核燃料》2016年12月19日刊报道】2016年12月8日,匈牙利放射性废物管理公司(Puram)总经理Ferenc Kereki在布达佩斯的新闻发布会上介绍了该公司的近期工作计划,包括扩建乏燃料中间贮存设施和近地表中低放废物处置设施,继续开展乏燃料最终处置库场址研究以及编制极低放废物处置设施建议书。     

国际原子能机构核燃料循环末端及核电站放射性废物管理技术国际研讨会会议概况

国际原子能机构于1999年8月30日～9月3日在韩国召开了“核燃料循环末端及核电站放射性废物管理技术国际研讨会”。会议交流了85篇论文,包括放射性废物管理的技术路线,核电站放射性废物管理,中低放和高放废物的处理、整备和中间储存,中低放和高放废物处置技术,退役废物管理等内容。本文介绍会议概况以及韩国的放射性废物管理概况。     

法国首座极低放废物贮存设施投入使用

【英国《国际核工程》2003年10月刊报道】 法国国家放射性废物管理局(Andra)的首座极低放废物(VLLW)贮存设施已于2003年8月中旬投入使用。 Andra表示,位于特华(Troyes)的这座设施能够对核装置退役过程中使用的混凝土和金属废物进行安全地贮存和管理。该设施将于2004年投入全面运营,目前仅接收不需要进行场区处理的废物。该设施耗资4000万法郎,是Andra与法国政府长期管理合同的部分内容。 法国首座极低放废物贮存设施投入使用     

俄罗斯完成地下放射性废物研究实验室设计

<正>【世界核新闻网站2015年4月1日报道】俄罗斯负责放射性废物管理的企业NO RAO公司近期完成了废物处置地下实验室的设计。该实验室将用于研究在热列兹诺戈尔斯克(Zheleznogorsk)的Nizhnekansky花岗岩中对固体高放废物(HLW)和长寿命中放废物进行最终处置的可行性。放射性废物将在地下450至525米进行处置。NO RAO是联邦独资企业,成立于2012年4月,负责所有核废物材料的处理以及放     

美国能源部公布高放废物和乏燃料处置方案评估报告

正【本刊2014年11月综合报道】美国能源部(DOE)于2014年10月24日公布了一份题为《能源部管理的高放废物和乏燃料处置方案评估》的报告。报告对由能源部管理的高放废物和乏燃料的永久性处置方案进行了评估。此次评估考虑了是否应当在一座通用处置库中对能源部高放废物和乏燃料与商业高放废物和乏燃料进行集中处置,或者在一座单独的处置库中对部分能源部高放废物和乏燃料进行处置是否能够带来好处。     

日本计划用3年时间开发退役技术

【世界核新闻网站2008年10月9日报道】2008年10月6日,匈牙利中低放废物最终处置库的放射性废物地表贮存与管理设施已正式投入使用。匈牙利已开始建设该处置库的地下处置室。这些处置室将最终用于存放波克什核电厂在运行与退役期间产生的所有低放废物与短寿命中放废物。对于该电厂产生的长寿命中放废物与高放废物,匈牙利将另行处置。     

意启动国家放射性废物贮存设施选址

正【世界核新闻网站2021年1月29日报道】2021年1月5日,意大利核电管理公司(Sogin)公布了放射性废物贮存设施候选场址清单,包括67个候选场址,开始向公众征寻意见。该公司拟建设一个占地150公顷的地表废物处置库和科技园:处置库占地110公顷,容纳7.8万立方米极低放和低放废物,以及在深层地质处置库投运之前贮存1.7万立方米中、高放废物;科技园占地40公顷,是一个研究中心,开放供开展能源、废物管理和可持续发展领域的国际合作活动。     

Characteristics,Conditioning and Acceptance Requirements for the Disposal of Radioactive Waste

Abstract

In the Federal Republic of Germany it is intended to dispose of all radioactive waste in deep geological formations. To provide the necessary data base for the disposal-related planning work, an extensive characterisation of this waste has been performed. Detailed information on the various compositions of primary waste, waste treatment and conditioning processes, waste forms, packagings and radionuclide inventories per waste package as well as on the respective waste arisings have been compiled. Waste acceptance requirements have been established for the planned Konrad repository and the Morsleben repository. For the conditioning of radioactive waste various strategies and techniques have been applied. According to the available interim storage capacities, the Konrad waste acceptance requirements and the waste type catalogue, the waste generators and the conditioners have started to select appropriate conditioning processes andlor to adjust existing methods to the requirements. Special emphasis was given to volume-reducing waste conditioning techniques.     

Service-oriented architecture for an overall radioactive waste package record management system

In Taiwan, there are a few radioactive waste package record management systems independently implemented by radioactive waste generators, operators of waste management facilities, transport organizations and storage facilities. To claim compliance of a radioactive waste package record meets with waste acceptance criteria for disposal, an overall radioactive waste package record management system which records and tracks all relevant information, from raw waste characteristics, through changes related to waste processing, to final checking and verification of waste package parameters should be constructed in accordance with IAEA recommendation. Service-Oriented Architecture (SOA) is widely accepted as a new paradigm for integrating heterogeneous systems in an effective way. It has formed a new trend being adopted by organizations in mitigating legacy system problems as in to maximizing interoperability, reusability and flexibility. Based on the current radioactive waste management processes, this paper proposes a three-tier SOA for the further overall radioactive waste package record management system design.     

Multiple lines of evidence for performance of the canister and waste form in long-term nuclear waste disposal: Reviews

The time scales required for nuclear waste disposal are very large compared with those for other engineering endeavors. Because of this, there are many uncertainties associated with the quantitative performance assessment of canisters containing high-level radioactive waste in a waste form. Multiple lines of evidence can be helpful in building confidence in the long-term behavior (corrosion and dissolution) of the canister and waste form. These lines of evidence are derived from long-term supports and probabilistic models and developed based on shorter term tests, bounding and conservative approaches, and available observations on natural analogs. This paper presents the progress made for important lines of evidence considered in quantitatively assessing radionuclide release behavior from canisters and waste forms. This paper considers risk-significant issues for canisters and waste forms (i.e., risk informed approach) in the probabilistic performance assessment of the disposal system which has also other components such as geology and hydrology.     

Thermal aspects of radioactive waste burial in hard rock

One of the possible methods that has been considered for the disposal of radioactive waste is deep burial in stable rock formations. This paper reviews recent work on modelling the way in which the heat emitted by the decaying radionuclides in the waste could affect this disposal option, emphasizing both the effects on depository design and on migration by flowing groundwater. It focuses particularly on research in the U.K. into the feasibility of burying high-level waste in fractured crystalline rock. After introductory sections on the characteristics of the waste and rock, there are three major sections on the temperature field in the surrounding rock, the stresses generated in the rock, and the groundwater flow.     

SiO2和B2O3含量对模拟高放废物玻璃结构的影响

硼硅酸盐玻璃具有特别高的化学稳定性、较好的热稳定性、较大的放射性废物包容量等优点,被广泛作为固化高放废液的基础玻璃料。废物玻璃固化体的结构与其组成存在一定的内在依存关系,它将对废物玻璃的性质产生影响。以组分含量作为变量,所引起的废物玻璃固化体的某些结构特征的变化,是探索影响高放废物玻璃固化体性能的内在线索。为了获取废物玻璃组分含量对其结构特征参数（非桥氧键数）的影响规律,以对废物玻璃固化体的性能进行估计,进而指导设计高效处理高放废液的玻璃固化体配方,以某模拟高放废物玻璃固化体的配方为基础,通过改变其中SiO₂和B₂O₃含量制备一系列的废物玻璃样品,并进一步采用拉曼光谱法对废物玻璃的硅酸盐网络结构单元（Qn,Q和n分别代表四面体单元和每个四面体结构单元所具有的桥氧键数）进行分析,讨论SiO₂和B₂O₃含量对此废物玻璃固化体网络结构的影响。结果表明：随着SiO₂含量（SiO₂的质量与剩余氧化物质量的比值）由0.721增加到1.037,废物玻璃固化体中桥氧键的比例随之而增多,同时玻璃网络结构的聚合度（N,非桥氧/桥氧的比例）减小,但是,随着B₂O₃的含量（B₂O₃的质量与剩余氧化物质量的比值）由0.117增加到0.143,再到0.176,桥氧键的比例先减小后增大。在本实验的范围内,废物玻璃固化体的密度变化不明显,无析晶现象。     

球床高温气冷堆核电站放射性废物最小化策略研究

放射性废物最小化是放射性废物管理的基本原则之一。高温气冷堆核电站放射性废物最小化策略研究对于优化设计与运行实践和全寿期放射性废物管理,以及高温气冷堆产业化发展具有重要意义。通过对世界上主要球床高温气冷堆运行历史和放射性废物数据的调研和论证,分析了球床高温气冷堆技术及其放射性废物特点,总结了高温气冷堆放射性废物管理值得借鉴经验及相关研究进展,提出了高温气冷堆核电站全寿期放射性废物最小化的策略和建议。     

核电厂放射性固体废物管理系统的研究与开发

目前我国在运核电厂和其他所有堆型（CPR1000、EPR和AP1000）的在建核电厂均缺少一套统一的放射性固体废物管理系统,缺乏对放射性固体废物从产生到最终处置的全周期跟踪管理。根据核电厂的放射性废物管理需求,研制了一套适合于各核电机型的核电厂放射性固体废物管理系统,对废物源项、处理、暂存、运输、处置全过程进行跟踪,使放射性废物管理安全、可控;研发了废物管理跟踪单和数据库,分析了废物管理工艺流程的逻辑关系,根据废树脂、浓缩液、废滤芯、检修废物等处理工艺分别设计了核素计算模型,可推算指定时刻的放射性水平,实现放射性废物数据的深度分析、应用以及对放射性废物安全管理的全过程追踪。研究成果已经在国内部分核电厂使用,有助于提高核电厂的放射性废物管理水平,具有较大的安全和社会意义。同时,该系统记录的数据有助于核电厂实现辐射防护优化设计和放射性废物最小化管理。     

Management Strategy to Reduce the Radioactive Waste Amount in Fusion

A waste management strategy for fusion activated materials aimed at reducing the amount of permanent nuclear waste is described. Three options are investigated: (1) clearance (declassification to nonactive waste). (2) recycling, (3) disposal as radioactive waste. Conditions allowing recycling are based on surface dose rates, those allowing clearance depend on the residual radioactivity, both after 50 years of interim storage. Analyses are carried out on two power reactor designs, the SEAFP Model 1 (SM-1) and Model 2 (SM-2). The activated waste arising from SM-2, is 69000 t: 48% could be recycled, 39% cleared, 13% needs permanent disposal. The SM-1 activated waste is 58000 t. No waste should be disposed of, 70% could be recycled, 30% could be cleared. The presence of residual tritium within the waste has been considered. An alternative to V-5Ti recycling has been analyzed, dealing with reprocessing of the alloy with elimination of noxious nuclides and subsequent clearance.     

Waste management scenario in the hot cell and waste storage for DEMO

Management strategy of radioactive waste generated in periodic replacement may be important in the point of view of fusion reactor design, because it has a large impact on the design of the hot cell and waste storage in the plant. In the replacement period of a fusion power reactor, the assembly of blanket or divertor modules needs to be removed from the reactor in order to minimize remote maintenance in the vacuum vessel and to attain reasonable plant availability. In the hot cell, the modules will be removed from the back plate of the assembly. Here, note that the active cooling must be done by a way that does not cause contamination of the hot cell environment due to dispersion of tritium and tungsten dust. In this sense, the cooling scenario is adopted that the existing pipe of cooling water in the assembly is connected to a different cooling water system in the hot cell. On the other hand, it is assumed that the structural material (F82H) of the blanket and divertor is not recycled due to its high contact dose rate. It should be crushed into small pieces to reduce volume of the waste and required storage space. In this paper, the basic idea of the waste management scenario and the conceptual design in the hot cell and waste storage for DEMO has been proposed.     

Use of poly(methyl methacrylate) in radioactive waste management: II. Monte Carlo simulations

Radioactive waste is generated from the nuclear applications and it should properly be managed in a radioactive waste management system. Different methods are available for treatment and conditioning of radioactive waste. Polymers can be used in the radioactive waste management as an embedding matrix. Poly(methyl methacrylate (PMMA) is a possible candidate material that can be used in the low level radioactive waste management. In this study, based on total resistible dose for PMMA, maximum waste activity that can be embedded into a waste drum was found via Monte Carlo simulations. In addition, Monte Carlo simulations for radioactive waste embedded into above mentioned polymer was performed and the dose rate distribution in the polymer matrix was determined for the initial and different periods of 15.1, 30.2 and 302 years after embedding of waste. Changes of mechanical properties in the polymer embedded waste drum was simulated for PMMA embedded waste matrices based on experimental data.