Handling radwastes during rehabilitation of contaminated objects and grounds of the Kirovo-Chepetsk Chemical Works

Possible ways to rehabilitate the objects and grounds of the Kirovo-Chepetsk Chemical Works are examined. The technology for handling radioactive wastes and methods for immobilizing radioactive wastes in repositories are briefly described. Ways to eliminate radwaste repositories containing medium-level wastes with fissile substances and α-emitters are proposed. The experience gained in such work abroad is examined and the problems which must be solved to rehabilitate the objects at the Works are noted.     

Extraction of radioactive wastes and liquidation of old repositories at the Russian Science Center Kurchatov Institute

The salient features of the organization and execution of the work performed to remove radioactive wastes from and rehabilitate ten old repositories located on a special site of the Institute, which were distinguished by their design and the form and composition of the wastes contained in them, are described. The old repositories were located close to a housing development, so that special attention was devoted to the choice of technologies and technical means used for the rehabilitation. The technical approach and the sequence of operations are presented, and the technology and technical means are described. The problems of providing the proper technological equipment for this work are analyzed. __________ Translated from Atomnaya énergiya, Vol. 103, No. 2, pp. 129–133 August, 2007.     

MANAGEMENT OF RADIOACTIVE WASTES IN CHINA

The policy and principles on management of radioactive wastes are stipulated.Cement solidification and bituminization unit has come into trial run.Solid radioactive waste is stored in tentative storage vault built in each of nuclear facilities.Seventeen storages associated with applications of nuclear technology and radioisotopes have been built for provinces.Disposal of low and intermediate level radioactive wastes pursues the policy of “regional disposal”.Four repositories have been planned to be built in northwest.southwest,south and east China respectively.A program for treatment and disposal of high level radioactive waste has been made.     

Safety assessment of liquid radioactive wastes buried for a long time in deep repositories

The concepts of specific and absolute toxicity permit distinguishing in radioactive wastes belonging to different categories the particular components that present the greatest ecological danger at different stages of their disposal in repositories. It is shown that transuranium elements determine the toxicity parameter of high-and medium-level wastes only 350–400 years after initial disposal. At the present stage of operation of deep repositories, the behavior of the long-lived fission products of ⁹⁰Sr and ¹³⁷Cs is most important. For low-level wastes, the chemical and not the radioactive component is most dangerous. __________ Translated from Atomnaya énergiya,Vol. 100, No. 2, pp. 86–92, February, 2006.     

Strategy for the environmental safety of radiologically dangerous objects

A strategy for environmental safety of radiologically dangerous objects is examined for one such object. The steps in performing the work oriented toward environmental safety are shown. The most likely variants for handling radioactive wastes are presented. The technological operations performed to ensure environmental safety of the object are examined. The choice of the final variant for increasing environmental safety is made after economic and environmental evaluation. The strategy developed for ensuring environmental safety can be used to examine other radiologically dangerous objects.     

Basic principles and proposals for rehabilitation of radioactively contaminated objects and grounds of the kirovo-chepetsk chemical works

The results of an examination of objects and grounds of the Kirovo-Chepetsk Chemical Works are presented. The methods used to perform a radiation survey are described briefly. The data obtained are used as a basis for a concept of rehabilitation of radioactively contaminated objects and grounds of the works. The radwaste volumes are determined for each object and possible ways to handle them are proposed. The technologies for handling radwastes are examined. The primary problems that must be solved without delay are determined.     

Rehabilitation of the radioactively contaminated objects and territory of the Russian Science Center Kurchatov Institute

This article is devoted to work done in 2002–2006 as part of the unified project Reabilitatsiya to rehabilitate radiation hazardous objects and sections of the radioactively contaminated territory of the Russian Science Center Kurchatov Institute. The main objects of the rehabilitation work were old storage sites built for radioactive wastes on the territory of the Institute when military and civilian nuclear technologies were under development. The structural features of the storage sites, including the volumes and characteristics of the wastes stored, are presented. The salient aspects of the disposal sites, taken into account during the rehabilitation work, are discussed. The organization of the rehabilitation operations and the sequence in which they are performed, the special features of the technical design solutions used, the technological methods, and ways for conducting the work are described. __________ Translated from Atomnaya énergiya, Vol. 102, No. 5, pp. 300–306, May, 2007.     

Inspection and preparation for liquidation of old radwaste repositories at the Russian Science Center Kurchatov Institute

Efforts to develop design materials and preparations for liquidation of old radwaste repositories at the Russian Science Center Kurchatov Institute have revealed problems due to the lack of archived information on the salient structural features of the repositories and the wastes placed there as well as due to the inadequate development of the technical and technological support base for restoration work. The technical approach implemented during the preparation for liquidation of the repositories is described. The sequence of operations is presented, and the technological and technical means are described. The problems of the technological support for inspection of the repositories are analyzed. __________ Translated from Atomnaya énergiya, Vol. 102, No. 6, pp. 374–377, June, 2007.     

放射性废物管理中值得关注的一些新概念

本文介绍了国际原子能机构及国际放射防护委员会近年来在放射性废物管理领域提出的一些新概念。诸如对放射性废物实行全过程管理；对长寿命固体放射性废物处置的安全评价采用有约束的最优化办法，并且指出最优化是一个判断过程等。本文用意在于引起同行对这些概念的注意和重视，以便对放射性废物的安全管理有所帮助。     

Development of a unified technological process for cementing solid radwastes

The results of research on cementing finely dispersed, mixed, closely packed, and coarsely fragmented solid radioactive wastes by mixing, flow-through, and impregnation to create a unified complex of technological processes are presented. A new method of impregnation which consists of feeding under pressure through a probe into the bottom of a container with solid wastes a cement solution with a high penetrating power is shown. The drawbacks of flow-through are eliminated, the integrity of the pouring is guaranteed, and the quality is monitored by determining the degree of impregnation and density of the cement solution which has passed through the layer of solid wastes. This method of cementing can be used for all solid wastes considered and the equipment and cement compositions are basic for the works cementing solid radioactive wastes.     

Handling of radioactive wastes formed outside the nuclear fuel cycle

Conclusions The system of regional specialized industrial plants "Radon" was created more than 30 years ago and over this time it has made it possible to utilize radioactive wastes from industrial and scientific centers in the country. The technology adopted by the specialized industrial plants for preparing and burying radioactive wastes makes possible safe localization of the wastes for a long period of time. Investigations designed to estimate the effect of the points of burial by the specialized industrial plants on environmental objects showed that the technical solutions adopted are reliable. At the present time the system of regional specialized industrial plants is experiencing difficulties on the legislative, financial, and technical levels. The system must be reconstructed and modernized. The basis for future decisions will be determined by the legislative base and the principles which are employed in the process. The optimal path toward modernization of the regional industrial groups is to produce complexes based on them for collecting, processing, and temporary storage of radioactive wastes formed within the service zone. The Moscow Scientific and Industrial Association "Radon" is now implementing this concept. Moscow Scientific and Industrial Association "Radon." Translated from Atomnaya énergiya, Vol. 79, No. 6, pp. 437–443, December, 1995.     

法国COGEMA核废物处理中心的环境保护

主要介绍了法国COGEMA集团核废物处理技术，即放射性环境影响、废物控制、空气中放射性含量的监测、水质的监测和保护、土地的恢复和开发等，以及对每一项工作所采取的措施；评价了该集团核废物处理中心的环境保护工作及其经验，以此借鉴国外有关核废物处理和环境保护的先进技术。     

放射性废物管理的国际动向

本文概述了放射性废物管理活动的国际新动向:高度重视减少废物量,大力开发退役和去污技术,积极解决废物安全处置,废物处理实行社会化服务,重视质量保证和实现量化管理等。最后,还对我国放射性废物管理工作提出了建议。     

Radioactive Waste Transport in the Russian Federation

Abstract

According to the national radwaste management programme, low and intermediate level wastes originating from nuclear power plant (NPP) operation, from the nuclear fuel cycle and from the application of radioisotopes in medicine, industry and research are centrally collected and transported for disposal at 16 special repositories. Packagings and conveyances for these purposes are discussed. A concept of regional repositories and transport of wastes from NPPs and the Navy is also considered together with transport packagings and transport methods.     

德国放射性废物地质处置的研究历程

本文简要介绍了德国放射性废物地质处置及相关研究的历程和现状,包括中低放废物和高放废物的处置情况,同时从技术层面分析了德国高放废物处置库场址评价所面临的问题。希望对于我国放射性废物地质处置的研究有所启示。     

溶度积约束—废物处置安全评价中不应忽视的问题

对废物处置安全评价中常用的核素迁移计算方法进行了分析。利用溶度积约束对废物源项进行修正，提出了一个计算核素在地下水中迁移的方法。     

Recent activities in the field of nuclear waste management

Buffer construction using bentonite pellets as filling material is a promising technology for enhancing the ease of repository operation. In this study, a test of such technology was conducted in a full-scale simulated disposal drift, using a filling system which utilizes a screw conveyor system. The simulated drift, which contained two dummy overpacks, was configured as a half-cross-section model with a height of 2.22m and a length of 6.0 m. The average dry density of the buffer obtained in the test was 1.29 Mg/m³, with an angle of repose of 35 to 40 degrees. These test results indicate that buffer construction using a screw conveyor system for pellet emplacement in a waste disposal drift is a promising technology for repositories for high level radioactive wastes.     

Research and development of a high-efficiency one-stage melting converter-burial-bunker method for vitrification of high-level radioactive wastes

A new high-efficiency one-stage melting converter-burial-bunker method for vitrification of high-level radioactive wastes has been developed and investigated. The method includes evaporation (concentration), calcination, and vitrification of high-level radioactive wastes in a one-stage process inside a melting converter for non-metallic minerals, followed by burial inside a bunker-storage facility located directly underneath a melting chamber. Specific to the melting process is the direct combustion of a gas-oxygen-air mixture inside a melt. The experimental data for different aspects of the proposed method are presented, including converter/bunker dimensions, burner types and sizes, data for used materials, contents of saturated salty solution and final glass product, and entrainment analysis. The effective flue-gases cleaning systems and the design of the burial-bunker storage facility are also discussed.