Important factors governing exposure of the population and countermeasure application in rural settlements of the Russian Federation in the long-term after the Chernobyl accident.

Rural settlements located in areas of the Russian Federation contaminated after the Chernobyl accident and exceeding an annual dose of 1 mSv a-1 have been classified according to 137Cs contamination density, internal dose and the neighbourhood of forests. It has been shown that, with the exception of the most contaminated areas, the internal doses decreased in accordance with a decline in 137Cs availability for plant root uptake. An inverse tendency was observed in areas with 137Cs contamination above 555 kBq m-2 which can be explained by a reduction or even termination of countermeasure application and by an increasing consumption of forest products in areas where restrictive countermeasures are still implemented. Twenty-seven settlements have been studied to estimate the effectiveness of countermeasures applied previously and to identify the most important factors governing the radiation exposure to the population and its change with time. It has been shown that the effectiveness of countermeasures which resulted in a decrease of up to 40% of doses has a tendency to decline in the long term. The need for continuation of remediation in rural settlements was evaluated both for selected settlements and extrapolated to the whole contaminated area and it has been shown that the application of countermeasures will be of importance at least up to the year 2045. Rather high effectiveness in terms of internal dose reduction (factor of 2-2.5) of radical improvement (disking, ploughing and reseeding) and administration of Cs binders to animals (Ferrocyn) was demonstrated for the selected settlements. It could be demonstrated that for forest-remote settlements there is a linear dependence between internal dose normalised to the density of contamination and the proportion of peat soils around settlements. For near-forest settlements, this dependence was less pronounced which can be explained by the high contribution of forest food products to the internal dose. Milk is still the major dose-forming product in rural Russian settlements (its contribution to internal dose in forest-remote settlements is above 70%); however, in near-forest settlements, the contribution of mushrooms to the internal dose is comparable to the contribution from milk.     

An ethical dimension to sustainable restoration and long-term management of contaminated areas

Experience after the Chernobyl accident has shown that restoration strategies need to consider a wide range of different issues to ensure the long-term sustainability of large and varied contaminated areas. Thus, the criteria by which we evaluate countermeasures need to be extended from simple cost-benefit effectiveness and radiological protection standards to a more integrated, holistic approach, including social and ethical aspects. Within the STRATEGY project, the applicability of many countermeasures is being critically assessed using a wide range of criteria. Attention is being given to issues such as practicability, feasibility, capacity and environmental side-effects, as well as social factors such as public perceptions of risk, communication of information and the need for dialogue and consultation with affected communities, and ethical aspects such as informed consent and the fair distribution of costs and doses. Although such socio-ethical factors are now the subject of a substantial field of research, there has been little attempt to integrate them in a practical context for decision makers. Within this paper, we specifically consider the ethical aspects of restoration strategies and suggest practical means by which these can be taken into account in the decision making process, introducing a value matrix. The paper covers two critical areas: evaluation of individual countermeasures, and use of the matrix to ensure transparent and systematic consideration of values in selection of a restoration strategy.     

Decision making framework for application of forest countermeasures in the long term after the Chernobyl accident

After the ChNPP accident a very large part of the territories covered by natural and artificial forests are contaminated with long-lived radionuclides, especially 137Cs. To protect people against exposure associated with forest contamination in the most affected regions of the NIS countries, countermeasures have been developed and recommended for the forest management. The paper presents a decision making framework to optimise forest countermeasures in the long term after the ChNPP accident. The approach presented is based on the analysis of the main exposure pathways and application of radiological, socio-economical and ecological criteria for the selection of optimal countermeasures strategies. Because of the diversity of these criteria modern decision support technologies based on multi-attributive analysis were applied. The results of the application of this approach are presented in a selected study area (Novozybkov district, Bryansk region, Russian Federation). The results prove and emphasize the need for a flexible technique to provide the optimised forest countermeasures taking into account radioecological, social and economic features of contaminated forests.     

How long is long-term? reflections based on over 20 years of post-Chernobyl management in Norway

The radiation protection community has only recently started the important work of preparedness for long-term post-accidental management of radioactively contaminated areas, like for instance the EC projects STRATEGY, FARMING and EURANOS and the French authorities' CODIRPA and PAREX programmes. There are, however, different views concerning how long a long-term management might last. Based on the Norwegian and former Soviet Union experience after the Chernobyl accident, it is clear that a nuclear accident can entail decades of necessary management and rehabilitation of living conditions. The time period is dependent on a number of factors, e.g. amount of fallout, type of radionuclides, land use of contaminated area, number and density of people affected and available techniques and resources for implementing countermeasures. This paper discusses the management strategy implemented in Norway after the Chernobyl accident, the need for changing strategy over time and the important involvement of affected groups. Careful planning and reflections should be undertaken before actions are taken in the recovery phase, keeping in mind the possibility of decades with problems.     

Attitude of a group of Belgian stakeholders towards proposed agricultural countermeasures after a radioactive contamination: synthesis of the discussions within the Belgian EC-FARMING group

In the case of radioactive contamination of the environment with an impact on the food chain, the remediation strategy will not only be based on scientific knowledge and technical experience, but will also be dictated by peculiarities of the country. These characteristics include the agro-industrial structure, the local and international economical contexts and the political configuration including the distribution of responsibilities and competencies. This paper identifies and illustrates the most relevant characteristics of the Belgian agricultural system and political environment; it also describes the past experience with food chain contamination, which is expected to influence the attitude of Belgian stakeholders, who would be involved in the setting up of countermeasure strategies for maintaining agricultural production and food safety. The picture drawn explains why several countermeasures aiming to reduce the contamination in food products, although scientifically sound and technically feasible, are hardly acceptable or even not acceptable at all, to the stakeholders.     

Communicating in Germany about the Fukushima Accident: How Direct Encounter Beat Media Representations

The Fukushima nuclear accident revived the question of whether current practices of technical communication can fulfill the needs of various audiences during a complex global crisis. In that context, the Institute of Nuclear Technology and Energy Systems in Stuttgart organized a public presentation on the technical aspects of the Fukushima nuclear accident. Its success indicates that direct encounter was preferred to media representations of the accident by Stuttgart's citizens. This event demonstrated that public presentation can provide a successful model for technical communication in situations of global sociotechnical crisis.     

Areas of uncertainty in comparing risks of energy systems

In the past, the safety of technology has mainly been ensured by deterministic criteria that were based on engineering principles and on experience. Recently, however, it has become necessary to include risk assessment into safety policy. This need arises due to the order of magnitude of possible health and environmental impact from normal operation or accidents, as well as the complexity of modern systems that no longer allow for intuitive understanding of possible accident sequences. Assessment of risks of technical installations is subject to large uncertainties that are caused by lack of data and inadequate quantification and evaluation methods. This paper reviews the main areas of uncertainties with regard to their importance for decisionmaking. Uncertainties are an inherent part of any risk assessment result and can never be avoided. It is thus important to pay particular attention to them including limitations of methods, sensitivity to assumptions about parameters, and site-specific considerations. All this information must be described in great detail so that it can be integrated into the decisionmaking process. If applied in this context, risk assessment is a useful tool for identifying major contributors to risk and effective actions of risk management.     

Chernobyl radioactivity persists in reindeer

Transfer of 137Cs in the soil-plant/lichen-reindeer food chain was studied in central (?stre Namdal) and southern Norway (V?g?) during 2000-2003. Reindeer from these areas have been continuously subjected to countermeasure application since the 1986 Chernobyl accident. In both areas no decline in 137Cs concentrations was detectable in reindeer slaughtered in autumn since 1995, or in reindeer slaughtered in winter since 1998-1999. Seasonal differences in 137Cs concentrations in reindeer have been less pronounced in recent years, with 137Cs concentrations occasionally higher in autumn than in winter. Soil-to-plant 137Cs transfer was significantly higher in ?stre Namdal than in V?g?. Climatic influences on lichen growth and abundance, and on soil properties that influence the availability of 137Cs for plant uptake, are hypothesized to have a larger impact on long-term transfer of radiocaesium in the soil-plant/lichen-reindeer food chain than has been previously observed.     

土壤铜形态及有机物质的影响

概述了土壤铜的形态区分，影响铜形态分配的因素，有机物质对土壤铜形态与活性的影响，以及有机物质改良铜污染土壤的效果。指出了有机物质改良重金属污染土壤是可行的方法，但有关机理尚待深入研究。     

关于安全减灾业的基础性研究及量化模式探讨

本文重点论证加强安全减灾业基础性研究的必要性,并从建立安全减灾量化模式及数学体系作出探讨。     

Identifying optimal agricultural countermeasure strategies for a hypothetical contamination scenario using the strategy model

A spatially implemented model designed to assist the identification of optimal countermeasure strategies for radioactively contaminated regions is described. Collective and individual ingestion doses for people within the affected area are estimated together with collective exported ingestion dose. A range of countermeasures are incorporated within the model, and environmental restrictions have been included as appropriate. The model evaluates the effectiveness of a given combination of countermeasures through a cost function which balances the benefit obtained through the reduction in dose with the cost of implementation. The optimal countermeasure strategy is the combination of individual countermeasures (and when and where they are implemented) which gives the lowest value of the cost function. The model outputs should not be considered as definitive solutions, rather as interactive inputs to the decision making process. As a demonstration the model has been applied to a hypothetical scenario in Cumbria (UK). This scenario considered a published nuclear power plant accident scenario with a total deposition of 1.7x10(14), 1.2x10(13), 2.8x10(10) and 5.3x10(9)Bq for Cs-137, Sr-90, Pu-239/240 and Am-241, respectively. The model predicts that if no remediation measures were implemented the resulting collective dose would be approximately 36 000 person-Sv (predominantly from 137Cs) over a 10-year period post-deposition. The optimal countermeasure strategy is predicted to avert approximately 33 000 person-Sv at a cost of approximately 160 million pounds. The optimal strategy comprises a mixture of ploughing, AFCF (ammonium-ferric hexacyano-ferrate) administration, potassium fertiliser application, clean feeding of livestock and food restrictions. The model recommends specific areas within the contaminated area and time periods where these measures should be implemented.     

Mesoscale modelling of radioactive contamination formation in Ukraine caused by the Chernobyl accident

This work is devoted to the reconstruction of time-dependent radioactive contamination fields in the territory of Ukraine in the initial period of the Chernobyl accident using the model of atmospheric transport LEDI (Lagrangian-Eulerian DIffusion model). The modelling results were compared with available 137Cs air and ground contamination measurement data. The 137Cs atmospheric transport over the territory of Ukraine was simulated during the first 12 days after the accident (from 26 April to 7 May 1986) using real aerological information and rain measurement network data. The detailed scenario of the release from the accidental unit of the Chernobyl nuclear plant has been built (including time-dependent radioactivity release intensity and time-varied height of the release). The calculations have enabled to explain the main features of spatial and temporal variations of radioactive contamination fields over the territory of Ukraine on the regional scale, including the formation of the major large-scale spots of radioactive contamination caused by dry and wet deposition.     

Stakeholder involvement in nuclear crisis management in Greece

The setting up of the Greek Stakeholders Group in the framework of the EC Food and Agriculture Restoration Management Involving Networked Groups (FARMING) project is described. The Group included members from more than 20 governmental and non-governmental organisations, having interest and/or responsibilities in the management of a crisis following a nuclear accident. The stakeholders, during their meetings in 2002, discussed the agricultural countermeasures and rural waste disposal options which have been compiled by the EC Sustainable Restoration and Long-Term Management of Contaminated Rural, Urban and Industrial Ecosystems (STRATEGY) project. All stakeholders agreed that the most preferable were those options that ensure public acceptance, minimise environmental impact and maintain farming practices and acceptable living and working conditions. Their views are synoptically presented along with the major conclusions from the stakeholders meetings regarding nuclear crisis management.     

东北农牧交错生态脆弱区可持续发展研究

生态脆弱区是经济落后、人民生活较为贫困的地区．是可持续发展领域重点研究地区之一。实现生态脆弱区可持续发展管理的重要基础之一是对其发展现状进行综合测度。以我国典型生态脆弱区-东北农牧交错区为例．运用所建立的指标体系对阜新、通辽、赤峰等典型样点地区的可持续发展现状进行评估．对引致区域可持续发展现状的主要原因进行剖析；对1990年和2002年两个不同时段的可持续发展状态进行对比分析。结果表明资源与环境状况是影响区域可持续发展的关键因子．经济发展是提高可持续发展能力的根本保证．社会、人口、科技子系统对区域可持续发展具有重要作用。基于对上述问题的分析．提出东北农牧交错区可持续发展能力建设的几点对策。     

Doses to members of the general public and observed effects on biota: Chernobyl Forum update

The Chernobyl Forum was organized by the United Nations to examine the health and environmental effects of the accident at the Chernobyl Nuclear Power Station. This paper is concerned with the environmental effects, as determined by Expert Group Environment. The accident resulted in release of a large amount of radioactive materials over a period of 10 days. These materials were deposited throughout Europe with the three more affected countries being Belarus, Russia, and Ukraine. More than 5 million persons lived on territories in these countries judged to be contaminated at >37kBqm(-2). Many countermeasures were employed to mitigate the effects of the accident. The collective effective dose to the residents of the contaminated territories is estimated to be about 55,000 person-Sv. Effects on non-human biota were observed that ranged from minor to lethal; the current increase in the number and diversity of species in the most contaminated area is due to absence of human pressure.     

Model testing using data on 137Cs from Chernobyl fallout in the Iput River catchment area of Russia

Data collected for 10 years following the Chernobyl accident in 1986 have provided a unique opportunity to test the reliability of computer models for contamination of terrestrial and aquatic environments. The Iput River scenario was used by the Dose Reconstruction Working Group of the BIOMASS (Biosphere Modelling and Assessment Methods) programme. The test area was one of the most highly contaminated areas in Russia following the accident, with an average contamination density of 137Cs of 800,000 Bq m-2 and localized contamination up to 1,500,000 Bq m-2, and a variety of countermeasures that were implemented in the test area had to be considered in the modelling exercise. Difficulties encountered during the exercise included averaging of data to account for uneven contamination of the test area, simulating the downward migration and changes in bioavailability of 137Cs in soil, and modelling the effectiveness of countermeasures. The accuracy of model predictions is dependent at least in part on the experience and judgment of the participant in interpretation of input information, selection of parameter values, and treatment of uncertainties.     

Effects of non-human species irradiation after the Chernobyl NPP accident

The area affected by the Chernobyl Nuclear Power Plant accident in 1986 has become a unique test site where long-term ecological and biological consequences of a drastic change in a range of environmental factors as well as trends and intensity of selection are studied in natural settings. The consequences of the Chernobyl accident for biota varied from an enhanced rate of mutagenesis to damage at the ecosystem level. The review comprehensively brings together key data of the long-term studies of biological effects in plants and animals inhabiting over 20 years the Chernobyl NPP zone. The severity of radiation effects was strongly dependent on the dose received in the early period after the accident. The most exposed phytocenoses and soil animals' communities exhibited dose dependent alterations in the species composition and reduction in biological diversity. On the other hand, no decrease in numbers or taxonomic diversity of small mammals even in the most radioactive habitat was shown. In a majority of the studies, in both plant and animal populations from the Chernobyl zone, in the first years after the accident high increases in mutation rates were documented. In most cases the dose-effect relationships were nonlinear and the mutation rates per unit dose were higher at low doses and dose rates. In subsequent years a decline in the radiation background rate occurred faster than reduction in the mutation rate. Plant and animal populations have shown signs of adaptation to chronic exposure. In adaptation to the enhanced level of exposure an essential role of epigenetic mechanisms of gene expression regulation was shown. Based on the Chernobyl NPP accident studies, in the present review attempts were made to assess minimum doses at which ecological and biological effects were observed.     

汉江流域开发史上的环境问题

汉江流域全面开发的契机是明清时流域外移民的大规模移入以及由此而引起的人口的大幅度增殖。流域经济的全面开发导致了对流域生态环境的破坏，主要表现在两方面：（）上中游山区因滥垦殖，导致森林破坏，水土流失逐渐加重，生态环境最终全面恶化；（２）下游江汉平原垸田围垦恶性膨胀，湮塞河湖，导致水系紊乱，洪涝灾害频繁。     

“一带一路”国家天然气投资绩效评价及其改进路径

运用超效率数据包络分析(SE-DEA)方法,综合考虑目标国资源现状、政治因素、经济技术、社会条件、市场体制和国际合作情况,构建天然气投资绩效评价线性规划模型,并以2003—2013年中国对"一带一路"国家的天然气投资绩效均值进行聚类,结合规模报酬和投入要素的影子价格分析,提出目标国天然气投资绩效改进路径。结果显示:(1)中国对中亚及北亚、东南亚和南亚的天然气投资普遍处于中高效区,对独联体、中东欧洲和西亚北非地区的天然气投资普遍处于中低效区。(2)高效区国家自2012年起投资绩效处于规模报酬不变阶段,技术水平和国家经济对天然气贸易的依赖程度是影响投资绩效的关键因素。(3)中效区国家投资绩效大多处于规模报酬递增阶段,从2013年起总储量、人文地理和与中国油气合作状况成为影响中效区投资绩效的关键因素。(4)低效区国家投资绩效处于规模报酬递增阶段,国家经济对天然气贸易的依赖程度和技术水平要素是影响低效区投资绩效的关键因素;此外,对于处于低效区的中亚国家资源现状是影响投资绩效的另一关键因素,政治因素则是中东欧洲和独联体国家的关键因素,东南亚和南亚地区的投资关键因素则包含社会条件。这意味着,中国要提高在"一带一路"区域的天然气投资绩效,就要针对不同地区投资现状制定改进策略。对于高效区和低效区的中亚国家,未来中国要加强同目标国政府间的沟通,达成"以技术换气条款";对中效区和低效区的中东欧洲、独联体国家可采用与油气企业合作方式降低合作风险;对低效区的东南亚和南亚国家,可签订天然气长期贸易合同。