Power-generating unit with dual-loop sodium-cooled fast reactor and dual-wall steam generator

The results of a probabilistic analysis performed to validate the safety of AES-2006 designed for the site of the Novovoronezh nuclear power plant are presented. The requirements for the AES-2006 design are examined. The characteristic features of the AES-2006 design for the conditions at the Novovoronezh nuclear power plant site are described, including the diversity of the equipment and operating regime, passive systems, and scheduled maintenance of safety systems with the reactor operating at power. The scope of the probabilistic safety analysis performed at the development stage of the technical design is described. The important problems which must be solved in a probabilistic safety analysis for the designs of new nuclear power plants are discussed. Translated from Atomnaya énergiya,Vol. 106, No. 3, pp. 123–129, March, 2009.     

Comparative Operation Risk Assessment for the No. 4 Unit of the Beloyarsk Nuclear Power Plant with a BN-800 Reactor

A quantitative assessment is made of the collective cancer risk for the population in Sverdlovsk oblast due to exposure to radiation during the 30-yr period of normal operation of the No. 4 unit in the Beloyarsk nuclear power plant with a BN-800 reactor and for possible accidents. The estimates are made using the linear zero-threshold concept based on ICRP Publication No. 60.The values obtained are compared with the different forms of cancer risk characteristic for Sverdlovsk oblast (due to radiation and chemical contamination of atmospheric air and drinking water) and the morbidity and mortality risk predominantly due to socioeconomic factors. It is shown that the socioeconomic risk factors determine most cases of death from unnatural causes. Against this background, the health risk due to contamination of the environment by natural radionuclides and chemical carcinogens is negligibly small.The desirability of introducing into domestic practice the health risk assessment methodology developed by the US Environmental Protection Agency is discussed in light of the results obtained.     

应急撤离模拟在核电厂道路方案优化中的应用北大核心CSCD

将概率风险评价方法应用于核电厂的应急撤离模拟,利用自主编写的简化撤离模拟程序,结合厂址事故源项、人口、道路、气象条件等特征,对多个核电厂应急撤离条件下公众与工作人员可能的受照剂量和风险进行了对比分析。在此基础上,结合霞浦厂址应急道路方案遇到的实际问题,在保证事故应急状态下公众和工作人员能够有效撤离的同时,对应急道路方案进行了比选,为工程的实施提供借鉴和参考。相关程序和方法也可为后续发展海岛核电、小型供热堆等提供技术支持,有助于更直观地开展核电公众沟通。     

Simulation of 60Co transport by ground waters

The results of calculations of the migration of ⁶⁰Co in a water-bearing layer after an incident at the Novovoronezh nuclear power plant in 1985, associated with leaking of liquid radioactive wastes into ground waters, are presented. Numerical three-dimensional models of ground-water filtration and migration of contaminants are used to calculate the characteristics of the propagation of ⁶⁰Co in the water-bearing layer and flow into the Don river. Retrospective and predictive estimates of the irradiation of the population show that the incident did not cause the established dose limits to be exceeded. __________ Translated from Atomnaya énergiya,Vol. 100, No. 3, pp. 220–225, March, 2006.     

Transition to a new size of the sanitary-protective zone of a nuclear power plant

In our country, in accordance with world-wide practice, nuclear power plant safety is ensured by the systematic implementation of the concept of deeply esheloned protection based on the use of a system of physical barriers, including a fuel matrix, fuel-element cladding, boundary of the reactor coolant loop, airtight sealing of the reactor system, and radiation protection. In the Soviet Union, in contrast to other countries, an additional barrier was introduced in the construction and operation of nuclear power plants-a sanitary-protective zone separating the atomic power plant from housing developments. The results achieved in nuclear power give every basis for concluding that it is in principle possible to reject the use of part of the environment for protecting the public from the radiation effects of a nuclear power plant operating under normal conditions, i.e., the size of the sanitary-protective zone of the territory of the industrial site of a nuclear power plant can be limited in accordance with the operative law and normative base. The results of calculations and validations are presented. __________ Translated from Atomnaya énergiya,Vol. 100, No. 6, pp. 458–465, June, 2006.     

AP1000核电厂厂外剂量风险定量化分析

为了分析AP1000核电厂各种潜在的严重事故对周围公众的影响,采用MACCS程序模拟释入大气中气载放射性物质的弥散过程,对6种代表性释放类别进行剂量风险定量化分析。计算结果表明,事故后24 h内厂址边界附近公众的急性红骨髓剂量风险为1.96×10^-7 Sv/（堆•年）,该风险大部分来自安全壳旁通释放(BP);早期健康效应风险在10^-10~10^-9 Sv/(堆•年),且随着与反应堆距离的增大降幅明显;集体全身有效剂量风险为6.94×10^-4 人•Sv/（堆•年）,引发的癌症致死风险非常低。研究结果还表明,核事故后及时撤离将显著降低公众剂量风险。     

Risk analysis using data from radioecological monitoring

A methodology for performing risk analysis based on data obtained from radioecological monitoring is presented. Examples of the application of risk analysis to optimization of radioecological monitoring and assessment of the total radiation effect on components of the environment are presented. The integral indicators of the effect on radioactivity of atmospheric air and surface waters are calculated according to the criterion that the negligibly small risk is not exceeded and modern data from observations for various types of radiation objects in Russia: Mayak Industrial Association; Krasnoyarsk Mining and Chemical Works; Beloyarskaya, Novovoronezh, and Smolensk nuclear power plants; and others. It is shown that under regular conditions the objects of a nuclear power complex do not have an appreciable radiation effect on the components of the environment.     

Experience in operating and upgrading the No. 5 unit of the Novovoronezh nuclear power plant – practical base for developing a reliable source of nuclear energy

The No. 5 unit of the Novovoronezh nuclear power plant, starting commercial operations on September 26, 1980, is the first power-generating unit with a 1000 MW VVER in our country. The assimilation of its power gave invaluable experience to designers, builders, and equipment manufacturers; this experience was taken into account in the design solutions for next-generation power-generating units. A large volume of work on increasing the efficiency, reliability, and safety was performed over a 30-year service life. At present, the power-generating unit has been shut down for a major overhaul for upgrading according a program for extending the service life by 25–30 years.     

Special features of 60Co migration in a water-bearing layer

The consequences of an incident, involving a leak of liquid radioactive wastes into ground water, at the Novovoronezh nuclear power plant in 1985 are examined. The ⁶⁰Co distribution in a water-bearing layer is formed with the migration of a cobalt ion which is not sorbed and which with time transforms into a cation which is sorbed. The characteristic transformation time is several years. The parameters describing these processes for the conditions of a nuclear power plant and used for calculating ⁶⁰Co migration to the Don are presented. The processes resulting in the transformation of cobalt ions in bottom deposits and wells are also investigated. __________ Translated from Atomnaya énergiya,Vol. 100, No. 6, pp. 465–470, June, 2006.     

Risks associated with nuclear material recovery and waste preparation

This paper presents an analysis of the risk associated with nuclear material recovery and waste preparation. The steps involve: (1) reprocessing of spent fuel to recycle fissionable material, (2) refabrication of the recovered material for use as reactor fuel, and (3) the transportation links connecting these plants with the power plants and waste repositories. The risks considered are radiological and non-radiological, accident and routine effects on the public and workers during plant construction, operation and decommissioning.The lightwater reactor fuel is considered to be in its fifth recycle. The reprocessing plant is sized to receive 2000 MTHM/year, which corresponds to the fuel from 75 one-G We nuclear power plants. The refabrication plant which is considerably larger than current designs is colocated (within 1 km), and receives all the recovered fissionable material from the reprocessing plant and produces the fuel for recycle to the power plants.Sabotage and material diversion is protected against by colocating the plants and by coprocessing, i.e., not separating plutonium from uranium. For this reason, this risk is not treated, nor is the risk from earthquakes and other natural occurrences, on the basis that the plant is appropriately designed.The results of the analysis are that the non-radiological risk is 0.34 fatalities/GWe-year and that the radiological risk is 2 x 10^?3 fatalities/GWe-year, of which 60% comes from occupational exposure, 40% from routine public exposure, and 0.025% from accidental public exposure. This distribution of risk is not generally perceived. The non-radiological aspects of the plants and transportation are often ignored, although statistically they contribute 170 times more risk than radiation; similarly, radiation exposure to workers and routine radiological releases contribute 4000 times more than radiological public accident risk, which receives a large fraction of the professional and public attention. To further give perspective, the total radiological risk (2 × 10^?3) is about $\text{1}\text{3500}$ of the risk that the same population group would experience from the natural background.     

用公众健康危害指标对一个较典型的燃煤电厂的环境危害评价

利用公众健康危害评价方法，计算了一个较典型的燃煤电厂气载释放的化学污染物质及放射性物质对人体产生的健康危害，比较了它们的相对大小，结果说明其释放的化学污染物产生的健康危害远高于放射性物质，约为后者的３０倍。     

核能风险接受性研究

公众接受性倏关核能的生存与发展。三里岛事故后 ,新建核电站的安全性得到了很大的提高 ,但是公众对核能的接受性并没有明显的改善 ,其主要原因在于公众与专家在核能风险问题上的态度存在极大的差异。本文从“风险认知”和“风险决策”两个角度对此进行了分析 ,并提出了几点力求有利于改善公众接受性的建议     

AP1000型核电机组运行期间的预期氚排放

AP1000型核电机组电站放射性废物处理的特点决定了其预期氚排放总量可能高于同功率水平的传统压水堆核电站。在AP1000机组正常运行期间,除了需要加强氚排放的环境监测,更重要的是从源头优化管理和控制氚排放,最大限度地减少氚排放对环境的影响,保障环境安全和公众健康。本文简要介绍了压水堆中氚的产生,详细分析了AP1000机组液态和气载氚的产生和排放机制,给出了采用保守和优化方法计算的AP1000机组的预期氚排放量,讨论了AP1000机组氚排放量最小化的优化控制措施。无论单机组还是6机组厂址,AP1000堆型核电站氚预期排放量都满足我国相关标准限值的要求。     

NOSA五星安全管理系统对核电站职业安全管理的作用

核电站的职业安全管理正在向综合一体化管理、风险预控管理、过程管理、全方位和全员参与管理的方向发展。适当的集核电站安全、健康、环保为一体的综合管理方法,使其与核安全运行管理体系有机结合,共同为构建良好的核安全文化提供坚实的框架。NOSA五星安全管理系统就是这样一种基于风险管理的安全、健康和环保的综合管理系统,目标是保障人身安全。NOSA的管理理念与核安全文化理念相一致且可操作性强,符合核电站职业安全管理的需要。采用NOSA五星安全管理系统并使其保持持续改进,是提高核电站职业安全管理水平的有效途径之一,它能够和核安全运行管理体系及持续改进的安全文化有机结合,在提高核电站安全性和改善经济性方面发挥重要作用。     

公众核电风险的认知过程及对公众核电宣传的启示

在总结国际上对风险认知研究的基础上,设计了一个公众对核电风险认知的概念性的模型,在这个概念性模型中,公众核电风险的认知是一个动态、复杂和闭合的系统,是公众主观认知客观风险的过程。根据公众核电风险的认知特点和影响因素,在5个方面提出公众核电宣传的建议,并指出核电公众宣传对保持公众核电风险认知系统平衡的稳定起着重要作用。     

镍特效树脂分离富集核电厂液态流出物中的63Ni及其测量方法研究

为准确评估核电厂液态排放对公众造成的辐射影响,需对液态流出物中排放量较大、半衰期较长的⁶³Ni进行分析。本工作以镍特效树脂作为分离纯化材料,结合阳离子树脂、原子吸收光谱和液闪谱仪,建立了快速分析核电厂液态流出物中⁶³Ni的方法。用本工作建立的方法和GB/T 14502-1993方法比对分析了核电厂的液态流出物样品,化学回收率均高于70%,方法探测下限为0.005 Bq/L,比对结果的E_n值均远小于1,表明该方法的分析结果准确可靠。相比于GB/T 14502-1993方法,本方法操作简单、分离流程短、工作效率高,适用于核电厂液态流出物中⁶³Ni的富集和分离。     

Risk assessment of nuclear power plants

The objective of the present work is to develop recommendations for controlling the safety of nuclear power plants on the basis of risk assessments and safety certification of nuclear power plants. The Kursk nuclear power plant is considered as an example of a nuclear power plant with an RBMK reactor. The concept of risk assessment of a nuclear power plant consists in constructing a set of scenarios of the appearance and development of possible accidents followed by an evaluation of the realization frequency and determination of the scales of the consequences of each one. The result of an analysis is an evaluation of a system of risk indicators in accordance with the requirements of the safety compliance certificate of the nuclear power plant as well as the development of recommendations for increasing plant safety. In risk assessment, the consequences are divided into categories of the seriousness of the damage, for which their probability is evaluated separately. The graphical interpretation of risk due to any dangerous object consists of frequency–consequences curves. Recommendations are developed on the basis of the results of risk analysis.     

基于PSA分析事故序列场内工作人员辐射风险研究

从总风险控制的角度,提出了事故工况下场内工作人员剂量与辐射风险接受准则,并建立了相应的评估方法。以典型压水堆核电厂为例,采用概率安全分析（PSA）的全范围事故序列进行验证评价,评估了典型压水堆核电厂事故后场内工作人员的辐射剂量与辐射致死风险。通过验证结果可知,事故后场内工作人员总的辐射致死风险远低于公众由于自然灾害、疾病、交通事故及不同行业的总死亡风险值;事故后工作人员在燃料厂房进行操作时的辐射致死风险占比最高,故工作人员在燃料厂房进行相关操作时,可提前制定相应的辐射防护措施来降低辐射风险;工作群组中其他人员和意外受照人员事故后辐射致死风险占比较高,可通过采用气面罩等方式对气载放射性进行防护以降低其辐射风险。相应的分析结果可为后续核电厂事故后处理方案的制定和事故后场内工作人员辐射防护措施的制定提供借鉴。      

Summary of Researches on ADS in China

China, as a developing country with a great number of population and relatively less energy resources, reasonably emphasizes the nuclear energy utilization development. To develop nuclear power in large scale, two problems must be solved. First, as we understand the technically and economically exploitable natural uranium resources are limited domestically or overseas, so the uranium utilization rate has to be raised greatly. Second, long-lived radioactive nuclear wastes have to be in disposal to reduce its impact to environment and public fear to nuclear power.     

核电厂辐射监测系统总体结构优化过程及改进方案

核电厂辐射监测系统用于对电厂工艺、流出物及工作场所的辐射监测,确保电厂的安全运行及保护工作人员和周围群众的健康。计算机技术的快速发展,为电厂辐射监测系统实现全数字化创造了条件。从岭澳核电一期、岭澳核电二期到宁德核电,电厂辐射监测系统总体结构发生了巨大的变化。本文针对核电厂辐射监测系统在优化过程中遇到的技术问题及改进方案进行分析讨论。