Dynamics of <Superscript>137</Superscript>Cs bottom contamination of the Tsimlyanskoe reservoir

Analysis of data obtained in 1990 and 2000 on the ¹³⁷Cs contamination of the bottom of the Tsimlyanskoe reservoir near the dam has revealed the salient variations of this contamination. The global fallout enters the water in the section near the dam from side tributaries and as a result of erosion from the closest water catchment areas. The fallout due to the accident at the Chernobyl nuclear power plant is added primarily with the solid runoff from the more highly contaminated catchment basins of the Don River. It is shown that shore abrasion, flows, and removal of sediment through the water outflow area influence the distribution of the ¹³⁷Cs content over the zones and the characteristics of the variation of this distribution in time. __________ Translated from Atomnaya énergiya, Vol. 103, No. 4, pp. 260–263, October, 2007.     

Radiation Accidents: Medical Consequences and Radiation Protection Experience

A generalization of scientific-practical experience with radiation accidents in our country is presented for the example of 175 incidents, three large-scale accidents – Tech River (1949–1952), Mayak combine (1957), the Chernobyl nuclear power plant (1986) – and irradiation of the public as a result of the first nuclear explosion on the Semipalatinsk test area (1949). The medical consequences of these accidents for professional workers and the public are analyzed. It is noted that the most efficient and effective system for organizing medical assistance to the public exposed to accidental irradiation is a differentiated approach to irradiated individuals. The effectiveness of counterradiation protection of people is assessed. Experience gained in this work shows that timely and accurate monitoring of adherence and especially nonadherence to the regulations for accidental and post-accident irradiation of the public and professional workers is one of the most important guarantees for minimizing the consequences of irradiation.     

某核电厂潜在表面污染风险管理探讨

某核电厂采用了国际上比较先进的"EVEREST"进出控制区模式,人员可以穿着普通劳保服进出辐射控制区。为避免或减少辐射控制区内因设备意外泄漏导致的污染扩散和人员沾污,该核电厂控制区采用潜在污染风险管理方式,包括通过分析反应堆回路主要设备的放射性介质包容可靠性以及已发生的污染事件原因,识别潜在污染区域,对控制区进行污染分区,并对潜在污染区和实际污染区设置边界,对进入的人员进行相应的防护。     

基于相依竞争失效模型的主泵多状态可靠性分析

基于核动力主泵运行环境和性能退化机理,考虑自身振动和外部冲击对其性能退化的影响,建立了主泵冲击与退化相依竞争失效过程的可靠度模型。采用该模型计算了考虑性能退化的主泵在振动和外部冲击条件下的退化状态概率和可靠度,为基于使用环境的核动力主泵的多状态可靠性分析提供了一种有效的分析途径。分析结果可为设计变更和维修优化提供决策依据。     

浮动核电站堆舱舷侧与底部辐射分区研究

浮动核电站是驻泊在海上的核动力电厂,主要辐射源集中在堆舱区域。堆舱内部是包容反应堆及一回路系统等辐射源的船舶舱室,堆舱外包括舷侧和船底两大区域。堆舱内部的辐射分区与陆上核电站相似,而堆舱外区域则需要重新考虑,导致在浮动核电站在辐射分区标准选择方面,堆舱内可参考陆上核电站设计方法,但堆舱外区域则缺乏参考标准。本文给出了浮动核电站辐射分区的总体特征,重点研究了影响浮动核电站堆舱外区域辐射分区的制约因素,给出了堆舱舷侧与底部分区设计的解决方案,兼顾了辐射安全、较高辐射区管理成本和经济成本要求,可供工程人员设计参考。     

Was the Chazhma Accident a Chernobyl of the Far East?

The 1985 reactivity accident on a submarine in bukhta Chazhma was accompanied by a substantial emission of fission products and activational radionuclides whose total activity reached 5 MCi. Some specialists have compared this emission to the emission resulting from the 1986 accident in Chernobyl, neglecting the large difference in the radionuclide composition: short-lived products of prompt fission of uranium (with an admixture of activational ⁶⁰Co) in Chazhma and long-lived fission products accumulated over the run of the power reactor with an admixture of short-lived nuclides from the spontaneous excursion of the RBMK-1000 reactor in the Chernobyl nuclear power plant. It is shown that the emission of long-lived radioecologically significant radionuclides in Chazhma was approximately 0.79 Ci, while in the Chernobyl accident this emission was 90 MCi.A quantitative comparison is presented of the activity and radionuclide composition between the accidents in Chazhma and Chernobyl taking account of the fraction of long-lived radionuclides and neglecting the radioactive inert gases. These quantitative estimates are used to show that the Chazhma accident is not analogous to the 1986 accident in Chernobyl.     

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.     

Calculation of the Equivalent Dose Rate Distribution Using Data Obtained with a γ Locator

A method is presented for calculating the equivalent dose rate for the interior spaces in enclosures. The method uses the results of remote measurements, performed with a locator, of radioactive contamination levels. The spectral characteristics of photon radiation are taken into account. The results of a calculation of the equivalent dose rate in the reactor room of the No. 4 unit of the Chernobyl nuclear power plant, which are based on measurements performed in the fall of 1996, are presented as an example.     

Particulars of radiolysis and mass transfer in two-phase water coolant of a nuclear power facility with steam generation at an interphase surface

A model of an interphase transfer of stable products of the radiolysis of water in boiling coolant is developed taking account of the intensity of their delivery to the interphase boundary in the liquid phase and removal into the vapor phase with vapor generation on the interphase surface. A computational study is made of the radiolysis of the coolant and interphase transfer of the products of the radiolysis of water in the core and on the pulling section of BWR of the Oskarshamn-2 nuclear power plant in Sweden. A comparison of the computational data with the results of the technical measurements of the coolant composition of the BWR at the Oskarshamn-2 nuclear power plant showed that the accumulation of stable products of the radiolysis of water in the vapor-gas phase of the coolant is determined by the kinetics of radiolysis in the liquid phase, the concentration of the oxygen-containing components in the liquid phase is due to the present of hydrogen peroxide in it.     

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。      

Method for liquidating the consequences of the chernobyl accident

Conclusions The proposed method is a safe, technically feasible, and economically acceptable solution to the problem of liquidating the focus of the environmental contamination at the Chernobyl nuclear power plant. The radioactive substances, materials, and objects will be removed from “Cover” and imperfect storage sites within the 100-km zone around the Chernobyl nuclear power plant and placed in storage sites which meet modern requirements. The storage of the wastes will be controllable and monitorable. The object “Cover” will be liquidated. Main Scientific Center of the Russian Federation — Physics and Power Engineering Institute. Translated from Atomnaya énergiya, Vol. 78, No. 3, pp. 214–217, March, 1995.     

压水堆核电厂辐射监测系统的设计与改造

辐射监测系统是压水堆核电厂安全运行的重要保障,研究压水堆核电厂辐射监测系统的设计方法和原则,对于提高压水堆核电厂辐射监测系统的设计水平,减少改造风险至关重要.根据核电厂的法规和设计规范,结合大亚湾核电厂辐射监测系统的设计与改造经验,提出了压水堆核电厂辐射监测系统的一般设计原则和要求,并简要介绍了大亚湾核电厂辐射监测系统...     

当前我国核电站辐射防护需要重点考虑和解决的问题

本文根据大亚湾核电站运行辐射防护的工作实践和遇到的困难与问题 ,提出了我国在辐射防护领域急需解决的管理标准化和规范化、在现场辐射防护实践中处理好辐射安全与核电生产和效益的关系 ,以及实现辐射监测设备和防护用品国产化等三个问题 ,并提出一些建议     

BINELOCA 程序与广东岭澳核电站大破口失水事故分析

ＢＩＮＥＬＯＣＡ程序是在吸收国外先进大破口失水事故分析计算机程序的基础上，针对我国现有大破口失水事故分析程序的不足和工程应用方面的问题，采用了一些成熟的、新型的和当今国际公认的瞬态热工水力数学物理模型以及水和蒸汽性质参数计算公式改编而成的大破口失水事故分析程序。通过对广东岭澳核电站大破口失水事故的计算表明，ＢＩＮＥＬＯＣＡ程序计算的结果与法国计算的结果是一致的。     

Mathematical Simulation and Analysis of the Behavior of Radionuclides in the System Krasnoyarsk Integrated Mining and Chemical Plant–Enisei–Kara Sea

The equations describing the transport of radionuclides in a system consisting of river water with a suspension and bottom deposits, taking account of the influx of radionuclides with the discharges from the plant and runoff from the basin area, are formulated. The coefficients in the equations are determined by analyzing the data from measurements. On this basis, the flood-plain deposits are dated and the time dependence of the radionuclide discharges over the entire period of operation of plant is determined and the concentration in water and bottom deposits is calculated. The balances between the discharge, the runoff from the basin area, and influx into the bottom deposits, the floodplain, and the Kara Sea are constructed for the past. A procedure is developed for estimating the outflow of mobile forms of radionuclides from the bottom deposits after a sharp decrease of discharges in 1992. The rate of self-purification of the river basin in the future is estimated taking account of this effect and the redistribution of radionuclides between the bottom and flood-plain deposits.     

Social-Economic Aspects of Radiation Safety

Among the many scientific, technical, and social problems which nuclear power in the past century has encountered, the most significant are economy, safety, and public acceptability.The possibilities of increasing the economic efficiency by using boiling water vessel reactors with natural coolant circulation, the need to take account of not only the dose but radiation intensity when estimating biological effects of irradiation, and the problems of insurance for compensating radiation harm to the health of workers in nuclear cycle enterprises and the population are discussed. 2 figures, 17 references.     

Tugsim-10, a computer code for transient analysis of closed gas turbine cycles and specific applications

A code has been developed to compute the kinetic and thermohydraulic transients in a nuclear gas turbine power plant for both operational and accidental conditions. A depressurization accident analysis demonstrates the performance of the code and shows how the core may be cooled by coolant circulation through the turbomachinery, using the afterheat to drive the gas turbine. Emergency shut-down calculations for a 30 MW(e) fossil fuel plant are compared with measurements.     

Experimental validation of the cooling loop for a passive system for removing heat from the AES-2006 protective envelope design for the Leningradskaya nuclear power plant site

Equipping new-generation nuclear power plants with passive means for controlling unanticipated accidents is one of the most promising directions for increasing safety, which is being implemented in the AES-2006 design for the site of the Leningradskaya nuclear power plant. An urgent problem is to obtain experimental validation of the passive system for removing heat from the protective envelope during unanticipated accidents with loss of coolant from the first loop in the case where the active systems fail. A particularity of the system is its state of constant readiness. The system functions with natural circulation of the coolant in both loops. Considering the importance of the passive heat removal system for ensuring the localizing properties of the protective envelope, OKBM Afrikantov has developed a large-scale stand and performed experimental investigations on validation of the effectiveness and serviceability of the cooling loop of a passive system for removing heat from the protective envelope. Translated from Atomnaya énergiya, Vol. 106, No. 3, pp. 148–152, March, 2009.     

Computational Estimates of the Radiation Characteristics of Irradiated Graphite after Final Shutdown of a Nuclear Power Plant with an RBMK Reactor

A method of calculating the radiation characteristics of irradiated graphite masonry of an RBMK reactor is described. The MCNP computer code is used to determine the spatial distribution of the neutron flux density in the interior volume of the graphite, the CHAIN code is used to determine the isotopic composition and the radition characteristics of the irradiated graphite on the basis of the MCNP fluxes.The results of the calculation of the radiation characteristics of graphite from the reactors in the Nos. 2 and 3 units of the Leningrad nuclear power plant and the No. 1 unit of the Chernobyl nuclear power plant are presented and the contribution made by the accident to the flow of fuel mass into the masonry is estimated.     

The causes and consequences of the Chernobyl nuclear accident and implications for the regulation of U.S. nuclear power plants

As in the case of the TMI accident public concern around the world over nuclear safety has been aroused by the Chernobyl nuclear accident. Because of its severity and enormous impact on public opinion, it is important to study the accident and its implications carefully and to provide accurate information to the public.Since this was the first nuclear accident with large offsite releases of radionuclides, valuable insights are to be gained especially, for example, from Soviet actions to terminate the accident and mitigate its consequences, emergency preparedness and evacuation measures, medical treatment, protection against contaminated food and water supplies, and a variety of post-accident recovery measures.With the perspective of a year since the accident and a recent visit by the Author to Chernobyl with a U.S. nuclear safety delegation this paper reviews a number of new studies to draw conclusions about the causes of the Chernobyl accident, its health and environmental consequences and some of the implications for regulation of the safety of U.S. nuclear power plants.