Sample records for rbmk mekhanizmy povrezhdeniya

  1. Thermophysical Reactivity Control of RBMK-1000

    Vorobiev Aleksander V.


    Full Text Available In this paper, viewed thermophysical characteristics of the moderator water graphite reactor RBMK. Indicated possibilities of controlling thermal state of graphite stack by regulation composition of the purge gas. Presents experimental results, but static thermal state characteristics of graphite moderator RBMK-1000. Developed a software code for integral characteristic engineering calculations, that determine value of margin reactivity reactor RBMK-1000, in the slow transients.

  2. Reactor Bolshoi Moshchnosti Kalani; Reacteurs RBMK

    Bastien, D. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)


    The Reactor Bolshoi Molshchnosti Kalani (RBMK) are pressure tubes reactor, boiling light water cooled. Exported since 1990 from the ex-USSR, they are today in three independent countries: Russian, Ukraine and Lithuania. Since this date, data exchange with the occident allowed the better knowledge of this reactor type. The design, the technical description (core, fuel, primary system), the safety and the improvement since Chernobyl are detailed. (A.L.B.)

  3. Deterministic Safety Technology for RBMK Reactors

    F. D'Auria


    The paper summarizes the activities performed at NIKIET in Moscow and at University of Pisa (UNIPI in Pisa. A top-down approach is pursued in structuring the executive summary that includes the following sections: (i the safety needed for the RBMK NPP, (ii the roadmap, (iii\tthe adopted computational tools, (iv\tkey findings, (v\tEmphasis is given to the multiple pressure tube rupture (MPTR issue and the individual channel monitoring (ICM proposal.

  4. RBMK-LOCA-Analyses with the ATHLET-Code

    Petry, A. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH Kurfuerstendamm, Berlin (Germany); Domoradov, A.; Finjakin, A. [Research and Development Institute of Power Engineering, Moscow (Russian Federation)


    The scientific technical cooperation between Germany and Russia includes the area of adaptation of several German codes for the Russian-designed RBMK-reactor. One point of this cooperation is the adaptation of the Thermal-Hydraulic code ATHLET (Analyses of the Thermal-Hydraulics of LEaks and Transients), for RBMK-specific safety problems. This paper contains a short description of a RBMK-1000 reactor circuit. Furthermore, the main features of the thermal-hydraulic code ATHLET are presented. The main assumptions for the ATHLET-RBMK model are discussed. As an example for the application, the results of test calculations concerning a guillotine type rupture of a distribution group header are presented and discussed, and the general analysis conditions are described. A comparison with corresponding RELAP-calculations is given. This paper gives an overview on some problems posed and experience by application of Western best-estimate codes for RBMK-calculations.

  5. Water chemistry at RBMK plants: Problems and solutions

    Mamet, V.; Yurmanov, V. [VNIIAES (Russian Federation)


    After around 15 years of operation RBMK-1000 units undergo a major refit, which includes safety system upgrading, fuel tube replacement, etc. The above upgrading has created problems for water chemistry. In particular, in late 80's in-core insertion time of the portion of control rods was reduced 10-fold thanks to a transfer from water to filming cooling of scram channels. Scram channels are cooled with inner surface water film cooling and nitrogen is injected into heads via special pipelines. Such cooling system modernization ensures fast insertion of absorber rods. The above upgrade intensified nitric acid radiolytic generation in water coolant and pH{sub 25} value shift to acid conditions (up to 4.5). The results of corrosion tests in such conditions proved the necessity to improve water chemistry to ensure corrosion protection of scram/control rod and circuit components, especially those made out of aluminium alloy. Since 1990 the new revision of the RBMK-1000 water chemistry standard specified the new normal operational limit and action levels for possible temporary deviations of pH{sub 25} value. RBMK plant specific measures were implemented at RBMK plants to meet the above requirements of the 1990 revision of the RBMK-1000 water chemistry standard. Clean-up systems of the above circuit were upgraded to ensure intensive absorption of nitric acid from water and pH{sub 25} maintenance in a slightly acid area. (authors)

  6. Problems in experimental and mathematical investigations of the accidental thermalhydraulic processes in RBMK nuclear reactors

    Nigmatulin, B.I.; Tikhonenko, L.K. [Engineering Centre (EREC) for Nuclear Plants Safety, Electrogorsk (Russian Federation); Blinkov, V.N. [Aviation Institute, Kharkov (Ukraine)] [and others


    In this paper the thermalhydraulic scheme and peculiarities of the boiling water graphite-moderated channel-type reactor RBMK are presented and discussed shortly. The essential for RBMK transient regimes, accidental situations and accompanying thermalhydraulic phenomena and processes are formulated. These data are presented in the form of cross reference matrix (version 1) for system computer codes verification. The paper includes qualitative analysis of the computer codes and integral facilities which have been used or can be used for RBMK transients and accidents investigations. The stability margins for RBMK-1000 and RBMK-1500 are shown.

  7. Actinides in irradiated graphite of RBMK-1500 reactor

    Plukienė, R., E-mail:; Plukis, A.; Barkauskas, V.; Gudelis, A.; Gvozdaitė, R.; Duškesas, G.; Remeikis, V.


    Highlights: • Activation of actinides in the graphite of the RBMK-1500 reactor was analyzed. • Numerical modeling using SCALE 6.1 and MCNPX was used for actinide calculation. • Measurements of the irradiated graphite sample were used for model validation. • Results are important for further decommissioning process of the RBMK type reactors. - Abstract: The activation of graphite in the nuclear power plants is the problem of high importance related with later graphite reprocessing or disposal. The activation of actinide impurities in graphite due to their toxicity determines a particular long term risk to waste management. In this work the activation of actinides in the graphite constructions of the RBMK-1500 reactor is determined by nuclear spectrometry measurements of the irradiated graphite sample from the Ignalina NPP Unit I and by means of numerical modeling using two independent codes SCALE 6.1 (using TRITON-VI sequence) and MCNPX (v2.7 with CINDER). Both models take into account the 3D RBMK-1500 reactor core fragment with explicit graphite construction including a stack and a sleeve but with a different simplification level concerning surrounding graphite and construction of control roads. The verification of the model has been performed by comparing calculated and measured isotope ratios of actinides. Also good prediction capabilities of the actinide activation in the irradiated graphite have been found for both calculation approaches. The initial U impurity concentration in the graphite model has been adjusted taking into account the experimental results. The specific activities of actinides in the irradiated RBMK-1500 graphite constructions have been obtained and differences between numerical simulation results, different structural parts (sleeve and stack) as well as comparison with previous results (Ancius et al., 2005) have been discussed. The obtained results are important for further decommissioning process of the Ignalina NPP and other RBMK

  8. Analysis of flow blockage of a single RBMK channel

    Franco Pierro; Iljiana Ivekovic; Parisi Carlo; Francesco D' Auria [University of Pisa, Department of Mechanical, Nuclear and Production Engineering - DMNP, Via Diotisalvi 2, 56122 Pisa (Italy)


    Full text of publication follows: The main aim of the following study is to perform an evaluation of a single RBMK reactor core channel and of its surrounding graphite structures in case of flow blockage. The paper presents an evaluation of the event with RELAP5 and FRAP code. The RBMK channel, the graphite stack and the He-N gap is modelled with the RELAP code and the thermo-mechanical fuel rod behaviour is studied by FRAP code. Two cases are analysed in order to demonstrate if the propagation of the break occurs: in the first case a single break in the pressure tube is postulated, in the second, a modelling of the pressure tube break propagation is studied. A blockage of 100% of the total flow area is considered. The paper concludes that the Pressure tube is broken and the propagation occurs, the ballooning does not appear. (authors)

  9. State of the Art of the Ignalina RBMK-1500 Safety

    E. Ušpuras


    Full Text Available Ignalina NPP is the only nuclear power plant in Lithuania consisting of two units, commissioned in 1983 and 1987. Unit 1 of Ignalina NPP was shut down for decommissioning at the end of 2004 and Unit 2 is to be operated until the end of 2009. Both units are equipped with channel-type graphite-moderated boiling water reactors RBMK-1500. The paper summarizing the results of deterministic and probabilistic analyses is developed within 1991–2007 by specialists from Lithuanian Energy Institute. The main operational safety aspects, including analyses performed according the Ignalina Safety Improvement Programs, development and installation of the Second Shutdown System and Guidelines on Severe Accidents Management are discussed. Also the phenomena related to the closure of the gap between fuel channel and graphite bricks, multiple fuel channel tube rupture, and containment issues as well as implication of the external events to the Ignalina NPP safety are discussed separately.

  10. Evaluation of Heat Removal from RBMK-1500 Core Using Control Rods Cooling Circuit

    A. Kaliatka


    Full Text Available The Ignalina nuclear power plant is a twin unit with two RBMK-1500, graphite moderated, boiling water, multichannel reactors. After the decision was made to decommission the Ignalina NPP, Unit 1 was shut down on December 31, 2004, and Unit 2 is to be operated until the end of 2009. Despite of this fact, severe accident management guidelines for RBMK-1500 reactor at Ignalina NPP are prepared. In case of beyond design basis accidents, it can occur that no water sources are available at the moment for heat removal from fuel channels. Specificity of RBMK reactor is such that the channels with control rods are cooled with water supplied by the system totally independent from the reactor cooling system. Therefore, the heat removal from RBMK-1500 reactor core using circuit for cooling of rods in control and protection system can be used as nonregular mean for reactor cooldown in case of BDBA. The heat from fuel channels, where heat is generated, through graphite bricks is transferred in radial direction to cooled CPS channels. This article presents the analysis of possibility to remove heat from reactor core in case of large LOCA by employing CPS channels cooling circuit. The analysis was performed for Ignalina NPP with RBMK-1500 reactor using RELAP5-3D and RELAP5 codes. Results of the analysis have shown that, in spite of high thermal inertia of graphite, this heat removal from CPS channels allows to slow down effectively the core heat-up process.

  11. RELAP5-3D multidimensional heat conduction enclosure model for RBMK reactor application

    Paik, S.


    A heat conduction enclosure model is conceived and implemented by RELAP5-3D between heat structures. The suggested model uses a lumped parameter model that is generally applicable to multidimensional calculational domain. This new model is applied to calculation of RBMK reactor core graphite blocks and is compared to the commercially available Fluid Dynamics Analysis Package (FIDAP) finite element code. Reasonably good agreement between the results of RELAP5-3D and FIDAP is obtained. The new heat conduction enclosure model gives RELAP5-3D a general multidimensional heat conduction capability. It also provides new routes for temperature cooloff of the RBMK graphite blocks from the ruptured channel to the surrounding ones. This ability to predict graphite temperature cooloff is very important during accidents or for transient simulation, especially concerning long-term coolability of the RBMK reactor core.

  12. Calculation of the Thermal State of the Graphite Moderator of the RBMK Reactor

    Vorobiev Alexander V.


    Full Text Available This work is devoted to study the temperature field of the graphite stack of the RBMK reactor. In work was analyzed the influence of contact pressure between the components of the masonry on the temperature of the graphite moderator.

  13. Determining safety criteria for reinforced concrete structures of power plants taking the example of a nuclear power plant with RBMK

    Nikolayev Valery


    Full Text Available The paper shows how safety criteria of nuclear power plants with reactor RBMK can be defined based on analytical, numerical and mixed calculation methods using data about strength characteristics of materials with the course of time.

  14. Study of possibility using LANL PSA-methodology for accident probability RBMK researches

    Petrin, S.V.; Yuferev, V.Y.; Zlobin, A.M.


    The reactor facility probabilistic safety analysis methodologies are considered which are used at U.S. LANL and RF NIKIET. The methodologies are compared in order to reveal their similarity and differences, determine possibilities of using the LANL technique for RBMK type reactor safety analysis. It is found that at the PSA-1 level the methodologies practically do not differ. At LANL the PHA, HAZOP hazards analysis methods are used for more complete specification of the accounted initial event list which can be also useful at performance of PSA for RBMK. Exchange of information regarding the methodology of detection of dependent faults and consideration of human factor impact on reactor safety is reasonable. It is accepted as useful to make a comparative study result analysis for test problems or PSA fragments using various computer programs employed at NIKIET and LANL.

  15. Actinides input to the dose in the irradiated graphite of RBMK-1500 reactor

    Plukienė, R., E-mail: [Institute of Physics, Center for Physical Sciences and Technology, Savanorių pr. 231, LT-02300 Vilnius (Lithuania); Plukis, A.; Puzas, A.; Gvozdaitė, R.; Barkauskas, V.; Duškesas, G. [Institute of Physics, Center for Physical Sciences and Technology, Savanorių pr. 231, LT-02300 Vilnius (Lithuania); Cizdziel, J.V.; Bussan, D. [University of Mississippi, Department of Chemistry and Biochemistry, 305 Coulter Hall, University, Oxford, MS 38677 (United States); Remeikis, V. [Institute of Physics, Center for Physical Sciences and Technology, Savanorių pr. 231, LT-02300 Vilnius (Lithuania)


    Highlights: • Actinides input to the dose in RBMK-1500 reactor graphite was estimated. • SCALE 6.1 and MCNPX models were used to calculate actinides specific activities. • ORIGEN-ARP was used for gamma power, neutron source and effective dose calculation. • Concentrations of Pu, Am and Cm isotopes in the RBMK graphite sample were measured. • {sup 244}Cm was found to be a critical contributor to effective dose of the personnel. - Abstract: The purpose of this work is to indicate the actinides input to the total radiation dose caused by the irradiated graphite of the RBMK-1500 reactor in comparison to the dose delivered by other nuclides. We used computer codes (SCALE 6.1 and MCNPX 2.7) to estimate the dose rate delivered by actinides giving special attention to the {sup 244}Cm isotope as a critical contributor to the total activity of actinides in the spent graphite for approximately up to 200 years. The concentrations of Pu, Am and Cm isotopes in the graphite sample from the Ignalina Nuclear Power Plant (NPP) Unit 1 have been measured with the inductively coupled plasma mass spectrometer and specific isotope ratios have been compared with alpha spectrometric results as well as with the values simulated by the computer codes. Good agreement of the experimental results and the simulated ratios serves as an additional confirmation of validity of the calculation models. The effective doses rates of inhalation and ingestion for personnel, gamma radiation power, and nuclides, which constitute the neutron source in the irradiated RBMK-1500 graphite constructions, have also been identified. The obtained results are important for decommissioning of the Ignalina NPP and other NPPs with graphite-moderated reactors.

  16. Effect of eccentric location of the RBMK CPS displacer graphite block in the shielding sheath

    Dostov, A.I. [Russian Research Centre ' ' Kurchatov Institute' ' (Russian Federation)


    Temperature conditions and accumulation of Wigner energy in the graphite block of the RBMK reactor CPS (control power system) displacer is examined. It is shown, that at eccentric location of the block in the shielding sheath average temperature of the block drops sharply. Due to the design demerit quantity of the stored energy in the block may be so great, that its release will result in melting of the displacer tube. (author)

  17. Validation of coupled Relap5-3D code in the analysis of RBMK-1500 specific transients

    Evaldas, Bubelis; Algirdas, Kaliatka; Eugenijus, Uspuras [Lithuanian Energy Institute, Kaunas (Lithuania)


    This paper deals with the modelling of RBMK-1500 specific transients taking place at Ignalina NPP. These transients include: measurements of void and fast power reactivity coefficients, change of graphite cooling conditions and reactor power reduction transients. The simulation of these transients was performed using RELAP5-3D code model of RBMK-1500 reactor. At the Ignalina NPP void and fast power reactivity coefficients are measured on a regular basis and, based on the total reactor power, reactivity, control and protection system control rods positions and the main circulation circuit parameter changes during the experiments, the actual values of these reactivity coefficients are determined. Graphite temperature reactivity coefficient at the plant is determined by changing graphite cooling conditions in the reactor cavity. This type of transient is very unique and important from the gap between fuel channel and the graphite bricks model validation point of view. The measurement results, obtained during this transient, allowed to determine the thermal conductivity coefficient for this gap and to validate the graphite temperature reactivity feedback model. Reactor power reduction is a regular operation procedure during the entire lifetime of the reactor. In all cases it starts by either a scram or a power reduction signal activation by the reactor control and protection system or by an operator. The obtained calculation results demonstrate reasonable agreement with Ignalina NPP measured data. Behaviours of the separate MCC thermal-hydraulic parameters as well as physical processes are predicted reasonably well to the real processes, occurring in the primary circuit of RBMK-1500 reactor. Reasonable agreement of the measured and the calculated total reactor power change in time demonstrates the correct modelling of the neutronic processes taking place in RBMK- 1500 reactor core. And finally, the performed validation of RELAP5-3D model of Ignalina NPP RBMK-1500

  18. Measurements of control rod efficiency in RBMK critical assembly upon dropping of the rods

    Zhitarev, V. E., E-mail:; Kachanov, V. M.; Sergevnin, A. Yu.; Lebedev, G. V., E-mail: [National Research Center Kurchatov Institute (Russian Federation)


    The efficiency of control rods in the RBMK critical assembly was measured in the case where one manual-control rod (MCR) is dropped from a steady critical state, and several other MCRs were additionally dropped after 44 s. The measured number of neutrons in the assembly during and after dropping of the rods was used to calculate the efficiency values of the rods by solution of the system of point kinetics equations. A series of methods of the initial data treatment for determination of the desired values of reactivity without the calculated corrections were used.

  19. Measurements of control rod efficiency in RBMK critical assembly upon dropping of the rods

    Zhitarev, V. E.; Kachanov, V. M.; Sergevnin, A. Yu.; Lebedev, G. V.


    The efficiency of control rods in the RBMK critical assembly was measured in the case where one manual-control rod (MCR) is dropped from a steady critical state, and several other MCRs were additionally dropped after 44 s. The measured number of neutrons in the assembly during and after dropping of the rods was used to calculate the efficiency values of the rods by solution of the system of point kinetics equations. A series of methods of the initial data treatment for determination of the desired values of reactivity without the calculated corrections were used.

  20. Development of RBMK-1500 Model for BDBA Analysis Using RELAP/SCDAPSIM Code

    Uspuras, Eugenijus; Kaliatka, Algirdas

    This article discusses the specificity of RBMK (channel type, boiling water, graphite moderated) reactors and problems of Reactor Cooling System modelling employing computer codes. The article presents, how the RELAP/SCDAPSIM code, which is originally designed for modelling of accidents in vessel type reactors, is fit to simulate the phenomena in the RBMK reactor core and RCS in case of Beyond Design Basis Accidents. For this reason, use of two RELAP/SCDAPSIM models is recommended. First model with described complete geometry of RCS is recommended for analysis of initial phase of accident. The calculations results, received using this model, are used as boundary conditions in simplified model for simulation of later phases of severe accidents. The simplified model was tested comparing results of simulation performed using RELAP5 and RELAP/SCDAPSIM codes. As the typical example of BDBA, large break LOCA in reactor cooling system with failure of emergency core cooling system was analyzed. Use of developed models allows to receive behaviour of thermal-hydraulic parameters, temperatures of core components, amount of generated hydrogen due to steam-zirconium reaction. These parameters will be used as input for other special codes, designed for analysis of processes in reactor containment.

  1. Application of 3D coupled code ATHLET-QUABOX/CUBBOX for RBMK-1000 transients after graphite block modernization

    Samokhin, Aleksei [Scientific and Engineering Centre for Nuclear and Radiation Safety (SEC NRS), Moscow (Russian Federation); Zilly, Matias [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Garching (Germany)


    This work describes the application and the results of transient calculations for the RBMK-1000 with the coupled code system ATHLET 2.2A-QUABOX/CUBBOX which was developed in GRS. Within these studies the planned modernization of the graphite blocks of the RBMK-1000 reactor is taken into account. During the long-term operation of the uranium-graphite reactors RBMK-1000, a change of physical and mechanical properties of the reactor graphite blocks is observed due to the impact of radiation and temperature effects. These have led to a deformation of the reactor graphite columns and, as a result, a deformation of the control and protection system (CPS) and of fuel channels. Potentially, this deformation can lead to problems affecting the smooth movement of the control rods in the CPS channels and problems during the loading and unloading of fuel assemblies. The present paper analyzes two reactivity insertion transients, each taking into account three graphite removal scenarios. The presented work is directly connected with the modernization program of the RBMK- 1000 reactors and has an important contribution to the assessment of the safety-relevant parameters after the modification of the core graphite blocks.

  2. Extending the features of RBMK refuelling machine simulator with a training tool based on virtual reality

    Khoudiakov, M.; Slonimsky, V.; Mitrofanov, S. (and others)


    The paper describes a continuation of efforts of an international Russian - Norwegian joint team to improve operational safety during the refuelling process of an RBMK-type reactor by implementing a training simulator based on an innovative Virtual Reality (VR) approach. During the preceding 1st stage of the project a display-based simulator was extended with VR models of the real Refuelling Machine (RM) and its environment in order to improve both the learning process and operation's effectiveness. The simulator's challenge is to support the performance (operational activity) of RM operational staff firstly by helping them to develop basic knowledge and skills as well as to keep skilled staff in close touch with the complex machinery of the Refuelling Machine. During the 2nd stage of the joint project the functional scope of the VR-simulator was greatly enhanced - firstly, by connecting to the RBMK-unit full-scope simulator, and, secondly, by including a training program and simulator model upgrade. The present 3rd stage of the Project is primarily oriented towards the improvement of the training process for maintenance and operational personnel by means of a development of the Training Support Methodology and Courses (TSMC) to be based on Virtual Reality and enlarged functionality of 3D and process modelling. The TMSC development is based on Russian and International Regulatory Bodies requirements and recommendations. Design, development and creation of a specialised VR-based Training System for RM Maintenance Personnel are very important for the Russian RBMK plants. The main goal is to create a powerful, autonomous VR-based simulator for training technical maintenance personnel on the Refuelling Machine. VR based training is expected to improve the effect of training compared to the current training based on traditional methods using printed documentation. The LNPP management and the Regulatory Bodies supported this goal. The VR-based Training System

  3. Heat transfer in the core graphite structures of RBMK nuclear power plants

    Knoglinger, E., E-mail: [Am Winklerwald 15, A 4020 Linz (Austria); Wölfl, H., E-mail: [Berg, Im Weideland 19, A 4060 Linz (Austria); Kaliatka, A., E-mail: [Laboratory of Nuclear Installation Safety, Lithuanian Energy Institute, Breslaujos 3, LT-44403 Kaunas (Lithuania)


    Highlights: • Proposed solution of heat transfer model from a hollow cylinder to a fluid through narrow duct. • Thermal conductance of annular gaps, filled by two component gas was discussed. • Xenon transient preceding the Chernobyl Accident was analyzed. • Reactivity balance during power manoeuvres and potenrial causes of the accident were discussed. - Abstract: Conductive and combined radiative/conductive gap conductance models are presented and discussed in great detail. The heat resistance concept and an exact solution to the one dimensional heat conduction equation for a 3-region composite hollow cylinder are used to calculate gap conductance in function of gap gas composition and fuel burn up. The study includes the back calculation of a reactor experiment performed at the Ignalina NPP Unit-1 which provides some insight in the function of the RBMK nitrogen supply and regulating device and an investigation of the role the graphite temperature played during the power manoeuvres preceding the Chernobyl Accident.

  4. Development of thermal hydraulic models for main circulation circuit of RBMK-1500 reactor using Apros and Cathare 2 codes

    Zemulis, G.; Jasiulevicius, A. [Kaunas University of Technology, Dept. of Thermal and Nuclear Energy, Kaunas, (Lithuania)


    Reactor safety is the most important issue in nuclear engineering. It concerns the capability of the nuclear object to withhold the main safety and reliability criterion within specified range during both normal operation and transient conditions. Three types of assessment are to be performed in order to establish the nuclear power plant safety level: neutronic calculations; thermal hydraulic calculations; mechanical design calculations. Calculations of the thermal hydraulic parameters of the RBMK-1500 reactor main circulation circuit (MCC) are presented in this paper. The aim of this work was to test the capability of the APROS code to simulate the behavior of the RBMK-1500 type reactor main circulation circuit during normal operation and transients. (author)

  5. Numerical modeling of radioactive neutron capture influence of Hf isotopic composition dynamics rate in the RBMK-1500 reactor

    Jurkevicius, A; Auzelyte, V; Remeikis, V


    The nuclide composition of the nuclear fuel and isotopic composition of the hafnium in the radial neutron flux detectors of the RBMK-1500 reactor were numerically modelled. The sequence SAS2 from package SCALE 4.3 was used for calculations. The nuclear fuel nuclide concentrations, the concentration of Hf isotopes, the neutron absorption rate on Hf isotopes and summary absorption rate dependences on the fuel assembly burn up are presented. (author)

  6. Actinide-only and full burn-up credit in criticality assessment of RBMK-1500 spent nuclear fuel storage cask using axial burn-up profile

    Barkauskas, V., E-mail:; Plukiene, R., E-mail:; Plukis, A., E-mail:


    Highlights: • RBMK-1500 fuel burn-up impact on k{sub eff} in the SNF cask was calculated using SCALE 6.1. • Positive end effect was noticed at certain burn-up for the RBMK-1500 spent nuclear fuel. • The non-uniform uranium depletion is responsible for the end effect in RBMK-1500 SNF. • k{sub eff} in the SNF cask does not exceed a value of 0.95 which is set in the safety requirements. - Abstract: Safe long-term storage of spent nuclear fuel (SNF) is one of the main issues in the field of nuclear safety. Burn-up credit application in criticality analysis of SNF reduces conservatism of usually used fresh fuel assumption and implies a positive economic impact for the SNF storage. Criticality calculations of spent nuclear fuel in the CONSTOR® RBMK-1500/M2 cask were performed using pre-generated ORIGEN-ARP spent nuclear fuel composition libraries, and the results of the RBMK-1500 burn-up credit impact on the effective neutron multiplication factor (k{sub eff}) have been obtained and are presented in the paper. SCALE 6.1 code package with the STARBUCKS burn-up credit evaluation tool was used for modeling. Pre-generated ARP (Automatic Rapid Processing) crosssection libraries based on ENDF/B-VII cross section library were used for fast burn-up inventory modeling. Different conditions in the SNF cask were modeled: 2.0% and 2.8% initial enrichment fuel of various burn-up and water density inside cavities of the SNF cask. The fuel composition for the criticality analysis was chosen taking into account main actinides and most important fission products used in burn-up calculations. A significant positive end effect is noticed from 15 GWd/tU burn-up for 2.8% enrichment fuel and from 9 GWd/tU for 2.0% enrichment fuel applying the actinide-only approach. The obtained results may be applied in further evaluations of the RBMK type reactor SNF storage as well as help to optimize the SNF storage volume inside the CONSTOR® RBMK-1500/M2 cask without compromising criticality

  7. Measuring the efficiency of control rods in the RBMK critical assembly using a model of RKI-1 reactimeter

    Zhitarev, V. E.; Lebedev, G. V.; Sergevnin, A. Yu.


    The efficiency of control rods of the RBMK critical assembly is measured in a series of experiments. The aim of measurements is to determine the characteristics of the model of an RKI-1 reactimeter. The RKI-1 reactimeter is intended for measuring the efficiency of control rods when, according to conditions of operation, the metrological certification of results of an experiment is required. Complications with the metrological certification of reactimeters arise owing to the fact that usually calculated corrections to the results of measurements are required. When the RKI-1 reactimeter is used, there is no need to introduce calculated corrections; the result of measurements is given with the indication of substantiated errors. In connection with this, the metrological certification of the results of measurements using the RKI-1 reactimeter is simplified.

  8. Modeling of the Radiation Doses during Dismantling of RBMK-1500 Reactor Pressurized Tanks from Emergency Core Cooling System

    A. Simonis


    Full Text Available Decommissioning of the Ignalina Nuclear Power Plant involves multiple problems. One of them is personnel radiation safety during the performance of dismantling activities. In this paper, modeling results of radiation doses during the dismantling of the pressurized tank from the emergency core cooling system (ECCS PT of RBMK-1500 reactor are presented. The radiological surveys indicate that the inner surface of the ECCS PT is contaminated with radioactive products of corrosion and sediments due to the radioactive water. The effective doses to the workers have been modeled for different strategies of ECCS PT dismantling. In order to select the optimal personnel radiation safety, the modeling has been performed by the means of computer code “VISIPLAN 3D ALARA Planning tool” developed by SCK CEN (Belgium. The impacts of dismantling tools, shielding types, and extract ventilation flow rate on effective doses during the dismantling of ECCS PT have been analyzed. The total effective personnel doses have been obtained by summarizing the effective personnel doses from various sources of exposure, that is, direct radiation from radioactive equipment, internal radiation due to inhalation of radioactive aerosols, and direct radiation from radioactive aerosols arising during hot cutting in premises. The uncertainty of the collective doses is also presented in this paper.

  9. Joint US/Russian study on the development of a decommissioning strategy plan for RBMK-1000 unit No. 1 at the Leningrad Nuclear Power Plant



    The objective of this joint U.S./Russian study was to develop a safe, technically feasible, economically acceptable strategy for decommissioning Leningrad Nuclear Power Plant (LNPP) Unit No. 1 as a representative first-generation RBMK-1000 reactor. The ultimate goal in developing the decommissioning strategy was to select the most suitable decommissioning alternative and end state, taking into account the socioeconomic conditions, the regulatory environment, and decommissioning experience in Russia. This study was performed by a group of Russian and American experts led by Kurchatov Institute for the Russian efforts and by the Pacific Northwest National Laboratory for the U.S. efforts and for the overall project.

  10. Joint US/Russian study on the development of a decommissioning strategy plan for RBMK-1000 unit No. 1 at the Leningrad Nuclear Power Plant



    The objective of this joint U.S./Russian study was to develop a safe, technically feasible, economically acceptable strategy for decommissioning Leningrad Nuclear Power Plant (LNPP) Unit No. 1 as a representative first-generation RBMK-1000 reactor. The ultimate goal in developing the decommissioning strategy was to select the most suitable decommissioning alternative and end state, taking into account the socioeconomic conditions, the regulatory environment, and decommissioning experience in Russia. This study was performed by a group of Russian and American experts led by Kurchatov Institute for the Russian efforts and by the Pacific Northwest National Laboratory for the U.S. efforts and for the overall project.

  11. Effect of nonlinear void reactivity on bifurcation characteristics of a lumped-parameter model of a BWR: A study relevant to RBMK

    Verma, Dinkar, E-mail: [Nuclear Engineering and Technology Program, Indian Institute of Technology Kanpur, Kanpur 208 016 (India); Kalra, Manjeet Singh, E-mail: [DIT University, Dehradun 248 009 (India); Wahi, Pankaj, E-mail: [Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)


    Highlights: • A simplified model with nonlinear void reactivity feedback is studied. • Method of multiple scales for nonlinear analysis and oscillation characteristics. • Second order void reactivity dominates in determining system dynamics. • Opposing signs of linear and quadratic void reactivity enhances global safety. - Abstract: In the present work, the effect of nonlinear void reactivity on the dynamics of a simplified lumped-parameter model for a boiling water reactor (BWR) is investigated. A mathematical model of five differential equations comprising of neutronics and thermal-hydraulics encompassing the nonlinearities associated with both the reactivity feedbacks and the heat transfer process has been used. To this end, we have considered parameters relevant to RBMK for which the void reactivity is known to be nonlinear. A nonlinear analysis of the model exploiting the method of multiple time scales (MMTS) predicts the occurrence of the two types of Hopf bifurcation, namely subcritical and supercritical, leading to the evolution of limit cycles for a range of parameters. Numerical simulations have been performed to verify the analytical results obtained by MMTS. The study shows that the nonlinear reactivity has a significant influence on the system dynamics. A parametric study with varying nominal reactor power and operating conditions in coolant channel has also been performed which shows the effect of change in concerned parameter on the boundary between regions of sub- and super-critical Hopf bifurcations in the space constituted by the two coefficients of reactivities viz. the void and the Doppler coefficient of reactivities. In particular, we find that introduction of a negative quadratic term in the void reactivity feedback significantly increases the supercritical region and dominates in determining the system dynamics.

  12. Results from studies of surface deposits on the claddings of fuel rods used in RBMK-1000 reactors

    Smirnova, I. M.; Markov, D. V.


    The results of studies on analyzing the element composition of deposits on the cladding surfaces of fuel rods used in a fuel assembly at the Leningrad nuclear power station are presented. The distribution of elements in deposits over the fuel rod height is analyzed, and the zones of their concentration are revealed. It is shown that deposits of copper penetrating into cracks in the surface layer of zirconium oxide introduce an essential contribution in the development of nodular corrosion of fuel rod claddings.

  13. Chernobyl accident and its consequences

    Gittus, J.H.


    The paper concerns the Chernobyl reactor accident, with emphasis on the design of the RBMK reactor and nuclear safety. A description is given of the Chernobyl nuclear power plant, including details of the RMBK reactor and safety systems. Comments on the design of the RBMK by UK experts prior to the accident are summarized, along with post-accident design changes to improve RBMK safety. Events of the Chernobyl accident are described, as well as design deficiencies highlighted by the accident. Differences between the USSR and UK approaches to nuclear safety are commented on. Finally source terms, release periods and environmental consequences are briefly discussed.

  14. Potential consequences in Norway after a hypothetical accident at Leningrad nuclear power plant. Potential release, fallout and predicted impacts on the environment

    Nalbandyan, A.; Ytre-Eide, M.A.; Thoerring, H.; Liland, A.; Bartnicki, J.; Balonov, M.


    The report describes different hypothetical accident scenarios at the Leningrad nuclear power plant for both RBMK and VVER-1200 reactors. The estimated release is combined with different meteorological scenarios to predict possible fallout of radioactive substances in Norway. For a hypothetical catastrophic accident at an RBMK reactor combined with a meteorological worst case scenario, the consequences in Norway could be considerable. Foodstuffs in many regions would be contaminated above the food intervention levels for radioactive cesium in Norway. (Author)

  15. Synthesis, expression and purification of a type of chlorotoxin-like peptide from the scorpion, Buthus martensii Karsch, and its acute toxicity analysis.

    Fu, Yue-jun; Yin, Li-tian; Wang, Wei; Chai, Bao-feng; Liang, Ai-hua


    A gene, rBmK Cta, encoding a chlorotoxin-like peptide from the scorpion, Buthus martensii Karsch, was synthesized according to the sequence optimized for codon usage in Escherichia coli and was expressed in E. coli BL21 (DE3) using a pExSecI expression system in which the IgG-binding domain-ZZ of protein A is fused to the N-terminal of rBmK CTa. The fusion protein, ZZ-rBmK CTa, was expressed in soluble form (7.8 mg l(-1)) and was purified to give a single band on SDS-PAGE. The domain-ZZ of fusion protein ZZ-rBmK CTa was removed by cleavage of an Asn-Gly peptide bond with hydroxylamine. The rBmK CTa was separated from the IgG-binding moiety by a second passage through the IgG affinity column. Western blot analysis demonstrated that this protein was rBmK CTa. Acute toxicity assay in mice demonstrated that the rBmK CTa had an LD(50) value of 4.3 mg kg(-1).

  16. Chernobyl accident and its consequences

    Gittus, J.H.; Bonell, P.G.; Hicks, D.


    The USSR power reactor programme is first described. The reasons for the accident at the Chernobyl-4 RBMK nuclear reactor on 26 April 1986, the sequence of events that took place, and the immediate and long-term consequences are considered. A description of the RBMK-type reactors is given and the design changes resulting from the experience of the accident are explained. The source terms describing the details of the radioactivity release associated with the accident and the environmental consequences are covered in the last two sections of the report. Throughout the text comments referring to the UK Nuclear Installations Inspectorate Safety assessment principles have been inserted. (U.K.).

  17. The Barselina Project Phase 4 Summary report. Ignalina Unit 2 Probabilistic Safety Analysis

    Johansson, Gunnar [ES-Konsult AB, Stockholm (Sweden); Hellstroem, P. [RELCON AB, Solna (Sweden); Zheltobriuch, G.; Bagdonas, A. [Ignalina Power Plant, Visaginas (Lithuania)


    The Barselina Project was initiated in the summer of 1991. The project is a multilateral co-operation between Lithuania, Russia and Sweden. The long range objective is to establish common perspectives and unified bases for assessment of severe accident risks and needs for remedial measures for the RBMK reactors. The Swedish BWR Barsebaeck is used as reference plant and the Lithuanian RBMK Ignalina as application plant. During phase 3, from March, 1993 to June, 1994, a full scope Probabilistic Safety Analysis (PSA) model of the Ignalina Nuclear Power Plant unit 2 (INPP-2) was developed to identify possible safety improvement of risk importance. The probabilistic methodology was applied on a plant specific basis for a channel type reactor of RBMK design. To increase the realism of the risk model a set of deterministic analyses were performed and plant/RBMK-specific data bases were developed and used. A general concept for analysing this type of reactor was developed. During phase 4, July 1994 to September 1996, the PSA was further developed, taking into account plant changes, improved modeling methods and extended plant information concerning dependencies (area events, dynamic effects, electrical and signal dependencies). The updated model is quantified and new results and conclusions are evaluated.

  18. Assessing deposition levels of 55Fe, 60Co and 63Ni in the Ignalina NPP environment

    Gudelis, A.; Druteikienė, R.; Lukšienė, B.


    Two RBMK-1500 reactor units operated in Lithuania in the 1987–2004 period (one of them was stopped for decommissioning in 2004). This study presents a preliminary investigation of surface deposition density levels of 55Fe and 63Ni in moss samples collected in the close vicinity of the Ignalina NPP...

  19. Measurement of Neutron Field Characteristics at Nuclear-Physics Instalations for Personal Radiation Monitoring

    Alekseev, A G; Britvich, G I; Kosyanenko, E V; Pikalov, V A; Gomonov, I P


    n this work the observed data of neutron spectra on Rostov NEP, Kursk NEP and Smolensk NEP and on the reactor IRT MIPHI are submitted. For measurement of neutron spectra two types of spectrometer were used: SHANS (IHEP design ) and SDN-MS01 (FEI design). The comparison of the data measurements per-formed by those spectrometers above one-type cells on the reactor RBMK is submitted. On the basis of the 1-st horizontal experimental channel HEC-1 of the IRT reactor 4 reference fields of neutrons are investigated. It is shown, that spectra of neutrons of reference fields can be used for imitation of neutron spectra for conditions of NEP with VVER and RBMK type reactors.

  20. Bootstrap and Order Statistics for Quantifying Thermal-Hydraulic Code Uncertainties in the Estimation of Safety Margins

    Enrico Zio


    Full Text Available In the present work, the uncertainties affecting the safety margins estimated from thermal-hydraulic code calculations are captured quantitatively by resorting to the order statistics and the bootstrap technique. The proposed framework of analysis is applied to the estimation of the safety margin, with its confidence interval, of the maximum fuel cladding temperature reached during a complete group distribution blockage scenario in a RBMK-1500 nuclear reactor.

  1. Chernobyl, 25 years later... Fukushima: what future for nuclear energy?; Tchernobyl, 25 ans apres... Fukushima: Quel avenir pour le nucleaire?

    Chouha, M.; Reuss, P.


    Starting from a precise analysis of the Chernobyl accident and of its consequences, this book follows with a general analysis of: the present day worldwide energy context and of its projections, the physical and technical aspects of nuclear energy, the place it can share with the other energy sources and its perspectives of development. Content: Introduction; man and energy; nuclear energy; RBMK-type reactors; the Chernobyl accident; the nuclear energy renaissance; conclusion. (J.S.)

  2. Thermal-hydraulic instabilities in pressure tube graphite - moderated boiling water reactors

    Tsiklauri, G.; Schmitt, B.


    Thermally induced two-phase instabilities in non-uniformly heated boiling channels in RBMK-1000 reactor have been analyzed using RELAP5/MOD3 code. The RELAP5 model of a RBMK-1000 reactor was developed to investigate low flow in a distribution group header (DGH) supplying 44 fuel pressure tubes. The model was evaluated against experimental data. The results of the calculations indicate that the period of oscillation for the high power tube varied from 3.1s to 2.6s, over the power range of 2.0 MW to 3.0 MW, respectively. The amplitude of the flow oscillation for the high powered tube varied from +100% to -150% of the tube average flow. Reverse flow did not occur in the lower power tubes. The amplitude of oscillation in the subcooled region at the inlet to the fuel region is higher than in the saturated region at the outlet. In the upper fuel region and outlet connectors the flow oscillations are dissipated. The threshold of flow instability for the high powered tubes of a RBMK reactor is compared to Japanese data and appears to be in good agreement.

  3. Joint U.S./Russian Study on the Development of a Preliminary Cost Estimate of the SAFSTOR Decommissioning Alternative for the Leningrad Nuclear Power Plant Unit #1

    SM Garrett


    The objectives of the two joint Russian/U.S. Leningrad Nuclear Power Plant (NPP) Unit #1 studies were the development of a safe, technically feasible, economically acceptable decom missioning strategy, and the preliminary cost evaluation of the developed strategy. The first study, resulting in the decommissioning strategy, was performed in 1996 and 1997. The preliminary cost estimation study, described in this report, was performed in 1997 and 1998. The decommissioning strategy study included the analyses of three basic RBM.K decommission- ing alternatives, refined for the Leningrad NPP Unit #1. The analyses included analysis of the requirements for the planning and preparation as well as the decommissioning phases.

  4. Application of the leak-before-break concept to the primary circuit piping of the Leningrad NPP

    Eperin, A.P.; Zakharzhevsky, Yu.O.; Arzhaev, A.I. [and others


    A two-year Finnish-Russian cooperation program has been initiated in 1995 to demonstrate the applicability of the leak-before-break concept (LBB) to the primary circuit piping of the Leningrad NPP. The program includes J-R curve testing of authentic pipe materials at full operating temperature, screening and computational LBB analyses complying with the USNRC Standard Review Plan 3.6.3, and exchange of LBB-related information with emphasis on NDE. Domestic computer codes are mainly used, and all tests and analyses are independently carried out by each party. The results are believed to apply generally to RBMK type plants of the first generation.

  5. The concepts of leak before break and absolute reliability of NPP equipment and piping

    Getman, A.F.; Komarov, O.V.; Sokov, L.M. [and others


    This paper describes the absolute reliability (AR) concept for ensuring safe operation of nuclear plant equipment and piping. The AR of a pipeline or component is defined as the level of reliability when the probability of an instantaneous double-ended break is near zero. AR analysis has been applied to Russian RBMK and VVER type reactors. It is proposed that analyses required for application of the leak before break concept should be included in AR implementation. The basic principles, methods, and approaches that provide the basis for implementing the AR concept are described.

  6. Use of software tools for calculating flow accelerated corrosion of nuclear power plant equipment and pipelines

    Naftal', M. M.; Baranenko, V. I.; Gulina, O. M.


    The results obtained from calculations of flow accelerated corrosion of equipment and pipelines operating at nuclear power plants constructed on the basis of PWR, VVER, and RBMK reactors carried out using the EKI-02 and EKI-03 software tools are presented. It is shown that the calculation error does not exceed its value indicated in the qualification certificates for these software tools. It is pointed out that calculations aimed at predicting the service life of pipelines and efficient surveillance of flow accelerated corrosion wear are hardly possible without using the above-mentioned software tools.

  7. Organisation of the state supervision and regulation of storage facilities for low- and intermediate level radioactive waste in the Northwest region of Russia

    Novikov, Sergey


    The North-European Interregional Territorial District of Gosatomnadzor of Russia was established in 1992. It supervises the fulfilment of the legislative requirements of the Russian Federation on nuclear and radiation safety in production, management and use of nuclear energy, and nuclear materials and radioactive substances. Among the subjects supervised are four nuclear power plants operating RBMK type of reactors. Gosatomnazdor also issues licences for working with radioactive materials. This presentation discusses some of the issues in waste treatment and management in the District.

  8. The effect of the composition of plutonium loaded on the reactivity change and the isotopic composition of fuel produced in a fast reactor

    Blandinskiy, V. Yu.


    This paper presents the results of a numerical investigation into burnup and breeding of nuclides in metallic fuel consisting of a mixture of plutonium and depleted uranium in a fast reactor with sodium coolant. The feasibility of using plutonium contained in spent nuclear fuel from domestic thermal reactors and weapons-grade plutonium is discussed. It is shown that the largest production of secondary fuel and the least change in the reactivity over the reactor lifetime can be achieved when employing plutonium contained in spent nuclear fuel from a reactor of the RBMK-1000 type.

  9. First international workshop on severe accidents and their consequences. [Chernobyl Accident


    An international workshop on past severe nuclear accidents and their consequences was held in Dagomys region of Sochi, USSR on October 30--November 3, 1989. The plan of this meeting was approved by the USSR Academy of Sciences and by the USSR State Committee of the Utilization of Atomic Energy. The meeting was held under the umbrella of the ANS-SNS agreement of cooperation. Topics covered include analysis of the Chernobyl accident, safety measures for RBMK type reactors and consequences of the Chernobyl accident including analysis of the ecological, genetic and psycho-social factors. Separate reports are processed separately for the data bases. (CBS)

  10. Best estimate approach for the evaluation of critical heat flux phenomenon in the boiling water reactors

    Kaliatka, Tadas; Kaliatka, Algirdas; Uspuras, Eudenijus; Vaisnoras, Mindaugas [Lithuanian Energy Institute, Kaunas (Lithuania); Mochizuki, Hiroyasu; Rooijen, W.F.G. van [Fukui Univ. (Japan). Research Inst. of Nuclear Engineering


    Because of the uncertainties associated with the definition of Critical Heat Flux (CHF), the best estimate approach should be used. In this paper the application of best-estimate approach for the analysis of CHF phenomenon in the boiling water reactors is presented. At first, the nodalization of RBMK-1500, BWR-5 and ABWR fuel assemblies were developed using RELAP5 code. Using developed models the CHF and Critical Heat Flux Ratio (CHFR) for different types of reactors were evaluated. The calculation results of CHF were compared with the well-known experimental data for light water reactors. The uncertainty and sensitivity analysis of ABWR 8 x 8 fuel assembly CHFR calculation result was performed using the GRS (Germany) methodology with the SUSA tool. Finally, the values of Minimum Critical Power Ratio (MCPR) were calculated for RBMK-1500, BWR-5 and ABWR fuel assemblies. The paper demonstrate how, using the results of sensitivity analysis, to receive the MCPR values, which covers all uncertainties and remains best estimated.

  11. Leningrad nuclear power plant pressure tube failure investigations

    Bruchertseifer, H.; Bart, G.; Restani, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Aden, V.G.; Abramov, V.Y.; Kalachikov, V.E.; Kozlov, A.V. [Research and Development Inst. of Power Engineering (RDIPE), Moscow and Sverdlovsk (Russian Federation); Subbotin, A.V.; Smirnov, E.A. [Moscow Engineering Physics Inst., Moscow (Russian Federation)


    During March 1992 a fuel pressure tube of a reactor channel of the Leningrad Nuclear Power Plant underwent a temperature excursion after a coolant flow blockage and was destroyed. In the following, within the Swiss Eastern European aid program a collaboration was set up for a project between the Moscow Research and Development Institute of Power Engineering, the designer of the RBMK-reactors, and the Paul Scherrer Institute. An intensive failure analysis program was started, based on modern equipment available at PSI for analysis of highly radioactive material and on the experience of both institutes in investing failures of reactor structure materials, with the goal of establishing the accident temperature evolution in time. This report presents the results of studies undertaken in order to determine the parameters which govern the events during the accident obtained from an analysis of the tube failure material together with evaluations of the apparent phase and structure changes. Our analysis of experimental data for oxygen distribution and the diffusion coefficient calculations showed that the temperatures exceeded 1300{sup o}C, which is much higher than results from previous studies performed in standard failure post-irradiation examination. The results obtained are important in that they have allowed to revise the previous assessments of the initial thermal conditions of the accident progression. In particular, they already served as a basis for determining the efficiency of the RBMK safety improvement measures carried out in response to the accident. (author) 8 figs., 5 refs.

  12. Establishing an effective plant maintenance strategy requires a consortium of information and coordinated resources; Para establecer un programa de mantenimiento eficaz, es necesario conocer desde el inicio el estado de los equipos

    Kozsky, T. A.


    Establishing an effective plant maintenance strategy requires a consortium of information and coordinated resources. A fundamental element of achieving such a program is to have a comprehensive knowledge base of equipment health derived from operational data, monitoring and diagnostic data, design base data, and others. This paper presents a summary of the elements of a maintenance strategy and focuses on the Westinghouse information integration scheme, called ALLY, that combines equipment health information, performs automated expert system reasoning, organizes and prioritizes equipment health diagnostics, and helps to identify maintenance actions. ALLY has been applied to a VVER nuclear plant located in the Czech Republic, a RBMK nuclear plant located in Rusia and a PWR nuclear plant located in China. A short discription of these applications is also presented. (Author)

  13. Simulation of accident and normal fuel rod work with Zr-cladding

    Tutnov, Anton A.; Tutnov, Alexander A. [Russian Research Centre, Moscow (Russian Federation). Kurchatov Inst.


    The technique of simulation of heat-physics, strength and safety characteristics of reactor RBMK and WWER rods under steady-state, transient and accident conditions is presented. That technique is used in mechanic and heat physics codes PULSAR-2 and STALACTITE. Simulation in both full scale and the most stress-loading part of cladding statement under accident conditions are considered. In this zone local swelling and cladding failure are possible. The accident simulation is based on the mechanical creep-plasticity problem solution in three-dimensional approach. The local cladding swelling is initiated with determining of little hot spot on the clad with several degrees temperature departure from average value. Mechanical problem is solved by finite elements method. Interaction of Zr with steam is taken in to account. Fuel and cladding melting, shortness and dispersion formation processes are simulated under subsequent rods warming up. (author). 2 refs., 6 figs.

  14. The causes of the Chernobyl event; Les causes de l'evenement Tchernobyl

    Frot, J


    The Chernobylsk event has two components, the explosion of the RBMK type nuclear reactor number 4 and the sanitary damages that resulted. The causes of the explosion are of three kinds: conception error, management fault, exploitation personnel mistakes and political causes. For the sanitary damages there are the immediate causes and the deep causes. No emergency planning to answer to a such disaster and no iodinated tablets delivery to protect the thyroid for the direct causes. The secret culture made that the knowledge developed by the Soviet researchers was not diffused to the medical and nuclear communities of USSR. The civil authorities were not aware of it or they neglected it. (N.C.)

  15. Critical analysis of major incidents risks in civil nuclear energy; Analyse critique des risques d'incidents majeurs dans l'energie nucleaire civile



    The differences existing between the PWR type reactors and the RBMK type reactors are explained as well as the risk associated to each type when it exists. The Ines scale, tool to give the level of an accident gravity comprises seven levels, the number seven is the most serious and corresponds to the Chernobyl accident; The number zero is of no consequence but must be mentioned as a matter of form. The incidents from 1 to 3 concern increasing incidents, affecting the nuclear power plant but not the external public. The accidents from 4 to 7 have a nature to affect the nuclear power plant and the environment. An efficient tool exists between nuclear operators it is made of the reports on incidents encountered by close reactors. Two others type reactors are coming, the high temperature type reactors and the fast neutrons reactors. different risks are evoked, terrorism, proliferation, transport and radioactive wastes. (N.C.)

  16. Comprehensive survey of the Russian nuclear industry; Le panorama nucleaire russe



    This document presents the organization of nuclear activities in the Russian federation: Minatom and its replacement by the federal agency of atomic energy, personnel, nuclear power plants (VVER, RBMK, fast neutron and mixed reactors), availability and power production, export of activities (construction of nuclear power plants in Slovakia, Iran, China, India, project in Viet Nam), expansion of the nuclear power plants park (improvement of plants safety, increase of service life), completion of uncompleted plants, the construction of which was stopped after the Chernobyl accident and the reorganization of the former-USSR, construction of new generation power plants (VVER-640, -1000 and -1500), fuel cycle facilities (geographical distribution, production of natural uranium, conversion and enrichment), fuel fabrication, reprocessing processes and spent fuel storage, management of radioactive wastes (leasing), R and D activities (organizations and institutes), research programs of the international scientific and technical center, nuclear safety authority (Gosatomnadzor - GAN). (J.S.)

  17. Modeling of irradiated graphite (14)C transfer through engineered barriers of a generic geological repository in crystalline rocks.

    Poskas, Povilas; Grigaliuniene, Dalia; Narkuniene, Asta; Kilda, Raimondas; Justinavicius, Darius


    There are two RBMK-1500 type graphite moderated reactors at the Ignalina nuclear power plant in Lithuania, and they are under decommissioning now. The graphite cannot be disposed of in a near surface repository, because of large amounts of (14)C. Therefore, disposal of the graphite in a geological repository is a reasonable solution. This study presents evaluation of the (14)C transfer by the groundwater pathway into the geosphere from the irradiated graphite in a generic geological repository in crystalline rocks and demonstration of the role of the different components of the engineered barrier system by performing local sensitivity analysis. The speciation of the released (14)C into organic and inorganic compounds as well as the most recent information on (14)C source term was taken into account. Two alternatives were considered in the analysis: disposal of graphite in containers with encapsulant and without it. It was evaluated that the maximal fractional flux of inorganic (14)C into the geosphere can vary from 10(-11)y(-1) (for non-encapsulated graphite) to 10(-12)y(-1) (for encapsulated graphite) while of organic (14)C it was about 10(-3)y(-1) of its inventory. Such difference demonstrates that investigations on the (14)C inventory and chemical form in which it is released are especially important. The parameter with the highest influence on the maximal flux into the geosphere for inorganic (14)C transfer was the sorption coefficient in the backfill and for organic (14)C transfer - the backfill hydraulic conductivity.

  18. ATHLET. Mod 3.0 Cycle A. Validation

    Lerchl, G.; Austregesilo, H.; Glaeser, H.; Hrubisko, M.; Luther, W.


    ATHLET is an advanced best-estimate code which has been initially developed for the simulation of design basis and beyond design basis accidents (without core degradation) in light water reactors, including VVER and RBMK reactors. Furthermore, this program version enables the simulation of further working fluids like helium and liquid metals. The one-dimensional, two-phase fluiddynamic models are based on a five-equation model supplemented by a full-range drift-flux model, including a dynamic mixture-level tracking capability. Moreover, a two-fluid model based on six conservation equations is provided. The heat conduction and heat transfer module allows a flexible simulation of fuel rods and structures. The nuclear heat generation is calculated by a point-kinetics or by a one-dimensional kinetics model. A general control simulation module is provided for a flexible modelling of BOP- and auxiliary plant systems. Systematic code validation is performed by GRS and independent organizations. This Validation Manual is the fourth volume of the ATHLET Code Documentation comprising four volumes. This manual presents an overview about the complete ATHLET validation effort spent up to now. In addition, the results of five test cases simulated with the present ATHLET program version are compared with the experimental data.

  19. Radioactive and other environmental threats to the United States and the Arctic resulting from past Soviet activities



    Earlier this year the Senate Intelligence Committee began to receive reports from environmental and nuclear scientists in Russia detailing the reckless nuclear waste disposal practices, nuclear accidents and the use of nuclear detonations. We found that information disturbing to say the least. Also troubling is the fact that 15 Chernobyl style RBMK nuclear power reactors continue to operate in the former Soviet Union today. These reactors lack a containment structure and they`re designed in such a way that nuclear reaction can actually increase when the reactor overheats. As scientists here at the University of Alaska have documented, polar air masses and prevailing weather patterns provide a pathway for radioactive contaminants from Eastern Europe and Western Russia, where many of these reactors are located. The threats presented by those potential radioactive risks are just a part of a larger Arctic pollution problem. Every day, industrial activities of the former Soviet Union continue to create pollutants. I think we should face up to the reality that in a country struggling for economic survival, environment protection isn`t necessarily the high priority. And that could be very troubling news for the Arctic in the future.

  20. US-Russian collaboration for enhancing nuclear materials protection, control, and accounting at the Elektrostal uranium fuel-fabrication plant

    Smith, H. [Los Alamos National Lab., NM (United States); Allentuck, J. [Brookhaven National Lab., Upton, NY (United States); Barham, M. [Oak Ridge National Lab., TN (United States); Bishop, M. [Sandia National Labs., Albuquerque, NM (United States); Wentz, D. [Lawrence Livermore National Lab., CA (United States); Steele, B.; Bricker, K. [Pacific Northwest National Lab., Richland, WA (United States); Cherry, R. [USDOE, Washington, DC (United States); Snegosky, T. [Dept. of Defense, Washington, DC (United States). Defense Nuclear Agency


    In September 1993, an implementing agreement was signed that authorized collaborative projects to enhance Russian national materials control and accounting, physical protection, and regulatory activities, with US assistance funded by the Nunn-Lugar Act. At the first US-Russian technical working group meeting in Moscow in February 1994, it was decided to identify a model facility where materials protection, control, and accounting (MPC and A) and regulatory projects could be carried out using proven technologies and approaches. The low-enriched uranium (LEU or RBMK and VVER) fuel-fabrication process at Elektrostal was selected, and collaborative work began in June 1994. Based on many factors, including initial successes at Elektrostal, the Russians expanded the cooperation by proposing five additional sites for MPC and A development: the Elektrostal medium-enriched uranium (MEU or BN) fuel-fabrication process and additional facilities at Podolsk, Dmitrovgrad, Obninsk, and Mayak. Since that time, multilaboratory teams have been formed to develop and implement MPC and A upgrades at the additional sites, and much new work is underway. This paper summarizes the current status of MPC and A enhancement projects in the LEU fuel-fabrication process and discusses the status of work that addresses similar enhancements in the MEU (BN) fuel processes at Elektrostal, under the recently expanded US-Russian MPC and A cooperation.

  1. Analysis of radwaste management alternatives during dismantling of Ignalina NPP systems with low level contamination

    Poskas, Gintautas [Lithuanian Energy Institute, Kaunas (Lithuania). Nuclear Engineering Lab.; Kaunas Univ. of Technology (Lithuania); Poskas, Povilas; Simonis, Audrius [Lithuanian Energy Institute, Kaunas (Lithuania). Nuclear Engineering Lab.


    Ignalina NPP was operating two RBMK-1500 reactors which are under decommissioning now. In this paper, analysis on radwaste management alternatives during the dismantling of systems with low level contamination and different types of components in buildings 117/1 and V1 are presented. After situation analysis and collection of the primary information related to components' physical and radiological characteristics, location and other data, two alternatives for radwaste management during the dismantling were formulated and evaluated: the first one (A1) when the decontamination of the dismantled components is performed (if it is reasonable), and the second one (A2) when no decontamination of the dismantled components is performed and after the dismantling, the components are routed to appropriate waste storage or disposal sites. To select the preferable alternative, MCDA method - AHP (Analytic Hierarchy Process) is applied. Hierarchical lists of decision criteria, necessary for assessment of alternatives performance, are formulated. Quantitative decision criteria values for these alternatives are calculated using software DECRAD, which was developed by Lithuanian Energy Institute Nuclear Engineering Laboratory. Qualitative decision criteria are evaluated using expert judgment. Analysis results show that alternative A1 has a preference against alternative A2. (orig.)

  2. Analysis of Alternatives for Dismantling of the Equipment in Building 117/1 at Ignalina NPP - 13278

    Poskas, Povilas; Simonis, Audrius [Lithuanian Energy Institute, Kaunas (Lithuania); Poskas, Gintautas [Lithuanian Energy Institute, Kaunas (Lithuania); Kaunas University of Technology, Kaunas (Lithuania)


    Ignalina NPP was operating two RBMK-1500 reactors which are under decommissioning now. In this paper dismantling alternatives of the equipment in Building 117/1 are analyzed. After situation analysis and collection of the primary information related to components' physical and radiological characteristics, location and other data, two different alternatives for dismantling of the equipment are formulated - the first (A1), when major components (vessels and pipes of Emergency Core Cooling System - ECCS) are segmented/halved in situ using flame cutting (oxy-acetylene) and the second one (A2), when these components are segmented/halved at the workshop using CAMC (Contact Arc Metal Cutting) technique. To select the preferable alternative MCDA method - AHP (Analytic Hierarchy Process) is applied. Hierarchical list of decision criteria, necessary for assessment of alternatives performance, are formulated. Quantitative decision criteria values for these alternatives are calculated using software DECRAD, which was developed by Lithuanian Energy Institute Nuclear engineering laboratory. While qualitative decision criteria are evaluated using expert judgment. Analysis results show that alternative A1 is better than alternative A2. (authors)

  3. International measures for supporting the Ukraine in decommissioning Chernobyl nuclear power plant; Internationale Massnahmen zur Unterstuetzung der Ukraine bei der Stilllegung des KKW Tschernobyl

    Wolf, J.


    The destruction of Block 4 of the Ukranian nuclear power plant in Chernobyl on 26 April 1986 was the largest and most momentous accident in the civil use of nuclear energy. Its far-reaching and lasting ecological, heath-related and economic effects confronted the then Soviet and later the Ukraine with grave problems. Particularly after the dissolution of the Eastern Bloc and the emergence of information about the safety shortcomings of RBMK-type (Chernobyl-type) reactors the Western states pressed for the decommissioning of these reactors. At the G7 summit in Naples in 1994 the Ukraine was offered an action plan of support if it were willing to close down Chernobyl nuclear power plant. This initiative led to the signing on 20 December 1995 of a Memorandum of Understanding on the Closure of Chernobyl Nuclear Power Plant between the G7 states, the European Commission and the Ukraine. It contained an assurance by President Kuchma that Chernobyl nuclear power plant would be closed by the year 2000.

  4. [Codon optimization and eukaryotic expression analysis of the analgesic peptide gene BmK AngM1 from Buthus martensii Karsch].

    Yang, Jin-ling; Gao, Li-li; Zhu, Ping; Hou, Qi; Wang, Fen; Yu, Wen-bo; Nie, Tao


    Codon bias is an important factor which influences heterologous gene expression. Optimizing codon sequence could improve expression level of heterologous gene. In order to improve the expression level of BmK AngM1 gene encoding the analgesic peptide from Buthus martensii Karsch in Pichia pastoris, the codon-optimized BmK AngM1 gene according to its cDNA sequence and the preference codon usage of P. pastoris were cloned into expression vector pPIC9K and then transformed into P. pastoris. The expersion of recombinant BmK AngM1 (rBmK AngM1) was inducced by methanol in the medium, and the expression level of the optimized BmK AngM1 gene was 3.7 times of the native one. These results suggested that the expression of BmK AngM1 in P. pastoris could be successfully improved by codon optimization.

  5. The Chernobyl and Fukushima Daiichi nuclear accidents and their tragic consequences

    CERN. Geneva


    On April 26, 1986, the Unit 4 of the RBMK nuclear power plant of Chernobyl, in Ukraine, went out of control during a test at low-power, leading to an explosion and fire. The reactor building was totally demolished and very large amounts of radiation were released into the atmosphere for several hundred kilometres around the site including the nearby town of Pripyat. The explosion leaving tons of nuclear waste and spent fuel residues without any protection and control totally contaminating the entire area. Several hundred thousand people were affected by the radiation fall out. The radioactive cloud spread across Europe affecting most of the Northern, Central and Eastern European countries. Some areas of southern Switzerland, of northern Italy as well as western France were subject to radioactive contamination. The initiative of the G7 countries to launch and important programme for the closure of some Soviet built nuclear plants was accepted by several donor countries. A team of engineers was established wi...

  6. Power regulating range broadening of the WWER-type reactor power units

    Dement' ev, B.A.; Petrov, V.A.; Proskuryakov, A.G.; Puchkov, V.V. (Moskovskij Ehnergeticheskij Inst. (USSR))


    Calculational studies on the use of sliding pressure (SP) regime to expand the regulating range of the WWER-440 reactor power units are presented. Two operation regimes of a power unit have been considered: according to weekly and daily load swings in electrical grids. The conclusion is made that the use of SP regime in the secondary circuit improves manoeuvable characterstics of the power unit in the second half of operating cycle. T of the reactor (0.6 RBMK reactors.

  7. Baltic states: self-sufficiency through nuclear electricity; Pays Baltes: une independance par le nucleaire

    Sainte Catherine, C. [CEA/Ambassade de France a Helsinki (Finland)


    The Baltic states are connected to the Russian power grid and direct connection to the European grid are scheduled through the ENTSO-E (European Network of Transmission System Operators for Electricity). In end 2009 Lithuania closed its last RBMK reactor on the Ignalina site, this plant provided Lithuania with 70% of its electricity demand. A project of new reactors on the Ignalina site has been considered since 2004 but this complex regional project including Estonia, Latvia but also Poland, lacks momentum to go ahead. Nevertheless, the project shows that a nuclear plant of 3400 MW would be necessary to assure 1000 MW to Poland and 500 MW to Latvia. Latvia has not nuclear plant and produces most of its electricity by hydro-energy and bio-energy (70%) and by natural gas combustion (30%). A share in the construction of the Lithuanian nuclear power plant will allow Latvia to be less dependent on Russian gas imports. The production of electricity of Estonia is based on the burning of oil shale which is very polluting. Estonia has committed itself to use only no-emitting CO{sub 2} energy sources to generate its electricity by 2030. A share in the Lithuanian power plant or in a new nuclear power plant in Finland might be an adequate solution. Since the end of 2008 Estonia authorities are studying the construction of a mid-size reactor whose power output would range between 400 and 900 MW. (A.C.)

  8. Dysprosium titanate as an absorber material for control rods

    Risovany, V. D.; Varlashova, E. E.; Suslov, D. N.


    Disprosium titanate is an attractive control rod material for the thermal neutron reactors. Its main advantages are: insignificant swelling, no out-gassing under neutron irradiation, rather high neutron efficiency, a high melting point (˜1870°C), non-interaction with the cladding at temperatures above 1000°C, simple fabrication and easily reprocessed non-radioactive waste. It can be used in control rods as pellets and powder. The disprosium titanate control rods have worked off in the MIR reactor for 17 years, in VVER-1000 - for 4 years without any operating problems. After post-irradiation examinations this type of control rod having high lifetime was recommended for the VVER and RBMK. The paper presents the examination results of absorber element dummies containing dysprosium titanate, irradiated in the SM reactor to the neutron fluence of 3.4×10 22 cm -2 ( E>0.1 MeV) and, also, the data on structure, thermal-physical properties of dysprosium titanate, efficiency of dysprosium titanate control rods.

  9. Technical Application of Nuclear Fission

    Denschlag, J. O.

    The chapter is devoted to the practical application of the fission process, mainly in nuclear reactors. After a historical discussion covering the natural reactors at Oklo and the first attempts to build artificial reactors, the fundamental principles of chain reactions are discussed. In this context chain reactions with fast and thermal neutrons are covered as well as the process of neutron moderation. Criticality concepts (fission factor η, criticality factor k) are discussed as well as reactor kinetics and the role of delayed neutrons. Examples of specific nuclear reactor types are presented briefly: research reactors (TRIGA and ILL High Flux Reactor), and some reactor types used to drive nuclear power stations (pressurized water reactor [PWR], boiling water reactor [BWR], Reaktor Bolshoi Moshchnosti Kanalny [RBMK], fast breeder reactor [FBR]). The new concept of the accelerator-driven systems (ADS) is presented. The principle of fission weapons is outlined. Finally, the nuclear fuel cycle is briefly covered from mining, chemical isolation of the fuel and preparation of the fuel elements to reprocessing the spent fuel and conditioning for deposit in a final repository.

  10. Scientific paradigms of structural safety of aged plants-Lessons learned from Russian activities

    Saji, Genn [Ex-Secretariat of Nuclear Safety Commission (Japan)], E-mail:; Timofeev, Boris [CRISM Prometey, Shpalernaja 49, St. Petersburg 193015 (Russian Federation)


    The study of the effects behind the degradation of components and materials is becoming increasingly important for the safe operation of aged plants especially when it comes to life extension. Since the Russian nuclear community began to examine life extension issues nearly 15 years ago, there is much to learn from these pioneering studies. At the Ninth International Conference entitled 'Material Issues in Design, Manufacturing and Operation of Nuclear Power Plants Equipment' held in St. Petersburg, 2006, recent data were introduced regarding the ageing effects of mechanical properties of various kinds of steel and welding joints of Russian NPP components. The meeting was organized by the Central Research Institute of Structural Materials (CRISM) 'Prometey' in cooperation with the IAEA and JRC-EU. In reviewing the recent data presented at the Ninth Conference, the authors believe that the paradigms of structural integrity issues in aged plants are now reasonably well established in (1) fracture mechanics and irradiation hardening of reactor vessels and core internals and (2) thermal ageing and annealing effects. However, the first author, G. Saji, believes that the current approach of low-cycle fatigue is still unable to prevent and predict environmentally assisted cracks such as demonstrated in the IGSCC issues in the down-comer pipes of RBMK plants and various steam generator corrosion issues. This fundamental flaw stems from design codes, which do not incorporate the basic knowledge of electrochemical corrosion mechanisms as represented by the corrosion current.

  11. Measurement of basic thermal-hydraulic characteristics under the test facility and reactor conditions

    Eduard A Boltenko; Victor P Sharov [Elektrogorsk Research and Engineering Center, EREC, Bezimyannaja Street, 6, Elektrogorsk, Moscow Region, 142530 (Russian Federation); Dmitriy E Boltenko [State Scientific Center of Russian Federation IPPE, Bondarenko Square, Obhinsk, Kaluga Region, 249020 (Russian Federation)


    Full text of publication follows: The nuclear power of Russia is based on the reactors of two types: water-water - WWER and uranium - graphite channel RBMK. The nuclear power development is possible with performance of the basic condition - level of nuclear power plants (NPP) safety should satisfy the rigid requirements. The calculated proof of NPPs safety made by means of thermal-hydraulic codes of improved estimation, verified on experimental data is the characteristic of this level. The data for code verification can be obtained at the integral facilities simulating a circulation circuit of NPP with the basic units and intended for investigation of circuit behaviour in transient and accident conditions. For verification of mathematical models in transient and accident conditions, development of physically reasonable methods for definition of the various characteristics of two-phase flow the experimental data, as the integrated characteristics of a flow, and data on the local characteristics and structure of a flow is necessary. For safety assurance of NPP it is necessary to monitor and determine the basic thermalhydraulic characteristics of reactor facility (RF). It is possible to refer coolant flow-rate, core input and output water temperature, heat-power. The description of the EREC works in the field completion and adaptation of certain methods with reference to measurements in dynamic modes of test facility conditions and development of methods for measurements of basic thermal-hydraulic characteristics of reactor facilities is presented in the paper. (authors)

  12. Simulating thermal behavior of AECL's spent fuel dry storage system with CATHENA

    Sabourin, G. [Atomic Energy of Canada Limited, Montreal, PQ (Canada)


    This paper documents the comparisons between CATHENA predictions and temperature measurements taken at the Gentilly-2 NPP spent fuel dry storage facility and in a mock--up of a storage basket placed inside a storage cylinder. It also presents CATHENA temperature predictions related to the storage of spent fuel in MACSTOR modules as planned for Ignalina NPP, Lithuania. CATHENA has been chosen because it can simulate many noncondensable gases including air and helium, and because of its great flexibility in the representation of the MACSTOR module geometry. The results of the simulations show good agreement with the experimental measurements. The two comparisons indicate that CATHENA can be used to simulate heat transfer from the fuel to the external air circuit of the spent fuel dry storage system. For the Ignalina MACSTOR module, containing RBMK fuel having higher heat release than typical CANDU fuel, CATHENA predicts that the maximum fuel temperature is expected to be around 240 deg C, giving an acceptable margin below the maximum allowed temperature of 300 deg C. In conclusion, this paper shows that the thermalhydraulic code CATHENA can accurately predict the thermal behavior AECL's air cooled spent fuel dry storage system. (author)

  13. 核能


    [ 篇名] A closed Brayton power conversion unit concept for nuclear electric propulsion for deep space missions, [ 篇名] A community approach to safety standards, [ 篇名 ] A comparative study on the fretting wear of steam generator tubes in korean power plants, [ 篇名 ] A mechanism for corrosion product deposition on the carbon steel piping in the residual heat removal system of BWRs, [篇名] A MECHANISM OF MAGNETIC PROPERTIES' CHANGE DUE TO NEUTRON IRRADIATION IN THE Ni-Cr-Mo STEEL, [篇名] A new finite element for generalized in-plane pipe loading. Experimental and numerical comparison, [ 篇名] A quantitative evaluation study on control boards of an actual Chinese NPP, [篇名] A simulation of the turbulence response of heat exchanger tubes in lattice-bar supports, [篇名] A unique experimental facility for chemistry monitoring at thermal and nuclear power stations and the possibility of its using in the remote access regime, [ 篇名] A vision of the future of radiological protection, [篇名 ] Accelerating decay, [ 篇名 ] Accident management for RBMK-1500 in the ease of loss of long-term core cooling, [篇名] Advanced nuclear power conversion process using high temperature electrolyte and multi power generation system of electric power and hydrogen energy productions temperature thin electrolyte film, [ 篇名 ] Advanced space propulsion with ultra-fast lasers.

  14. Nuclear safety in EU candidate countries



    Nuclear safety in the candidate countries to the European Union is a major issue that needs to be addressed in the framework of the enlargement process. Therefore WENRA members considered it was their duty to offer their technical assistance to their Governments and the European Union Institutions. They decided to express their collective opinion on nuclear safety in those candidate countries having at least one nuclear power plant: Bulgaria, the Czech Republic, Hungary, Lithuania, Romania, Slovakia and Slovenia. The report is structured as follows: A foreword including background information, structure of the report and the methodology used, General conclusions of WENRA members reflecting their collective opinion, For each candidate country, an executive summary, a chapter on the status of the regulatory regime and regulatory body, and a chapter on the nuclear power plant safety status. Two annexes are added to address the generic safety characteristics and safety issues for RBMK and VVER plants. The report does not cover radiation protection and decommissioning issues, while safety aspects of spent fuel and radioactive waste management are only covered as regards on-site provisions. In order to produce this report, WENRA used different means: For the chapters on the regulatory regimes and regulatory bodies, experts from WENRA did the work. For the chapters on nuclear power plant safety status, experts from WENRA and from French and German technical support organisations did the work. Taking into account the contents of these chapters, WENRA has formulated its general conclusions in this report.

  15. Evolution of the CYCLE code for the system analysis of the nuclear fuel cycle

    A.G. Kalashnikov


    Full Text Available The CYCLE code is intended to simulate mathematically the operation of a nuclear power system (NPS with thermal and fast reactors in an open or closed nuclear fuel cycle, to develop scenarios of efficient nuclear power evolution in Russia and to analyze trends in global nuclear power. The code is based on a well-known software program, WIMSD-5B, broadly used for the design of thermal reactor cells, and on a 2D multi-group software system, RZA, for the fast neutron reactor simulation. The CYCLE code was developed at IPPE in Obninsk. This paper presents a brief review of the capabilities and information on the current status of the CYCLE code. The code allows simulation of key facilities of the external fuel cycle (fuel fabrication and reprocessing facilities, SNF storage, uranium, plutonium, neptunium, americium and curium stores, RW long-term storage sites, nuclear reactors, including RBMK-1000 reactors, existing and advanced VVER reactors (using different fuel types, and fast reactors (both existing and innovative. As an important feature, the CYCLE code allows the evolution of the fuel's nuclide composition both in reactors and at the external fuel cycle phase to be considered in details. Offered as an extra option is the capability to calculate a variety of the nuclear fuel cycle cost parameters for nuclear power plants with thermal and fast reactors. For years, the code has been successfully used as part of INPRO, an international innovative nuclear reactor and fuel cycle project. The results of studies into the Russian NPS evolution scenarios were presented at Global 2011. Some other of the CYCLE-based simulation results were presented at Global 2015.

  16. Experience of international projects implementation at Leningrad Nuclear Power Plant

    Zavialov, L.A. [Leningrad Nuclear Power Plant ' Rosenergoatom' , Leningrad Region, 188540, Sosnovy Bor (Russian Federation)


    During the period of 1992-2007 more than 60 different projects of different specificity and budget have been successfully implemented in frames of Technical Assistance for the Commonwealth of Independent States (TACIS) Program, Project financed by European Bank for Reconstruction and Development (EBRD), as well as in frames of Agreements on Cooperation between Leningrad NPP and Radiation and Nuclear safety Authority of Finland (STUK) and Swedish Nuclear Power Inspectorate, International Co-operation Program SKI-ICP(SIP). All these projects were directed to the safety increasing of the Leningrad NPP reactor, type RBMK-1000. Implementation of the technical aid projects has been performed by different foreign companies such as Aarsleff Oy, (Finland), SGN (France), Nukem (Germany), Jergo AB (Sweden), SABAROS (Switzerland), Westinghouse (USA), Nordion (Canada), Bruel and Kjer (Denmark), Data System and Solutions (UK), SVT Braundshuz (Germany) WICOTEC (Sweden), Studsvik (Sweden) and etc. which has enough technical and organizational experience in implementation of such projects, as well as all necessary certificates and licenses for works performance. Selection of a Contractor/Supplier for a joined work performance has been carried out in accordance with the tender procedure, technical specification and a planned budget. Project financing was covered by foreign Consolidated Funds and Authorities interested in increasing of Leningrad NPP safety, which have valid intergovernmental agreements with Russian Federation on the technical assistance to be provided to the NPPs. At present time all joined international projects implemented at Leningrad NPP are financed jointly with LNPP. All projects can be divided into technical aid projects connected with development and turnkey implementation of systems and complexes and projects for supply of equipment which has no analogues in Russia but successfully used all over the world. Positive experience of the joined projects

  17. Airborne and deposited radioactivity from the Chernobyl accident. A review of investigations in Finland

    Paatero, J. (Finnish Meteorogical Inst., Helsinki (Finland)); Haemeri, K. (Helsinki Univ., Dept. of Physics (Finland)); Jaakkola, T. (Helsinki Univ., Lab. of Radiochemistry (Finland)); Jantunen, M. (National Public Health Inst., Kuopio (Finland)); Koivukoski, J. (Ministry of the Interior, Rescue Dept., Government (Finland)); Saxen, R. (STUK Radiation and Nuclear Safety Authority, Helsinki (Finland))


    The Chernobyl nuclear accident happened in the former Soviet Union on 26 April 1986. The accident destroyed one of the RBMK-1000 type reactors and released significant radioactive contamination into the environment. At first the emissions were transported north-westwards over Poland, the Baltic States, Finland, Sweden and Norway. During 27 April 1986 emissions were spreading to eastern-central Europe, southern Germany, Italy and Yugoslavia. Radioactivity mapping over Finland between 29 April and 16 May 1986 showed that the ground deposition in Finland covered southern and central parts of the country but had an irregular distribution. The highest (over 100 muR h-1 [1 muSv h-1]) contamination disclosed by the mapping was around the city of Uusikaupunki in western Finland and the city of Kotka in southeastern Finland. The Uusikaupunki region was an area of heavy fallout associated with the air mass that was located in the Chernobyl area at the time of the accident. The fallout pattern of reftractory nuclides, e.g. plutonium isotopes, had their spatial maximum in this region. Medical consequences in Finland were luckily mild, the most important symptoms being psychological ones. No increase in thyroid cancer or birth defect occurrence has been observed. The Chernobyl accident boosted the radioecological research which had already been calming down after the last atmospheric nuclear test in China in October 1980. Important new results concerning e.g. hot particles have been achieved. The most important effects of the accident in Finland were, however, the increase of public awareness of environmental issues in general and especially of nuclear energy. In Finland, the nuclear energy programme was halted until 2002 when the Parliament of Finland granted a licence to build the fifth nuclear reactor in Finland. (orig.)

  18. Dry spent fuel storage with the MACSTOR system

    Pare, F. [Atomic Energy of Canada Ltd., Montreal, PQ (Canada). CANDU Operations


    Atomic Energy of Canada Limited (AECL), and Transnuclear Inc. (TNI) began in 1989 the development of the concrete spent fuel storage system, called MACSTOR (Modular Air-Cooled Canister STORage) for use with LWR spent fuel assemblies. It is a hybrid system which combines the operational economies of metal cask technology with the capital economies of concrete technology. The MACSTOR Module is a monolithic, shielded concrete vault structure that can accommodate up to 20 spent fuel canisters. Each canister typically holds up to 21 PWR or 44 BWR spent fuel assemblies with a nominal fuel burn up rate of 40,000 MWD/MTU and a 7 year minimum cooling period. The structure is passively cooled by natural convection through an array of inlet and outlet gratings and galleries serving a central plenum where the (vertically) stored canisters are located. The canisters are continuously monitored by means of a pressure monitoring system developed by TNI. Thus, the utility can be assured of both positive cooling of the fuel and verification of the integrity of the fuel confinement boundary. The structure is seismically designed and is capable of withstanding site design basis accident events. The MACSTOR system includes the storage module(s), an overhead gantry system for cask handling, a transfer cask for moving fuel from wet to dry storage and a cask transporter. The canister and transfer cask designs are based on Transnuclear transport cask designs and proven hot cell transfer cask technology, adapted to requirements for on-site spent fuel storage. The MACSTOR system can economically address a wide range of storage capacity requirements. The modular concept allows for flexibility in determining each module`s capacity. Starting with 8 canisters, the capacity can be increased by increments of 4 up to 20 canisters. The MACSTOR system is also flexible in accommodating the various spent fuel types from such reactors as VVER-440, VVER-1000 and RBMK 1500. (J.P.N.)

  19. Irradiation effects on Zr-2.5Nb in power reactors

    Song, C., E-mail: [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)


    Zirconium alloys are widely used as structural materials in nuclear applications because of their attractive properties such as a low absorption cross-section for thermal neutrons, excellent corrosion resistance in water, and good mechanical properties at reactor operating temperatures. Zr-2.5Nb is one of the most commonly used zirconium alloys and has been used for pressure tube materials in CANDU (Canada Deuterium Uranium) and RBMK (Reaktor Bolshoy Moshchnosti Kanalnyy, 'High Power Channel-type Reactor') reactors for over 40 years. In a recent report from the Electric Power Research Institute, Zr-2.5Nb was identified as one of the candidate materials for use in normal structural applications in light-water reactors owing to its increased resistance to irradiation-induced degradation as compared with currently used materials. Historically, the largest program of in-reactor tests on zirconium alloys was performed by Atomic Energy of Canada Limited. Over many years of in-reactor testing and CANDU operating experience with Zr- 2.5Nb, extensive research has been conducted on the irradiation effects on its microstructures, mechanical properties, deformation behaviours, fracture toughness, delayed hydride cracking, and corrosion. Most of the results on Zr-2.5Nb obtained from CANDU experience could be used to predict the material performance under light water reactors. This paper reviews the irradiation effects on Zr-2.5Nb in power reactors (including heavy-water and light-water reactors) and summarizes the current state of knowledge. (author)

  20. Results of operation and current safety performance of nuclear facilities located in the Russian Federation

    Kuznetsov, V. M.; Khvostova, M. S.


    After the NPP radiation accidents in Russia and Japan, a safety statu of Russian nuclear power plants causes concern. A repeated life time extension of power unit reactor plants, designed at the dawn of the nuclear power engineering in the Soviet Union, power augmentation of the plants to 104-109%, operation of power units in a daily power mode in the range of 100-70-100%, the use of untypical for NPP remixed nuclear fuel without a careful study of the results of its application (at least after two operating periods of the research nuclear installations), the aging of operating personnel, and many other management actions of the State Corporation "Rosatom", should attract the attention of the Federal Service for Ecological, Technical and Atomic Supervision (RosTekhNadzor), but this doesn't happen. The paper considers safety issues of nuclear power plants operating in the Russian Federation. The authors collected statistical information on violations in NPP operation over the past 25 years, which shows that even after repeated relaxation over this period of time of safety regulation requirements in nuclear industry and highly expensive NPP modernization, the latter have not become more safe, and the statistics confirms this. At a lower utilization factor high-power pressure-tube reactors RBMK-1000, compared to light water reactors VVER-440 and 1000, have a greater number of violations and that after annual overhauls. A number of direct and root causes of NPP mulfunctions is still high and remains stable for decades. The paper reveals bottlenecks in ensuring nuclear and radiation safety of nuclear facilities. Main outstanding issues on the storage of spent nuclear fuel are defined. Information on emissions and discharges of radioactive substances, as well as fullness of storages of solid and liquid radioactive waste, located at the NPP sites are presented. Russian NPPs stress test results are submitted, as well as data on the coming removal from operation of NPP

  1. Chernobyl, 13 years after; Tchernobyl, 13 ans apres

    Regniault-Lacharme, Mireille; Metivier, Henri [Inst. de Protection et de Surete Nucleaire, CEA Centre d' Etudes de Fontenay-aux-Roses, 92 (France)


    This is an annual report, regularly issued by IPSN, that presents the ecological and health consequences of the Chernobyl Nuclear Accident. The present status of the Chernobyl Nuclear Plant, which Ukraine engaged to stop definitively in year 2000, is summarized. The only reactor unit now in operation is Chernobylsk-3 Reactor which poses two safety questions: evolution of cracks in part of the tubing and behaviour of the pressure tubes. Although, some improvements in the RBMK reactor types were introduced, problems remain that make IPSN to stress the requirement of stopping this NPP completely. In the contaminated territories surrounding Chernobyl incidence rate of infant thyroid cancers continues to grow, reaching values 10 to 100 times higher than the natural rate. In France the IPSN analyzed 60,000 records carried out in 17 sites during May 1986 and April 1989. It was estimated that the individual dose received during 60 years (1986-2046) by the inhabitants of the most affected zone (eastern France) is lower than 1.5 mSv, a value lower than 1% of the natural cosmic and telluric radioactivity exposure for the same period. For the persons assumed to live in the most attacked forests (from eastern France) and nourishing daily with venison and mushrooms the highest estimate is 1 mSv a year. Concerning the 'hot spots', identified in mountains by IPSN and CRIIRAD, the doses received by excursionists are around 0.015 mSv. For an average inhabitant of the country the dose piled up in the thyroid due to iodine-131 fallout is estimated to 0.5-2 mSv for an adult and 6.5-16 mSv for an infant. These doses are 100 to 1000 times lower than the ones to which the infants living in the neighbourhood of Chernobyl are exposed to. The contents of the report is displayed in the following six chapters: 1. Chernobyl in some figures; 2. The 'sarcophagus' and the reactors of the Chernobyl NPP; 3. Health consequences of the Chernobyl accident;. 4. The impact of

  2. Glasses for immobilization of low- and intermediate-level radioactive waste

    Laverov, N. P.; Omel'yanenko, B. I.; Yudintsev, S. V.; Stefanovsky, S. V.; Nikonov, B. S.


    with high-power channel reactors (HPCR; equivalent Russian acronym, RBMK) and the Kalinin nuclear power plant with pressurized water reactors (PWR; equivalent Russian acronym VVER) after their 14-yr storage in the shallow-seated repository at the MosNPO Radon testing ground has confirmed the safety of repositories ensured by confinement properties of borosilicate matrix. The most efficient vitrification technology is based on cold crucible induction melting. If the content of a chemical element in waste exceeds its solubility in glass, a crystalline phase is formed in the course of vitrification, so that the glass ceramics become a matrix for such waste. Vitrified waste with high Fe; Na and Al; Na, Fe, and Al; Na and B is characterized. The composition of frit and its proportion to waste depends on waste composition. This procedure requires careful laboratory testing.

  3. Validity aspects in Chernobyl at twenty years of the accident; Aspectos vigentes en Chernobyl a veinte anos del accidente

    Arredondo, C. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail:


    For April 25, 1986 the annual stop of the unit 4 of the nuclear power plant of Chernobyl was programmed, in order to carry out maintenance tasks. This unit was equipped with a reactor of 1000 MW, type RBMK, developed in the former Soviet Union, this type of reactors uses graphite like moderator, the core is refrigerated with common water in boil, and the fuel is uranium enriched to 2%. Also it had been programmed to carry out, before stopping the operation of the power station, a test with one of the two turbogenerators, which would not affect to the reactor. However, the intrinsic characteristics of the design of the reactor and the fact that the operators disconnected intentionally several systems of security that had stopped the reactor automatically, caused a decontrolled increase of the power (a factor 1000 in 4 seconds), with the consequent fusion of the fuel and the generation of a shock wave, produced by the fast evaporation of the refrigeration water and caused by the interaction of the fuel fused with the same one. It broke the core in pieces and destroy the structure of the reactor building that was not resistant to the pressure. When being exposed to the air, the graphite of the moderator entered in combustion, while the radioactive material was dispersed in the environment. The radionuclides liberation was prolong during 10 days, and only it was stopped by means of the one poured from helicopters, of some 5000 tons of absorbent materials on the destroyed reactor, as long as tunnels were dug to carry out the cooling of the core with liquid nitrogen. Later on, the whole building of the damaged reactor was contained inside a concrete building. The immediate consequence of the accident was the death of 31 people, between operators of the nuclear power station and firemen. One of people died as consequence of the explosion and 30 died by cause of the irradiation, with dose of the order of 16 Gy. The liberated radioactive material was the entirety of the

  4. Cooperation in Nuclear Waste Management, Radiation Protection, Emergency Preparedness, Reactor Safety and Nuclear Non-Proliferation in Eastern Europe

    Dassen, Lars van; Delalic, Zlatan; Ekblad, Christer; Keyser, Peter; Turner, Roland; Rosengaard, Ulf; German, Olga; Grapengiesser, Sten; Andersson, Sarmite; Sandberg, Viviana; Olsson, Kjell; Stenberg, Tor


    The Swedish Radiation Safety Authority (SSM) is trusted with the task of implementing Sweden's bilateral assistance to Russia, Ukraine, Georgia, Belarus and Armenia in the fields of reactor safety, nuclear waste management, nuclear non-proliferation as well as radiation protection and emergency preparedness. In these fields, SSM also participates in various projects financed by the European Union. The purpose of this project-oriented report is to provide the Swedish Government and other funding agencies as well as other interested audiences in Sweden and abroad with an encompassing understanding of our work and in particular the work performed during 2008. the activities are divided into four subfields: Nuclear waste management; Reactor safety; Radiation safety and emergency preparedness; and, Nuclear non-proliferation. SSM implements projects in the field of spent nuclear fuel and radioactive waste management in Russia. The problems in this field also exist in other countries, yet the concentration of nuclear and radioactive materials are nowhere higher than in north-west Russia. And given the fact that most of these materials stem from the Cold War era and remain stored under conditions that vary from 'possibly acceptable' to 'wildly appalling' it is obvious that Sweden's first priority in the field of managing nuclear spent fuel and radioactive waste lies in this part of Russia. The prioritisation and selection of projects in reactor safety are established following thorough discussions with the partners in Russia and Ukraine. For specific guidance on safety and recommended safety improvements at RBMK and VVER reactors, SSM relies on analyses and handbooks established by the IAEA in the 1990s. In 2008, there were 16 projects in reactor safety. SSM implements a large number of projects in the field of radiation protection and emergency preparedness. The activities are at a first glance at some distance from the activities covered and


    Bradley, D. J.; Schneider, K. J.


    The Soviet Union operates a vast and growing radioactive waste management system. Detailed information on this system is rare and a general overall picture only emerges after a review of a great deal of literature. Poor waste management practices and slow implementation of environmental restoration activities have caused a great deal of national concern. The release of information on the cause and extent of an accident involving high-level waste at the Kyshtym production reactor site in 1957, as well as other contamination at the site, serve to highlight past Soviet waste management practices. As a result, the area of waste management is now receiving greater emphasis, and more public disclosures. Little is known about Soviet waste management practices related to uranium mining, conversion, and fuel fabrication processes. However, releases of radioactive material to the environment from uranium mining and milling operations, such as from mill tailings piles, are causing public concern. Official Soviet policy calls for a closed fuel cycle, with reprocessing of power reactor fuel that has been cooled for five years. For power reactors, only VVER-440 reactor fuel has been reprocessed in any significant amount, and a decision on the disposition of RBMK reactor fuel has been postponed indefinitely. Soviet reprocessing efforts are falling behind schedule; thus longer storage times for spent fuel will be required, primarily at multiple reactor stations. Information on reprocessing in the Soviet Union has been severely limited until 1989, when two reprocessing sites were acknowledged by the Soviets. A 400-metric ton (MT) per year reprocessing facility, located at Kyshtym, has been operational since 1949 for reprocessing production reactor fuel. This facility is reported to have been reprocessing VVER-440 and naval reactor fuel since 1978, with about 2000 MT of VVER-440 fuel being reprocessed by July 1989. A second facility, located near Krasnoyarsk and having a 1500 MT per

  6. Condensed Matter Nuclear Science

    Biberian, Jean-Paul


    . Bloch ions / T. A. Chubb. II. Inhibited diffusion driven surface transmutations / T. A. Chubb. III. Bloch nuclides, Iwamura transmutations, and Oriani showers / T. A. Chubb. Bose-Einstein condensate. Theoretical study of nuclear reactions induced by Bose-Einstein condensation in Pd / K.-I. Tsuchiya and H. Okumura. Proposal for new experimental tests of the Bose-Einstein condensation mechanism for low-energy nuclear reaction and transmutation processes in deuterium loaded micro- and nano-scale cavities / Y. E. Kim ... [et al.]. Mixtures of charged bosons confined in harmonic traps and Bose-Einstein condensation mechanism for low-energy nuclear reactions and transmutation processes in condensed matters / Y. E. Kim and A. L. Zubarev. Alternative interpretation of low-energy nuclear reaction processes with deuterated metals based on the Bose-Einstein condensation mechanism / Y. E. Kim and T. O. Passell. Multi-body fusion. [symbol]He/[symbol]He production ratios by tetrahedral symmetric condensation / A. Takahashi. Phonon coupling. Phonon-exchange models: some new results / P. L. Hagelstein. Neutron clusters. Cold fusion phenomenon and solid state nuclear physics / H. Kozima. Neutrinos, magnetic monopoles. Neutrino-driven nuclear reactions of cold fusion and transmutation / V. Filimonov. Light monopoles theory: an overview of their effects in physics, chemistry, biology, and nuclear science (weak interactions) / G. Lochak. Electrons clusters and magnetic monopoles / M. Rambaut. Others. Effects of atomic electrons on nuclear stability and radioactive decay / D. V. Filippov, L. I. Urutskoev, and A. A. Rukhadze. Search for erzion nuclear catalysis chains from cosmic ray erzions stopping in organic scintillator / Yu. N. Bazhutov and E. V. Pletnikov. Low-energy nuclear reactions resulting as picometer interactions with similarity to K-shell electron capture / H. Hora ... [et al.] -- 5. Other topics. On the possible magnetic mechanism of shortening the runaway of RBMK-1000 reactor