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Sample records for cernavoda npp unit

  1. NPP Cernavoda Unit 2 Financing Completion Works

    Chirica, T.; Stefanescu, A.; Constantin, C.; Dobrin, M.

    2002-01-01

    NPP Cernavoda Unit 2 completion is the highest priority of the Romanian power sector strategy. The nuclear energy represents, through its technological features of adopted solution (a CANDU nuclear power plant) and also through technological and economical performance indicators, the best solution to fulfill the demands concerning the sustainable development and the electricity request. The guidelines of energy strategy regarding the nuclear sector development in Romania are framing in the general policy for energy system development at least costs and they are responding to requests concerning the environment and people protection. The paper presents the financing alternatives for Unit 2 completion works taking into consideration the financing market conditions. The paper presents the impact of the financing conditions on the project efficiency, as well as the facilities offered by the Romanian Government in order to support this project. (author)

  2. Balancing preventive and corrective maintenance in Cernavoda Unit 1 NPP

    Riedel, M.; Marinescu, S.

    2000-01-01

    The paper presents a short reminder of Romania's Cernavoda NPP entering commercial operation and a brief description of the CANDU-6 project on which Unit 1 is based. The short term objectives of the maintenance management, the status of the existing maintenance programmes as well as future predictable maintenance programmes are outlined together with the Government plan to complete the balance of NPP. (author)

  3. Cernavoda NPP Unit 1 - a plant of several generations

    Rotaru, I.; Metes, M.; Anghelescu, M.S.

    2001-01-01

    The paper reflects some key aspects related to the shift of generations during the project's development, including the present stage. Further, the place of Cernavoda NPP Unit 1 in the Romanian power sector and among other nuclear stations in the world is presented. The operational performances achieved 'in service' up to the end of 1999, with reference to the performance indicators for electrical energy production, nuclear safety, radiation protection, radioactive wastes and nuclear fuel are illustrated. For all of these items, comparisons are performed with similar indicators reported by other worldwide nuclear power plants, in order to assess our results. Finally, some comments about Cernavoda NPP Unit 2 project status and need to completion and commissioning it are included. (authors)

  4. Cernavoda NPP Unit 1 - a plant of several generations

    Rotaru, I.; Metes, M.; Anghelescu, M.S.

    2000-01-01

    Cernavoda NPP Unit 1, the first nuclear power unit in Romania, has a long and tormented history. It represents a rather unique case in Eastern Europe. The project started well before 1989 (the construction phase lasted 17 years and generations were involved in its completion), but it is effectively based on western technology (Candu). Meanwhile, the national nuclear program underwent many changes, affecting the lives and careers of Romanian nuclear professionals. Finally, on December 2 nd 1996, the unit began its c ommercial operation , being operated at its nominal power rating of 706 MW e . It now provides a reliable source of electricity for Romanian economy, supplying to the national grid about 10% of the country's average annual demand. The paper reflects some aspects related to the shift of generations during the project's development, including the present stage. The operational performances achieved 'in service' by Cernavoda NPP Unit 1 up to the end of 1999 , are also presented. Reference to the electrical energy production, performance indicators, production costs, nuclear safety, radiation protection, radioactive wastes, nuclear fuel consumption and nuclear fuel performances are included. Comparisons are performed with similar indicators reported by other worldwide nuclear power plants, in order to assess our results. (authors)

  5. Implementing the Environmental Management System ISO 14001 at the Cernavoda NPP Unit 1

    Jelev, Adrian

    2003-01-01

    An environmental management plan (EMP) has been developed for the Cernavoda NPP Unit 1. It contains the necessary components for identification and management of the environmental aspects of NPP. The environmental policy of the 'Nuclearelectrica' National Society and the associated EMP are the basis for the Environment Management System that will be implemented at Cernavoda NPP. The final step of this process will be the ISO 14001 certification. This paper points out to the main aspects concerning the implementation of the ISO 14001 system at Cernavoda NPP Unit 1. (author)

  6. Risk management solutions for Cernavoda Unit #2 NPP completion

    Chirica, T.; Pall, S.

    2002-01-01

    The greatest risk facing today's electric utilities is change. Utility risk managers are being challenged to address the changes of deregulation, new technologies and changing work force. The utilities must be more aware of where all its costs are located to face with the challenge of competition, forcing them to respond with lower prices and innovative services. For completion of large projects, like Cernavoda NPP, Unit 2, the utilities are facing also with certain specific risks: politic, economic, social. The natural perils or machinery breakdown are common risks for operation as well as for construction-commissioning projects. Beyond the explicit challenges associated with the completion of a nuclear power plant in a transition economy environment, the utilities are facing with new risk factors such as professional liability, political risk, product warranty and liability, international exposure, etc. Changes in other governmental policies are also affecting large projects, mentioning healthcare, workplace safety, workers' compensation, environmental clean up, etc.(author)

  7. Financing Nuclear Projects. Case Study: Unit 2 Cernavoda NPP

    Chirica, Teodor; Constantin, Carmencita; Dobrin, Marian

    2003-01-01

    The implementation of a Nuclear Power Plant (NPP) is a major undertaking for all entities involved, due to the necessity of planning work and coordination of the implementation process of the different fields of interest, starting with the governmental authorities and ending with the public. Having in view the specific investment costs (relatively high) for a NPP, finding an adequate financing structure is possible through an iterative process that involves first an assessment of the technical performances of the project and secondly, the mathematical modelling of the financing structure effects on the projects. In this respect, the paper will be focused on the main steps needed in order to promote an investment project in nuclear field, starting with the decision phase, providing the documentation requested by the local and international authorities to promote the project and ending with the negotiation of the contracts (commercial contract, financing contract, purchase contract, etc). The case study will be focused on the phases achieved in order to promote the Unit 2 NPP Cernavoda completion works project. (authors)

  8. Financing nuclear projects. Case study: Unit 2 Cernavoda NPP

    Chirica, T.; Pall, S.; Lebedev, A.; Dobrin, M.

    2003-01-01

    The implementation of a Nuclear Power Plant (NPP) in a country is a major undertaking for all entities involved, due to the necessity of planning work and co-ordination of the implementation process of the different fields of interest, starting with the governmental authorities and ending with the people. Having in view the specific investment cost (relatively high) for a NPP, to find an adequate financing structure is possible through an iterative process that involves first an assessment of the technical performances of the project and second, the mathematical modelling of the financing structure effects on the project. In this respect, the paper proposed will be focused on the main steps needed in order to promote an investment project in nuclear field, starting with the decision phase, providing the documentations requested by the local and international authorities to promote the project and ending with the negotiation of the contracts (commercial contract, financing contract, power purchase contract, etc.) The case study will be focused on the phases achieved in order to promote the Unit 2 Cernavoda NPP completion works project. (author)

  9. Specific aspects for Cernavoda - Unit 1 NPP life assurance

    Rucareanu, R.

    2002-01-01

    Full text: The main scope of a Plant Life Management Program is to operate the NPP in a safe manner and at a competitive cost during the reactor life. To achieve this goal, it is important to continuously evaluate the degradation of the main structures and components of the NPP. Background -Cernavoda NPP design life is 30 years. Compared with this target, the operation history is not long (Unit 1 is in commercial operation since 1997). It is still important to begin a plant life management program early to identify the critical components and structures, to establish the data needed for their monitoring and to find methods to mitigate their degradation. A specific aspect for Cernavoda NPP - Unit 1 is the long delay between the fabrication of the main components and the start-up. Most components were procured 10-15 years before start-up. First criticality was achieved in 1996, but the containment perimeter wall sliding was complete in 1983, the Calandria vessel was installed in 1985, the Steam Generators were in position in 1987, the fuel channels were installed in 1989. In evaluating the history of these components, the preservation period must be observed. For Unit 2, which will be in service around 2005, the delay will be longer. For this reason, CNCAN (the Romanian Regulatory Authority) imposed, as a condition to resume the work, to evaluate the ageing of the existing components and structures in order to establish their acceptability for use in the plant. The results of this evaluation can be used as references for subsequent evaluations. Plant Life Assurance Programme - The first step of a PLIM programme is to identify the components and structures that are important for the plant life management. Critical components and structures selection is done using the following criteria: safety criteria - components and structures whose failure can cause a release of radioactivity or which have to mitigate the release of radioactivity in case of a failure of other

  10. Configuration management and change control at Cernavoda NPP Unit 1

    Gheorghiu, Virgil

    1998-01-01

    Effective configuration management requires that: 1. the design basis of station structures, systems, equipment and components be maintained at all times; 2. only accurate and approved technical, operational and maintenance information is available for performance of station activities; 3. correct operating manuals, flowsheets, operating sequences, operating task and training manuals are prepared and maintained currently. Design Engineering at Cernavoda NPP is primarily the responsibility of the Engineering Services Department supported if necessary by the Technical Unit. The key elements needed to achieve excellence in design engineering support for station operation, including design process and implementation of modification are investigated by answering the questions: 1. What is the station expectation for design change control?; 2. How is this provided?. Concerning design, the following aspects are stressed: Detailed Design Development; Design Verification; Design Change Implementation. The present design process is auditable and well documented. It consists of detailed design development, and design output documents such as applicable drawings, procurement specifications, installation and test requirement and the results of design and safety reviews. The design change implementation does not proceed until an Inspection Test Plan has been developed and approved as required. (author)

  11. Cernavoda NPP Unit 2 and Romanian nuclear industry

    Mocanu Horia

    2001-01-01

    On 18 May 2001, in the presence of Mr. Adrian Nastase, the Prime-Minister of Romania, the presidents of AECL, ANSALDO and Director General of SN Nuclearelectrica, the commercial and management contract for completing the Cernavoda NPP Unit 2 was signed. This document stipulates the goal and the partners' commitments, leadership organization, the SN Nuclearelectrica's control of the Budget, costs for the technical assistance (around 180 specialists from abroad), as well as the costs of equipment supplied from Canada and Italy. Services and equipment supplied by Canada and Italy amounts up to around USD 300 millions. Efforts are currently undertaken to obtain a loan of USD 300 millions from EURATOM, beginning from 2003. An auction process, implying around 10 companies, is underway and by the completion of the process, in February 2002, the practical delivery of equipment will start. The so-far invested capital amounts around USD 650 millions while the capital funds remaining to be invested amounts up to about USD 689 millions. From the latter figure, around USD 100 millions represent the costs for heavy water and the initial nuclear fuel charging. The personnel dynamics is presented as well as problems relating with recruitment and salary policy. Romanian nuclear industry is engaged for supply of a series of important components. General Turbo SA, supplied already components of some tens USD millions for the turbogenerator complex. PETROTUB company from Roman, Romania supplied already one thousand tones of non-nuclear carbon steel tubing valued at about USD 300 millions. ARIO, Bistrita, Romania, has signed contracts valued at about USD 400,000 for non-nuclear reinforcing materials. Other companies like AVERSA SA and Ventilatorul SA supplied reliable equipment for Unit 1 and will continue to do the same for Unit 2. Contracts of over one million USD are carried on with VULCAN for carbon steel fittings and with TITAN Nuclear Equipment for components of the fueling

  12. Experimental determinations of the turbine condenser operation at Cernavoda NPP Unit 1

    Romascu, Gabriel; Dragusin, Dumitru; Rogociu, Ioan; Macodean, Luminita; Marciulescu, George

    1999-01-01

    The condenser system represents one of the most important BOP (balance of plant) systems of the CANDU 700 MW Unit at Cernavoda NPP. The paper presents theoretical calculation elements, mathematical model for simulation of condenser operation and the results obtained by model implementation as compared to operation data. The model could be adapted to other turbine and operation regime types. (authors)

  13. Cernavoda NPP Unit 2: 'A year of progress'

    Cullen, Ronald G.

    2004-01-01

    available for installation. An unfortunate incident in shipping of the generator stator from the USA at the end of 2003 meant a delay in the delivery by 10 months. Through a major team effort by all concerned the unit was rebuilt and delivery successfully effected in November. All of the major obstacles have been overcome and the project is currently on schedule. The project has now completed 482 days of work without a lost time accident which is notable considering that over 4 million man-hours were worked during this period. AECL Canada and ANSALDO Energia have worked hard to support the project. The foreign engineering scope of work is nearing completion and all contract scope purchase orders have been placed with most deliveries now completed. Work still continues on procurement to support the commissioning of the plant systems. The success to date is attributed partly to providing a strong Management Team consisting of personnel who bring experience from similar projects in China, Italy and of course Cernavoda Unit 1. The client and Romanian ministry of trade and industry are fully supportive of the project and working as a team with the MT is a key element to meeting the challenges that exist on a large project such as the Cernavoda 2 Plant and has been a key factor in the success to date. The coming year will be no less demanding, by the end of 2005 virtually all systems will be transferred from the construction to the commissioning group. The key issue that will have to be addressed by the project will be acquiring sufficient site construction contractor's manpower to meet the demands imposed by the aggressive systems turn over schedule and delivery of large amounts of materials. Commissioning will also have a major challenge to keep up with some 25 systems being turned over on a monthly basis. Staffing levels for Construction Division will be reduced while a similar increase will occur in Commissioning. With the support of the client SNN the Management Team at

  14. Cernavoda NPP Knowledge Transfer

    Valache, C. M.

    2016-01-01

    Full text: The paper presents a description of the Knowledge Transfer (KT) process implemented at Cernavoda NPP, its designing and implementation. It is underlined that applying a KT approach should improve the value of existing processes of the organization through: • Identifying business, operational and safety risks due to knowledge gaps, • Transfer of knowledge from the ageing workforce to the peers and/or the organization, • Continually learning from successes and failures of individual or teams, • Convert tacit knowledge to explicit knowledge, • Improving operational and safety performance through creating both new knowledge and better access to existing knowledge. (author

  15. The contract for the completion and commissioning of Cernavoda NPP - Unit

    2001-01-01

    On May 18, 2001 the commercial contract for the completion and commissioning of the Cernavoda NPP Unit 2 has been signed by Nuclearelectrica National Company (SNN SA) and its partners, AECL-Canada and ANSALDO-Italy. This contract represents a continuation of the cooperation with AECL-Canada (the owner of the licence and the designer of the nuclear part of Cernavoda NPP Unit1) and ANSALDO-Italy (the designer of the conventional part of Cernavoda NPP Unit1). The completion is scheduled to last for 54 months (4.5 years) since the date the contract takes effect and the nuclear reactor start-up (the first criticality) is scheduled for the 49 th month. The total negotiated cost for the completion was estimated to amount to 689 million dollars, against the 750 million dollars initially estimated. The works at the site will be managed by an integrated staff team of specialized personnel form AECL-Canada (111 positions), ANSALDO-Italy (72 positions) and Romania (1200 positions)

  16. Cernavoda NPP simulator - next generation

    Tatar, F.; Ionescu, T.; Dascalu, M.

    2003-01-01

    Demand for extending the amount of training and scope for Cernavoda Unit 1 as well as the new trend in the simulator owners world, led to a change in the Romanian philosophy of simulator specification. Up to now the training was conducted on a Full Scope simulator, a 1:1 replica of Cernavoda Unit 1 reference plant. The present task is to define the simulation facilities and structure capable to meet the requirements for training, qualification and licensing of personnel for both Cernavoda Unit 1 and Unit 2. Obviously, the Cernavoda Unit 2 belongs to the same technological family but has rather different control room layout. Since this target requires a new simulator the costs would be rather high in accordance to the degree of automation of Cernavoda NPP. Therefore, depending on training requirements and financing, the Cernavoda Unit 1 simulator modernization, which also provides an alternative to full scope control room simulator, may be a viable option. Therefore the solution that with discuss for Cernavoda training extension is the migration of Cernavoda Unit 1 simulator to state-of-the-art. Consequently, the Cernavoda Unit 1 simulator modernization task will be organized as project including the following major items: 1. Rehost existing U1 simulation software from VAX 4500 to: - Best commercial multi-processor server for simulation server (HP, O/S Linux); - Best commercial single processor PC for I/O communications (HP, O/S Linux); 2. Replace DCC with enhanced emulated version: Best commercial individual PC for DCC emulation (HP, O/S Windows); Support for actual keyboards; Replacement of RAMTEK System and CONRAC Monitors with X terminals or PC's; 3. Conversion of AutoCAD-based panel graphic pages to RAVE-based; 4. Install the required software tools for developing enhanced simulation modules; 5. Replace the simulation modules with advanced modules; 6. Replace the present Windows Instructor Facilities with ISIS; 7. Development of a selection of MCR-U1 virtual

  17. ICEMENERG technologies of water treatment applied at Cernavoda NPP Unit 1

    Stanca, Angela; Bolma, Aurelia; Serbanescu, Agnes; Raducanu, Alice

    2002-01-01

    The paper presents the ICEMENERG technologies for water treatment applied at Cernavoda Unit 1, the treatment of the additional water for power steam generators and the chemical treatment of cooling system water. The requirements for quality of water totally demineralized as imposed by the AECL-ANSALDO consortium are as following: electrical conductivity, < 0.2 mS/cm; total silicon, <0.02 mg/L; ionic silicon, <0.01 mg/L; sodium, < 0.05 mg/L; TOC, <0.300 mg/L. These requirements raise rather difficult problems to be solved because the raw water source in case of Cernavoda NPP is Danube River which presents a raising trend of organic and inorganic contamination. Accordingly, experiments at laboratory scale reproducing the entire technological flow were conducted. The following operations were studied: pretreatment with limewash, ferric chloride (with and without coagulation additives); demineralization with ion exchangers of Purolite and Amberlite types. The system consisted of a cationic stage, formed of an strongly acid step with countercurrent recovery and an anionic stage formed of two steps, namely, a weakly basic step and a strongly basic step with recovery inserted; finishing on mixed bed. The paper presents also the chemical treatment/conditioning of the cooling loop of turbine condenser. The Cernavoda NPP cooling system is an open system with a single flow of cooling water comprising two systems, namely, the circulation water system ensuring the steam condenser cooling and the servicing water system ensuring the cooling of heat exchangers in the recirculated water circuit (RCWS), the turbine oil coolants, the coolants of auxiliary steam as well as the emergency core cooling system. Studies were conducted to ensure the chemical conditioning of the raw water from Danube River, particularly, to destroy and remove the shells, the algae and other components. Finally, the following four steps of conditioning the water of the cooling system are summarized: 1

  18. Public debates - key issue in the environmental licensing process for the completion of the Cernavoda NPP Unit 2

    Rotaru, Ioan; Jelev, Adrian

    2003-01-01

    SN 'NUCLEARELECTRICA' S.A., the owner of Cernavoda NPP, organized, in 2001, several public consultations related to environmental impact of the completion of the Cernavoda NPP Unit 2, as required by the Romanian environmental law, part of project approval. Public consultations on the environmental assessment for the completion of the Cernavoda NPP - Unit 2 took place in 2001 between August 15 and September 21 in accordance with the provisions of Law No. 137/95 and Order No. 125/96. Romanian environmental legislation, harmonization of national environmental legislation with European Union, Romanian legislative requirements, information distributed to the public, issues raised and follow-up, they all are topics highlighted by this paper and they are addressing the environmental licensing process of the Cernavoda 2 NPP. The public consultation process described fulfils all the Romanian requirements for carrying out meaningful consultation with its relevant shareholders. The process also satisfies EDC (Export Development Corporation - Canada) requirements for public consultation and disclosure with relevant shareholders in the host country. SNN is fully committed to consulting as necessary with relevant shareholders throughout the construction and operation of the Project. Concerns of the public have been taken into account with the operations of Unit 1 and will continue to be addressed during the Unit 2 Project

  19. Considerations related to Cernavoda NPP lifetime management

    Cojan, Mihail

    2007-01-01

    Cernavoda NPP, the first CANDU in Europe, is one of the original CANDU 6 plants and the first CANDU 6 producing over 706 MWe. While the first series of CANDU 6 plants (which entered service in the early 1980 s) have now reached the 2/3 of their 30 years design life, the Cernavoda NPP was put into service on the 2nd December 1996. After 10 years of operation the Plant Life Management (PLiM) Program for Cernavoda should be an increasingly important program to Utility ('CNE - Prod') in order to protect the investment and the continued success of plant operation. The goal of the paper is to present some considerations related to Cernavoda NPP lifetime management. The Plant Life Management Program, known as PLiM Program is concerned with the analysis of technical limits of the safe operation - from the point of view of nuclear safety - in NPP units, aiming at attaining the planned 30 years life duration and its extension to 40 or even 50 years of safe and economical operation. For the CANDU reactors the so-called PLiM and PLEX Programs are just applied. These are applied research programs that approach with priority the current practices for assessing the capability of safe operation within the limits of nuclear safety (fitness-for-service assessment). These programs also approach inspection, monitoring are prevention of degrading due to the ageing of critical systems, structures and components (CSSCs). As each nuclear plant is somewhat different in its components and systems, materials composition, procurement, construction, and operational history, directed research and development programs into materials behavior, monitoring techniques, and methods to mitigate ageing are required to support the lifetime management. Over the past 6 years, INR Pitesti (Institute for Nuclear Research - Romania) has been working on R and D Programs to support a comprehensive and integrated Cernavoda NPP Life Management Program (PLiM) that will see the Cernavoda NPP successfully and

  20. Overview of Cernavoda NPP training programme

    Valache, Cornelia

    2005-01-01

    Full text: The paper presents a general assessment of Cernavoda NPP personnel training programme, highlighting the role of training in human performance improvement. Cernavoda NPP Personnel Training and Authorization Department (PTAD) is the one responsible for the training of Unit 1 and 2 staff. PTAD is structured in such a manner as to support and respond to all Cernavoda NPP training, qualification and authorization requirements. The training of personnel is continuously adapted based on IAEA Guides and INPO/WANO recommendations, to keep with world standards, based on the internal and external reviews. At Cernavoda NPP the Training Concept and the Training Programmes are based on SAT - Systematic Approach to Training. The Training Concept is established on a set of training documents (RD's, SI's, IDP's), which address all the SAT phases: Analysis, Design, Development, Implementation and Evaluation. The Training Programmes are structured on the initial and continuing personnel training. Their content and goals respond to the training specific needs for each plant major job family. In order to successfully support NPP training programmes, CNPP training center has upgraded classrooms with new presentation facilities and there are plans to expand the space of the building, to develop additional operator and maintenance skills facilities. There are also a number of general areas for improvement of PTAD activity, such as operators and maintenance training, initial and continuing training of both Unit 1 and 2 staff. By responding in a timely and completely manner to all plant training requirements PTAD will help in rising human performance of Cernavoda NPP personnel, supporting the safe, efficient and cost effective production of power. (author)

  1. Analysis of electrical systems from Cernavoda NPP - Unit 1 based on commissioning activity

    Goia, M.L.; Manolescu, I.

    1996-01-01

    Several design solutions regarding the electrical part of Cernavoda NPP Unit 1 station auxiliaries are discussed in this paper. The solutions mentioned may have different variants which should be taken into consideration in the design of Units U2 - U5. This work offers an ample debate on such matters as the supply source connection of the station auxiliaries, the use of two different voltages for the mean voltage (MV) supply, the consequence of the lack of breakers on the 24 kV part of station auxiliary transformers T03 - T04, the protection devices non correlated with the breakers to which they react, as well as the consequences of low subtransient reactance of the new stand-by Diesel generators. Besides these design solutions that can influence the station auxiliaries reliability, matters as malfunctioning of the dry type MV/LV transformers and unreliable behaviour of some MV composite insulators are also discussed. For some of the above mentioned problems the authors proposed several solutions. (authors). 1 fig., 1 tab

  2. Cernavoda NPP Unit 1: Ensuring heat sink at very low Danube river levels

    Urjan, D.

    2005-01-01

    Full text: On August 24, 2003 the summer heat wave has caused the Danube River to drop to its lowest level in more than a century, forcing a government commission of experts and a team of technical specialists from Cernavoda NPP to close Romania's unique nuclear reactor in operation at Cernavoda. The paper presents some of the required actions needed for plant shutdown and ensuring adequate fuel cooling at very low suction bay levels, due to the Danube River level drop (Danube waters cools the reactor). The water level in the Danube River at Cernavoda village, where the reactor is located, fell to a depth of less than three meters (10 feet) on Saturday, down from its usual level of almost seven meters (23 feet). Consequently, the Unit 1 nuclear power plant was shut down Sunday due to this record drought, which left insufficient water to cool down the reactor. Operating Instruction procedures were elaborated in order to provide a logical sequence of actions when the bay level decreases under 2.25 m, or the estimated level after 3 days will be lower than 1.8 m. When Raw Service Water (RSW) is lost, Recirculated Cooling Water (RCW) will remain in service only for Moderator, ESC, HT Pumps, HT Purification, D/C Cooler, LAC's, and D 2 O Feed Pump. Alternate water sources, like potable water and water from the fire protection system were taken in consideration in order to ensure heat sink to the RCW loads. At the same time, in case of total loss of Class III and Class IV Power, and Stand-By Diesel Generators unavailable because of the loss of heat sink provided by the RSW, Emergency Power System (EPS) was configured to supply directly the Class III Power 6 kV bus (BUG bus). Economical Impact According to a report, closing the nuclear plant costs Romania $500,000 a day. The total cost includes also losses due to a 40 percent reduction in hydroelectric power generation due to reduced river flow. The country had to cease power exports until the reactor comes back on line

  3. An integrated approach for investigation of failed nuclear fuel used at NPP Cernavoda Unit 1

    Tuturici, I.L.; Parvan, M.; Popov, M.; Dobrin, R.; Staicu, C.

    1996-01-01

    At NPP Cernavoda-Unit 1 the fuel surveillance and the defect detection system in operation are based on monitoring the coolant activity concentration and on measuring the flux of delayed neutrons emitted by some short-lived fission products. In order to identify the failed fuel underwater non-destructive examination has to be performed. The major interest for the availability of underwater examination consists in the necessity of a speedy acquisition of the data on failed fuel in operation and of appropriate follow-up actions to be taken. Often the identification operation will be followed by more detailed examinations on selected fuel rods in the hot cells of the Post-irradiation Examination Laboratory of the Institute for Nuclear Research at Pitesti. Transfer of selected fuel rods will be done by the use of a type B(U) road transportation cask. Such an integrated approach will help to keep the level of activity concentration of the primary circuit well below the authorized limits. (author). 2 figs., 1 tab., 2 refs

  4. NPP Cernavoda unit 2 economic viability: The challenge for an advanced financing scheme

    Condu, M.; Popescu, D.

    1999-01-01

    The completion of Cernavoda Unit-2 being no doubt, the viability of the project was analyzed and strengthened. Economic justification of the decision to complete Unit-2 is described, including assessment of its safety design guides, design requirements and engineering design solutions in the light of changes in codes, guideline, standards and actual regulatory requirements. Cost-benefit analysis demonstrates the economic viability of the project

  5. Characterisation of radioactive waste at Cernavoda NPP Unit 1 during normal operation

    Iordache, M.; Bujoreanu, L.; Popescu, I. V.

    2008-01-01

    During the operation of a nuclear plant significant quantities of radioactive waste results that have a very large diversity. At Cernavoda NPP the important waste categories are non-radioactive wastes and radioactive wastes, which are manipulated completely different from which other. For a CANDU type reactor, the production of radioactive wastes is due to contamination with the following types of radioactive substances: - fission products resulting from nuclear fuel burning; - activated products of materials which form part of the technological systems; - activated products of process fluids. Radioactive wastes can be in solid, liquid or gas form. At Cernavoda NPP the solid wastes represent about 70% of the waste volume which is produced during plant operation and as a consequence of maintenance and decontamination activities. The most important types of solid wastes that are obtained and then handled, processed (if required) and temporarily stored are: solid low level radioactive wastes (classified as compact and non-compact), solid medium radioactive wastes, spent resins, used filters and filter cartridges. The liquid radioactive waste class includes organic liquids (used oil, scintillator liquids and used solvents) and aqueous wastes resulting from process system operating, decontamination and maintenance operations. Radioactive gas wastes occur subsequent to the fission process inside the fuel elements as well as due to the process fluids neutron activation in the reactor systems. As result of the plant operation, iodine, noble gases, tritium and radioactive particles occur and are passed to the ventilation stack in a controlled manner so that an exceeding of the maximum permissible concentrations of radioactive material to the environment should not occur. (authors)

  6. Strengthening the control on radioactive sources - Cernavoda NPP operating experience

    Daian, I.; Simionov, V.

    2005-01-01

    This paper presents the national legal frame governing the radioactive source management, legislative requirements introduced during last years and current status of controlled radioactive sources program at Cernavoda NPP. Romania has only one nuclear power plant, Cernavoda NPP, equipped with five PHWR - CANDU-6 Canadian type reactors - with a 700 MW(e) gross capacity each, in different implementation stages. The legal representative of the nuclear power production sector in Romania is 'Nuclearelectrica' S.A. National Company (SNN). SNN is a governmental company controlled by the Ministry of Industry and Trade. The company has headquarters in Bucharest and three subsidiaries: - CNE-PROD Cernavoda (CNE-PROD), operating the Cernavoda NPP - Unit 1; - CNE-INVEST Cernavoda, in charge with the completion of Unit 2 and with the preservation of Units 3,4,5; - Nuclear Fuel Plant in Pitesti (FCN). Unit 1 is in commercial operation since December 2, 1996, Unit 2 is under construction (80% completed) and Units 3, 4, 5 are under preservation. The operation of Cernavoda NPP implies use of radioactive sources that may present a significant risk to health, property and the environment when control is lost. Within the last years CNCAN issued new regulations stating clear responsibilities for the different institutions involved in radioactive materials control programs. To manage radioactive sources in a safe way CNE-PROD established and revised the Controlled Radioactive Sources Program, as part of Station Radiation Protection Regulation, ensuring strict recording of the radioactive sources and their usage, ensuring physical and radiological security, protecting the personnel, members of the public and the environment from the hazards of ionizing radiation during the life cycle of the plant, including decommissioning. (authors)

  7. Strengthening the control on radioactive sources - Cernavoda NPP operating experience

    Daian, I.; Simionov, V.

    2005-01-01

    Full text: This paper presents the national legal frame governing the radioactive source management, legislative requirements introduced during last years and current status of controlled radioactive sources program at Cernavoda NPP. Romania has only one nuclear power plant, Cernavoda NPP, equipped with five PHWR - CANDU-6 Canadian type reactors - with a 700 MW(e) gross capacity each, in different implementation stages. The legal representative of the nuclear power production sector in Romania is 'Nuclearelectrica' S.A. National Company (SNN). SNN is a governmental company controlled by the Ministry of Industry and Trade. The company has headquarters in Bucharest and three subsidiaries: - CNE-PROD Cernavoda (CNE-PROD), operating the Cernavoda NPP - Unit 1; - CNE-INVEST Cernavoda, in charge with the completion of Unit 2 and with the preservation of Units 3,4,5; - Nuclear Fuel Plant in Pitesti (FCN). Unit 1 is in commercial operation since December 2, 1996, Unit 2 is under construction (80% completed) and Units 3, 4, 5 are under preservation. The operation of Cernavoda NPP implies use of radioactive sources that may present a significant risk to health, property and the environment when control is lost. Within the last years CNCAN issued new regulations stating clear responsibilities for the different institutions involved in radioactive materials control programs. To manage radioactive sources in a safe way CNE-PROD established and revised the Controlled Radioactive Sources Program, as part of Station Radiation Protection Regulation, ensuring strict recording of the radioactive sources and their usage, ensuring physical and radiological security, protecting the personnel, members of the public and the environment from the hazards of ionizing radiation during the life cycle of the plant. (authors)

  8. Results and development prospects for the Cernavoda NPP

    Rotaru, Ioan

    2001-01-01

    The new competitive market in the power sector offers favorable conditions for continual developing of Nuclear Power in Romania. The principal arguments in this respect are: the CANDU technology is a western technology recognized world wide both for its operation reliability and its economical performances. The results obtained by Cernavoda NPP Unit 1 over a period of four years and a half commercial operation confirms the validity of the CANDU project in Romania in the new conditions of competitive market. Accomplishing the Unit 2 of Cernavoda NPP represents for the time being one of the most cost-effective investment in the Romanian power sector. Also, the participation of the local industry to the project implementation is important as it ensures the initial heavy water and nuclear fuel charging, specific materials and equipment production, design and construction works, etc. Heaving in view all these favorable arguments, the construction of Unit 2 of Cernavoda NPP represents one of the highest priorities of the State Budget of the present administration in year 2001. The Nuclear Power Project in Romania, based on CANDU technology meets national as well as EU regulations concerning nuclear power and as such its development poses no significant problems both in the context of EU extension and in the frame of the developing competitive market in the power sector. For SNN SA the main objectives in view for the next stage are: operating Cernavoda NPP Unit 1 in conditions of highest nuclear safety and economical efficiency; finalizing the Cernavoda NPP Unit 2 and creation of an organisation for operating the two units; promoting of a functional system characteristic to the competitive market economy and open to privatization; creating opportunities for exporting electrical energy. The contribution contains the following sections: 1. General overlook; 2. Performance of the power production in the year 2000; 2.1. Unit 1 of Cernavoda NPP; 2.2. Nuclear Fuel Plant

  9. Cernavoda NPP operations training programs

    1993-01-01

    The purpose of this document is to describe the philosophy, content and minimum requirements for the Cernavoda Training Programs for all Station staff and to identify the training department organization and respective responsibilities necessary to provide the required training. The hierarchical documentation and requirements related to these programs is shown in figure Rd-TR1-1

  10. Development of new process network for gas chromatograph and analyzers connected with SCADA system and Digital Control Computers at Cernavoda NPP Unit 1

    Deneanu, Cornel; Popa Nemoiu, Dragos; Nica, Dana; Bucur, Cosmin

    2007-01-01

    The continuous monitoring of gas mixture concentrations (deuterium/ hydrogen/oxygen/nitrogen) accumulated in 'Moderator Cover Gas', 'Liquid Control Zone' and 'Heat Transport D 2 O Storage Tank Cover Gas', as well as the continuous monitoring of Heavy Water into Light Water concentration in 'Boilers Steam', 'Boilers Blown Down', 'Moderator heat exchangers', and 'Recirculated Water System', sensing any leaks of Cernavoda NPP U1 led to requirement of developing a new process network for gas chromatograph and analyzers connected to the SCADA system and Digital Control Computers of Cernavoda NPP Unit 1. In 2005 it was designed and implemented the process network for gas chromatograph which connected the gas chromatograph equipment to the SCADA system and Digital Control Computers of the Cernavoda NPP Unit 1. Later this process network for gas chromatograph has been extended to connect the AE13 and AE14 Fourier Transform Infrared (FTIR) analyzers with either. The Gas Chromatograph equipment measures with best accuracy the mixture gases (deuterium/ hydrogen/oxygen/nitrogen) concentration. The Fourier Transform Infrared (FTIR) AE13 and AE14 Analyzers measure the Heavy Water into Light Water concentration in Boilers Steam, Boilers BlownDown, Moderator heat exchangers, and Recirculated Water System, monitoring and signaling any leaks. The Gas Chromatograph equipment and Fourier Transform Infrared (FTIR) AE13 and AE14 Analyzers use the new OPC (Object Link Embedded for Process Control) technologies available in ABB's VistaNet network for interoperability with automation equipment. This new process network has interconnected the ABB chromatograph and Fourier Transform Infrared analyzers with plant Digital Control Computers using new technology. The result was an increased reliability and capability for inspection and improved system safety

  11. Cernavoda NPP environmental management system - tool for managing the impact on the environment

    Gabriel, B.; Adrian, J.

    2009-01-01

    Nuclearelectrica SA (SNN SA) is a state owned company which produces nuclear-generated electricity, heat and CANDU 6 type nuclear fuel. The company has also an active participation in the power development program in Romania. The Cernavovoda NPP, one of the SNN branches is situated at 180 km east of Bucharest, in Constanta County at about 2 km SE from Cernavoda town is a CANDU 6 type. Cernavoda Nuclear Power Plant (NPP) is dedicated to generate electrical and thermal power, safely and efficiently for at least 30 years. Having an annual gross output of 5.2 - 5.4 MWh, the Cernavoda Unit 1 NPP provides 10% of the Romanian electric power production. Starting January 01 2007, the Cernavoda Unit 1 NPP supplied into the grid 5518346 MWh electric power and during 1997 - 2007 the Cernavoda Unit 1 NPP supplied into the grid 55769213 MWh electric powers. Over the same period Unit 1 also provided the partial district heating of the town of the Cernavoda supplying about 601517.9 Gcal. Romania second CANDU nuclear power plant, Cernavoda Unit 2, was officially placed in service on Friday, October 5, 2007 together with Unit 1, the CNE-Cernavoda Station is the largest power producer in the country. It now accounts for about 18 per cent of Romania energy supply and significantly reduces its dependency on expensive energy resources from outside of Europe. It provides a structured approach to planning and implementing environmental protection measures. It also establishes a framework for tracking, evaluating and communicating environmental performance. SNN SA mission is to operate the Cernavoda NPP - in a competitive, safe and environmental friendly manner so that the production is optimized and the economic life time of the plant is as long as possible. One major accomplishment is the achievement of ISO 14001 certification for our Environmental Management System (EMS) at Cernavoda NPP. The aim of this paper is to present the EMS implemented and to emphasize the outcomes of the

  12. Cernavoda NPP impact study on terrestrial and aquatic biota. Preliminary results

    Bobric, Elena; Bucur, Cristina; Popescu, Ion; Simionov, Vasile; Titescu, Gheorghe; Varlam, Carmen

    2010-01-01

    Recently, the awareness of the vulnerability of the environment has increased and the need to protect it against industrial pollutants has been recognized. The concept of sustainable development, requires new and developing international policies for environmental protection. See 'Protection of the environment from the effects of ionizing radiation' IAEA-TECDOC-1091, International Atomic Energy Agency, Vienna. As it is recommended in 'Cernavoda Unit No. 2 NPP Environmental Impact Assessment CES-03702-IAD-006', it is Cernavoda NPP responsibility to conduct an Ecological Risk Assessment study, mainly to assess the impact of nuclear power plant operation on terrestrial and aquatic biota. Long records from normal operation of Cernavoda Unit 1, wind pattern, meteorological conditions, and source terms data were used to evaluate areas of interest for environmental impact, conducting to a circle of 20 km radius around mentioned nuclear objective. The screening campaign established tritium level (because Cernavoda NPP is a CANDU type reactor, and tritium is the most important radioisotope evacuated in the environment) in air, water, soil and vegetation, focusing the interest area on particular ecosystem. Using these primary data it was evaluated which are the monitored ecological receptors and which are the measurement endpoints.This paper presents the Ecological Risk Assessment at Cernavoda NPP technical requirements, and the preliminary results of evaluating criteria for representative ecosystem components at Cernavoda NPP. (authors)

  13. Training needs analysis at Cernavoda NPP - Romania

    Georgescu, L.M.

    2002-01-01

    The paper is mainly on training needs analysis applied at Cernavoda NPP and will outline the Cernavoda (CNPP) approach in establishing what kind of training is necessary for CNPP employees, from the moment they are hired until they become qualified. The training methodology adapted at CNPP is one which adheres to the principles of the Systematic Approach to Training (SAT). SAT adoption at CNPP provides a broad integrated approach emphasizing not only technical knowledge and skills but also human factors knowledge, skills and attitudes. The analysis of SAT at CNPP consists of a 'table-top' analysis of training and qualification requirements. This paper will illustrate how a 'table-top' analysis by Subject Matter Experts is organized, carried out and recorded, and which categories of staff have begun this table-top analysis at CNPP. It will also give an example how this analysis is done: how the tasks of each job are rated, which are the used criteria, and how to proceed with the incorporation of the tasks into initial and continuing training, as appropriate. (author)

  14. Perspectives on managing nuclear safety at Cernavoda NPP past, present and future

    Serban, M.

    1997-01-01

    The presentation considers the following issues: background of Romanian nuclear programme; 1990 management issues involved in Cernavoda project, nuclear safety perspectives; Cernavoda U1 operating organization today (safety related issues); good practices at Cernavoda NPP

  15. Perspectives on managing nuclear safety at Cernavoda NPP past, present and future

    Serban, M [Technical Safety Directorate, Unit 1., Cernavoda Nuclear Power Plant (Romania)

    1997-12-01

    The presentation considers the following issues: background of Romanian nuclear programme; 1990 management issues involved in Cernavoda project, nuclear safety perspectives; Cernavoda U1 operating organization today (safety related issues); good practices at Cernavoda NPP.

  16. Training change control process at Cernavoda NPP

    Valache, Cornelia Mariana

    2005-01-01

    The paper presents the process of 'Training Change Control' at Cernavoda NPP. This process is a systematic approach that allows determination of the most effective training and/or non-training solutions for challenges that may influence the content and conditions for a training program or course. Changes may be the result of: - response to station systems or equipment modifications; - new or revised procedures; - regulatory requirements; - external organizations requirements; - internal evaluations meaning feedback from trainees, trainers, management or post-training evaluations; - self-assessments; - station condition reports; - operating experience (OPEX); - modifications of job scope; - management input. The Training Change Control Process at Cernavoda NPP includes the following aspects. The first step is the identification of all the initiating factors for a potential training change. Then, retain only those, which could have an impact on training and classify them in two categories: as deficiencies or as enhancement suggestions. The process is different for the two categories. The deficiency category supposes the application of the Training Needs Analysis (TNA) process. This is a performance-oriented process, resulting in more competent employees, solving existing and potential performance problems. By using needs analysis to systematically determine what people or courses and programs are expected to do and gathering data to reveal what they are really doing, we can receive a clear picture of the problem and then we can establish corrective action plans to fix it. The process is supported by plant subjects matter and by training specialists. On the other hand, enhancements suggestions are assessed by designated experienced persons and then are implemented in the training process. Regarding these two types of initiating factors for the training change control process, the final result consists of a training improvement, raising the effectiveness, efficiency or

  17. Radiological impact on the surrounding area of Cernavoda NPP operation

    Busnita, M.; Penescu, M.; Neacsu, L.; Ion, M.; Moldoveanu, E.

    1996-01-01

    The objective of this paper is to present the protective measures provided to Cernavoda NPP for population and environment in case of normal operation and accidental situations. The paper describes the nuclear safety concept with the two aspects, the technical safety and the radiation protection, respectively, which represent the theoretical basis of the NPP design, construction and operation. The assessment of the potential radiological effects of Cernavoda NPP operation on the population and other environmental factors have been done by using the following input data: the natural and social characteristics of the site and the technical characteristics of the plant. The effects of Cernavoda NPP operation are also exposed in health risks which are compared with the daily risks of the population exposed of the natural phenomena or to the activities like transportation, domestics or industrial. (author). 1 tab., 6 refs

  18. Cernavoda - Unit 2. A strategic project for Romania

    Saroudis, J.I.; Chirica, T.; Villabruna, G.

    1999-01-01

    The paper presents some key aspects of the Romanian nuclear program, focusing on Cernavoda NPP Unit No. 2 and the partnership with Atomic Energy of Canada Ltd. (AECL) and ANSALDO Italy for completion of this project. A brief historical presentation of the Romanian nuclear program is included. The success of Cernavoda NPP Unit 1 represents an important element in finalizing Unit 2 in an advanced state of equipment installation and more than 40 % complete. Also, the national infrastructure, including the legal framework and new Electricity Law represents a positive element for Project completion. The Romanian Nuclear Regulatory Body represents the guarantee for the safe operation of CANDU reactors in Romania.(author)

  19. Full scope simulator commissioning and training experience at Cernavoda NPP

    Balan, M.

    2000-01-01

    The paper presents the experience gained during commissioning and the initial use of the CANDU training full-scope simulator for operation personnel at Cernavoda NPP. The full-scope simulator as an integral part of the training programs that take place in Cernavoda Nuclear Training Department (CNTD), is mainly used for the development of operational skills, knowledge and attitudes required to operate the plant in a safe and efficient manner. (author)

  20. Diagnosis methods based on noise analysis at Cernavoda NPP, Romania

    Banica, Constantin; Dobrea, Dumitru

    1999-01-01

    This paper describes a recent noise analysis of the neutronic signals provided by in-core flux detectors (ICFD) and ion chambers (IC). This analysis is part of on-going program developed for Unit 1 of the Cernavoda NPP, Romania, with the following main objectives: - prediction of detector failures based on pattern recognition; - determination of fast excursions from steady states; - detection of abnormal mechanical vibrations in the reactor core. The introduction presents briefly the reactor, the location of ICFD's and IC's. The second section presents the data acquisition systems and their capabilities. The paper continues with a brief presentation of the numerical methods used for analysis (section 3). The most significant results can be found in section 4, while section 5 concludes about useful information that can be obtained from the neutronic signals at high power steady-state operation. (authors)

  1. Management of maintenance activities at Cernavoda NPP

    Riedel, M.; Urjan, R.; Marinescu, S.; Corlan, L.

    2000-01-01

    After the Construction and Commissioning phases are over, the safety and economic performances of each nuclear unit are determined by the quality of its operation as well as by the combination of reliability and availability of the systems consisting the whole unit. Therefore, the value of a good maintenance program in making a safe and profitable operation is now widely recognized; all stations operating with excellent performance have well-defined policies and effectively administered programs to govern maintenance activities. The Cernavoda maintenance optimization initiative is derived from good practices suggested by such recognized bodies as the IAEA, INPO and EPRI. It should be noted that the program is evolving at this time and that this paper is an attempt to summarize the myriad of activities and plans required to finally implement the maintenance program. Although many of the elements of the program are in place, many are in various stages of completion. The main components of the program (policy's objectives, strategies used, specific subprograms, maintenance plans and their integration) are presented in brief along with the performance indicators used to assess the effectiveness of the program and maintenance activities. The new programs intended to be developed are also specified, as well as the main comments and recommendations received from IAEA experts. (author)

  2. Elements and strategies of Knowledge Management at Cernavoda NPP

    Valache, C.

    2010-01-01

    The paper highlights that there are Knowledge Management (KM) elements already implemented at Cernavoda NPP, ensuring the safe operation of the plant. The KM process is not formalized yet, but the following elements are part of existing KM practices for Cernavoda NPP organization: Plant policies and procedures are in place; Document control is in place using Document Management system; Configuration management is a complex and well structured process; Training and qualification is based on SAT; Learning from operating experience internal and external is a day by day practice, (procedures, PJB, PROEM, Simulator, RCA, Training, etc.); Work control system is implemented via Ventrix Work Management System; Corrective action tracking is implemented; Workforce planning and human resources management is a continuous process; Communications are implemented by the plant personnel; Company intranet and other web-based solutions (CBT) are put in place; Human performance improvement programme is on going. Also, it is reinforced the need to develop and implement a structured knowledge transfer and retention process for the Cernavoda NPP in order to preserve unique knowledge and skills that could be lost through attrition or planned staffing changes. (author)

  3. Radioactive waste management at Cernavoda NPP after 5 years of experience

    Raducea, D.

    2002-01-01

    Many human activities generate waste but people are worried about those produced in nuclear power plants. Their concern is an unjustified fear toward the hazard from radioactive wastes because any country, which produces electrical power in this way, pays a lot of attention of all relevant parties involved in radioactive waste management. The same policy is applied for Cernavoda NPP. Our concept establishes the general approach required for the collection, handling, conditioning and storage of radioactive waste from Cernavoda NPP Unit 1 and will be ready for expansion when other units are brought into service. Among others, a major objective is to reduce the radioactive waste production and volume. In this regard we are trying to improve as much as possible our procedures and radioactive wastes management. Further, it will be presented the radioactive waste management, including the improvements in our program and the future plans.(author)

  4. Management of occupational exposure at Cernavoda NPP

    Chitu, C.; Popescu, I.; Simionov, V.

    2009-01-01

    Full text. Ionising radiations represent a particular risk associated with nuclear power plant operation. An effective and efficient radiation protection program must: - prevent the detriment of health due to deterministic effects; - keep all the exposures as low as reasonably achievable in order to limit the detriment of health due to stochastic effects. - provide safety and health conditions as good as other safe industries. Radiation protection of occupationally exposed workers is part of Health and Safety of Work Program. Effective dose limits, as recommended by ICRP and required by CNCAN regulations are reasonably low in order to avoid deterministic effects and to limit the probability of stochastic effects to an acceptable level. The health status of CNE Cernavoda employees is appropriately surveyed. There were not recorded cases of occupational diseases and / or other indicators of relevant biological effects in order to establish the specific response of the human body to the occupational illness risk factors. Starting since 2002 cytogenesis blood analysis for occupationally exposed individuals have been performed at the beginning of their employment and periodically for those working for more than five years in the plant. A number of up to 1900 employees have been investigated with no indication of genetic modifications. (authors)

  5. Aspects of accident management in Cernavoda NPP

    Dascalu, N.

    1999-01-01

    As a general conclusion, the accident management system as implemented at Cerna voda NPP is expected to be appropriate for handling a severe accident, should it occur, in such a way that the environmental radiological consequences would be insignificant and radiation exposure of the personnel be within recommendations. It is recognized, however, that continued development and verification of the system as well as effective personnel training programs are essential to maintain the safety level achieved. (author)

  6. Modelling the impact of Cernavoda NPP on the environment

    Constantin, A.-I.

    2001-01-01

    In connection with a stay as a visiting researcher at VTT Energy (Technical Research Center of Finland), a study was conducted related to the atmospheric dispersion and dose assessment for radioactive releases from nuclear power plants. The most important aspects of this study are described in this paper. These include: the application of the TRADOS dispersion and dose assessment model in the case of the Cernavoda NPP and the development of a special program INTEGRATION for the calculation of cloud gamma dose rate of 72 nuclides. (authors)

  7. ALARA and radiation protection optimization status of Cernavoda NPP

    Hau, D.I.

    2000-01-01

    ALARA in Radiation Protection is specifically applied as a tool in lowering B the risk of high exposure when performing necessary activities by reducing the doses as much and as reasonably possible. Is ALARA also a matter of IMAGE? ALARA is one of the main aspects that contributes to forming the image of a certain facility. Many experiences in the world show a decrease in the collective dose per station after proper ALARA implementation. This trend is more relevant for 'adult' nuclear sites. At Cernavoda NPP the authorization process itself included implementation of an effective ALARA program. (author)

  8. Cernavoda NPP: The contribution of ANSALDO ENERGIA to the development of the Nuclear Program in Romania

    Graziosi, G.; Benvenuto, F.

    2005-01-01

    Full text: The development of east European countries has been very slow during the second part of the 20th century, but, with the end of the cold war, they are recovering through a continuous improvement of their economy. The continuous improvement of the countries is usually accompanied by an increase of the energy demand and, as consequence, a rapid increase of their energy production is taking place. It is strategic that the energy production of these countries be based on earliest technologies available today, in order to avoid the worsening of the problems deriving from the energy policies adopted by the western countries: one for all the CO 2 emission in the atmosphere. Clearly to promote the use of new technologies in the growing east European countries, a tied collaboration between western and eastern European countries is essential. This is the case of Romania. The agreement reached by Romania with the Italian and Canadian industries (Ansaldo Energia and AECL) has permitted: - The construction and commissioning of Cernavoda Unit 1 NPP, realized adopting CANDU technology and in operation since 1996; - The continuous maintenance / surveillance / improvement (through a specific service agreement) that assures the safe production of the energy; - The realization of a new Nuclear Power Station: Cernavoda Unit 2, adopting the last technology available for the CANDU type. Its operation is expected to start in 2007. Furthermore, benefit/cost evaluation is under analysis in order to verify the possibility to realize Cernavoda Unit 3 NPP. (authors)

  9. Cernavoda NPP: The contribution of ANSALDO ENERGIA to the development of the Nuclear Program in Romania

    Graziosi, G.; Benvenuto, F.

    2005-01-01

    The development of east European countries has been very slow during the second part of the 20th century, but, with the end of the cold war, they are recovering through a continuous improvement of their economy. The continuous improvement of the countries is usually accompanied by an increase of the energy demand and, as consequence, a rapid increase of their energy production is taking place. It is strategic that the energy production of these countries be based on earliest technologies available today, in order to avoid the worsening of the problems deriving from the energy policies adopted by the western countries: one for all the CO 2 emission in the atmosphere. Clearly to promote the use of new technologies in the growing east European countries, a tied collaboration between western and eastern European countries is essential. This is the case of Romania. The agreement reached by Romania with the Italian and Canadian industries (ANSALDO ENERGIA and AECL) has permitted: - The construction and commissioning of Cernavoda Unit 1 NPP, realized adopting CANDU technology and in operation since 1996; - The continuous maintenance / surveillance / improvement (through a specific service agreement) that assures the safe production of the energy; - The realization of a new Nuclear Power Station: Cernavoda Unit 2, adopting the last technology available for the CANDU type. Its operation is expected to start in 2007. Furthermore, benefit/cost evaluation is under analysis in order to verify the possibility to realize Cernavoda Unit 3 NPP. (authors)

  10. Cernavoda NPP: Training for safety and reliability

    Postolache, Laura Lia

    2001-01-01

    The safe and reliable operation of NPP require successful integration of plant and system design (1), programmes and procedures (2) and qualified human resources (3). Of these three components, station personnel and management have capability to influence and improve programmes and competence of qualified personnel. Qualifying personnel includes selection, training and evaluation that meet the established performance standards. Training, therefore prepares people to achieve such competence. The critical role of operations personnel has been rightly emphasized by every country with a nuclear power programme. So far as operation team is concerned, they have to work, on the one hand with exacting safety rules and at the same time, they have to do the right thing at all times. In essence, they have to be prepared for new, emergency situations as well as for routine work. The plant operation in the Control Room is essentially a man - machine interaction and a safe and reliable operation requires them to take high quality decisions even under stressful conditions. Here lies therefore the need for high competent and licensed operations engineers who will ensure operation within the operating license of the station under the all conditions. The development of a long-term comprehensive training for Operation Staff is a requirement. The program addresses the qualification requirements of the various nuclear positions on shift, the outline content of the required training programs and the evaluation per the Systematic Approach to Training (SAT). A nuclear operator's training begins the moment he/she enters the station. It takes four to six years to develop the skills required to demonstrate that the candidate is an appropriate choice for the position. Then there's a further about two years of intense training at the Training Center on a simulator. After successful completion of the program, the candidate is authorized by the CNCAN (National Commission for Control of Nuclear

  11. The environmental constraint needs for design improvements to the Saligny I/LLW-repository near Cernavoda NPP

    Barariu, Gheorghe

    2007-01-01

    The paper presents the new perspectives on the development of the L/ILW Final Repository Project which will be built near Cernavoda NPP. The Repository is designed to satisfy the main performance objectives in accordance to IAEA recommendation. Starting in October 1996, Romania became a country with an operating nuclear power plant. Reactor 2 reached the criticality on May 6, 2007 and it will be put in commercial operation in September 2007. The Ministry of Economy and Finance has decided to proceed with the commissioning of Units 3 and 4 of Cernavoda NPP till 2014. The Strategy for radioactive waste management was elaborated by National Agency for Radioactive Waste (ANDRAD), the jurisdictional authority for definitive disposal and the coordination of nuclear spent fuel and radioactive waste management (Order 844/2004) with attributions established by Governmental Decision (GO) 31/2006. The Strategy specifies the commissioning of the Saligny L/IL Radwaste Repository near Cernavoda NPP in 2014. When designing the L/IL Radwaste Repository, the following prerequisites have been taken into account: 1) Cernavoda NPP will be equipped with 4 Candu 6 units. 2) National Legislation in radwaste management will be reviewed and/or completed to harmonize with UE standards 3) The selected site is now in process of confirmation after a comprehensive set of interdisciplinary investigations. (author)

  12. Cernavoda NPP integration in the Romanian grid

    Prodan, R.C.

    2000-01-01

    The intention of this material is to present our point of view about some specific matters that arise from having a relatively large power production unit (706 MW) connected to a National Grid in which the second largest units are only 330 MW. The material consists in three major parts. In the first section is presented the 'big picture' of the Romanian National Grid. The second section covers the role played by CNPP in the grid power balance and frequency/voltage adjustment. CNPP is located at the base of the daily load curve and thus not normally participating at frequency adjustment. CNPP also has a contribution in increasing the dynamic stability of the National Grid. The third section is a more detailed presentation of CNPP behavior during grid upsets, with reference to the reactor and turbine control systems, and also the types of transients that our plant could induce to the grid due to internal malfunctions. The over-all unit control is based on the 'reactor power constant' policy, all the fluctuations in the power output to the grid being compensated by the Boiler Pressure Control System. Some features of the Turbine Electro-Hydraulic Control System and how it interacts with the Boiler Pressure Control Sys. will also be presented. The types of transients that CNPP could experience are reactor power setbacks (automatic ramped power reductions), reactor power step-backs (fast controlled power reduction) and unit trips, which are the most severe. There are two ways from the grid point of view to deal with such transients; to compensate the power loss by increasing the production and to disconnect unimportant power consumers. These actions are taken both automatically and manually (some details will be presented). (author)

  13. Operator refresher training and requalification at Cernavoda NPP

    Timoftei, D.

    2002-01-01

    The paper presents the Operator's training program for refresher and requalification purposes, which were developed using the CANDU training full-scope simulator at Cernavoda NPP. First the purpose of both programs is described, and then more details on how these programs are delivered are given. The Refresher Training Program, part of the Operator Continuing Training Program, and the Requalification Training Program are periodically training given to the previously authorised operating personnel. The training and the evaluation are conducted both on an individual and on the team basis. Both programs are tailored according with Systematic Approach to Training concept. In addition to that the importance of the training on simulator arises from the fact that the training is mostly related to plant transients/accidents that in real life may never happens, but the operators should be always prepared for the worst. Continuing Training Program (CTP) applies to the authorized positions of Shift Supervisor (SS) and Control Room Operator (CRO) at CNE-PROD Cernavoda. Also, the program is establishing the criteria and the process, which will allow the authorised SS and CRO to maintain their authorised status. (author)

  14. Characterization of the solid radioactive waste from Cernavoda NPP

    Iordache, M.; Lautaru, V.; Bujoreanu, D.

    2005-01-01

    During the operation of a nuclear plant significant quantities of radioactive waste result that have a very large diversity. At Cernavoda NPP large amounts of wastes are either non-radioactive wastes or radioactive wastes, each of these being managed completely different from each other. For a CANDU type reactor, the occurrence of radioactive wastes is due to contamination with the following types of radioactive substances: - fission products resulting from nuclear fuel burning; - activated products from materials composing the technological systems; - activated products in process fluids. Radioactive wastes can be in solid, liquid or gas form. At Cernavoda NPP the solid wastes represent about 70% of the waste volume which is produced during plant operation and as a consequence of maintenance and decontamination operations. The most important types of solid wastes that are obtained and then handled, processed (if necessary) and temporarily stored are: solid low-level radioactive wastes (classified as compactible and non-compactible), solid medium radioactive wastes, spent resins, used filters and filter cartridges. The liquid radioactive waste class includes organic liquids (used oil, scintillator liquids and used solvents) and aqueous wastes resulting from process system operating, from decontamination and maintenance operations. Radioactive gas wastes occur subsequently to the fission process inside the fuel elements as well as due to the neutron activation of process fluids in the reactor systems. As result of plant operation, iodine, noble gases, tritium and radioactive particles occur and are passed toward the ventilation stack in a controlled manner so that environmental release of radioactive materials with concentrations exceeding the maximum permissible level could not occur. (authors)

  15. Characterization of the solid radioactive waste From Cernavoda NPP

    Iordache, M.; Laotaru, V.

    2005-01-01

    Full text: During the operation of a nuclear plant significant quantities of radioactive waste result that have a very large diversity. At Cernavoda NPP large amounts of wastes are either non-radioactive wastes or radioactive wastes, each of these being managed completely different from which other. For a CANDU type reactor, the appearance of radioactive wastes is due to contamination with the following types of radioactive substances: - fission products resulting from nuclear fuel burning; - activated products from materials composing the technological systems; - activated products in process fluids. Radioactive wastes can be in solid, liquid or gas form. At Cernavoda NPP the solid wastes represent about 70% of the waste volume which is produced during plant operation and as a consequence of maintenance and decontamination operations. The most important types of solid wastes that are obtained and then handled, processed (if necessary) and temporarily stored are: solid low-level radioactive wastes (classified as compactible and non-compactible), solid medium radioactive wastes, spent resins, used filters and filter cartridges. The liquid radioactive waste class includes organic liquids (used oil, scintillator liquids and used solvents) and aqueous wastes resulting from process system operating, from decontamination and maintenance operations. Radioactive gas wastes occur subsequently to the fission process inside the fuel elements as well as due to the neutron activation of process fluids in the reactor systems. As result of plant operation, iodine, noble gases, tritium and radioactive particles occur and are passed toward the ventilation stack in a controlled manner so that environmental release of radioactive materials with concentrations exceeding the maximum permissible level could not occur. (authors)

  16. Status of the spent fuel dry storage programme for Cernavoda NPP

    Radu, M.

    1999-01-01

    The Cernavoda NPP Unit 1 (600 MWe Standard type) is in operation since December 1996. Within the framework of the R and D Radioactive Waste and Spent Fuel Management Programme, investigations, studies and research are carried out on site identification and conceptual designs for both a Spent Fuel Interim Storage Facility and a Spent Fuel Disposal Facility. The status of the work performed in the framework of this programme as well as the situation of the spent fuel resulting from the Research Institutes will be presented in the paper. (author)

  17. The Romanian experience on introduction of CANDU-600 reactor at the Cernavoda NPP

    Rapeanu, S.N.; Bujor, A.; Comsa, O.

    1998-01-01

    The Cernavoda Nuclear Power Plant (NPP) Project is a key component of the Romanian nuclear development program. Selection of the CANDU design represents a major contribution to this development, due to the technological feasibility for manufacturing of parts, components and the nuclear fuel based on the uranium resources in Romania. The Romanian nuclear development program also involves a nuclear fuel manufacturing plant, a heavy water production plant and organizations specialized in research, engineering, manufacturing and completion for systems and components. The agreement on technological transfer between Canada and Romania is supporting the Romanian involvement to the achievement of the Project, with a degree of participation that is gradually increasing from the first to the last NPP Unit. (author)

  18. Preliminary evaluation of the seismic hazard at Cernavoda NPP site

    Mingiuc, C.; Serban, V.; Androne, M.

    2001-01-01

    The probabilistic seismic hazard analysis (PSHA) is a methodology by which one evaluates the probability of exceeding different parameters of the ground motions (the maximum ground acceleration - PGA and the ground response spectrum - SA) as effect of the seismic action, on a given site at a future time moment. Due to the large uncertainties in the geological, geophysical, seismological input data, as well as, in the models utilised, various interpretation schemes are applied in the PSHA analyses. This interpretation schemes lead to opinion discrepancies among specialists which finally lead to disagreements in estimating the values of the seismic design for a given site. In order to re-evaluate the methodology and to improve the PSHA result stability, U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) and Electric Power Research Institute (EPRI) sponsored a project for defining methodological guides of performing PSHA analyses. The project was implemented by a panel of 7 experts, the Senior Seismic Hazard Analysis Committee - SSHAC. This paper presents a preliminary evaluation of the seismic hazard for the Cernavoda NPP site by application of the methodology mentioned, by taking into account the possible sources which could affect the site (the Vrancea focus, Galati - Tulcea fault, Sabla - Dulovo fault and local earthquakes)

  19. Conditioning the radioactive oils released from the Cernavoda NPP operation

    Popescu, I.; Deneanu, N.; Dulama, M.; Baboiescu, E.

    2001-01-01

    The radioactive oils released during the Cernavoda NPP operation are lubricating oils used in the primary circuit pumps, hydraulic oils used in the reactor charging machine, as well as, waste turbine oils. The primary cooling circuit is the main way of contamination. This waste contain variable amounts of tritium of activities up to 10 8 Bq/l and relatively small amounts of β/γ emitting radionuclides. The radioactive oils resulting of the heat transport system may contain as much as 1.8 TBq/l of tritium. At INR Pitesti, Department of Radioactive Waste Processing, studies were done concerning the radioactive oils conditioning in concrete. It was found that the minimal compression level required for disposal, of 50 MPa, was exceeded. As consequence, the conditioned waste fulfils the conditions of acceptance provided by the Radioactive Waste National Repository at Baita-Bihor. The main stages of the process are: - dosing the radioactive oil, water and NOFOX9 and NOFOX4 emulsion additives for the 220 l or 80 l barrel; - mixing these ingredients up to reaching the emulsion state; - dosing the cement and lime; - adding the enhancing silicate and shaking the mixture to get a homogeneous matrix; - closing the barrel; - conditioning the 80 l barrel within the 220 l container. The production capacity is of 5 to 8 barrels/shift

  20. Estimation of radionuclide releases in atmosphere from Cernavoda NPP based on continuous gaseous effluent monitoring

    Bobric, E.; Murgoci, S.; Popescu, I.; Ibadula, R.

    2001-01-01

    Monitoring of gaseous effluents from Cernavoda NPP is performed to assess the environmental impact of the plant operation. The results of the monitoring program are used to evaluate the population doses in order to ensure that the emissions of radionuclides in air are below regulatory limits and radiation doses are maintained ALARA. It complements, but is independent from the Operational Environmental Monitoring Program for Cernavoda NPP. Gaseous effluent monitors provide continuous indication of the radioactivity content in atmospheric emissions. Except for noble gases, these monitors also collect samples for later detailed analysis in the station Health Physics Laboratory. This paper presents the main equipment and the results of the gaseous effluents monitoring program in order to assess the impact of Cernavoda NPP operation and to predict the future releases as function of radionuclides concentrations in CANDU systems, based on the identified trends.(author)

  1. Reliability problems in the recirculated cooling water system at Cernavoda NPP and corrective maintenance operations adopted

    Bucur, Ionel; Metes, Mircea

    2002-01-01

    Between February 18 and March 5, 2002 the Unit 1 of Cernavoda NPP was shutdown in an un-planned outage necessary to repair a crack on the piping of the Recirculated Cooling Water System. The large pipe diameter and the requirement of maintaining the system in operation during the outage, imposed a special technology for fixing the leak (isolation of the line with ice plugs). The paper presents information about the performed repair work. After repair operations the failed duct was checked by non-destructive methods and the results were submitted and approved by regulation authorities. The repair was considered successfully completed and the Unit restarted on March 5, 2002 at 0.57 am when the electric generator was switched on in parallel to the national electric power system. (authors)

  2. Cernavoda unit2 recirculated cooling water system transient analysis

    Nita, I. P.; Pancef, R.

    2015-01-01

    The paper is an approach to calculate the response of Cernavoda NPP Unit 2 RCW System to transient regimes during normal and abnormal regimes. Then one started to analyse the system response to reactor trip on class III and IV of power, LOCA on class IV of power, LOCA on class III power, LOIA on class IV of power, and LOIA on class III power. Moreover, one analysed the system transient due to requirement of changeover of a RCW operating pump, planned and unplanned changeover. This is the first transient approach to this system that took in consideration all building of the system, obtaining a very large system model, with over 900 pipe, 4 pumps, 50 consumers, 21 control valves. The changeover procedure was required to be analysed in order to change the nominal operating mode for Unit 2, from current 2 pumps in operation to 3 pump operations during summer operating mode. (authors)

  3. Management of the used ion-exchangers contaminated with C-14 generated by NPP Cernavoda

    Boteanu, O.; Valeca, M.; Arsene, C.

    2016-01-01

    For the conditioning of ion-exchangers generated from operation of Cernavoda NPP Unit 1, techniques of direct immobilization in cement, bitumen and organic polymers have been experimented. The selected process for conditioning of spent resins is the bituminization. The bituminization process consists of the incorporation in bitumen of the spent resin, at temperatures between 110 and 1200C, and the solidification of the mixture by cooling. The percentage of incorporated spent resin in bitumen is ranged from 40 to 50% dry resin. The advantages of bituminization are: the bitumen is insoluble in water, the bituminization installation is simple, the matrix is not cost expensive, the temperature process is low, bitumen is compatible with wastes having various compositions, and the volume of the final product is smaller. The main disadvantage is that bitumen is combustible, although not easily flammable, and, at high temperature, interaction between bitumen matrix and chemical components, might occur. (authors)

  4. Annx IV. Delayed nuclear power plant project management experience Cernavoda 2 NPP, Romania

    2008-01-01

    The Cernavoda Unit 2 NPP work was originally started in 1982 with work coming to a halt in 1989, and a preservation program implemented in 1991 while work continued on Unit 1. In 1995 attention turned to the completion of Unit 2 and status verification reports were commissioned. Work proceeded, as funds were available, up until 2002 when an interim contract was signed. Subsequently a Contract Completion Effective Date (CCED) was signed in March 2003 with completion duration of 48 months. A project schedule is a necessity for any project whether it is a new build or a restart to a delayed project. There are 5 major elements that are included in all CANDU project schedules, Engineering, Procurement, Construction, Commissioning and the conversion from Construction to Commissioning. The Engineering schedule of deliverables was not fully defined at CCED. Design changes defined prior to CCED were not fully defined and the scope of work associated with these only became known during the actual construction program. A significant number of new design changes were introduced after CCED, which compounded the impact to the construction program. All projects require their budgets to be built up within a defined structure. Delayed projects are no different from other projects in that respect. The standard Work Brakout Structure (WBS), which is applicable to most CANDU projects, is equally applicable for a delayed project. On Cernavoda Unit 2 we used a Budget Breakdown Structure, which was a combination of a traditional WBS and an Organization Structure. This structure was adopted in order to have consistency with the structure, which had been used prior to the delay on the project and also it was a requirement of the three party agreements with funding from different sources and in different currencies. All major construction projects normally carry a contingency allowance for undefined work and a risk allowance for the possibility of major changes. Delayed projects require

  5. Estimation of the future nuclear power research in Romania, based on the present Cernavoda NPP evolution

    Dumitrache, Ion

    2001-01-01

    For more than four decades, the electric power needs of Romania were evaluated on the basis of the State Plan for Economic Development. To identify the optimal solution, the 'least price per produced MWh' was practically the only criterion. Now, there is no convincing estimation of the future economic development and at least two additional criteria play a significant role, 'the safety in the supply of the needed electric power', and 'the need of limiting the environmental impact of electricity generation'. The analysis dedicated to evaluation of future electric power solutions must take into account several features of the present situation. There are no available internal funds to finance the construction of new generating units of the order of several hundreds of MW. Even the so-called 'refurbishing' of the existing thermal power plants is based on foreign loan. In the 2000 year, about 80 electricity generation units reached 30 years of operation, i.e., the design life. Other thermal power plants proved very modest performances during 15-20 years of operation. Consequently, the future of almost 100 generating units is either in shutdown + decommissioning or shutdown + modernization situation. The Government analyzed the situation and decided to continue the completion of the Cernavoda NPP. The Unit 2 will be commissioned in a couple of years, and there is a schedule of negotiations relating the future of the Unit 3. After almost five years of successful operation of the Unit 1, the collaboration between RDT Institutes and NPP has clear features. Based on the experience related to this collaboration and taking into account the evolution of the Cernavoda NPP, we estimated that five research domains have significant chances to obtain a stable (and, hopefully, consistent) financial support. 1. Nuclear Safety, in particular Accident Analysis. As the Government re-iterated the firm decision to meet the conditions required for European integration, most of the nuclear

  6. Determination of the NPP Cernavoda reactor building seismic response

    Krutzik, N.J.; Rotaru, I.; Bobei, M.; Mingiuc, C.; Serban, V.

    1997-01-01

    Seismic input for systems and equipment installed in buildings depends on: - the seismic movement in free field on site; - the building movement in the soil; - the building deflection. The percentage of the 3 movements for the system and equipment input, depends on the position of the systems and equipment inside the building as well on the type of the foundation soil. The type of the foundation soil is important because if it is stiff it transfers a lot of energy to the building, energy which amplify the movement of the building on the top. If the foundation soil is soft, it accommodates the overall movement of the building in the soil, amplifying the movement to lower levels and the building response is attenuated if a resonance phenomenon between the whole building movement and the seismic excitation does not exist. This input is given with the design floor response spectra (FRS), in the logarithmic scale and seismic anchor movement (SAM). The design floor response spectra for NPP Cernavoda U1 Nuclear Building were determined in several stages starting with simple models (STICK type) without twisting movement and ending with detailed 3-dimensional models. From the point of view of dynamic behavior, the Reactor Building can be considered to be made up of 4 sub-structures: the containment building, internal structures containing separate elements such as the reactor vault, the fuel transfer structure and itself. Each sub-structure has its own movement (some of the structures present also some local effects) which combines with the overall movement of the building in the soil and the seismic excitation produce the total movement so that the response spectrum for each point of the sub-structure is specific. One should note that for structures which also show the twisting effect, the selection of the points on the floor, for the determination on the response spectra, is an engineering decision so that the response should be relevant for the equipment installed on the

  7. Technical solutions for tritium removal from Cernavoda NPP heavy water systems

    Barariu, Gheorghe; Panait, Adrian

    2002-01-01

    In CANDU nuclear plants 2400 KCi/GW(e) - year tritium is generated. At a CANDU - 600 reactor similar to Cernavoda NPP Unit 1, 1500 KCi/year of tritium is generated 95% being in the D 2 O moderator, which can achieve a radioactivity level of 80 - 100 Ci/kg. Tritium in heavy water contributes with 30 - 50% to the doses received by operation personnel and with 20% to the radioactivity released to the environment. The extraction of tritium heavy water at CANDU reactors implies the following possibilities: - the radioactivity level reduction in the operation area; - the maintenance and repair cost reduction due to reduction of personnel protection measures and increased labor productivity; - the increase of NPP utilization factor by shutdown time reduction for maintenance and repair; - tritium concentration reduction from technological systems, ensuring thus the possibility of redesigning the systems in order to lower the cost of investment; - profitable use of extracted tritium. Technical measures provided by AECL project for CANDU 600 at Cernavoda make possible to satisfy the current standards concerning tritium concentration in the operation area atmosphere of 5 x 10 -6 Ci/m 3 . The regulations recommend that the radioactivity level should be maintained as low as possible in conformity with ALARA principles. Also, it is possible that norms will become more restrictive in the future, so the tritium removal technology is a good preventive measure which may become very necessary. The methods, which currently reached the industrial or pilot stages, are based on catalyzed chemical exchange, the heavy water electrolysis, and deuterium distillation. They are known as: VPCE - Vapour Phase Catalytic Exchange; LPCE - Liquid Phase Catalytic Exchange; DE - Direct Electrolysis; CD - Cryogenic Distillation. As transfer processes the catalyzed chemical exchange and heavy water electrolysis are used while concentration of tritium gas is done by cryogenic distillation. At present the

  8. The influence of increased temperature of waters from Cernavoda NPP on underground water sources

    Isbasoiu, Eugen Constantin; Marinov, Anca Mariana; Moraru, Carina Nicoleta; Rizescu, Gheorghe

    1997-01-01

    The operation of Cernavoda NPP implies the change of thermal regime of waters in the Danube-Black Sea channel zone. The Danube water is used to cool the NPP systems before being delivered into channel and used in irrigations. The temperature increase of water in Cernavoda NPP installations is between 7 and 12 deg. C. The negative effects of this warming are: 1. limitation of water use for irrigations; 2. occurrence and persistence of fog in channel area; 3. thermal pollution of underground waters and limitation of underground potable water supply. The paper presents a general approach of thermal pollution problems of an aquifer and a mathematical model of forecasting the underground water temperature variation in Danube-Black Sea channel area. (authors)

  9. Knowledge capture and preservation at Cernavoda Unit 2 Project

    Condu, M.; Chirica, T.; Popescu, D.; Marculescu, N.

    2007-01-01

    Full text: As it is known, Cernavoda Unit 2 - Romania, is a delayed nuclear power plant (NPP), started in early '80s, works were frozen in 1990 and resumed in 2003 under a management contract concluded by Nuclearelectrica, the Romanian nuclear utility, with Atomic Energy of Canada Ltd (AECL)-Canada and Ansaldo - Italy. This project has many specificities, including long time stored equipment, some works done 15 to 20 years ago; technology developments during these years; only couple of staff available from those initially involved; and a forthcoming project (Cernavoda Units 3 and 4) in its latest development phase. On top of that, like in other Eastern European countries, Nuclearelectrica is losing people due to salary issue and 'brain drain'. In the actual international situation where the nuclear energy contribution to energy mix is under reconsideration and where the demand for qualified personnel significantly exceeds the offer, it is estimated that maybe the biggest challenge of the forthcoming Cernavoda Units 3 and 4 would be availability of human resources. As Cernavoda Unit 2 Project goes towards a successful completion, all those who put lots of efforts and a difficult to overestimate contribution to overcome all challenges of this special Project will leave one after the other. Special attention is being given by Nuclearelectrica and the main contractors AECL and Ansaldo capturing the knowledge (both explicit and tacit) accumulated in these last almost five years and to leave to those who will continue the forthcoming Unit 3 and 4 Projects and to the nuclear industry in general. The objective on knowledge capture and preservation is to gather all experience and lessons learned during contracting, financing, constructing and commissioning of NPP Cernavoda Unit 2, with a focus on tacit knowledge and to asses potential improvements that might be applied in the forthcoming projects, in order to improve nuclear and economic performance. There are couple of

  10. Experience in the application of S.A.T. for maintenance training at Cernavoda N.P.P. - U1

    Erdinici, Abdula

    1999-01-01

    A short history of Maintenance Training at Cernavoda NPP Unit 1 will be presented highlighting the fact that: - Cernavoda NPP Unit 1 is the first nuclear power plant in Romania; - Construction/Commissioning and initial operation was done under the direct supervision of expert specialists (from Canada, Italy and US). In addition, the application of Systematic Approach to Training (S.A.T.) principles at Cernavoda NPP for all training activities will be addressed. A short history of how maintenance training activity developed over time will be detailed to address the following issues: - how the S.A.T. stages were applied; - how maintenance experience was gained during Unit 1 Construction/Commissioning initial operation and how this experience has been evaluated, credited and transferred; - how maintenance training was documented; - how the maintenance training activity is organized; - on-the-job training for maintenance personnel. Concerning other training activities at Cernavoda NPP the maintenance begins with a training needs analysis for each maintenance position. These needs are documented through Job Related Training requirements (JRTR's) produced for each maintenance position. During commissioning/initial operation, only necessary maintenance training has been delivered, such as: pump alignments, use of maintenance procedure, application of maintenance documentation. The 'hands-on' activities under expatriates specialists supervision was the main training activity. Training coordinators for each maintenance activity (Mechanical, EI. I-and-C, and Services maintenance) have been appointed to administer maintenance training. Following the declaration of the unit in commercial operation, a new approach has been taken related to maintenance Bucharest A Task Force to evaluate maintenance training status and experience has been established. This group was initiated at the Training Department initiative and it was initially co-ordinated by a Canadian maintenance

  11. Cernavoda NPP risk - Based test and maintenance planning - Methodology development

    Georgescu, G.; Popa, P.; Petrescu, A.; Naum, M.; Gutu, M.

    1997-01-01

    The Cernavoda Power Plant starts the commercial operation in November 1996. During operation of the nuclear power plant, several mandatory tests and maintenance are performed on stand-by safety system components to ensure their availability in case of accident. The basic purpose of such activities is the early detection of any failure and degradation, and timely correction of deteriorations. Because of the large number of such activities, emphasis on plant safety and allocation of resources becomes difficult. The probabilistic model and methodology can be effectively used to obtain the risk significance of these activities so that the resources are directed to the most important areas. The proposed Research Contract activity is strongly connected with other safety related areas under development. Since, the Cernavoda Probabilistic Safety Evaluation Level 1 PSA Study (CPSE) was performed and now the study is revised taking into account the as-built information, it is recommended to implement into the model the necessary modeling features to support further PSA application, especially related to Test and Maintenance optimization. Methods need to be developed in order to apply the PSA model including risk information together with other needed information for Test and Maintenance optimization. Also, in parallel with the CPSE study updating, the software interface for the PSA model is under development (Risk Monitor Software class), methods and models needing to be developed for the purpose of using it for qualified monitoring of Test and Maintenance Strategy efficiency. Similar, the Data Collection System need to be appropriate for the purpose of an ongoing implementation of a risk - based Test and Maintenance Strategy. (author). 4 refs, 1 fig

  12. Developing technologies for conditioning the liquid organic radioactive wastes from Cernavoda NPP

    Deneanu, N.; Popescu, I. V.; Teoreanu, I.

    2004-01-01

    The Institute for Nuclear Research (INR)-Pitesti has developed technologies for conditioning liquid organic radioactive wastes (oils, miscellaneous solvent and liquid scintillation cocktail) for Cernavoda NPP. This paper describes the new and viable solidification technology to convert liquid organic radioactive wastes into a stable monolithic form, which minimizes the probability to release tritium in the environment during interim storage, transportation and final disposal. These are normally LLW containing only relatively small quantities of beta/gamma emitting radionuclides and variable amounts of tritium with activity below E+08Bq/l. The INR research staff in the radwaste area developed treatment/conditioning techniques and also designed and tested the containers for the final disposal, following the approach in the management of radwaste related to the nuclear fuel cycle. Thus, the INR focused this type of activity on treating and conditioning the wastes generated at Cernavoda Nuclear Power Plant consisting of lubricants from primary fuelling machines and turbine, the miscellaneous solvent from decontamination operation and the liquid scintillation cocktail used in radiochemical analysis. Laboratory studies on cementation of liquid organic radioactive wastes have been undertaken at INR Pitesti. One simple system, similar to a conventional cement solidification unit, can treat radioactive liquid wastes, which are the major components of low- and medium-level radioactive wastes generated by a Nuclear Power Plant. It was proved that the solidified waste could meet the Waste Acceptance Criteria of the disposal site, in this case Baita-Bihor National Repository, as follows: - The wastes are deposited in type A packages; - The maximum expected quantities of this waste stream that will be produced in the future are 50 drums per year. The maximum specific tritium activity per drum is 10 9 Bq/m 3 ; - Compressive strengths of the samples should be greater than 50 MPa

  13. Design configuration for Cernavoda - 2

    Lindsay, R.I.; Keil, H.; Hapwood, J.M.; Hum, J.

    1998-01-01

    The Cernavoda - 2 NPP project is based on a repeat of the recently completed plant, Cernavoda - 1 NPP which has been operating well, and the other CANDU 6 units in Canada, Argentina and Korea, which have had an excellent operating record. The reference plant design for Cernavoda - 2 is Cernavoda - 1 with appropriate design enhancements incorporating lessons learned from CANDU 6 and other nuclear operations, and including appropriate design enhancements from the most recent CANDU 6 projects at Wolsung in Korea, and Qinshan in China, while recognizing the significant degree of project completion. The results of this combination of proven design with systematic design feedback, will be a unit which combines reliability supported by the many years of successful operation of CANDU 6 units, together with a significant number of design enhancements. (authors)

  14. Modelling of preheated regenerative chain in Cernavoda NPP using MMS calculation code

    Bigu, M.; Nita, I.; Prisecaru, I.; Dupleac, D.

    2005-01-01

    Full text: In this work it was studied operation of preheated regenerative chain from NPP Cernavoda. To obtain this analysis coupled analyses of condensate system, water supply system, and drain cooler system were effected. The analysis boundaries are: Upstream: - Steam condensers - Turbine Bleed Steam Downstream: - Steam Generators. The analysis was made in two steps: 1) Getting of hydraulic characteristic of pipe network from steam condensers to steam generators at nominal regime; this step was obtained with hydraulic package called PIPENET. 2) Real thermal hydraulic analyses were done based on hydraulic characteristic of pipe network and supplementary data required for heat transfer calculation in equipment of preheated regenerative chain. Thermal analyses were done using MMS package and refered to normal operating regimes, namely, nominal operating regime required for calibration of calculating model, shutdown regime, start-up regime from zero power hot to nominal power and to abnormal operating regimes, namely, turbine trip, reactor trip and loss of two condensate pumps. The results were compared with already existing analysis and showed the largest differences at interface areas (i.e. 5%). This led us to idea of extending analysis to all secondary circuits in order to reduce the number of boundary conditions which can generate uncertainty in analysis. In this analysis we obtained an advanced model of preheated regenerative chain of secondary circuit in Cernavoda NPP which could be extended up to cover the whole secondary circuit by including the analysis of steam generators, turbine, and steam condenser. (authors)

  15. Modelling of preheated regenerative chain in Cernavoda NPP using MMS calculation code

    Bigu, M.; Nita, I.; Prisecaru, I.; Dupleac, D.

    2005-01-01

    In this work it was studied operation of preheated regenerative chain from NPP Cernavoda. To obtain this analysis coupled analyses of condensate system, water supply system, and drain cooler system were effected. The analysis boundaries are: Upstream: - Steam condensers - Turbine Bleed Steam Downstream: - Steam Generators. The analysis was made in two steps: 1) Getting of hydraulic characteristic of pipe network from steam condensers to steam generators at nominal regime; this step was obtained with hydraulic package called PIPENET. 2) Real thermal hydraulic analyses were done based on hydraulic characteristic of pipe network and supplementary data required for heat transfer calculation in equipment of preheated regenerative chain. Thermal analyses were done using MMS package and referred to normal operating regimes, namely, nominal operating regime required for calibration of calculating model, shutdown regime, start-up regime from zero power hot to nominal power and to abnormal operating regimes, namely, turbine trip, reactor trip and loss of two condensate pumps. The results were compared with already existing analysis and showed the largest differences at interface areas (i.e. 5%). This led US to idea of extending analysis to all secondary circuits in order to reduce the number of boundary conditions which can generate uncertainty in analysis. In this analysis we obtained an advanced model of preheated regenerative chain of secondary circuit in Cernavoda NPP which could be extended up to cover the whole secondary circuit by including the analysis of steam generators, turbine, and steam condenser. (authors)

  16. Satellite infrared imagery for thermal plume contamination monitoring in coastal ecosystem of Cernavoda NPP

    Zoran, M. A.; Zoran, Liviu Florin V.; Dida, Adrian I.

    2017-10-01

    Satellite remote sensing is an important tool for spatio-temporal analysis and surveillance of NPP environment, thermal heat waste of waters being a major concern in many coastal ecosystems involving nuclear power plants. As a test case the adopted methodology was applied for 700x2 MW Cernavoda nuclear power plant (NPP) located in the South-Eastern part of Romania, which discharges warm water affecting coastal ecology. The thermal plume signatures in the NPP hydrological system have been investigated based on TIR (Thermal Infrared) spectral bands of NOAA AVHRR, Landsat TM/ETM+/OLI, and MODIS Terra/Aqua time series satellite data during 1990-2016 period. If NOAA AVHRR data proved the general pattern and extension of the thermal plume signature in Danube river and Black Sea coastal areas, Landsat TM/ETM and MODIS data used for WST (Water Surface Temperature) change detection, mapping and monitoring provided enhanced information about the plume shape, dimension and direction of dispersion in these waters. Thermal discharge from two nuclear reactors cooling is dissipated as waste heat in Danube-Black -Sea Channel and Danube River. From time-series analysis of satellite data during period 1990-2016 was found that during the winter season thermal plume was localized to an area of a few km of NPP, and the mean temperature difference between the plume and non-plume areas was about 1.7 oC. During summer and fall, derived mean temperature difference between the plume and non-plume areas was of about 1.3°C and thermal plume area was extended up to 5- 10 km far along Danube Black Sea Channel.

  17. Using residual tritiated water from Cernavoda NPP to study Danube - Black Sea Canal hydrodynamics

    Varlam, C.; Stefanescu, I.; Lazar, R.; Varlam, M.; Patrascu, V.; Bucur, C.; Bobric, E.

    2003-01-01

    By benefiting of Cernavoda NPP's location in the neighbourhood of Danube - Black Sea Canal one suggests extending the area of interest along this canal particularly to use the residual tritiated water from this CANDU type reactor as tracing means in the study of canal's hydrodynamics. This canal appears to be ideal for such a study because releases in normal operation of NPP are occasional. The tritiated water can be used for simulating the transport and dispersion of soluble pollutants because it has the same physical characteristics as the usual water. By measuring response curves produced at injecting a known amount of tracer one can developed an efficient method for estimating: the soluble pollutant velocity along the canal; attenuation rate of concentration peak as a function of time as well as the time required by the propagation front of the soluble pollutant to reach a given point along the canal. In this work the calculation of the mixture length as a function of the particular characteristics of the canal is presented as well as different experimental formulas. Also the reference level of tritium concentration in the investigated area is established for future experiments

  18. Overview of the solid radioactive waste management programme for Cernavoda NPP

    Raducea, D.

    2001-01-01

    The wastes generated from nuclear power plants have a very large diversity, and can be grouped into non-radioactive and radioactive wastes. These two types are manipulated completely different ways from each other. Among radioactive wastes, solid radioactive wastes are important, because of their diversity, their method of treatment and of their volume compared to the others types. The strategy for their treatment and characterisation has a dynamic character and allows modification after the identification of new solutions at the international level, or after the production of new waste types. The Radioactive Waste Management concept for Cernavoda NPP established the general approach required for the collection, handling, conditioning and storage of radioactive wastes, while maintaining acceptable levels of safety for workers, members of the public and the environment. The radioactive waste management programme has the following major characteristics: plant operation at all times ensures that radioactive wastes are minimised; procedures are established to ensure that radiation doses to operating staff and members of the public are in accordance with ALARA and contamination from collection, transportation and storage of wastes are eliminated; all staff is trained and qualified to carry out their responsibilities. This presentation does not address the management of spent fuel, contaminated heavy water and the disposal of the solid radioactive wastes.(author)

  19. Economic viability of Cernavoda project

    Condu, M.; Popescu, D.; Chirica, T.; Glodeanu, F.

    1998-01-01

    Cernavoda project started in 1978, when the CANDU technology procurement contract and other contracts for engineering, technical assistance and procurement were signed with AECL. The works on site started in 1980. In February 1981, a contract was signed with GE - USA and Ansaldo - Italy for balance of plant. After 1989 the concept for project implementation was essentially changed. The completion of Cernavoda NPP Unit-1, established as the first priority by Romanian authorities was implemented by AECL-Ansaldo Consortium (AAC). The objective of the contract signed with AAC consisted in overtaking the management of Cernavoda Unit-1 project, in order to complete, commission and operate the plant for 18 months. The plant was successfully completed, commissioned and commercially operated since December 2, 1996. As concerns Unit-2, only preservation and some remedial works were performed since 1991. In order to support the decision to complete Unit-2, a complete process was initiated: - identification of the activities and associated costs required for plan completion; - plant integration in the utility's least cost development study; - Unit-2 cash flow analysis. A joint RENEL-AECL-ANSALDO team performed a detailed analysis using Cernavoda Unit-1 as reference project and taking advantage of the experience gained during construction, commissioning and operation of the first unit. The least cost power generation development study finalized by SEP and EDF, based on a PHARE funding, ranked Cernavoda Unit-2 on the second place, after two small hydroelectric plants of 53 and 8 Mw e. A cash flow model developed by a RENEL-ANSALDO joint team shows that Cernavoda Unit-2 is an economically feasible project. The financing scenario provides that all resources will be from loans. Other arguments for completion of Cernavoda Unit-2 are: - good performances in operation of Unit-1; - the need to provide jobs for the specialists in the nuclear field; - opportunity for electricity export

  20. Radiation shielding and dose rate evaluation at the interim storage facility for spent fuel from Cernavoda NPP

    Stanciu, Marcela; Mateescu, Silvia; Pantazi, Doina; Penescu, Maria

    2000-01-01

    At present studies necessary to license the Interim Storage Facility for the Spent Fuel (CANDU type) from Cernavoda NPP are developed in our country.The spent fuel from Cernavoda NPP is discharged into Spent Fuel Bay in Service Building of the plant, where it remains several years for cooling. After this period, the bundles of spent fuel are to be transferred to the Interim Storage Facility.The dry interim storage solution seems to be the most appropriate variant for Cernavoda NPP.The design of the Spent Fuel Interim Storage Facility must meet the applicable safety requirements in order to ensure radiological protection of the personnel, public and environment during all phases of the facility achievement. In this paper we intend to present the calculation of radiation shielding at the spent fuel interim storage facility for two technical solutions: - Concrete Monolithic Module and Concrete Storage Cask. In order to quantify the fuel composition after irradiation, the isotope generation and depletion code ORIGEN 2.1 has been used, taking into account a cooling time of 7 years and 9 years, respectively, for these two variants. The shielding calculations have been performed using the computer codes QAD-5K and MICROSHIELD-4. The evaluations refer only to gamma radiation because the resulting neutron source (from (α,n) reactions and spontaneous fission) is insignificant as compared to the gamma source. The final results consist in the minimum thickness of the shielding and the corresponding external dose rates, ensuring a design average dose rate based on national and international regulations. (authors)

  1. Management of tritium exposures for professionally exposed workers at Cernavoda 1 NPP

    Chitu, Catalina; Simionov, Vasile [CNE-PROD Cernavoda NPP, No. 1, Medgidiei Str. Cernavoda 905200 (Romania)

    2004-07-01

    Operating experience to date of CANDU reactors has indicated that the major contributor to the internal dose of professionally exposed workers is the tritiated heavy water (DTO). CANDU reactors are both moderated and cooled by heavy water (D{sub 2}O). Tritium is produced in CANDU reactors by neutron reactions with deuterium, boron, and lithium and by ternary fission. Even small leaks from these systems can produce important contaminations with tritiated water vapours of the air in the reactor building and thus increased individual and collective internal doses. Professionally exposed workers are subject to a combination of acute and chronic tritium exposure and HTO dosimetry program at Cernavoda NPP is based on multiple sample results. The routine urine bioassay program performs the monitoring and dosimetry functions for DTO. A specialized laboratory using Liquid Scintillation Spectrometry methods currently determines tritium activities in urine samples. The frequency of biological samples submission depends on the tritium concentration in the last sample. Dose assignments resulting from routinely measured weekly and monthly urinary levels of tritium oxide are based on the method of linear interpolation unless it is known that there has been no exposure between samples (vacation). All information about these doses is stored into a dedicated electronic database and used to make periodical reports and to ensure that the legal and administrative individual and annual limits are not exceeded. A chronic unprotected exposure to small tritium dose rate (< 50{mu}Sv/h) may lead to internal doses that exceed the intervention level. In case of acute exposure an increased daily water intake combined with a proper medical intervention could reduce the effective half time of tritium 2-3 times. (authors)

  2. The FMEA Analysis for Fuel Handling System at Cernavoda Unit 2

    Park, Jin Hee; Kim, Tae Woon; Rhee, Bo Wook; Yoon, Chul; Kim, Hyeong Tae; Cho, In Gil; Kim, Seong Ho

    2006-01-01

    A Nuclear Safety Evaluation was performed by an independent assessor at the request of the regulatory authority CNCAN (Comisia Nationala pentru Controlul Activitatilor Nucleare. National Committee for Nuclear Activities Control in Romania) to provide an independent overview of all the nuclear safety aspects of Cernavoda Unit 2 under construction and an expert opinion whether the completed Cernavoda Unit-2 Nuclear Power Plant would satisfy current Western European nuclear safety objectives and practices. A report was produced (Cernavoda 2 Nuclear Safety Expert Project, 'Task 10 . Safety Evaluation Report', A.F.Parsons, NNC Limited, December 2001) and contains recommendations either mandatory or advisory. The FMEA study, one of the mandatory recommendations, is performing now for fuel handling system and radioactive waste handling system for Cernavoda unit 2 in Romania sponsored by KHNP. In this paper, only the FMEA study for fuel handling system is presented

  3. Installing the detritiation facility at Cernavoda NPP. Technical solutions and national participation

    Barariu, Gheorghe

    2002-01-01

    Generation and accumulation almost linear of tritium in the heavy water used as moderator and coolant in CANDU type reactors appears to be a drawback with implication upon the long term operation of the nuclear station. In the CANDU type reactors about 2400 kCi/GW(e) of tritium is generated annually. In case of CANDU-600 reactors as, those operating at Cernavoda NPP, the amount of tritium generated is 1500 kCi/y from which about 95% is found in moderator water what leads to an activity level of about 80-100 Ci/kg. Due to the specific working conditions about 85 Mg/y of D 2 O are eliminated from the circuits of which some 95% is recovered. About 30-50% of the radiation dose to which the operation personnel is exposed is due to the tritium from heavy water, while its contribution to the radioactivity released in the environment is about 20%. Detritiation ensures a radioactivity level due to the tritium contained in the moderator heavy water of about 5 Ci/kg in D 2 O moderator and about 1 Ci/kg in the coolant. Consequently, the radiation dose due to tritium is reduced three times while the tritium amount released in the environment is diminished by about 10 times. At present, the price of tritium is 2-3 USD/Ci what means that the tritium recovered from a CANDU reactor could reach a value of about USD 3 - 4.5 million/y. The detritiation procedures are based on catalyzed chemical exchange, heavy water electrolysis and deuterium distillation. Following experimentations and cost/benefit analyses the Institute for Cryogenics and Isotopic Technologies, ICSI, at Rm. Valcea, adopted for detritiation the procedure LPCE - CD, i.e. Liquid Phase Catalytic Exchange - Cryogenic Distillation. The procedure allows tritium transfer from the heavy water in gaseous deuterium in a column equipped with hydrophobic catalyst and phosphorous bronze packing. In the second stage of the technological process, the tritium is extracted from the gaseous phase by liquid deuterium distillation and

  4. Contributions to a methodology for periodical verification of the parameters of the control systems at Cernavoda Nuclear plant Unit 1

    Tapu, Cornel; Anescu, George

    1998-01-01

    A model identification methodology for periodical verification of the regulating system parameters at Cernavoda NPP Unit 1 was developed. As support to this methodology, the computer program MODELIDENT was implemented in the Java programming language. This program is used for off-line evaluation of the real regulating systems characteristic parameters using an identification algorithm which takes as input data the system response collected for different input excitation signals, a structurally similar model of the analyzed regulating system, and some starting guess value of the unknown parameters. The real values of the parameters are determined during MODELIDENT program execution by applying an iterative algorithm and afterwards are retained as nominal reference values. The success of the identification algorithm is strongly dependent on how appropriately the structure of model's transfer function is chosen. By repeating periodically the identification method, using newly collected data from the process, the current value of the parameters are determined. Any deviations of the new values relative to the nominal reference values are interpreted as de-calibration of the control equipment and in this case corrective maintenance actions have to be taken. With the implementation of the presented methodology at Cernavoda NPP Unit 1 we can make the statement that the preventive maintenance activity is gaining a predictive feature, which can lead to the elimination of major degradation possibilities in the performances of the RS equipment and consequently to increase the NPP availability. On the basis of the experience gained in the practical application of the presented methodology we expect that the identification method will also have beneficial effects in the optimal control of the process systems and also in the activity of Full Scope Simulator software maintenance (the reference values of the identified parameters being used for fine tuning of the simulation models

  5. Probabilistic safety assessment (Cernavoda). Experience and strategies

    Mircea, Mariana

    2000-01-01

    An IAEA project named 'Support for PSA related activities for Cernavoda NPP' was agreed at the beginning of 2000. The objectives were: upgrading of capability and framework to perform deterministic analyses as support for PSA (accident analyses and severe accident analyses); upgrading of capability and framework to extend the scope of PSA model for Cernavoda NPP to include internal and external hazards (internal fire, internal flooding, earthquake); upgrading of capability and framework to perform the Level 2 PSA for Cernavoda NPP. valuation was done for the status of the development of the seismic PSA, fire PSA and flooding PSA. For seismic PSA it was concluded by IAEA experts that this work needs adequate human and financial resources. Decision was taken to coordinate this project from Cernavoda but using specialists from external institutions. A Fire Hazard Assessment-FHA is in progress for Unit 1. First stage, regarding the methodology, was reviewed by IAEA experts in November 1999. In present, work is done for Reactor and Service Buildings. Work on flooding PSA was not started yet. To extend the PSA scope: Capability will be extended to develop the seismic PSA, fire PSA, flooding PSA (procurement of supplementary computer codes and specialist training); the extension of PSA scope to include internal and external hazards will continue after the completion of deterministic studies and is expected that the effective inclusion in the PSA model will start at the end of 2002

  6. Time depending assessment of low and intermediate radioactive waste characteristics from Cernavoda NPP

    Mateescu, S.; Pantazi, D.; Stanciu, M.

    2002-01-01

    Low and intermediate radioactive gaseous, liquid and solid waste produced at Cernavoda Nuclear Power Plant must be well known from the point of view of contained radionuclide activity, during all steps of their processing, storage and transport, to ensure the nuclear safety of radioactive waste management. As in intermediate storage stage, the waste activity changes by radioactive decay and nuclear transmutation, the evolution in time of these sources is necessary to be assessed, for the purpose of biological shielding determination at any time. On the other hand, during the transport of waste package at the repository, the external dose rates must meet the national and international requirements concerning radioactive materials transportation on public roads. In this paper, a calculation methodology for waste characterization based on external exposure rate measurement and on sample analysis results is presented. The time evolution of waste activity, as well as the corresponding shielding at different moments of management process, have been performed using MICROSHIELD-5 code. The spent resins proceeded from clean-up and purification systems and solutions from decontamination have been analyzed. The proposed methodology helps us to assess radiation protection during the handling of low and intermediate - level radioactive waste drums, ensuring safety conditions for the public and environment.(author)

  7. The licensing process of the design modifications of Cernavoda 2 NPP resulting from the operating experience of CANDU plants

    Goicea, L.

    2005-01-01

    The CANDU 6 plant now under construction in Cernavoda include over two hundred significant improvements made in order to comply with current codes and standards and licensing requirements relative to the operating CANDU 6 in Romania. These evolutionary improvements are incorporated in CANDU 6 design taking advance of CANDU operating experience, of the designer company research and development and technical advances worldwide in order to further enhance safety, reliability and economics. This paper gives a general idea of the evaluation of the modifications of the Cernavoda 2 nuclear power plant against the design of Cernavoda 1 and states the safety principles and requirements which are the basis for this evaluation. (author)

  8. New approach of second Romanian NPP siting

    Mauna, Traian

    2010-01-01

    The NPP sitting studies in Romania began before 1975. The first Romanian NPP CANDU 6 type reactor gone to erection in 1980 on Cernavoda site planned to have 5 units. Gained the experience from Cernavoda NPP sitting, the first mission of new multi-branch of specialists team was to choose new NPP sites adapting the NPP Cernavoda project to the new parameters of close water cooling circuit and hard less and no rock foundation strata. The studies were carrying out in different stages on the inner rivers Olt, Mures, Somes in Transylvania historical region. This paper tries to reconsider shortly the old analysis according to the last IAEA Safety Standards, taking into account the new NPP generation requirement. Paper is focused on geological aspects and other local sites characteristics. (authors)

  9. The GMF (Group of European Municipalities with Nuclear Facilities) conference at Cernavoda. Opening talk

    Chirica, Teodor

    2006-01-01

    The conference 'Local Competence Building and Public Information in European Nuclear Territories', part of an European Commission project, took place at the Training Center of Cernavoda NPP, on 5-6 April, 2006. Organized by GMF with the support of the town hall and of the Cernavoda NPP, the manifestation gathered over 200 participants, among which representatives of the local public administration in Cernavoda, SN Nuclearelectrica SA, Ministry of Economy and Commerce, Nuclear Agency, CNCAN, ANDRAD, Local Communities and NGOs. The main topics of discussion was the collaboration relationship between local authorities and representatives of the plant regarding public safety and local development. The Mayor of Cernavoda, Gheorghe Hansa and the director of the NPP, Ionel Bucur, stressed that the location of the nuclear plant brings important contributions to the local budget, the socio-economical development of the area, ensuring jobs for most of the town's inhabitants. Speeches were given by Mr Gheorghe Hansa, Ms Blohm-Hieber, the director of the Transport and Energy Division from European Commission, and Mr Ionel Bucur who spoked about the relationship of the plant with the local community. Representatives from France, Slovenia, Sweden, Spain, Hungary and Romania shared their experience about 'The impact on the neighboring areas and the demands from the local authorities'. In his opening talk Mr Chirica Teodor, director general of SN Nuclearelectrica SA, showed that nuclear power in Romania has been based from its very inception on the Western safe technology, as reflected by the excellent safety an economical performances of Cernavoda NPP-Unit 1. Based on the long-term-commitment to nuclear power of the Romanian Government, the commercial operation of Cernavoda NPP Unit 2 is scheduled for the mid of 2007, and will supply 17-18% of the electricity production in Romania. The Romanian Government stressed his strong intention to complete Unit 3 and possibly Unit 4 at

  10. The experience in the Cernavoda Unit 1 operation - a stimulating argument for future nuclear power development in Romania

    Rotaru, I.; Bucur, I.; Galeriu, A.C.; Budan, O.

    1999-01-01

    The Romanian nuclear program has been developed based on the option for CANDU type reactors. At the beginning, this program was unrealistically conceived and its management was inappropriate. The program was reconsidered in 1990 and the management policy and organization structure were also adapted accordingly. The paper presents, in the first part, the actual organization structure, adapted for the execution of the current and future activities, related to the nuclear power program. The performance achieved by Cernavoda Unit 1 constitutes the main part of the paper. The performances described demonstrate that the Cernavoda Unit 1 is a success and the Romania's electricity needs are satisfied in a proportion of about 12% by the nuclear power. The paper also presents a general view on Cernavoda Unit 2 perspectives. The essential conclusion of the paper is that the continuation of the nuclear program appears to be a logical option, generally accepted in Romania, limited only by financial restraints. (author)

  11. Romania: Cernavoda unit 2. Assessments and evaluations. Annex 9B

    Rotaru, I.; Condu, M.

    1999-01-01

    This annex describes the various assessments and evaluations undertaken to confirm economic and technical viability of unit 2. The extent of modifications and improvements arising out of the suspension period are also identified. (author)

  12. Cernavoda power simulator modernization - A step forward in Romanian low cost maintenance simulation technology

    Bucur, I.; Tatar, F.; Ionescu, Teodor

    2004-01-01

    At Cernavoda NPP the training is conducted on a Full Scope Simulator, a 1:1 replica of Cernavoda Unit 1 reference plant. For the improvement of training delivery the current task is to define the simulation facilities and structure capable to meet the increased requirements for training, qualification and licensing of nuclear personnel. Besides, this upgrade of simulation facilities should be considered if we are addressing the task of extension of training for Cernavoda Unit 2. In order to achieve this target, if we take into account the deployment of a new simulator, the costs would be extremely high. Many utilities carried out similar strategies, utilizing alternative simulators as a complement to full scope simulator in the areas of training and model maintenance. Therefore, depending upon training requirements and finances, the Cernavoda Unit 1 Simulator modernization providing also an alternative to full scope control room simulator may be a viable option. In this case, the solution that we discuss for Cernavoda training extension is the migration of Cernavoda Unit 1 Simulator to state-of-the-art. The paper has the following contents: - Considerations; - Benefits; - Required tasks; - Simulator Modernization Hardware; - Software Scope; - Executive System Programs; - Development and Debug Programs; - Modeling Software; - Plant System Models; - Graphical Model Builder; - Emulation Software; - Instructor Station Software; - Cernavoda 2 simulation facilities; - Limitations

  13. Degradation tests for C 32/40 concrete used for perimetral wall, reactor base and components of Cernavoda NPP containment, under thermal stress conditions and liner degradation

    Carlan, P.; Paraschiv, I.; Dinu, A.; Stanciulescu, M.; Olteanu, A. M.; Voica, I.; Stelian, R.; Buc, G.

    2016-01-01

    In order to evaluate the effect of thermal degradation on C 32/40 concrete used in nuclear constructions at Cernavoda NPP, continuous thermal stress tests were performed at 65, 80 and 100°C and cyclic thermal stress tests at 65°C in dry conditions. This paper presents the macroscopic properties of concrete, obtained after these treatments and also the microstructural changes that occur in the cement paste from the concrete composition, which has been tested in the same conditions as the concrete samples. Determinations performed for macroscopic properties of concrete included: compressive strength, loss of density, permeability and modulus of elasticity. Cement paste samples were analysed by XRD (for mineralogical composition) and SEM (for morphology). The obtained results shown an appropriate behaviour of the concrete used in this study; changes are insignificant and follow the normal evolution process of concrete, proving that concrete will preserve its safety functions, as part of the containment structure. (authors)

  14. Considerations related to plant life management for Cernavoda-1

    Cojan, Mihail

    2002-01-01

    Cernavoda-1 NPP, the first CANDU 6 Unit in Eastern Europe, is one of the original five CANDU 6 plants and the first CANDU 6 producing over 700 MWe. CANDU Pressurized Heavy Water Reactors (PHWR) continues to play a significant role in electricity supply both in Canada and some offshore countries (Korea, Argentina, Romania). The commercial versions of CANDU reactors were put into service more than 30 years ago. While the first series of CANDU 6 plants (which entered service in the early 1980's) have now reached the middle portion of their 30 years design life, the Cernavoda-1 was put into service on 2 December 1996. However, the Cernavoda-1 Plant Life Management should be an increasingly important program to Utility ('CNE-Prod') in order to protect the investment and the continued success of plant operation. Over the past three years, INR (Institute for Nuclear Research - Romania) has been working with AECL-Canada on R and D Programs to support a comprehensive and integrated Cernavoda-1 Plant Life Management (PLiM) program that will see the Cernavoda-1 NPP successfully and reliably through to design life and beyond. The PLiM program has a focus on critical systems, structures, and components (CSSCs) and will be applied in three phases: Phase 1 - Planning (assessment and recommendations); Phase 2 - Life attainment implementation, and; Phase 3 - Plant Life Extension (PLEx), also known as plant extended operation. The key activities during each phase are shown. The schedule of each Phase are shown using the in service date of 1983 as the basis. This schedule applies to three original CANDU 6 plants with an in-service date of 1983: Point Lepreau, Gentilly-2, Wolsong-1 and shortly thereafter (1984) the 4th original CANDU 6 Embalse NPP was declared in service. Cernavoda-1 is the 5th original CANDU 6 plant and was put into service on 2 December 1996 (on site activities were started in 1980). The paper will describe the elements of an integrated program, the multiphase

  15. Customization of RODOS 5.0 system for the assesment of a CANDU Cernavoda NPP nuclear accident scenario

    Mateescu, Gh.; Galeriu, D.; Slavnicu, D.; Vamanu, D.; Craciunescu, T.; Turcanu, C.; Melintescu, C.A.; Gheorghiu, D.; Gheorghiu, A.

    2003-01-01

    The RODOS expert system is designed to be run in real time and on-line for multiuser operation in local, regional and national nuclear emergency centers responsible for off-site nuclear emergency management. RODOS provides continuously updated, consistent, comprehensive and timely information as an input for making decisions at local, national and European scale, in early or late phase of an accident, for all types of actions and countermeasures in an emergency situation. For testing the customization of RODOS in prototype version 5.0 to Romanian conditions an accident scenario for CANDU reactor was considered. This accident scenario is the early reactor core disruption with hydrogen burning. For customization a more detailed geographic database was created and was updated according to the radioecological database for our country. The goal of testing is to assess the accident consequences in early phase and also the banning, processing and disposal of agricultural products. One figure presents the evacuation zone and a second one shows the iodine tablet intake (for children). Another application was the estimation of HTO concentration and OBT (organic bound tritium) in cow's milk and also the tritium ingestion dose, having in view that CANDU reactor is an important source of tritium in the case of an accidental release. Other important estimations regard the assessment of concentration of important radionuclides as Cs-137, I-131 and Sr-90 which has an important impact on organs like muscles, thyroid and bones. In case of countermeasures for long term it is very important to estimate the number of persons to be relocated as well as the relocation lapse. The system provides economic estimations corresponding to different countermeasure strategies regarding the costs of food consumption and decontamination activities of radioactively contaminated regions. RODOS is adapted to evaluate accident or incident consequences for all nuclear risk zones in Romania (Cernavoda

  16. About choosing the power unit of NPP

    Alekseev, P.N.; Mordashev, V.M.; Proshkin, A.A.; Stukalov, V.A.; Subbotin, S.A.; Tsibul'skij, V.F.; Chernilin, Yu.F.

    2008-01-01

    The present-day domestic nuclear power industry faces the necessity to make both process and economy related decisions. The mentioned decisions should cover all the aspects of the nuclear power complex. In particular, as of now, no substantiation of the present-day and the future requirements for the power unit of the WWER and fast reactor NPPs is available. The choice of the unit power of an NPP should involve consideration of all factors and should not be boiled down to the efforts to ensure the minimization of the investment and the operation constituents of the electric power generation costs. The aim of the present paper was to ensure elaboration of the recommendations to substantiate the optimal unit power of NPP power units based on the analysis of various factors to design, to construct and to operate an NPP (investment, time of construction, the unscheduled shutdown losses, the unification, the fabrication quality, the accident damage, etc.), and the electrical network potentialities and the regional electric power demands [ru

  17. Unit Commissioning of “Belene” NPP (Bulgaria)

    2009-01-01

    This presentations gives detailed information about the following topics about commissioning: principles of NPP commissioning; phases of NPP commissioning; organization of commissioning activities; duties and responsibilities of the parties for carrying out unit commissioning activities; responsibility and obligations of the sides during commissioning of power unit; documentation required for power unit commissioning; quality assurance for commissioning activities

  18. Analyses of thermal plume of Cernavoda nuclear power plant by satellite remote sensing data

    Zoran, M. A.; Nicolae, D. N.; Talianu, C. L.; Ciobanu, M.; Ciuciu, J. G.

    2005-10-01

    The synergistic use of multi-temporal and multi-spectral remote sensing data offers the possibility of monitoring of environment quality in the vicinity of nuclear power plants (NPP). Advanced digital processing techniques applied to several LANDSAT, MODIS and ASTER data are used to assess the extent and magnitude of radiation and non-radiation effects on the water, near field soil, vegetation and air for NPP Cernavoda , Romania . Cernavoda Unit 1 power plant, using CANDU technology, having 706.5 MW power, is successfully in operation since 1996. Cernavoda Unit 2 which is currently under construction will be operational in 2007. Thermal discharge from nuclear reactor cooling is dissipated as waste heat in Danube-Black -Sea Canal and Danube river. Water temperature distributions captured in thermal IR imagery are correlated with meteorological parameters. Additional information regarding flooding events and earthquake risks is considered . During the winter, the thermal plume is localized to an area within a few km of the power plant, and the temperature difference between the plume and non-plume areas is about 1.5 oC. During the summer and fall, there is a larger thermal plume extending 5-6 km far along Danube Black Sea Canal, and the temperature change is about 1.0 oC. Variation of surface water temperature in the thermal plume is analyzed. The strong seasonal difference in the thermal plume is related to vertical mixing of the water column in winter and to stratification in summer. Hydrodynamic simulation leads to better understanding of the mechanisms by which waste heat from NPP Cernavoda is dissipated in the environment.

  19. Report of the IPERS (International Peer Review Service) review mission for the Cernavoda nuclear power plant probabilistic safety evaluation (CPSE -PHASE B) in Romania 3 to 14 July 1995

    1995-01-01

    This report presents the results of the IAEA International Peer Review Services review of the internal events Level 1 probabilistic safety assessment (PSA) for the Cernavoda, Unit 1 NPP. The review was based on the PSA documentation available and on intensive communications with the analysis team and representatives from the utility and the plant operator. 7 refs, figs, tabs

  20. Cernavoda NPP Unit 1: Operating experience program and plant specific performance indicators (level 2)

    Teodor, Vasile; Popa, Viorel

    1998-01-01

    The basis for the Operating Experience Program was set in place since early stages of the commissioning phase (1993), when a system based on the Canadian approach was implemented for reporting, reviewing, assessing and establishing of the necessary corrective action for unplanned events. This system provided excellent opportunity to train staff in unplanned event assessment methodology, and prepare the station for the formal reporting process following criticality in accordance with the licensing requirements. The formal process, set in place after criticality is described in Station Instruction Procedure SI-01365-P13 'Unplanned Event Report' and was developed under the supervision of Safety and Compliance Department. In parallel, a program for information exchange and trending of performance indicators was developed by Technical Services Department. The WANO recommendations following August 1997 Peer Review provided the opportunity for a better understanding and reconsideration of the Operating Experience Program. As a result, all the activities related to this topic were assigned to a new structure, within Safety and Compliance Department. As such an Operating Experience Group was created and a new program is now being developed in an integrated and centralized manner. The content of the paper is the following: - Overview; - Operating Experience Program; - Event Analysis (Unplanned Events Assessment System - UEIR Process- and Systematic Analysis of Operational Events - ACR Process); - Information Exchange Program; - Monitoring of Operating Experience - Plant Specific Performance Indicators; - Purpose; - Level 2 Performance Indicators. Four appendices are added containing: - A. Station performance indicators/targets (Level 2); - B. SPI (Station Performance Indicators - Level 2) - Graphics; - C. UEIR, LRS (Safety and Licensing Review Sheet), UEFR (Unplanned Event Follow-up Report), ACR and OPEX forms. (authors)

  1. Successful factors to a better maintenance effectiveness in Cernavoda NPP 's Unit 1

    Riedel, M.; Bigu, D.

    2001-01-01

    Two tables are presented titled 'Existing maintenance-specific and maintenance-related plant programs' and 'New programs intended to be developed', respectively. In the first table the following items are indicated and commented: 1. Corrective maintenance program; 2. EQ Program; 3. Equipment maintenance history program; 4. In service inspection program; 5. Lube oil analysis program; 6. MOVs program; 7. Operational test procedures; 8. Performance evaluation program; 9. Preventive maintenance program; 10. Spares management program; 11. Vibration monitoring program. In table 2 the following items are indicated and commented: 1. Check Valves program; 2. Electrical Cable Diagnostics; 3. Erosion-corrosion; 4. Temperature monitoring (infra red thermography; noncontact thermometer); 5. Airborne Ultrasound Detection program; 6. PdM Program. A flowchart is presented in figure 1 showing the maintenance strategies' selection. In figure 2 there is presented a flowchart showing the plants maintenance current approach. Finally, in figure 3 the station maintenance program is presented in a diagram structured on the following fields: concepts, requirements, strategies, specific programs and plans

  2. Cernavoda Unit 2: - BOP 3D model proposal for a possible organization of site activities

    Ghiesura, G.; Scarsin, Sioli; Orlandi, S.

    1999-01-01

    The scope of this activity is to define characteristics and advantages of the 3D model of Cernavoda BOP to this set up at site for engineering and construction activities. This model will provide a modern and proven tool able to strongly support the site activities with particular regard to the following: 1. engineering activities, - plant arrangement 'double check' for resolution of clashing; - easy management of future design changes; - real time plant configuration updating as soon as any design modification is approved and integrated in the model; - preparation of high quality documentation for procurement, construction and commissioning; - prompt availability of the as built configuration of the plant as soon as the last modification is frozen; 2. material procurement activities, - definition of the priorities in the construction material procurement according to the construction planning by area; - inventory list of equipment, pipes, fittings, valves, cable trays and ventilation ducts to be installed in each construction area; 3. construction activities, - definition of construction sequences, with particular reference in the congested areas, for piping cable trays (electrical and C-and-I) and ventilations ducts; - definition of piping spools by construction contractors; - follow-up of the activities in each area (i.e. construction, painting, insulation, flushing, pressure testing, etc); 4. turn-over and commissioning, - check of the progress. The success of this approach is based on the following: i) proper management of the remote workstations providing easy and reliable access to the model; ii) subdivision of the Integrated Building in construction areas, whose detail design may be allotted to Romanian organizations with multidisciplinary tasks; iii) integration in the model of the remote developed engineering in order to validate the details of the design. (authors)

  3. Update on Cernavoda

    Boucher, R.

    1994-01-01

    The Cernavoda project in Romania is for five 700 MWe CANDU units. Construction began in 1980, but because of problems occurring, many of them associated with political, social, and economic changes in Romania, in 1991 the management of construction of Unit 1 was transferred from RENEL (Regia Nationala de Electricitate) to a consortium formed by AECL and Ansaldo. This had been one of the chief recommendations of a pr-operational safety review conducted by the I.A.E.A. By May 1994, Unit 1 was 93.4% complete, but progress was hampered by the need to rework a number of components, mainly piping. A continuous quality assurance program was in place. Ninety-two Romanian operators were trained by New Brunswick Power at Point Lepreau. As of the date of the conference, the target date for grid connection was March 1995, nine months ahead of the contractual target

  4. NPP Mochovce units 1 and 2 diagnostic systems

    Heidenreich, S.

    1997-01-01

    In this paper the diagnostic systems (leak detection monitoring, vibration monitoring, lose parts monitoring, fatigue monitoring) of NPP Mochovce units 1 and 2 are presented. All of the designed diagnostic systems are personal computer based systems

  5. Update from Cernavoda

    Sommerville, J.D.

    1996-01-01

    On April 16 1995 Cernavoda Unit 1 achieved criticality. This event marked the culmination of roughly 17 years of effort and one of the most troubled histories experienced by any nuclear construction project worldwide. It was also a major milestone in the program begun by AAC (AECL-ANSALDO CONSORTIUM) in 1991 and due to end in June 1997 with the hand-over to RENEL (The Romanian National Electric Utility) of a fully operational CANDU 600 Power Plant. This paper briefly outlines the history of the project, the organisational structure in place and the funding schemes used to ensure its completion. Most attention is given to the present status of the project and those areas and/or issues which have been or continue to be significant problem areas. The future program for the achievement of 100% power and hand-over of the station to RENEL is outlined and potential future problem areas are discussed. (author). 9 appendices

  6. Cernavoda CANDU severe accident evaluation

    Negut, G.; Marin, A.

    1997-01-01

    The papers present the activities dedicated to Romania Cernavoda Nuclear Power Plant first CANDU Unit severe accident evaluation. This activity is part of more general PSA assessment activities. CANDU specific safety features are calandria moderator and calandria vault water capabilities to remove the residual heat in the case of severe accidents, when the conventional heat sinks are no more available. Severe accidents evaluation, that is a deterministic thermal hydraulic analysis, assesses the accidents progression and gives the milestones when important events take place. This kind of assessment is important to evaluate to recovery time for the reactor operators that can lead to the accident mitigation. The Cernavoda CANDU unit is modeled for the of all heat sinks accident and results compared with the AECL CANDU 600 assessment. (orig.)

  7. Assessment of financial expenditure for Rivne NPP power units decommissioning

    Nosovskij, A.V.; Salij, L.M.

    2007-01-01

    The article covers some financial aspects of developing a decommissioning concept for Rivne NPP power units with reactor VVER-440 and VVER-1000. Possible methodological approaches to costs estimate have been analyzed. Preliminary results of cost estimation are presented for two decommissioning options: deferred and immediate dismantling. Principally possible options for accumulating assets have been analyzed to finance measures related to Rivne NPP decommissioning. A mathematical model has been proposed for creating decommissioning financial reserve

  8. Autoevaluation process at SNN SA-CNE PROD Cernavoda

    Florescu, N.

    2005-01-01

    Implementation of the autoevaluation process requires identification of the activities carried with performance under the limits imposed by international standards. The following activity areas were established for autoevaluation at Cernavoda NPP: 1. General activities; 2. Operation activities; 3. Work control; 4. Maintenance activities; 5. Preparing activities; 6. Technical activities; 7. Radioprotection activities; 8. Emergency plans; 9. Environment control activities; 10. Chemical control; 11. Materials control; 12. Physical protection; 13. Document control; 14. Fuel manipulation. In order to improve the performances at Cernavoda NPP the WANO autoevaluation model was adopted

  9. To the problem of reliability standardization in computer-aided manufacturing at NPP units

    Yastrebenetskij, M.A.; Shvyryaev, Yu.V.; Spektor, L.I.; Nikonenko, I.V.

    1989-01-01

    The problems of reliability standardization in computer-aided manufacturing of NPP units considering the following approaches: computer-aided manufacturing of NPP units as a part of automated technological complex; computer-aided manufacturing of NPP units as multi-functional system, are analyzed. Selection of the composition of reliability indeces for computer-aided manufacturing of NPP units for each of the approaches considered is substantiated

  10. Some problems connected with the Chernobyl NPP Unit 4 Accident

    Bar'yakhtar, V.G.

    1994-01-01

    The description of the eruption of radionuclides caused by the Chernobyl NPP Unit 4 Accident, including the effective time of the accident, quality and quantity of radio waste, is presented. A particular attention is given to the spotty structure of Chernobyl's contamination. The assumption that the spots distribution may be a consequence of the turbulent processes in the atmosphere is made

  11. Using the WIMS-DIREN bigroup and multigroup methodology for Cernavoda Unit 1 and Unit 2 adjuster rods comparative reactivity calculations at Phase B commissioning

    Prodea, Iosif; Patrulescu, Ilie; Rizoiu, Andrei; Danila, Nicolae; Prisecaru, Ilie

    2007-01-01

    One of the most important CANDU reactor regulation system is the Adjuster Rods System (ADJ). The individual and bank calibration and performance evaluation of this system is carried out during the Phase B commissioning. The ADJ rods are grouped into seven banks based on full power reactivity control requirements. The Cernavoda Unit 2 adjuster rods characteristics were designed more than twenty years ago at INR Pitesti in the end of a fruitful collaboration between INR Pitesti (as designer) and Bristol Aerospace Limited (as manufacturer). In 1996, during the Phase B commissioning tests only AECL diffusion and Westcott approximation methodology was used. An alternative integral transport and high-modes diffusion approximation methodology was developed in INR Pitesti during the last years. As a result, the first collision probability code PIJXYZ was created and developed to carry out the supercell calculations as well as the code DIREN for 3D diffusion-based core simulations. The aim of this work was to evaluate comparatively the two adjuster rods systems (from Unit 1 and 2) in commissioning conditions. The concrete results will consist of individual, bank and total adjuster rods reactivity estimations with an emphasis on the differences and similarities between them. (authors)

  12. Modernization of tritium in air monitoring system for CANDU type NPP

    Purghel, L.; Iancu, R.; Popescu, M.

    2009-01-01

    Nuclear energy provides at present one third of Europe's electricity with nearly no greenhouse-gas emissions. Sustained efforts are now being conducted to harmonize regulations all over Europe through WENRA and to converge on technical nuclear safety practices within the TSO network ETSON (European Technical Safety Organizations Network). In order to achieve this goals of safety function, IFIN-HH together with CITON developed a new solution to improve the Tritium Monitoring System (TMS) of Cernavoda NPP and the new generation of CANDU type reactors, using Tritium in air Intelligent Monitors (TIM) developed and patented by IFIN-HH. The paper presents a comparative analysis between the technical characteristics of traditional solutions implemented in CANDU type NPP, particularly in Cernavoda NPP Unit 2 and the newly proposed solution. (authors)

  13. Project No. 7 - Decommissioning unit at Ignalina NPP. (Engineering and project management)

    2000-01-01

    In order to manage decommissioning process at Ignalina NPP, a new unit should be established in the framework of the Ignalina NPP organizational structure. The on-site Engineering Project Management Unit (PMU) will adopt an integrated approach to project management , engineering design, planning, procurement, safety and licensing activities at Ignalina NPP site. The PMU will assist the Ignalina NPP management in the development of an integrated decommissioning and waste management strategy

  14. Life extension program of KORI Unit 1 NPP in Korea

    Hong, Sun-Yull

    1998-01-01

    The two phases of Life extension program for KORI Unit 1 NPP are presented. Phase I is completed. It was concluded that life extension is a feasible option in technical and economic aspects. Detailed analysis of RPV is underway, plan for Phase II is finished. It deals with screening and sorting of all relevant SSCs, detailed life evaluation of SSCs, ageing management program and documentation for license renewal application

  15. Fuel assembly leakage, unit 4, cycle 22, Paks NPP

    Szecsenyi, C.; Burjan, T.; Torma, B.; Bona, G.

    2009-01-01

    At the beginning of Cycle 22, Unit 4, Paks NPP the Iodine isotopes activity concentrations raised irregularly in the water of the primary circuit. Analysis supposed that from 1 to 10 fuel rods in one or more newly loaded follower assemblies had lost their integrity. Due to the fact it was not necessary to shut down the reactor, but at the end of the cycle sipping tests were performed for the entire core to find out the facts using a telescope sipping device supplied by H and B Co., Germany. This paper describes the circumstances of the emergence of the problem, the operational inspection and limitation rules in Paks NPP, the theoretical analysis to estimate the scope and kind of the problem, the sipping device and the measurement/evaluation methods applied for the practical tests, fulfilment the tests, the results and their evaluation and the conclusions regarding the event. (Authors)

  16. Fuel assembly leakage, Unit 4, Cycle 22, Paks NPP

    Szecsenyi, Z.; Burjan, T.; Torma, B.; Bona, G.

    2009-01-01

    At the beginning of Cycle 22, Unit 4, Paks NPP the Iodine isotopes activity concentrations raised irregularly in the water of the primary circuit. Analysis supposed that from 1 to 10 fuel rods in one or more newly loaded follower assemblies had lost their integrity. Due to the fact it was not necessary to shut down the reactor, but at the end of the cycle sipping tests were performed for the entire core to find out the facts using a telescope sipping device supplied by H and B Co., Germany. This paper describes the circumstances of the emergence of the problem, the operational inspection and limitation rules in the Paks NPP, the theoretical analysis to estimate the scope and kind of the problem, the sipping device and the measurement/evaluation methods applied for the practical tests, fulfilment the tests, the results and their evaluation and the conclusions regarding the event. (authors)

  17. Full scale dynamic testing of Kozloduy NPP unit 5 structures

    Da Rin, E.M.

    1999-01-01

    As described in this report, the Kozloduy NPP western site has been subjected to low level earthquake-like ground shaking - through appropriately devised underground explosions - and the resulting dynamic response of the NPP reactor Unit 5 important structures appropriately measured and digitally recorded. In-situ free-field response was measured concurrently more than 100 m aside the main structures of interest. The collected experimental data provide reference information on the actual dynamic characteristics of the Kozloduy NPPs main structures, as well as give some useful indications on the dynamic soil-structure interaction effects for the case of low level excitation. Performing the present full-scale dynamic structural testing activities took advantage of the experience gained by ISMES during similar tests, lately performed in Italy and abroad (in particular, at the Paks NPP in 1994). The IAEA promoted dynamic testing of the Kozloduy NPP Unit 5 by means of pertinently designed buried explosion-induced ground motions which has provided a large amount of data on the dynamic structural response of its major structures. In the present report, the conducted investigation is described and the acquired digital data presented. A series of preliminary analyses were undertaken for examining in detail the ground excitation levels that were produced by these weak earthquake simulation experiments, as well as for inferring some structural characteristics and behaviour information from the collected data. These analyses ascertained the high quality of the collected digital data. Presumably due to soil-structure dynamic interaction effects, reduced excitation levels were observed at the reactor building foundation raft level with respect to the concurrent free-field ground motions. measured at a 140 m distance from the reactor building centre. Further more detailed and systematic analyses are worthwhile to be performed for extracting more complete information about the

  18. Startup physics tests at Temelin NPP, Unit 1

    Sedlacek, M.; Minarcin, M.; Toth, L.; Elko, M.; Hascik, R.

    2002-01-01

    The objective, scope and proceedings of the physics tests of Temelin NPP, Unit 1 physical commissioning are given in this paper. Furthermore, some results of selected physics tests are presented: reactor initial criticality test, determination of reactor power range for physics testing, measurement of control rod cluster assembly group no. 10 reactivity worth in case of limitation system LS(a) actuation, control rod cluster assembly system reactivity worth measurement with single rod cluster assembly of greatest reactivity worth stuck in fully withdrawn position, measurement of differential reactivity worth of control rod cluster assembly group no. 9, boron 'endpoint' determination and measurement of power reactivity coefficient (Authors)

  19. New appraisement of siting for a NPP on Mures river

    Traian Mauna

    2010-01-01

    The studies for a second NPP siting on inner Romanian rivers began in a careful manner since 1982 as a first part of the Nuclear Power Plant Romanian Program adopted by political and governmental authorities at the time. The experience gained from Cernavoda NPP siting, the first mission of new multi-branch of specialists team was to choose new NPP sites adapting the CANDU type NPP Cernavoda project to the new parameters of close water cooling circuit and of hard less or no rock foundation strata. The new sites conditions mean a lot of changes of CANDU license and a decrease the output power supplied to the national electric grid. The studies on the Mures river as alternative site of Olt river in Transylvania region began in 1986 and were stopped after 1990. This paper tries to reconsider shortly the old analysis focused on geological and geotechnical aspects and other local sites characteristics according to the last IAEA Safety Standards taking into account also the last types of NPP generations and the number of units. (author)

  20. Thermal-hydraulic analyses of the recirculated cooling water from cernavoda n.p.p. unit 1

    Pancef, R.; Anghel, N.; Nita, I. P.

    2013-01-01

    The paper presents the results from a very complex and large analysis performed for the Recirculated Cooling Water System. The analysis was required in order to increase the flow rate for moderator heat exchangers and introduction of a new consumer: urban heating. The system capability to supply with cooling agent all this consumers at all operating regimes from the design manual of the system had to be checked. One concluded that the required modification to the system had no influence in operating the system in all operating condition but there is an issue is regarding the necessity to recalculate the heat load from the moderator heater. The analysis was calibrated by using measurements from the plant, which have been obtained with ultrasonic flowmeters and local indicators. The analysis concludes that the system can change the requirements to the moderator heat exchangers and a new turbine building consumer (urban heating) can be introduced. (authors)

  1. Actual status of project Mochovce NPP units 3 and 4 completion

    Niznan, S.

    2005-01-01

    In this presentation author deals with actual status of project Mochovce NPP units 3 and 4 completion. Present state of Mochovce NPP, Units 3 and 4 enables real assumption to completion. It is expected that such supplier companies can be used which are experienced in field of nuclear projects. Based on budget of 2002, it seems that completion costs of 45 billions SKK are real. These figures were confirmed by study performed by TRACTEBEL in 2004. Based on experience from Bohunice NPP completion as well as from Mochovce NPP, Units 1 and 2 completion and if decision milestone and project start up deadlines will be observed according to modified preliminary schedule of Mochovce NPP Units 3 and 4 completion, it seems as real that Unit 3 will be completed till 06/2011 and Unit 4 - till 12/2011.

  2. Maintenance philosophy and program at Cernavoda NPP

    Bobos, M.; Enciu, G.

    1994-01-01

    Maintenance plays a key role in ensuring safe and reliable operation. An effective maintenance program should ensure that installed equipment operates when needed and the equipment malfunctions or deficiencies are corrected in time and rarely recur. Maintenance includes not only the activities traditionally associated with identifying or correcting current or potential equipment deficiencies but also extends to supporting technical functions for the conduct of these activities (for example, engineering, technical support, chemistry control, radiological protection, industrial safety and training). The maintenance management program should clearly define the relationship among these supporting groups as it is related to overall plant maintenance and promotes the concept of a successful integrated team effort. (Author)

  3. Redundant filtration system of the fuel buildings,units 1 and 2 Almaraz NPP

    Lopez Tanco, J.

    2011-01-01

    The project redundant filtering fuel buildings in units 1 and 2 of Almaraz NPP, will compliance to the requirements established in the complementary technical instructions to the authorization of exploitation of Almaraz NPP, established by the CSN and will consist of the installation of a new filtration unit.

  4. The Cernavoda project - past and future

    Glodeanu, F.; Campureanu, T.; Chirica, T.; Popescu, D.

    1995-01-01

    The history of the Cernavoda nuclear power station in Romania is traced. It was conceived in 1977 as five unit CANDU-6 station and agreements were concluded on engineering, procurement and financial assistance with Atomic Energy of Canada Ltd (AECL) and Ansaldo of Italy. Delays in construction were created from the first, however, by efforts to manufacture as many components as possible in Romania, unfamiliarity with nuclear project management and the disadvantages of a highly centralised economy. Political changes since December 1989 have led to a new approach to project implementation. The Romanian Electricity Authority (RENEL), signed a new contract with AECL and Ansaldo in August 1991 to perform the project management for the completion of Cernavoda 1. The project has progressed very well and by the beginning of 1995 more than 90% of the plant systems were ready for commissioning and a full operating shift was in place. As a second phase of the nuclear power programme RENEL plans to complete Cernavoda 2, the construction of which was suspended at 30% completion. The three other units will be preserved in their present preliminary stage of construction up to 2000 while finance is sought for their completion. Nuclear power is seen as an environmentally clean means of meeting Romania's growing energy demand as the economy develops. (UK)

  5. Operational benchmark for VVER-1000, unit 6, Kozloduy NPP

    Apostolov, T.; Petrov, B.

    1999-01-01

    Benchmark calculations have been carried out using the 3D nodal code TRAPEZ. Global neutron-physics characteristics of the VVER-1000 core, Kozloduy NPP Unit 6, have been determined taking into account the real loading patterns and operational history of the first three cycles. The code TRLOAD has been used to perform the fuel reloading between any two cycles. The reactor and components descriptions as well as material compositions are given. The results presented include the critical boric acid concentration, the radial power distribution, the axial power distribution for the maximum overload assembly, and the burnup distribution at three different moments during each cycle. Calculated values have been compared with measured data. It is shown that the results obtained by the TRAPEZ code are in good agreement with the experimental data. The information presented could serve as a test case for validation of code packages designed for analyzing the steady-state operation of VVERs. (author)

  6. Neutron embrittlement of the Kozloduy NPP unit 1 reactor

    Vodenicharov, S.; Kamenova, Tz.

    1996-01-01

    Activities made in the period 1989-1996 according to the Program for metal state monitoring of the Kozloduy NPP Unit 1 are described. Data on P and Cu content in the welded joint 4 are reported. Determination is made by wet chemical analysis of shavings taken out from the inner side of the wall, direct spectral analysis of the vessel itself and spectroscopy of the inner and outer side of 6 templates. The results obtained from 4 different study teams showed a good agreement. The real average P content is 0.046% and tends to diminish in depth. Microstructural investigation does not show any expressed inter-crystalline mechanism of brittle failure at low temperatures. The data on real P and Cu content, as well as the experimental values of the initial critical temperature of embrittlement (Tk o ), the residual part of temperature shift (Tk r ) and the re-embrittlement temperature after annealing at 475 o (Tk) allow to predict the change in Tk o of the joint 4 during the next refueling cycles. The measured low value of Tk after 18-th refueling cycle is considerably lower than that forecasted by lateral re-embrittlement law. This means that the forecasting of Tk for the next cycles is made with big enough conservatisms, and that a second annealing of the vessel until 26-th cycle is not necessary. So according to the most conservative estimate, the Unit 1 can operate safely until the end of the 26-th refueling cycle. It is also concluded, that in terms of radiation degradation of the vessel metal the operation life time of the Unit 1 can reach and exceed the designed one. 2 tab., 7 ref

  7. Search and Retrieval of Foreign Objects for the Steam Generator of Wolsung NPP Unit 1

    Jeong, Woo-Tae; Lee, Kyung-Ho

    2016-01-01

    We developed a foreign object search and retrieval (FOSAR) system for Wolsung NPP unit 1 steam generators. The steam generators of Wolsung NPP unit 1 have one 2.5 inch hand hole and two 4 inch hand holes. The FOSAR system was designed to be installed through 4 inch hand holes. Using permanent magnet, the FOSAR system was firmly attached to the vertical annulus wall of the steam generator. We successfully developed the FOSAR system for Wolsung NPP unit 1. Using the developed FOSAR system, technicians successfully found and removed various foreign objects. Most of the foreign objects, we found, were made of carbon steel sheet, therefore magnet tool was the most useful to remove it. Alligator tool was sometimes used. Based on the experience during the FOSAR activities, we are developing a lancing system for Wolsung NPP unit 1. It will be designed and manufactured until November 2016

  8. Search and Retrieval of Foreign Objects for the Steam Generator of Wolsung NPP Unit 1

    Jeong, Woo-Tae; Lee, Kyung-Ho [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    We developed a foreign object search and retrieval (FOSAR) system for Wolsung NPP unit 1 steam generators. The steam generators of Wolsung NPP unit 1 have one 2.5 inch hand hole and two 4 inch hand holes. The FOSAR system was designed to be installed through 4 inch hand holes. Using permanent magnet, the FOSAR system was firmly attached to the vertical annulus wall of the steam generator. We successfully developed the FOSAR system for Wolsung NPP unit 1. Using the developed FOSAR system, technicians successfully found and removed various foreign objects. Most of the foreign objects, we found, were made of carbon steel sheet, therefore magnet tool was the most useful to remove it. Alligator tool was sometimes used. Based on the experience during the FOSAR activities, we are developing a lancing system for Wolsung NPP unit 1. It will be designed and manufactured until November 2016.

  9. Seismic upgrading of WWER 440-230 structures, units 1/2, Kozloduy NPP

    Stafanov, D.; Kostov, M.; Boncheva, H.; Varbanov, G.

    1995-01-01

    The purpose of this paper is to present final results from a big amount of computational work in connection with the investigations of the possibilities for upgrading of WWER 440-230 structures, units 1/2, Kozloduy NPP. (author)

  10. Sitting Safety Aspects of Second Romanian NPP

    Mauna, T.

    2010-01-01

    The first Romanian NPP CANDU 6 type reactor gone to erection in 1980 on Cernavoda site planned to have 5 units like the Wolsong applied design project for nuclear island. For the BOP parts the ASALDO-GE project was applied with the careful about the interface connection NSP requirements. The new NPP sitting studies began from 1982 in a serious manner as first part on Nuclear Power Plant Romanian Program adopted by political and governmental authorities at the time. For develop the all package of the studies in concordance with the first IAEA Safety Standards recommendations. Till the 1982 the first mission of design and research multi-branch of specialists team was to adapt the NPP Cernavoda project having a open water cooling circuit to the new parameters of close water cooling circuit. But the team was looking at the other type of NPP for sitting. Also in the same time was studied the possibility of NSP foundation on hard less or soft soil foundation strata in connection with safety aspects. The close circuit of cooling water means others parameters of systems and need very large cooling towers. Also must be reconsidering the safety systems design and performance as new solution. In the south of Transylvania historical region in Romania the Olt River run from west to east having medium multi annual flow around 70 m3/s. The Olt River has a chain of small hydropower in operation and other planned. From geological and geophysical points of view two main faults, along the Olt river valley, one of this having seismically small activities was detected. Site region geotechnical studies show small quantity underground natural gas, salt and peat. The initial nuclear program has imposed 4 NPP units site near Olt River. Taking into account the orogenesis, water cooling needs and other local feature can't be built more than two NPP units on a site. This paper tries to reconsider the old analysis from the last IAEA Safety Standards point of view taking into account the new

  11. The Bohunice NPP V-1 units nuclear safety upgrading

    Mlcuch, M.

    2000-01-01

    Safety upgrading and operational reliability improvement was carried out by the Bohunice NPP V-1 staff continuously since the plant commissioning. By now, more than 1200 minor or major modifications have been implemented, either by the NPP maintenance staff or by the contractors. Based on findings of safety assessment missions invited by Bohunice NPP in 1990 - 1991, the Czecho-slovak Nuclear Regulatory Authority (CSKAE) issued the decision No. 5/91 of 81 safety upgrading measures to be taken in different areas. These improvements are referred to as the 'Small Reconstruction of the Bohunice V-1 NPP'. Realization of measures during Small reconstruction of the Bohunice NPP V-1 became a power plant, which further operation is acceptable from safety point of view, but it is also necessary further safety improvement. During the period of the Small Reconstruction the development of a Safety Report for the Gradual reconstruction has been completed. Based on this report the SR Nuclear Regulatory Authority issued the Decision No. 1/94, in which requires 59 upgrading measures in different areas to be addressed. The development of Basic Engineering of the Gradual Reconstruction has been contracted to the Siemens AG. Implementation of safety measures are provided through contract with the consortium REKON (which consists of Siemens AG company and Nuclear Power Plants Research Institute Trnava) and other Czech, Russian and Slovak companies. The Gradual Reconstruction of Bohunice NPP V-1 will be finished in 2000. By implementation of the measures carried out during Gradual Reconstruction achievement of an internationally acceptable nuclear safety level will be reached. (author)

  12. Operation experience of the advanced fuel assemblies at Unit 1 of Volgodonsk NPP within four fuel cycles

    Vasilchenko, I.; Kobelev, S.; Kushmanov, S.

    2006-01-01

    The first commissioning of Volgodonsk NPP Unit 1 with standard reactor WWER-1000 (project V-320) was in 2001. The reactor core, starting from the first fuel charge, was arranged completely with Advanced Fuel Assemblies (AFAs). In this way, it is possible to obtain the experience in startup and operation of the core, completely arranged with AFAs, and also to get a possibility of performing the comprehensive check for justification of newly commissioned units and justification of design solutions accepted in the design of reactor core for Taiwan NPP, Bushehr NPP and Kudankulam NPP. The first fuel charge of the Volgodonsk NPP Unit 1 is a reference and unified for Tiawan NPP (V-428), Bushehr NPP (V-446), Kudankulam NPP(V-412) with small differences caused by design features of RP V-320. The first core charge of Unit 1 of Volgodonsk NPP was arranged of 163 AFAs, comprising 61 CPS ARs and 42 BAR bundles. The subsequent fuel charges were arranged of AFAs with gadolinium oxide integrated into fuel instead of BAR. By 2005 the results of operation of the core at Unit 1 of Volgodonsk NPP during four fuel cycles showed that AFA is sufficiently reliable and serviceable. The activity of the primary coolant of the Volgodonsk NPP is at stable low level. During the whole time of the core operation of the Volgodonsk NPP Unit 1 no leaky AFAs were revealed. The modifications of the internals, made during pre-operational work, are reasonable and effective to provide for fuel mechanical stability in the course of operation. The modifications, made in AFA structure during operation of the Volgodonsk NPP Unit 1, are aimed at improving the service and operational reliability of its components. Correctness of the solutions taken is confirmed by AFAs operation experience both at the Volgodonsk NPP, and at other operating Russian NPPs

  13. Perspectives for utilization of the experience from the electrical equipment modernization of Kozloduy NPP units 5 and 6 in case of construction of new NPP

    Bogdanov, D.

    2005-01-01

    In 2005 a governmental decision for continue the project for construction of Belene NPP was adopted. In case of start of this significant project in short terms, a good option will be to utilize the already achieved experience by the modernization program of units 5 and 6 of Kozloduy NPP. The process of construction of new NPP is associated with significant amount of engineering, civil construction works, equipment order and delivery, installation works, testing and commissioning activities. It is vital necessity to have optimal technology, strict organization for project implementation and excellent documentation. From technical point of view the experience from the modernization of units 5 and 6 of Kozloduy NPP will be very important in case of utilization of similar types of WWER 1000 units. According to the 'Feasibility study for construction of Belene NPP', the most favorable option is to accomplish the already partially constructed Unit 1 on the basis of upgraded WWER B-320 design - WWER 1000 B-392, in order to fulfill IEC 331-3A, IEC 332-3A, and of US NRC Regulatory Guide 1.70 and to construct the second unit on the basis of ASE WWER/1000 B-466. However, for any type of unit selected, the achieved experience will be an important basis. This article is focused mostly on the modernization aspects of some electrical systems of Kozloduy NPP

  14. Top level risk study for units 1 to 4 at NPP Kozloduy

    Shishkova, I.

    1997-01-01

    The first Top Level Study of NPP Kozloduy Units 1/4 was started in 1991 and completed in March 1992 by BEQE. The Primary objective of the project was to provide in a short term a tool for quantified comparison of the relative risk benefits that various design or operational modifications would have if implemented on NPP Kozloduy Units 1/4. This original version of the Study was reviewed by the IAEA who agreed in general with the conclusions indicating that the report provides valuable insights which should be used in the decision making process. The IAEA made suggestion for some changes. These comments were taken into account in the subsequent version. In early 1994 the new version was issued. The objective of this second project, in addition to revising the original study to reflect the IAEA comments, was to address the potential benefits from further improvements at NPP Kozloduy. The work on the second version was going on in parallel with the activities carried out in the mainframe of several NPP Kozloduy Units 1/4 Upgrading Program (WANO Six-Month Program, Program for the NPP Kozloduy Units 1-4 Upgrading, Twinning Program, etc.). And at last, a Top-Level Probabilistic Safety Study was carried out by EQE - Bulgaria and completed early in 1995 at the request of NPP Kozloduy. The objective of the project was the contribution of the different activities performed in the mainframe of the Program for the NPP Kozloduy Units 1-4 Safety Upgrading in the overall safety improvement to be assessed. 3 figs, 1 tab

  15. Conceptual Design of a Combined Power Generation Unit at the NPP Seaside

    Cha, Kyung H.

    2011-01-01

    In order to improve operational performance, an undersea tunnel is being utilized for in-taking and out-taking seawater as coolant in Nuclear Power Plant (NPP). This paper describes a Combined solar-wind-wave Power Generation Unit (CPGU) to be specialized for in-taking and out-taking seawater as coolant in NPP. Accordingly, the purpose of the CPGU is twofold: one is to contain some tunnels to be maintained on the bottom of the CPGU body in order to in-take and out-take coolant water, and the other is to generate a combined power at the NPP seaside. Fig. 1 shows the conceptual CPGU to be configured at the NPP seaside

  16. Analysis of the behaviour of the Kozloduy NPP Unit 3 under severe accident conditions

    Velev, V.; Saraeva, V.

    2004-01-01

    The objective of the analysis is to study the behaviour of the Kozloduy NPP Unit 3 under severe accident conditions. The analysis is performed using computer code MELCOR 1.8.4. This report includes a brief description of Unit 3 active core as well as description and comparison of the key events

  17. Periodical safety review of units 1 and 2 of PAKS NPP. Examples from summary report

    Hammar, K.

    1998-01-01

    On the basis of American practice of qualification and relevant IAEA recommendations detailed guidelines of the qualification procedure were developed and executed on the Units 1 and 2 of the Paks NPP. Periodic safety supervision will be performed by evaluation of the following reports to be submitted by NPP: real technical conditions of the facility; existing practice and proposals for equipment qualification; evaluation of the existing safety reports estimating their validity up to the plant lifetime; ageing and ageing management; procedures of operation, maintenance, supervision; organisation and administration; safety impact of human factor, training, education, qualification of personnel

  18. Seismic soil-structure-equipment interaction analysis of unit 5/6, Kozloduy NPP

    Kostov, M [Bulgarian Academy of Sciences, Central Laboratory for Seismic Mechanics and Earthquake Engineering, Sofia (Bulgaria)

    1995-07-01

    This research project is aimed to analyse problems of soil-structure-equipment interaction under seismic excitation in case of Kozloduy NPP. Reevaluation and upgrading of Kozloduy NPP has started after 1977 Vrancea earthquake. New Safe Shutdown Earthquake (SSE) level was defined, upgrading most of structural equipment was performed, seismic instrumentation was installed. New investigations were initiated after 1990 IAEA mission visited the site. A comprehensive site confirmation project was started with a subsequent structural and equipment reevaluation and upgrading. This work deals with Units 5 and 6 of WWER-1000 type only.

  19. Kozloduy NPP units 3 and 4 rest life time program execution

    Genov, S.

    2005-01-01

    In this paper the following tasks are considered: Kozloduy NPP units 3 and 4 life time evaluation; programme for the units life time assuring; units 3 and 4 renewals. The main activities for the programme implementation are described and the obtained results are presented. In conclusion, the executed activities of program for assuring the life time of units 3 and 4 of Kozloduy NPP, cogently prove that the lifetime of structures, systems and components, is assured duly and those structures, systems and components will be in service safely, economically effectively and mostly reliable till the end of the 30 years design lifetime. For some of them it has been proved even for 35 and 40 years. Program activities continue during 2005, although the early shutdown of units 3 and 4 is possible

  20. Units 3 and 4 of Kozloduy NPP - modernized in compliance with the contemporary international standards

    Urutchev, V.

    2005-01-01

    In this paper the Kozloduy NPP units 1- 4 original design characteristics are given. The main results from units 3 and 4 modernization programme as well as: assurance of reactor core safety; assurance of SLA reliability; assurance of unit safety and reliability are presented. The Kozloduy NPP units 3 and 4 modernization programme and the position of the units in the generally accepted scale of risk assessment are illustrated. The fulfillment of the IAEA and EC requirements and AQG recommendations is also presented. At the end the author concluded that: 1) The results from units 3 and 4 large scale modernization programs realization are assessed by international community as one of the most effective examples of good international practices applying in the filed of the nuclear facilities safety; 2) There are not any technical reasons behind discussions for early closure of units 3 and 4; 3) Taking into account the Balkans electricity consumption prognosis and the condition of the electricity production facilities, Kozloduy NPP units 3 and 4 can have sufficient contribution for the region reliable electricity delivery in the future years

  1. Integrated risk assessment for multi-unit NPP sites—A comparison

    Kumar, C. Senthil; Hassija, Varun; Velusamy, K.; Balasubramaniyan, V.

    2015-01-01

    Highlights: • Framework for integrated risk assessment for multi-unit NPP sites. • Categorization of external and internal events. • Modelling of key issues: mission time, cliff-edge, common cause failures, etc. • Safety goals for multi-unit NPP sites. • Comparison of site core damage frequency in one, two, three and four unit sites. - Abstract: Most of the nuclear power producing sites in the world houses multiple units. Such sites are faced with hazards generated from external events: earthquake, tsunami, flood, etc. and can threaten the safety of nuclear power plants. Further, risk from a multiple unit site and its impact on the public and environment was evident during the Fukushima nuclear disaster in March 2011. It is therefore important to evolve a methodology to systematically assess the risk from multi-unit site. For a single unit site, probabilistic risk assessment technique identifies the potential accident scenarios, their consequences, and estimates the core damage frequency that arise due to internal and external hazards. This challenging task becomes even more complex for a multiple unit site, especially when the external hazards that has the potential to generate one or more correlated hazards or a combination of non-correlated hazards are to be modelled. This paper presents an approach to evaluate risk for multiple NPP sites and also compare the risk for sites housing single, double and multiple nuclear plants.

  2. Integrated risk assessment for multi-unit NPP sites—A comparison

    Kumar, C. Senthil, E-mail: cskumar@igcar.gov.in [AERB-Safety Research Institute, Kalpakkam (India); Hassija, Varun; Velusamy, K. [Reactor Design Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Balasubramaniyan, V. [AERB-Safety Research Institute, Kalpakkam (India)

    2015-11-15

    Highlights: • Framework for integrated risk assessment for multi-unit NPP sites. • Categorization of external and internal events. • Modelling of key issues: mission time, cliff-edge, common cause failures, etc. • Safety goals for multi-unit NPP sites. • Comparison of site core damage frequency in one, two, three and four unit sites. - Abstract: Most of the nuclear power producing sites in the world houses multiple units. Such sites are faced with hazards generated from external events: earthquake, tsunami, flood, etc. and can threaten the safety of nuclear power plants. Further, risk from a multiple unit site and its impact on the public and environment was evident during the Fukushima nuclear disaster in March 2011. It is therefore important to evolve a methodology to systematically assess the risk from multi-unit site. For a single unit site, probabilistic risk assessment technique identifies the potential accident scenarios, their consequences, and estimates the core damage frequency that arise due to internal and external hazards. This challenging task becomes even more complex for a multiple unit site, especially when the external hazards that has the potential to generate one or more correlated hazards or a combination of non-correlated hazards are to be modelled. This paper presents an approach to evaluate risk for multiple NPP sites and also compare the risk for sites housing single, double and multiple nuclear plants.

  3. Adjustment of the Kompleks Titan-2 monitoring computerized system at the Rovno NPP third unit

    Zigaev, B.P.

    1987-01-01

    Information signal origin and processing processes in the monitoring computerized system 'Komplex Titan-2' at the Rovno NPP third unit are considered. The system exercises control over the following production equipment parameters: the state of keys of control of lock fittings, mechanisms, regulators, reserve mechanism automatic shut-down circuit; the state of lock fittings, mechanisms, regulators, reserve mechanism automated switching on; parameter deviation from permissible values; interlock operation; protection system state; the state of autonomous units and devices

  4. Bases of updating of nuclear safety regulations for NPP in Romania

    Biro, Lucian; Serbanescu, Dan

    1999-01-01

    The paper presents the basic principles of reviewing and updating process of the regulatory environment pyramid. The main part of this review process refers to Cernavoda NPP Unit 2. However, there is an important impact on Cernavoda NPP Unit 1. The basic principles were defined in 1993/1994 when the licensing process for Unit 1 was resumed in order to be in accordance with the latest developments of Candu 600 worldwide and with the IAEA and NEA latest recommended documents and practices. After the licensing process for the Unit 1 was completed up to operation stage, CNCAN developed new updated regulations on nuclear safety and the regulatory pyramid in the framework of the RAMG PHARE project. CNCAN issued in 1996 the regulatory Policy for Unit 2, self-sustained and independent of future possible revisions of the regulations. The use of the concept of hierarchical systems, systematic review of safety criteria and objectives and margins along with the feedback from international and national experience on this topic ensured issuance of a reference document for future approach of nuclear safety in Romania. (authors)

  5. Prestart-up hydrogen peroxide solution washing of NPP unit with the RBMK-type reactor

    Gruzdev, N.I.; Man'kina, N.N.; Al'tshuller, M.A.

    1979-01-01

    Presented are the results of industrial hydrogen peroxide solution washing of condensating-feed system conducted on the second unit of the Kursk NPP. Duration of the washing constituted 8 hours. The hydrogen peroxide concentration during first 4 hours was 10-20 mg/kg at a flow rate of 260 m 2 /h, during the following 4 hours it constituted 2-5 mg/kg at a flow rate of 1000 m 3 /h. It is found out that prestart-up hydrogen peroxide washing of NPP power units with the RBMK-type reactor permits: to simplify essentially the technology and scheme of washing process; to reduce a flow rate of desalt washing water; to except environmental contamination with washing solutions and reagents being neutralized; to reduce the time of washing process; to reduce the time necessary for the achievement of reference water condition factors, and to increase the unit reliability and to improve a radiation situation

  6. Results from modernization of the containment localization systems of the Kozloduy NPP units 3 and 4

    Sabinov, S.

    2005-01-01

    The improvements of the Accident Localization System (SLA) of units 3 and 4 systematically implemented by Kozloduy NPP shows an important direction for increasing the safety of NPP with WWER-440/V-230 containments. During the years Kozloduy NPP implemented a large scope of activities aimed in full resolution of all generic shortcomings identified in the original design of these containments. These activities allowed already in 2002 to justify that integrity of the containment is assured for all postulated events and the radiological consequences for all DBAs and BDBAs without core degradation are within the regulatory limits. The last phase of this modernization was oriented toward achieving the same goals in case of severe accidents by installation of systems for avoiding long term pressurization of the SG compartments and by installation of a system for keeping of negative pressure (slight vacuum) during the late phases of development of the accidents thus minimizing significantly the uncontrolled radioactive releases from the containment and assured controlled purified release of radioactivity to environment, and for elimination of conditions for H2 deflagration within the localization system. This paper summarizes the results of the whole modernization process with an emphasis of the implementation of the latest phase successfully completed by Kozloduy NPP in first quarter of 2005 which allowed the plant to demonstrate remarkable mitigation capability for a comprehensive set of very low probability severe accidents scenarios in line with the approach now being promoted for the modern design NPPs

  7. Report of the ASSET (Assessment of Safety Significant Events Team) mission to the Cernavoda nuclear power plant in Romania 8-12 August 1994 Division of Nuclear Safety. Root cause analysis of a significant event that occurred during commissioning of unit 1

    1994-01-01

    The IAEA Assessment of Safety Significant Events Team (ASSET) report presents the results of the team's investigation of a significant event that occurred during commissioning of Unit 1 of Cernavoda nuclear power plant. The results, conclusions and suggestions presented herein reflect the views of the ASSET experts. They are provided for consideration by the responsible authorities in Romania. The ASSET team's views presented in this report are based on visits to the plant, on review of documentation made available by the operating organization and on discussions with utility personnel. The report is intended to enhance operational safety at Cernavoda by proposing improvements to the policy for the prevention of incidents at the plant. The report includes, as a usual practice, the official response of the Regulatory Body and Operating Organization to the ASSET recommendations. Figs

  8. Main summaries of construction of the Rovno NPP third unit

    Smoktij, I.P.; Tsetsenko, I.K.

    1987-01-01

    The main technical and economic indices attained at the Rovno and Zaporozhe NPPs are considered. The estimated costs of the main installations of the building site, organizations participating in construction, labor forces at different building sections, duration of different stages of construction, actual labor costs associated with the reactor unit, volumes of construction and installation work, the construction schedule for the Rovno Unit-3 are given

  9. Electromagnetic compatibility of tools and automated process control systems of NPP units

    Alpeev, A.S.

    1994-01-01

    Problems of electromagnetic compatibility of automated process control subsystems in NPP units are discussed. It is emphasized, that at the stage of development of request for proposal for each APC subsystem special attention should be paid to electromagnetic situation in specific room and requirements to the quality of functions performed by the system. Besides, requirements to electromagnetic compatibility tests at the work stations should be formulated, and mock-ups of the subsystems should be tested

  10. Calculation of the real states of Ignalina NPP Unit 1 and Unit 2 RBMK-1500 reactors in the verification process of QUABOX/CUBBOX code

    Bubelis, E.; Pabarcius, R.; Demcenko, M.

    2001-01-01

    Calculations of the main neutron-physical characteristics of RBMK-1500 reactors of Ignalina NPP Unit 1 and Unit 2 were performed, taking real reactor core states as the basis for these calculations. Comparison of the calculation results, obtained using QUABOX/CUBBOX code, with experimental data and the calculation results, obtained using STEPAN code, showed that all the main neutron-physical characteristics of the reactors of Unit 1 and Unit 2 of Ignalina NPP are in the safe deviation range of die analyzed parameters, and that reactors of Ignalina NPP, during the process of the reactor core composition change, are operated in a safe and stable manner. (author)

  11. Level 1 shutdown and low power operation of Mochovce NPP, Unit 1, Slovakia

    Halada, P.; Cillik, I.; Stojka, T.; Kuzma, M.; Prochaska, J.; Vrtik, L.

    2004-01-01

    The paper presents general approach, used methods and form of documentation of the results that have been applied within the shutdown and low power PSA (SPSA) study for Mochovce NPP, Unit 1, Slovakia. The SPSA project was realized by VUJE Trnava Inc., Slovakia in 2001-2002 years. The Level 1 SPSA study for Mochovce NPP Unit 1 covers internal events as well as internal (fires, floods and heavy load drop) and external (aircraft crash, extreme meteorological conditions, seismic event and influence of surrounding industry) hazards. Mochovce NPP consists of two operating units equipped with VVER 440/V213 reactors safety upgraded before construction finishing and operation start. 87 safety measures based on VVER 440 operational experience and international mission insights were implemented to enhance its operational and nuclear safety. The SPSA relates to full power PSA (FPSA) as a continuation of the effort to create a harmonized level 1 PSA model for all operational modes of the plant with the goal to use it for further purposes as follows: Real Time Risk Monitor, Maintenance Optimization, Technical Specifications Optimization, Living PSA. (author)

  12. Preparation status for continuous operation of Kori unit 1 NPP in Korea

    Choi, C.H. . E-mail : chechee@khnp.co.kr

    2005-01-01

    Kori unit 1 Nuclear Power Plant is the first commercial operation plant in Korea. In Korea, the life extension of NPP beyond design lifetime reached practically application stage. Preparations status for continuous operation of Kori unit 1, Many researches have demonstrated that life extension beyond design lifetime is possible in terms of technology. This paper is to introduce and to share the continuous operation preparations status and schedule for Kori unit 1 License Renewal Process an additional every 10 years beyond the design life 30 years term. (author)

  13. Modernization program of NPP Kozloduy, units 5 and 6

    Protze, M.

    2000-01-01

    A rather brief overview is given of the programme for upgrading units 5 and 6 of the Bulgarian Kozloduy plant, as it was established in 1994/95. A brief characterization is given of individual steps, either already taken or being planned. (A.K.)

  14. European cooperation under the modernization program of the Kozloduy NPP units 5 and 6 and its evolution during the Belene NPP construction

    Hoch, G.

    2005-01-01

    The major part of the modernization program for the Kozloduy NPP units 5 and 6 is being performed by the European Consortium Kozloduy (ECK), consisting of AREVA - FRAMATOME ANP (Germany and France) and Atomenergoexport (Russia). The ECK main project, consisting of 76 separate measures, shall be finished in the first half of 2006. One of the major tasks was to form the different teams on contractors and employers side such that the works can be executed effectively in a timely manner and as per the technical and quality requirements. Different actions were undertaken on both sides in order to assure the main target, namely to implement the complete scope of work within the contractual time schedule. So far it can be reported that the teams have successfully worked and as a matter of fact at present more than 100 outage days have been saved compared to the initial contractual time schedule. This important result is based on different success factors in the field of planning, engineering and design, outage organization, implementation including testing and commissioning, quality assurance. After the decision of Bulgaria to continue the erection of Belene NPP, a bidding consortium has been founded by the ECK Consortium members, in order to provide a joint offer for this project. The good reputation, expertise and the experience gained from the Kozloduy NPP units 5 and 6 modernization project together with a reliable network with Bulgarian industrial partners may contribute the utmost to a successful finalization of the Belene NPP. (author)

  15. Diversity of microflora at the fourth destroyed unit of the ChNPP

    Parenyuk, O.Yu.; Shavanova, K.Je.; Yilljenko, V.V.; Gudkov, Yi.M.; Nanba, K.; Takasi, T.; Syimutyin, Yi.O.; Samofalova, D.O.; Ribalka, V.B.

    2017-01-01

    DNA of the substrate, sampled from six points in the destroyed 4-th power unit of ChNPP, where the dose rate on the microorganisms ranges from 0.008 to 0.12 Gy/h, was analyzed by New Generation Sequencing technology. It was found that the most diverse and stable microbiome occurs in sample, located outside of the ''Ukryttya'' object on the industrial site (conditional control). There are no dominants in it, which means that it is the most balanced and approximate to the general state of the soil microbiome of ecosystems surrounding the ChNPP. As for the sample, taken from the spot, where the dose rate was the highest, total number of species represented appeared eight times smaller, but dominance index was the highest, which indicates the formation of distinct microbiome dominants.

  16. Kozloduy NPP units 1-4 significance for Bulgaria

    Georgiev, J.

    2003-01-01

    General data about nuclear power in Bulgaria is presented. The main topics covered are: estimated energy reserve; energy balance, new capacities, installed in 2002; information about the WWER-230 reactors operation; environmental impact and global warming; Bulgarian export and regional electricity demand; public opinion etc. The problem 'Long term safe operation vs forced early closure' is discussed. It is concluded that the decision on early closure of any unit should be made on economic grounds or failure to meet regulatory safety standards and must not be politically motivated

  17. An assessment of the fire protection requirements throughout a NPP life related to current IAEA regulations and American, Canadian and UE regulations

    Branzeu, N.; Necula, D.; Badea, M.; Teodorescu, D.; Peteu, M.

    2006-01-01

    Statistics on fires has surprisingly shown that the frequency of fires in a nuclear power plant are as high as in the conventional industrial units. The analyses on fires occurred in a NPP need to consider both their well-known severe damages and the nuclear consequences. In 1975 a severe fire occurred in BROWNS FERRY NPP due to the ignition of the polyurethane foam used in the electric cable penetration sealings. The fire propagated to the cable channels and damaged over 1600 cables. The fire event revealed important shortcomings in the fire protection design and procedures. The fire represented a crucial event that changed fundamentally the fire protection regulation in the United States nuclear industry. The fire protection programs, standards and guides currently applied, have been developed on basis of this fire analysis and gained conclusions/experience. The purpose of the article is to be a short presentation of the fire protection requirements for all NPP life stages (i.e. design, construction, commissioning, operation and decommissioning), including the most recent issues of the standards, codes, guides and regulations in US, Canada, IAEA and some European countries. Such documentation represented the main technical support in establishing the national fire protection standard design regarding all the stages of a CANDU-6 NPP life, all the types of operational NPPs, particularly for Cernavoda NPP Unit 1 and Unit 2 (now in an advanced stage of construction). In order to satisfy the requirements provided by this documentation, as practically as possible, a list of analyses and fire protection improvement measures for Cernavoda NPP is presented. (authors)

  18. Systematic evaluation of the Cernavoda nuclear power plant physical protection system

    Ionescu, D.S.

    2002-01-01

    Full text: For three years at Cernavoda NPP is working a process to systematic evaluating the effectiveness of the Physical Protection System (PPS). Due to the fact that this evaluation has to be continuous, the first important step is to define a baseline to compare periodically the performance of PPS against it. The necessity of that process has been identified as follows: the continuous changes in the field of perceived threats against Cernavoda NPP and the necessary measures to respond to that changing climate; the needful to improve the performance of PPS against certain threats in conjunction with the needful to allocate substantially financial and human resources to cover the discovered weakness in the system; an assistant to take the appropriate measure in case of indisponibility of one or more components or parts of the PPS. The second step is the continuous tracking of the behavior of PPS in order to determine: the maintenance resource allocation and the priorities of the work; the predictive behavior of installed components to determine the future appropriate measures, including budget dimensioning. SAVI is a PC compatible program developed by SANDIA Laboratory (USA) for comprehensive analysis of PPS effectiveness. That program is organized in two modules: the Adversary Sequence Diagram (ASD) module and the outsider module modeling trough specific codes both the characteristics of PPS and of the predicted adversary. Combining the two modules related to a specific PPS and adversary is possible to find out the effectiveness of the physical protection system for each vital zone along to ten possible paths to penetrate by adversary, starting with the most vulnerable one. Because of two conservative assumption considered by the SAVI algorithm (adversary know the PPS characteristics and they use an optimal penetration strategy), the measure of effectiveness (probability of interruption - P I ) is very realistic and conservative related to the necessary

  19. Redesign of emergency water supply system by-pass line from Cernavoda NPP Unit 1 and 2 using self regulating valves

    Tenescu, Mircea; Bigu, Melania; Nita, Iulian Pavel

    2010-01-01

    In this paper one considered improving the EWS (emergency water supply system) by-pass line in order to replace current manual operated valve with an self operated valve. This change is necessary in order to reduce the human error events in operation of the system in case of a DBE (design basis earthquake). The paper describes a theoretical and practical operation of a system using self regulating flow rate valves. Basically, the elimination of a possible human error in operating a system is important for nuclear safety in case of a DBE because it makes it avoidable in normal reactor cooling systems. The paper describes checking of the functioning of this equipment in operating conditions, investigating how it responds to various operating regimes. (authors)

  20. Preparation phase of Mochovce NPP unit 3 and 4 construction completion

    Cillik, I.; Tvaroska, V.; Liska, P.; Ziman, V.

    2005-01-01

    In this presentation authors deal with preparation phase of Mochovce NPP unit 3 and 4 construction completion. The preparation phase of the Mochovce unit 3 and 4 construction completion gives following main outputs: (a) Detail Safety Concept gives definitive complex safety and technical improvement of MO34, more precise analysis of the total cost of construction completion, a list of potential suppliers and construction completion time schedule; (b) Appendices of Basic Design Documentation and Preliminary SAR serves as basic documentation for UJD SR decision making according to Law No. 541 for start of Realization Phase; (c) The Preparation Phase represents effective tool for start of MO34 construction completion Realization Phase.

  1. Completion of Units 3 and 4 at Mochovce NPP

    Aquilanti, G.

    2009-01-01

    After the completion of a feasibility study, SE/ENEL decided to complete Mochovce Nuclear Power Plant Units 3 and 4 in April 2007. In July 2008, after a revision of the Basic Design that led to the inclusion of additional safety improvements, the European Commission issued a positive viewpoint on the decision. In August 2008 the Slovak Nuclear Regulatory Authority issued a permit for 'modification of a construction project prior to its completion', approving the Basic Design modifications: the kick-off of site activities was on November 2008. In December 2008, SE initiated the Environmental Impact Assessment (EIA) procedure aimed at obtaining the Operational License by submitting the EIA intent to the Ministry of Environment. A multi contractual strategy was adopted for the completion works: the total number of foreseen contracts is about 250 (90 main and additional 160 minor). In the following the present status of the project is presented: in particular, the Project Management system implemented by SE/ENEL is described and the progress of the engineering, fabrication and construction activities is analyzed. (author)

  2. Continuous operation of NPP Kori Unit 1 - Fireproof paint for cables

    Wendt, Dipl-Ing. Ruediger; Kim, Duill; Sik, Cho Hong

    2008-01-01

    Fireproof cable coating materials have been used in European NPP, especially in Germany, Russia, Ukraine, Czech Republic, Lithuania, Switzerland. Wide experiences were made during operation while applying these systems. In NPP Kori, Unit 1, a fire proof cable coating project was realised for the first time in a NPP of KHNP. The scope of services of the cable trays to coat amounts to 15,587m 2 . In different fire compartments and rooms the cables should be coated partially respectively completely with the fire proof cable coating system. The extent of cable surfaces to coat was stipulated by KHNP on the basis of an analysis made by KHNP. The project was tendered on the basis of a technical specification of KHNP. The specification is mainly predicted on Korean and US standards. The most important criteria for the fire proof cable coating is resumed as follows: The fireproof cable coating has to assure the fire protection of the cables for a period defined and for operational conditions defined in such a manner that the general conditions for the operation of the cable installation will not be affected

  3. Commissioning tests at Bohunice NPP V1 unit 2 after reconstruction in 1998

    Pajtinka, A.; Tvaroska, V.; Wiening, K.-H.; Mueller, B.

    2000-01-01

    The last and the most extensive stage in the reconstruction project of the Bohunice NPP started in July 1998. The main activities performed during a 6-month scheduled unit 2 outage included: - Installation of a new emergency core cooling system with an increased capacity according to the defined broader break spectrum for LOCA; - Reconstruction of the existing confinement spray system and installation of a new confinement pressure suppression system; - Completion of upgrading measures to increase the reliability of emergency power supply systems (replacement of low voltage switchgear, installation of new cabling for all loads important to safety, installation of new motor-generators and rectifier sets); - Connection to the plant and commissioning of the new reactor protection system. Comprehensive tests and checks performed on completion of installation work on the modified mechanical, electrical and I and C systems were important reasons for the absence of major problems during restart of the unit after the several project implementation phases. Operating experience at unit 2 since its recommissioning in January 1999 has confirmed that the required safety standards have been met and that operational reliability has been substantially increased at the sometime. Periodic testing is being performed in accordance with the limits and conditions for safe operation of Bohunice NPP. To date all these tests were completed without significant problems. The functions implemented in the new technology met the test program criteria, which were approved with authority, in all essential areas. Through the close cooperation of the partners involved and through the combined efforts of the various engineering and operating disciplines, technical and scheduling problems could be immediately identified and quickly resolved. In general, these kinds of projects require optimum cooperation among the parties involved. Modernization of the NPP Bohunice V1 unit 2 has shown, that all

  4. Study on the power control system for NPP power unit with the WWER-440 reactor

    Aleksandrova, N.D.; Naumov, A.V.

    1981-01-01

    Results of model investigations into basic version of the power control systems (PCS) conformably to the WWER-440 NPP power unit are stated. Transient processes in the power unit system when being two PCS versions during perturbations of different parameters: unit power, vapour pressure or position of control rods have been simulated. Investigations into the different PCS versions show that quality of operation of a traditional scheme with a turbine power controller and reactor pressure controller can be significantly improved with the introduction of a high-speed signal of pressure into the reactor controller. The PCS version with the compensation of interrelations between the turbine and reactor controllers constructed according to the same principles as the standard schemes of power units of thermal electric power plant is perspective as well [ru

  5. Assessment of the state of modernization of NPP Kozloduy units 3 and 4

    Horstmann, R.

    2002-01-01

    The status of the implemented modernization programmes for the Kozloduy NPP is presented. The Three Stage Term Modernization Program for units 1-4 has been implemented between 1991 and 1997 and includes the installation of new safety systems and components such as pressurized safety valves, main steam safety valves, complementary emergency feedwater system, second fire fighting system etc. The total investment od the Program amounted to 129.1 mill. ECU. The Complex Modernization Program for units 1-4 has been developed 1996 -1997 and further updated in 2000. The total investment necessary for the implementation are assessed at about 66 mill. USD. The safety assessment shows that due to the modernization programs the units have been upgraded to additional accident management capabilities. The reactor confinement has been fundamentally improved by the Jet Vortex Condenser System. PSA has been also conducted for the units 3 and 4

  6. Compex system for teaching and training operators for TPP and NPP power units

    Tsiptsyura, R.D.

    1985-01-01

    Requirements, taken as a principle for constructing the system for operator teaching and training (OTT), have been formulated on the basis of investigation of operators' work at TPP and NPP power units. Functional structure and a structural block-diagram for OTT are built. As a criterion, which determines the structure of any trainers, being a part of OTT a requirement has been chosen satisfying the correspondence beetween habits developed with the help of trainers and habits of real operators' work. Results of analysis permit to confirm that refusal or under statement of the role of any stage of operator training leads to reduction of quality of his training

  7. Project realization of jet vortex condenser at units 3 and 3 of the Kozloduy NPP

    Genovski, I.; Grigorov, A; Bonev, B; Sabinov, S.; Petkov, M.

    2003-01-01

    In the implementation of the contract between the Kozloduy NPP and Department 'Thermal and Nuclear Energy' at the Technical University, Sofia a project has been realized for the demonstration of the modernization of the system for accident localization in the units 3 and 4, based on the jet-vortex condenser (JVC). The final result is multimedia presentation in English and Bulgarian languages. In this paper the last part of the project is presented, including: installing of the JVC, auxiliary systems, executors of the project and expert opinions on the projects

  8. Results from probabilistic safety analysis level 2 for Kozloduy NPP units 3 and 4

    Velev, V.; Mancheva, K.

    2006-01-01

    The study considers full power operation analysis results and impact of strategies and modernisation implementations of Kozloduy NPP units 3 and 4. In this paper the following issues are discussed: the development of Severe Accident Management Guidelines and Symptom Based Emergency Operating Procedures, installation of brand new system as Emergency Filter Ventilation System, Passive Autocatalytic Hydrogen recombiners, etc. In order to respond to the objectives of the study, the analyses assets the impact of different initiating events on risk based on the frequencies of various plant damage states, the confinement failure and the radiological release frequencies and finally estimates the total risk as frequency of radiological releases

  9. Determination of reactor parameters during start up test at the Taiwan NPP, Unit 1

    Astakhov, S.; Kravchenko, A.; Kraynov, Ju.; Nasedkin, A.; Tsyganov, S.

    2006-01-01

    Unit 1 of Taiwan NPP with WWER-1000 reactor reached the first criticality at December 20 of 2005. Series of start up experiments were carried out under scientific advisory of RRC 'Kurchatov Institute' specialists. At the Hot Zero Power state the reactivity coefficients, control rod group and scram worth were measured and symmetry of the core loading and power reactivity effect due to reaching 1% of nominal were assessed. Paper describes in brief special features of experiments and presented some results obtained at a measurements (Authors)

  10. Calculation of the effectiveness of manual control rods for the reactor of Ignalina NPP Unit 2

    Bubelis, E.; Pabarcius, R.

    2001-01-01

    On the basis of one of the recent databases of the reactor of Ignalina NPP Unit 2, calculations of the effectiveness of separate manual control rods, groups of manual control rods and axial characteristic of effectiveness of separate manual control rods were performed. The results of the calculations indicated, that all analyzed separate manual control rods have approximately the same effectiveness, which doesn't depend on the location of a control rod in the reactor core layout Manual control rod of the new design has about 10% greater effectiveness than manual control rod of the old design. (author)

  11. Numerical Simulation of Measurements during the Reactor Physical Startup at Unit 3 of Rostov NPP

    Tereshonok, V. A.; Kryakvin, L. V.; Pitilimov, V. A.; Karpov, S. A.; Kulikov, V. I.; Zhylmaganbetov, N. M.; Kavun, O. Yu.; Popykin, A. I.; Shevchenko, R. A.; Shevchenko, S. A.; Semenova, T. V.

    2017-12-01

    The results of numerical calculations and measurements of some reactor parameters during the physical startup tests at unit 3 of Rostov NPP are presented. The following parameters are considered: the critical boron acid concentration and the currents from ionization chambers (IC) during the scram system efficiency evaluation. The scram system efficiency was determined using the inverse point kinetics equation with the measured and simulated IC currents. The results of steady-state calculations of relative power distribution and efficiency of the scram system and separate groups of control rods of the control and protection system are also presented. The calculations are performed using several codes, including precision ones.

  12. Some results of periodical analysis of the behavior of unit 4 at the Dukovany NPP - II

    Jirsa, P.

    1993-01-01

    The results of a detailed spectral analysis of noise signals recorded at the unit 4 reactor of the Dukovany NPP during and after the start-up stage are presented. The changes in the noise source signal spectra during the start-up and in normal operation were evaluated by multidimensional autoregression analysis. The temperature dependence of the signal spectra peaks from individual detectors is described. The sources of the peaks at 27.9 and 37 Hz during normal operation were identified as standing pressure waves in the primary circuit of the reactor. 3 tabs., 23 figs., 6 refs

  13. Seismic response analysis and upgrading design of pump houses of Kozloduy NPP units 5 and 6

    Jordanov, M.; Marinov, M.; Krutzik, N.

    2001-01-01

    The main objective of the presented project was to perform a feasibility study for seismic/structural evaluation of the safety related structures at Kozloduy NPP Units 5 and 6 for the new site seismicity and determine if they satisfy current international safety standards. The evaluation of the Pump House 3 (PH3) building is addressed in this paper, which was carried out by applying appropriate modeling techniques combined with failure mode and seismic margin analyses. The scope of the work defined was to present the required enhancement of the seismic capacity of the Pump House structures.(author)

  14. Response of the main building, unit 5, Kozloduy NPP (Bulgaria) to an explosion input motion

    Kostov, M.; Boncheva, H.; Varbanov, G.; Kaneva, A.; Stefanov, D.; Koleva, N.

    1999-01-01

    The main building of Unit 5, NPP Kozloduy is one of the two selected prototypes of WWER-type plants included in the project 'Benchmark study for seismic analysis and testing of WWER-type nuclear power plants', co-ordinated by IAEA. The dynamic in-situ testing of the structure of Unit 5 WWER-1000 MW reactor containment building and the adjacent auxiliary structures is performed by specialists of ISMES (Italy), assisted by Hungarian consultants (GEOPARD) and Bulgarian specialist of NPP Kozloduy. The aim of the experiment is to assess the dynamic characteristics and behaviour of the structures, the soil-structure interaction effects, the equipment-structure interaction, etc. The dynamic excitation is a low level ground motion induced by underground explosions. The measuring of the response is done at different pre-selected structure points. Two experiments are performed. The registrations during the second experiment of 01.07.1996 are used in the present report. One set of free field records are given up to the participant institutions for the benchmarking. The purpose is to perform a dynamic analysis of the main building of Unit 5, to assess the response to the explosion ground motion and to compare the analytical results with the recorded motion. In this report are discussed soil and structure modelling and computation results consisting in acceleration response spectra obtained at foundation level and at different points of the structure

  15. External hazards in the PRA of Olkiluoto 1 and 2 NPP units - Accidental oil spills

    Tunturivuori, Lasse

    2014-01-01

    Oil transports in Finnish territorial waters have increased significantly during the last 10 years. The Gulf of Finland is at this moment a very important route of oil being transported from Russia to the Western Europe. Although the number of accidental oil spills is decreasing in amount and in size, there is a growing concern of their effects to nuclear power plants (NPPs). The amounts of oil transported on the Gulf of Bothnia are much smaller than on the Gulf of Finland. However, accidental oil spills have occurred also there, the size and amount of which are smaller, though. Accidental oil spills are often a result of grounding of a ship or collision of two ships, and often occur during harsh weather conditions like storm or dense fog. However, also coastal oil depots may break, the oil of which may spread over wide distances on the sea. The modelling of initiating events resulting from accidental oil spills includes oil spill response actions performed by the regional rescue services, alarming of the oil spill by the emergency response centre to the NPP rescue services and spill response by the NPPs rescue services. It is unclear what the consequences are if drifted oil would enter the coolant water tunnels. The effect of different oil types to the operation of the safety-related service water systems and components are being assessed. In the ultimate case, an oil spill would clog the inlet channels thus failing the ultimate heat sink of the NPP units. The licensee is evaluating what is the optimal way to operate the NPP units in the case that an oil slick is threatening the plant to ensure reactor core cooling and RHR. The continued operation of, and especially the cooling of, at least one auxiliary feedwater pump is critical in the mitigation of the initiating event. Strategies, like reversing the water flow of the cooling water channels or closing of the cooling water channels, are being evaluated. (authors)

  16. Level 1 PSA study of Mochovce unit 1 NPP (SM AA 10 and 08)

    Cillik, I.

    1997-01-01

    This paper presents genesis of Level 1 PSA project preparation for all operational modes of Mochovce NPP unit 1 including the description of its' main objectives, scope and working method. The PSA study which includes full power (FPSA) as well as shutdown and low power conditions (SPSA) Level 1 PSA has to support the nuclear safety improvements of the unit. They evaluate the basic design and the benefits of all improvements, which were found necessary to be incorporated before the start-up of the unit. The study includes internal events (transients and under-loss of coolant accident, LOCAs), internal hazards as fires and floods and selected external hazards as earthquake, influence of external industry, extreme meteorological conditions and aircraft crash.The PSA (both FPSA and SPSA) models is developed using the RISK SPECTRUM PSA code. (author)

  17. Study of environmental impact assessment for Mochovce NPP Units 3 and 4. Executive summary. September 2007

    Anon

    2007-09-01

    SE/ENEL, on a voluntary basis, has prepared new EIA Study for the completion of Units 3 and 4 of Mochovce Nuclear Power Plant (MO34 NPP) according to International current practices and European Directives. The results of the analysis, according to SE/ENEL Environment and Corporate Social Responsibility policies, will be provided to local Communities and Public Authorities. The Environmental Impact Assessment is performed: - in compliance with appendix 11 of Slovak Act. No. 24/2006 'On the assessment of the effects on the environment and on the modification and enlargement of some laws'; - meeting the requirements of the Exhibit II 'Illustrative list of potential social and environmental issues to be addressed in the Social and Environmental Assessment documentation' as reported in the document 'Equator Principles' of 2006 July developed by the International Finance Corporation (IFC). The area of Mochovce NPP is situated in Central Europe in the south-western region of the Slovak Republic (SR) at the western border of the Levice district. The area lies in the south-western part of the Kozmalovske hills mainly in the Hron highlands. From the point of view of the terrestrial and administrative organization of the SR, Mochovce NPP is situated in the eastern part of the Nitra region, in the north-western part of the Levice district, close to the border with the Nitra and Zlate Moravce districts. Mochovce NPP is approx. 12 km from the district capital Levice, which is the largest town within a 20 km distance from the power plant. Initial site preparation began in August 1983. In April 1998 the first fuel was loaded into Unit 1 of Mochovce NPP. The operation started in August 1998. Unit 2 started operation in January 2000. The original Construction Permit No. Vyst. 2010/86 for MO 34 was issued by the District National Committee in Levice on the basis of the Land Planning Decisions on 12 November 1986. This Permit has been renewed firstly on 5 May 1997 by letter of the

  18. Novelly formed products of the interaction of fuel with construction materials of the 4th unit of Chernobyl NPP

    Borovoj, A.A.; Galkin, B.Ya.; Krinitsyn, A.P.; Pazukhin, Eh.M.; Kheruvimov, A.N.; Chechcherov, K.P.; Anderson, E.B.

    1991-01-01

    Radiation environment and map of sampling route in the steam distributing collector of the 4th unit of the Chernobyl NPP are described. The results of gamma- and alpha radiometric analyses as well as chemical analysis are presented. Samples of core materials taken from the depth of fuel-containing masses by drilling through reactor vault wall of the damaged power unit are described

  19. Rupture of DN 500 - design basic accident at units 3 and 4 of Kozloduy NPP

    Uruchev, V.; Vassilev, P.; Ivanova, A.; Sartmadjiev, A.

    2005-01-01

    The original design of Kozloduy NPP Units 3 and 4 assumes as Design Basis Accident (DBA) the rupture of DN 32 mm primary pipeline, while an initial event of double-sided guillotine break of primary pipeline with maximal diameter is not considered. In the course of units modernization it have been demonstrated once and again that both the emergency core cooling systems and the localization systems can cope with larger and larger primary circuit leaks. After the installation of a Jet-Vortex Condenser (JVC) at Units 3 and 4 it was substantiated that, the integrity of the hermetic rooms is ensured even in case of double-sided guillotine break of a primary circuit pipeline with maximal diameter (DEGB). The technical justification of the jet-vortex condenser, elaborated by VNIAEC, contains calculations determining both the source term and the doses obtained outside the NPP site after LOCA DN 500. LOCA DN 500 is considered in these analyses as a beyond design basis accident and it is so included in the SAR and approved by the Nuclear Regulatory Agency (NRA). The thermo-hydraulic calculations performed later on show that the emergency core cooling systems can cope with this initial event at conservative assumptions. In order to classify this initiating event as a design basis accident it is necessary to demonstrate that the core cooling criteria are fulfilled and the internal and external doses outside the NPP site are within the permissible limits fixed for design basis accident by the Bulgarian regulatory body (NRA), when using conservative assumptions. For this purpose two consecutive studies were performed - evaluation of the DEGB probability and categorization of the initial event according to the contemporary regulations acting in Republic of Bulgaria. The presented report summarizes the results of the performed conservative analyses of double-sided guillotine break accident of main circulation line taking into account the probability of rupture of large diameter

  20. Managing delayed projects. Cernavoda NPP - Romania. Importance of NGO involvement

    Rotaru, I.

    2003-01-01

    In Romania there is a diversity of civil societies with respect to the attitude towards nuclear power. Among the dedicated societies supporting nuclear power development there are: the Romanian Atomic Forum (Ratomet), affiliated to the European Atomic Forum; the Romanian Nuclear Power Association (Arden), affiliated to the European Nuclear Society; the Romanian Radioprotection Society (SR Rp), affiliated to the Radiation Protection Association. The main dedicated activities of above mentioned Non-governmental Organizations (Ng) are: establishing contacts and organizing meeting with Romanian political decision making factors, mass media representatives, institutional entities, civil society ect.; orienting and co-coordinating activities of Romanian companies involved in production and services for nuclear energy; serving as contact point for relevant international communication and business relation; creating internal working groups for certain theme or sub-domain and suggested solution for a particular issue, including experts even from outside of the association; performing lobby activities ect

  1. ALARA tools and performance indicators at Cernavoda NPP

    Chitu, C.; Popescu, V.; Simionov, V.

    2009-01-01

    Work efficiency is an area of high concern to nuclear power plant operators. Job planning has to be done so that there will be enough time for ALARA actions to be implemented. The control of the activities involving radiological risk is part of ALARA Process. An effective control supposes the implementation of a process to systematically identify the activities performed in radiological areas. Plant Performance Indicators related to ionizing radiation exposure have been established to improve station safe performance. They are assessed and reported periodically to reflect the safe operation objectives. If target values are exceeded 'abnormal condition reports' are generated. Corrective and preventive actions aim at work planning, technical aspects, and human performance. All the staff is informed about these events and corrective actions described through the training program are implemented. (authors)

  2. ALARA and radiation protection optimization status of Cernavoda NPP

    Hau, D.I.

    2001-01-01

    ALARA (As Low As Reasonably Achievable) in Radiation Protection is specifically applied as a tool in lowering the risk of exposure when performing necessary activities, leading to a reduction of individual and collective doses of workers as much and as reasonable possible. (authors)

  3. Digital control computer upgrade at the Cernavoda NPP simulator

    Ionescu, T.

    2006-01-01

    The Plant Process Computer equips some Nuclear Power Plants, like CANDU-600, with Centralized Control performed by an assembly of two computers known as Digital Control Computers (DCC) and working in parallel for safely driving of the plan at steady state and during normal maneuvers but also during abnormal transients when the plant is automatically steered to a safe state. The Centralized Control means both hardware and software with obligatory presence in the frame of the Full Scope Simulator and subject to changing its configuration with specific requirements during the plant and simulator life and covered by this subsection

  4. Cernavoda NPP - A competitive energy source for sustainable development

    Rotaru, Ioan; Bilegan, I.C.; Jelev, Adrian

    2004-01-01

    At present a trend manifests world wide toward promoting nuclear power, for increasing its performances, toward maintaining competitiveness and sustaining the programs of development and application of advanced nuclear technologies. These objectives will be achieved by improving: operation performances; management of life-cycle, quality management; technical infrastructure; human resource performances; international cooperation for developing innovative nuclear technologies; technologies and applications of advanced reactors. Fostering the Romanian nuclear power on the basis of CANDU 6 type rectors, the developing in Romania of an advanced industrial infrastructure, the economical, environmental and social aspects and their interplay with nuclear power development are the main subjects presented in this work

  5. Cernavoda NPP - Boiler and steam cycle chemistry control

    Zotica, D.

    2001-01-01

    Steam generators protection against corrosion and fouling is an ongoing issue for nuclear power plants. The true effectiveness of the secondary chemistry control program is best judged by the absence of secondary side corrosion related tube degradation particularly that leads to tube plugging or sleeving or tube support degradation. To continue striving for excellence in chemical control, the following issues should be considered: Continuous evaluation of the effectiveness of the chemistry control program in mitigating SG damage; Evaluation of plant compliance with the program; Laboratory quality assurance program to assure that laboratory analyses are accurate and reproductibile; Quality assurance program for on-line monitoring equipment to assure that results from this equipment are accurate. (R.P.)

  6. Project Management Unit for decommissioning of NPP Bohunice VI (2003-2014)

    Gonzalez Fernandez-conde, A.; Brochet, I.; Ferreira, A.

    2015-01-01

    From October 2003 until december 2014 the Consortium consisting of Iberdrola Engineering and Construction (leader). Empresarios Agrupados Internacional, and Indra Sistemas has carried out the project Project Management Unit ((PMU) for the decommissioning of Bohunice V1 NPP (units 1 and 2), type VVER-440/V-230 in Slovakia. during the first phase (2003-2007) EdF was also part of the Consortium. The project is funded by the Bohunice International Decommissioning Support Fund (BIDSF) administered by the RBRD. The main objective of the project is to provide the necessary engineering and resources of project management for planning, execution, management, coordination and monitoring of all tasks in support of the decommissioning. (Author)

  7. Analysis of the foreign systems for classification and marking the NPP unit components during their application in information systems

    Bylkin, B.K.; Shaposhnikov, V.A.; Sadovoj, Yu.K.; Tikhonovskij, V.L.; Chujko, D.V.

    2006-01-01

    Procedures accepted and permitted in an information system (IS) to arrange and to rank information drawn up to ensure the information support of decommissioning of an NPP power unit affect the application convenience and efficiency of the IS taken as a whole. The IS supporting the decommissioning efforts stores large volume of information, that is why, the problem to choose systems to ensure information ranking is the urgent one. The paper deals with the analysis of the foreign systems to rank the components used during an NPP operation. Besides, one considers the application of the mentioned systems to arrange and to rank the information on decommissioning of an NPP power unit presented to users [ru

  8. Report of the IPERS (International Peer Review Service) pre-review mission for the Cernavoda nuclear power plant probabilistic safety evaluation (CPSE - PHASE B) in Romania 31 October to 3 November 1994

    1994-01-01

    This report presents the results of the IAEA international peer review services pre-review mission which reviewed the status of the present version of the Cernavoda probabilistic safety evaluation, a Level 1 internal events Probabilistic Safety Assessment for the Cernavoda, Unit 1, nuclear power plant. 2 refs

  9. Informing the Lithuanian public about the decommissioning of Unit 1 at Ignalina NPP

    Medeliene, D.; Alvers, M.

    2001-01-01

    The final decision about decommissioning of Unit 1 at Ignalina NPP by 2005 was taken when the Lithuanian Parliament approved the National Energy Strategy in 1999. In 2000 the Board of the European Bank of Research and Development (EBRD) approved the establishment of the Ignalina International Decommissioning Support Fund and the International Donors' Conference took place in Vilnius. Sweden's longterm co-operation with Lithuania in the area of nuclear safety started already in 1992, soon after the country had regained its independence. SIP (Swedish International Project Nuclear Safety) administers this bilateral assistance. Public information has been included in the Swedish programme since the establishment of the Information Centre at INPP and is also a part of the bilateral decommissioning support. SIP finances a series of TV-programmes on a national channel and the local cable TV in Visaginas (the town close to Ignalina NPP) about various aspects of decommissioning. The Lithuanian regulatory authority VATESI uses its experience in public relations to inform about the situation related with decommissioning. The authority organizes 'Open Doors' days and press conferences to provide objective and trustworthy information. The reaction of the viewers to the TV-programmes were very positive and Sweden will continue the support to the information programme in Lithuania. (author)

  10. Foreign Material Exclusion Program at CNE Cernavoda Nuclear Generating Station

    Urjan, Daniel [S.N. ' Nuclearelectrica' SA, CNE Cernavoda Nuclear Power Plant, Medgidiei 2 Street, 905200 Cernavoda, Constanta (Romania)

    2008-07-01

    In the face of a continuing attention to operations and maintenance costs at nuclear power plants, the future of the industry depends largely upon increasing plant availability and improving operating efficiency. The success in achieving these objectives is dependent upon the success of each plant's equipment maintenance program. Preventing the introduction of foreign materials into a nuclear power plant system or component requires a careful, thoughtful, and professional approach by all site personnel. This paper describes a proactive approach to prevent the introduction of foreign material into systems and components, by providing an overview of technical considerations required to develop, implement, and manage a foreign material exclusion program at CNE Cernavoda Unit 1 and 2 Nuclear Power Station. It is also described an example of Foreign Material Intrusion which happened during the 2003 planned maintenance outage at Cernavoda Unit no.1. This paper also defines personnel responsibilities and key nomenclature and a means for evaluating prospective work tasks and activities against standardized criteria, in order to identify the appropriate level of the required FME controls. (author)

  11. Foreign Material Exclusion Program at CNE Cernavoda Nuclear Generating Station

    Urjan, Daniel [S.N. ' Nuclearelectrica' SA, CNE Cernavoda Nuclear Power Plant, Medgidiei 2 Street, 905200 Cernavoda, Constanta (Romania)

    2008-07-01

    In the face of a continuing attention to operations and maintenance costs at nuclear power plants, the future of the industry depends largely upon increasing plant availability and improving operating efficiency. The success in achieving these objectives is dependent upon the success of each plant's equipment maintenance program. Preventing the introduction of foreign materials into a nuclear power plant system or component requires a careful, thoughtful, and professional approach by all site personnel. This paper describes a proactive approach to prevent the introduction of foreign material into systems and components, by providing an overview of technical considerations required to develop, implement, and manage a foreign material exclusion program at CNE Cernavoda Unit 1 and 2 Nuclear Power Station. It is also described an example of Foreign Material Intrusion which happened during the 2003 planned maintenance outage at Cernavoda Unit no.1. This paper also defines personnel responsibilities and key nomenclature and a means for evaluating prospective work tasks and activities against standardized criteria, in order to identify the appropriate level of the required FME controls. (author)

  12. Foreign Material Exclusion Program at CNE Cernavoda Nuclear Generating Station

    Urjan, Daniel

    2008-01-01

    In the face of a continuing attention to operations and maintenance costs at nuclear power plants, the future of the industry depends largely upon increasing plant availability and improving operating efficiency. The success in achieving these objectives is dependent upon the success of each plant's equipment maintenance program. Preventing the introduction of foreign materials into a nuclear power plant system or component requires a careful, thoughtful, and professional approach by all site personnel. This paper describes a proactive approach to prevent the introduction of foreign material into systems and components, by providing an overview of technical considerations required to develop, implement, and manage a foreign material exclusion program at CNE Cernavoda Unit 1 and 2 Nuclear Power Station. It is also described an example of Foreign Material Intrusion which happened during the 2003 planned maintenance outage at Cernavoda Unit no.1. This paper also defines personnel responsibilities and key nomenclature and a means for evaluating prospective work tasks and activities against standardized criteria, in order to identify the appropriate level of the required FME controls. (author)

  13. Rest lifetime evaluation and ageing management in NPP 'Kozloduy' unit 1-4

    Erve, M.; Heck, R.; Schmidt, J.; Daum, G.; Bataklieva, L.; Stoev, M.

    1999-01-01

    In 1992 as a result of an IAEA SRM review the 'WANO 6-month program' has been issued to improve operation, maintenance nad safety culture for the four WWER 440/230 units at the NPP 'Kozloduy' Siemens has awarded 3 contracts related to RTL evaluation of the main equipment, integrity of reactor pressure vessel and to the leak-before-break behaviour of the main piping od unit 2. It is pursuit an overall strategy that allows to: implement on the basis of RTL evaluation a long term ageing management program (AMAP) for Kozloduy's units 1-4 to assure their operation until the end of their design life; identify those components and equipment for which from the safety point of view urgent and immediate actions have to be performed; increase step by step the safety and reliability according to the Western standards and to internationally accepted safety culture; keep open the possibility of life extension as far as this would be technically feasible and acceptable and economically reasonable. Under the technical leadership of Siemens studies have been performed related to the subject of integrity and RTL, such as: reirradiation of RPV samples from Unit 1 and 2; evaluation of PV embrittlement of Unit 1; transfer of the results of LBB assessment of Unit 2 to Units 1, 3 and 4; transfer of results of RTL evaluation of Unit 2 to Units 1, 3 and 4; PTS analysis of RPV of Unit 1, 2,3 and 4. The main remarkable results are: no life-limiting mechanisms detected, requiring immediate actions, except for RPVs; residual lifetime determined for RPVs on reliable basis of advanced modern PTS analysis and sample testing; necessary activities in monitoring of ageing and in-service inspection clearly identified successful proof of lBB for main primary piping after slight modification of supports; international experts agreement reached (e.g. Risk Audit, successful IAEA experts meetings and OSART missions)

  14. Reliability research based experience with systems and events at the Kozloduy NPP units 1-4

    Khristova, R; Kaltchev, B; Dimitrov, B [Energoproekt, Sofia (Bulgaria); Nedyalkova, D; Sonev, A [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

    1996-12-31

    An overview of equipment reliability based on operational data of selected safety systems at the Kozloduy NPP is presented. Conclusions are drawn on reliability of the service water system, feed water system, emergency power supply - category 2, emergency high pressure ejection system and spray system. For the units 1-4 all recorded accident protocols in the period 1974-1993 have been processed and the main initiators identified. A list with 39 most frequent initiators of accidents/incidents is compiled. The human-caused errors account for 27% of all events. The reliability characteristics and frequencies have been calculated for all initiating events. It is concluded that there have not been any accidents with consequences for fuel integrity or radioactive release. 14 refs.

  15. Reliability research based experience with systems and events at the Kozloduy NPP units 1-4

    Khristova, R.; Kaltchev, B.; Dimitrov, B.; Nedyalkova, D.; Sonev, A.

    1995-01-01

    An overview of equipment reliability based on operational data of selected safety systems at the Kozloduy NPP is presented. Conclusions are drawn on reliability of the service water system, feed water system, emergency power supply - category 2, emergency high pressure ejection system and spray system. For the units 1-4 all recorded accident protocols in the period 1974-1993 have been processed and the main initiators identified. A list with 39 most frequent initiators of accidents/incidents is compiled. The human-caused errors account for 27% of all events. The reliability characteristics and frequencies have been calculated for all initiating events. It is concluded that there have not been any accidents with consequences for fuel integrity or radioactive release. 14 refs

  16. Main features of the unit 1-4 building complex, Kozloduy NPP in respect to seismic safety

    Kostov, M; Boncheva, H; Stafanov, D [Central Laboratory for Seismic Mechanics and Earthquake Engineering, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    1993-07-01

    The Units 1 and 2 of Kozloduy NPP were originally designed to resist a IV-V degree MSK earthquake. They have been subsequently upgraded for a VII degree earthquake. Since that structure basically do not meet the safety requirements to resist the new earthquake with a maximum acceleration of 0.2 g and very broad spectrum. The performed analyses are clearly pointing out that an upgrading for the new earthquake level is possible. The problems common for all the structures of Kozloduy NPP are summarized in this presentation.

  17. Main features of the unit 1-4 building complex, Kozloduy NPP in respect to seismic safety

    Kostov, M.; Boncheva, H.; Stafanov, D.

    1993-01-01

    The Units 1 and 2 of Kozloduy NPP were originally designed to resist a IV-V degree MSK earthquake. They have been subsequently upgraded for a VII degree earthquake. Since that structure basically do not meet the safety requirements to resist the new earthquake with a maximum acceleration of 0.2 g and very broad spectrum. The performed analyses are clearly pointing out that an upgrading for the new earthquake level is possible. The problems common for all the structures of Kozloduy NPP are summarized in this presentation

  18. Implementing Data Acquisition Systems DAS1 and DAS2 at Cernavoda Full-Scope Simulator Main Control Room based on the SIEN2007 solution

    Ionescu, Ana Maria; Tutuianu, Bogdan; Ionescu, Teodor

    2009-01-01

    Modern personnel training, re-training and licensing is a guarantee of NPP's safe reliable operation. Cernavoda NPP personnel training system is the main objective of its specialized department built up as Training Center (TC), directly supervised by Administration of the National Nuclearelectrica Society (SNN) and National Regulatory Body for Nuclear Activities (CNCAN). It was implemented to ensure the abilities, skills and knowledge required by the safe reliable operation of the nuclear reactor by the Main Control Room (MCR) operators. This objective was reached through training lessons taught and tested on the Full Scope Simulator (FSS), the TC's main training tool, a replica of the MCR of the real plant. Its description is the subject of this paper. The TC's FSS includes a computer network equipped with a software connected to the specialized program DATAPATH supplied for Cernavoda FSS by the FSS provider, delivered by L-3/ MAPPS. An alternative to DATAPATH Communication of the L 3/MAPPS Simulation System, developed by Cernavoda Full Scope Simulator Staff, was presented in the previous edition of the symposium (see the SIEN 2007 paper). This original solution is now already applied in order to connect to simulation process Data Acquisition Systems DAS1 and DAS2, two new systems already installed in the real MCR but not included by the Cernavoda FSS initial design. Communication between simulation software and DAS1 and DAS2, considered to be simple receivers of simulated data both as much alike as the two DASs from real plant, is performed in parallel with DATAPATH in a safe mode and without affecting simulation process. This paperwork presents the above mentioned application of this communication solution, developed by the Cernavoda NPP Full Scope Simulator Staff with details about the hardware/software solutions and their performance, training impact, cost and benefits. (authors)

  19. Methodology and measures for preventing unacceptable flow-accelerated corrosion thinning of pipelines and equipment of NPP power generating units

    Tomarov, G. V.; Shipkov, A. A.; Lovchev, V. N.; Gutsev, D. F.

    2016-10-01

    Problems of metal flow-accelerated corrosion (FAC) in the pipelines and equipment of the condensate- feeding and wet-steam paths of NPP power-generating units (PGU) are examined. Goals, objectives, and main principles of the methodology for the implementation of an integrated program of AO Concern Rosenergoatom for the prevention of unacceptable FAC thinning and for increasing operational flow-accelerated corrosion resistance of NPP EaP are worded (further the Program). A role is determined and potentialities are shown for the use of Russian software packages in the evaluation and prediction of FAC rate upon solving practical problems for the timely detection of unacceptable FAC thinning in the elements of pipelines and equipment (EaP) of the secondary circuit of NPP PGU. Information is given concerning the structure, properties, and functions of the software systems for plant personnel support in the monitoring and planning of the inservice inspection of FAC thinning elements of pipelines and equipment of the secondary circuit of NPP PGUs, which are created and implemented at some Russian NPPs equipped with VVER-1000, VVER-440, and BN-600 reactors. It is noted that one of the most important practical results of software packages for supporting NPP personnel concerning the issue of flow-accelerated corrosion consists in revealing elements under a hazard of intense local FAC thinning. Examples are given for successful practice at some Russian NPP concerning the use of software systems for supporting the personnel in early detection of secondary-circuit pipeline elements with FAC thinning close to an unacceptable level. Intermediate results of working on the Program are presented and new tasks set in 2012 as a part of the updated program are denoted. The prospects of the developed methods and tools in the scope of the Program measures at the stages of design and construction of NPP PGU are discussed. The main directions of the work on solving the problems of flow

  20. Four years Re-Use of low burned fuel assemblies from units 1 and 2 in core loadings of units 3 and 4 WWER-440 at Kozloduy NPP

    Stoyanova, I.; Antov, A.; Spasova, V.

    2006-01-01

    At the end of 2002 units 1 and 2 of Kozloduy NPP were shutdown before their design life time which left a large number of assemblies yet with a significant energy resources. A decision to load these assemblies into the cores of Units 3 and 4 during the next 4 cycles has been taken. In 2003, 43 assemblies from Unit 1 cycle 23 rd and 55 assemblies from Unit 2 cycle 24 th are loaded in the cores of units 3 and 4 respectively. In 2004, new 49 assemblies from Unit 1 cycle 23rd and new 55 assemblies from Unit 2 cycle 24th are loaded in the cores of units 3 and 4 respectively. In 2005, the next new 25 assemblies from Unit 1 cycle 23 rd and 66 assemblies from Unit 2 cycle 24th are loaded in the cores of units 3 and 4 respectively. In 2006, the next new 54 assemblies from Unit 1 cycle 23 rd and 52 assemblies from Unit 2 cycle 24 th + 2 assemblies from Unit 3 cycle 19th are loaded in the cores of Units 3 and 4 respectively. The SPPSHB computer code system is used for development and safety assessment of the fuel loading patterns of Units 3 and 4 at Kozloduy NPP with low burned assemblies from units 1 and 2 (Authors)

  1. Phase C commissioning-Cernavoda Unit 2

    Munro, Robert

    2007-01-01

    Phase C commissioning program includes over 500 individual tests and checks which are carefully planned and scheduled at the correct power level. Some of the major tests are the following: - heat transport thermosyphoning test at 3% Full Power (FP); - dual computer failure test at 15% FP; - turbine overspeed test and generator first synchronization; - load rejection tests at 25, 50, 75 and 100% FP; - loss of Class IV Power test at 25% FP; - shutdown system (SDS nr. 1 and SDS nr. 2) tests at >60% FP; - condensate extraction and boiler feedwater pump trip tests at 100% FP; - power cycling through reactor setback from 100 to 10 and back to 100% FP; - condenser steam discharge valve tests with reactor at 100% FP and turbine at 60% output; - low pressure and high pressure heater box-up tests at 100% FP. Progress through the Phase C program is controlled at six specific Commissioning Control Points (CCPs) which meet the Romanian Regulatory Authority (CNCAN) and Management requirements. These CCPs are the following: PI - Approval for Power increase to 5% FP; PP1 - Approval for Power increase to 25% FP; PP2 - Approval for Power increase to 50% FP; PP3 - Approval for Power increase to 75% FP; PP4 - Approval for Power increase to 100% FP. Prior to releasing each of these CCPs both Management and CNCAN complete an assessment of the 'Readiness' to proceed to the next power plateau. The readiness includes a review of the plant material condition, results of previous tests, documentation status, and operability maintainability issues. (author)

  2. Novelly formed products of the interaction of fuel with construction materials of the 4th unit of Chernobyl NPP

    Borovoj, A.A.; Galkin, B.Ya.; Drapchinskij, L.V.; Krinitsyn, A.P.; Pazukhin, Eh.M.; Petrov, B.F.; Pleskachevskij, L.A.; Checherov, K.P.

    1991-01-01

    Radiation environment and position of fuel-containing masses in the bubbler pond of the 4th unit of the Chernobyl NPP are described. Classification of the products of fuel interaction with structural materials is given. Amounts of fuel on the 1st and 2nd floor of the bubbler pond are estimated. Postaccident pictures of the premises of the bubbler pond are presented for the first time

  3. Integrity Analysis of Turbine Building for the MSLB Using GOTHIC code for Wolsong NPP Unit 2

    Ko, Bong-Jin; Jin, Dong-Sik; Kim, Jong-Hyun; Han, Sang-Koo; Choi, Hoon; Kho, Dong-Wook

    2015-01-01

    A break in the piping between the steam generators and the turbine can lead to rapid loss of secondary circuit inventory. A break inside the turbine building leads to pressure differentials between different areas of the turbine building. In order to improve the environmental protection of various components within the turbine building, a wall has been erected which effectively separates the area in which these components are housed from the rest of the turbine building. Relief panels installed in the turbine building ensure that the pressure differential across the wall would be less than that required to jeopardize the wall integrity. The turbine building service wing is excluded from the scope of this analysis. It is further assumed that any doors in the heavy wall are as strong as the wall itself, with no gaps or leakage around the doors. For the full scope safety analysis of turbine building for Wolsong NPP unit 2, input decks for the various objectives, which can be read by GOTHIC 7.2a, are developed and tested for the steady state simulation. The input data files provide simplified representations of the geometric layout of the turbine building (volumes, dimensions, flow paths, doors, panels, etc.) and the performance characteristics of the various turbine building subsystems

  4. Integrity Analysis of Turbine Building for the MSLB Using GOTHIC code for Wolsong NPP Unit 2

    Ko, Bong-Jin; Jin, Dong-Sik; Kim, Jong-Hyun; Han, Sang-Koo [ACT, Daejeon (Korea, Republic of); Choi, Hoon; Kho, Dong-Wook [KHNP-CRI, Daejeon (Korea, Republic of)

    2015-05-15

    A break in the piping between the steam generators and the turbine can lead to rapid loss of secondary circuit inventory. A break inside the turbine building leads to pressure differentials between different areas of the turbine building. In order to improve the environmental protection of various components within the turbine building, a wall has been erected which effectively separates the area in which these components are housed from the rest of the turbine building. Relief panels installed in the turbine building ensure that the pressure differential across the wall would be less than that required to jeopardize the wall integrity. The turbine building service wing is excluded from the scope of this analysis. It is further assumed that any doors in the heavy wall are as strong as the wall itself, with no gaps or leakage around the doors. For the full scope safety analysis of turbine building for Wolsong NPP unit 2, input decks for the various objectives, which can be read by GOTHIC 7.2a, are developed and tested for the steady state simulation. The input data files provide simplified representations of the geometric layout of the turbine building (volumes, dimensions, flow paths, doors, panels, etc.) and the performance characteristics of the various turbine building subsystems.

  5. Analysis of the first stage in the reactor accident development at the Chernobyl NPP fourth unit

    Adamov, E.O.; Vasilevskij, V.P.; Ionov, A.I.

    1988-01-01

    Results of analyzing possible development of the first stage of the accident at the Chernobyl NPP fourth unit from the moment of pressing the Az-5 push button are presented. Calculations were conducted using the TRIADA three-dimensional dynamic program both for conditions without pump switching off and with their switching off. Distribution of neutron field over the core volume was determined according to actual readings of in-core detectors immediately before turbogenerator switching off. It is shown that sufficient reconstruction of neutron field begins immediately after pressing the Az-5 push button. Prohibitive decrease of operative reactivity margin which was admitted by personnel in the accident resulted in the growth of neutron power in reactor lower part within 1.5 s, predominating over power decrease in the upper part. Thus, the average integral power grows achieving the maximum during 7.5 s, after which its sharp decrease begins. Conditions with switching off of 4 circulating pumps lead to intesive growth of power and reactor runaway, initiated in the lower part of the core, which safety rods have not managed to reach. Fuel element temperature at that exceeds fuel melting point in the most power-intensive regions. This causes extremely intensive process of steam generation and overheating, pressure growth in the circuit, short-time decrease of the rate of operating pumps, destruction of fuel channels and the whole reactor. Primary measures assuring RBMK ractor safety were formulated on the basis of conducted investigation

  6. Construction of Site Risk Model using Individual Unit Risk Model in a NPP Site

    Lim, Ho Gon; Han, Sang Hoon [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Since Fukushima accident, strong needs to estimate site risk has been increased to identify the possibility of re-occurrence of such a tremendous disaster and prevent such a disaster. Especially, in a site which has large fleet of nuclear power plants, reliable site risk assessment is very emergent to confirm the safety. In Korea, there are several nuclear power plant site which have more than 6 NPPs. In general, risk model of a NPP in terms of PSA is very complicated and furthermore, it is expected that the site risk model is more complex than that. In this paper, the method for constructing site risk model is proposed by using individual unit risk model. Procedure for the development of site damage (risk) model was proposed in the present paper. Since the site damage model is complicated in the sense of the scale of the system and dependency of the components of the system, conventional method may not be applicable in many side of the problem.

  7. Operation time extension for power units of the first generation NPP and the liability for potential damage

    Kovalevich, O.M.

    2000-01-01

    The problem on the operation time extension for the six operating NPP first generation power units is discussed. However it is not advisable to improve the safety of these power units up to the acceptable level, therefore there arises the contradiction between the operation time extension of these power units and potential damage for the population. The possibility of having the increased civilian-legal responsibility for potential harm and losses in case of an accident is proposed to be considered as a compensating measure. The measures for realization of this civilian-legal responsibility are described [ru

  8. The analysis in real time, during the pre-commissioning period, of the overall plant control system of the CANDU NPP unit

    Tapu, C.; Irimia, M.

    1994-01-01

    The physical processes in the CANDU NPP are controlled by a computer system which, based on the associated package of programmes, performs both the monitoring function at the level of the operational area, and the digital regulation function of the technological systems within the NPP. For an optimal operation of the NPP, in dynamic as well as in stationary regime, the correlation of the direct digital control of the technological systems is very important for the NPP's overall digital control system. Taking into account the fact that during the pre-commissioning period of a CANDU unit it is necessary to test in dynamic regime the performance of the overall digital control function of the NPP, a system of verification and testing in real time was developed, by connecting a micro simulator of the physical process in the NPP to the actual computer system of the unit. The paper presents the methods and techniques used, as well as the results of the tests for various operational modes, which highlight the functioning of the digital control system of the CANDU NPP unit. (Author)

  9. Development of a GUI based RETRAN running environment for Kori NPP units 1 and 2

    Kim, Kyung Doo

    2000-09-01

    RETRAN was developed by EPRI and introduced for domestic use. RETRAN, which is a best-estimate system code approved by USNRC and used by most utilities in US, can be used in various plant support activities such as licensing calculations for plant design changes, EOP validation, and training. RETRAN, however, has been limited to only a few groups of specialists because of the difficulty involved in its usage. The aim of this project is to develop a graphic user interface (GUI) based code running environment for RETRAN named PRE (RETRAN Running Environment) in order to assist ordinary users in their input preparation, code execution, and output interpretation. TRIP and CONTROL BLOCK and VOLUME/JUNCTION input cards from base input are designed to be able to modify the existing input cards and add a new input cards through dialog boxes for users who have not much expertise in use of RETRAN. The RRE is designed to provide the calculated results though on-line X-Y graphs, plant mimics, indicators, nodalization window for easy interpretation of its output. It also provides the replay function using pre-calculated results saved in files. The RRE was developed for Kori NPP units 1 and 2 using Delphi 4.0 and Visual Fortran 6.0 and it runs on personal computers to increase the accessibility. The RRE developed in this study for Kori units 1 and 2 can be used in various plant support activities which require thermal-hydraulic analysis of the NSSS (Nuclear Steam Supply System) such as licensing calculations for plant design change, validation of EOP improvement, and operator training. The RRE developed can be expanded its application to other nuclear plants with low expense.

  10. Development of a GUI based RETRAN running environment for Kori NPP units 1 and 2

    Kim, Kyung Doo

    2000-09-01

    RETRAN was developed by EPRI and introduced for domestic use. RETRAN, which is a best-estimate system code approved by USNRC and used by most utilities in US, can be used in various plant support activities such as licensing calculations for plant design changes, EOP validation, and training. RETRAN, however, has been limited to only a few groups of specialists because of the difficulty involved in its usage. The aim of this project is to develop a graphic user interface (GUI) based code running environment for RETRAN named PRE (RETRAN Running Environment) in order to assist ordinary users in their input preparation, code execution, and output interpretation. TRIP and CONTROL BLOCK and VOLUME/JUNCTION input cards from base input are designed to be able to modify the existing input cards and add a new input cards through dialog boxes for users who have not much expertise in use of RETRAN. The RRE is designed to provide the calculated results though on-line X-Y graphs, plant mimics, indicators, nodalization window for easy interpretation of its output. It also provides the replay function using pre-calculated results saved in files. The RRE was developed for Kori NPP units 1 and 2 using Delphi 4.0 and Visual Fortran 6.0 and it runs on personal computers to increase the accessibility. The RRE developed in this study for Kori units 1 and 2 can be used in various plant support activities which require thermal-hydraulic analysis of the NSSS (Nuclear Steam Supply System) such as licensing calculations for plant design change, validation of EOP improvement, and operator training. The RRE developed can be expanded its application to other nuclear plants with low expense

  11. The management of safety within the completion of units 3. and 4. in NPP Mochovce

    Ocenas, M.

    2009-01-01

    The contribution defines the way of management of safety and protection of health and protection against the fire during completion of units 3. and 4. in NPP Mochovce. The creation of the management of safety raised from the legal and other requirements applied in the civil activities and mainly from the requirements for coordination of safety on the site. The whole system is methodically managed through the 5 basic documents so-called 'Building rules': 1) Safety-technical conditions of performance in SE, Inc. Bratislava (project MO34); 2) MO34/1/MNA-003.00-02 the elaboration of the integrated safety plan; 3) MO34/1/NA-003.00-03 risks analyse; 4) PNM3460100 Integrated safety plan for completion of Units 3.and 4 in NPP Mochovce; 5) Project of construction organization. The system itself of the management of the safety prevention must by provided by the supplier in compliance with the standard OHSAS 18 001 and ISO 14001, and in compliance with the requirement of the builder applied in the technical specification for the contract. Most of necessary related documentation of Safety plan for the site is usually part of the documentation for quality management of contractor. Therefore it is necessary to put the reference in each chapter of the Safety plan for site and the standpoint how to apply it for the particular specific situation. The coordinator is mandatory to manage the prevention for the part of safety of specified site and to coordinate the activity of suppliers during the works tie in this way, that the each contractor shall meet the safety requirements given by safety plan and also to identify and to eliminate the risks menaced in the particular work places or the suppliers each other. The builder established its own control system and for this purpose he settled the data base so-called 'The system of corrective and precautionary activities'. The system registers in its data base all discrepancies determined during the regular controls of the head workers

  12. Role of the team of scientific and technical commissioning support (TSTCS) during Mochovce NPP unit 3 and 4 commissioning

    Hermansky, J.; Prachar, M.; Sedlacek, M.; Petenyi, V.

    2011-01-01

    The Team of Scientific and Technical Commissioning Support (TSTCS) shall provide an independent support for the Mochovce NPP 3 and 4 Commissioning Department during Mochovce Units 3 and 4 commissioning. This independent support will be in line with the Mochovce NPP 3 and 4 Directive 'Non-active tests and commissioning' and it will be carried out in form of professional and expert works focusing on supervision of fulfilment of requirements for nuclear safety observance. The TSTCS duty to provide for such services during NPP commissioning is specified by Slovak Regulatory Body legislation. The independent TSTCS will supervise; - fulfilment of requirements for nuclear safety during preparation and implementation of commissioning tests; -scientific and technical level of commissioning programmes, and reflection on nuclear safety requirements in commissioning programmes,- commissioning process and test results. Main standpoints of the Team activities for individual unit commissioning stages will be; - assesment of the selected programs of functional tests in installations having an impact on nuclear safety and evaluation of the results of these tests; - assesment of the programs of physics and power commissioning, - assesment of the unit preparedness before fuel loading start; - assesment of the unit preparedness for performing initial criticality and low power commissioning and power commissioning stages; - evaluation of the results of physics and power commissioning stages and sub-stages; - final evaluation of the results from implementing the physics and power commissioning stages. The paper also presents a short description of the Team scope activities, the Team organisation, and a procedure for issuing of standpoints to individual unit commissioning stages. (Authors)

  13. NPP Decommissioning: the concept; state of activities

    Nemytov, S.; Zimin, V.

    2001-01-01

    The main principles of NPP decommissioning concept in Russia are given. The conditions with fulfillment of works on NPP unit pre-decommissioning and decommissioning including: development of the normative documentation, creation of special fund for financing NPP decommissioning activities, deriving the Gosatomnadzor license for decommissioning of shut down NPP units, development of the equipment and technologies for waste and spent fuel management are presented. The decommissioning cost and labour intensity of one WWER-440 unit are shown. The practical works, executed on shut down units at Beloyarsk NPP (Unit1 and 2) and Novo Voronezh NPP (Unit 1 and 2) are outlined

  14. The main conditions ensured problemless implementation of 235U high enriched fuel in Kozloduy NPP (Bulgaria) - WWER-1000 Units

    Dobrevski, I.; Zaharieva, N.; Minkova, K.; Michaylov, G.; Penev, P.; Gerchev, N.

    2009-01-01

    The collected water chemistry and radiochemistry data during the operation of the Kozloduy NPP Unit 5 for the period 2006-2009 (12-th, 13-th 14-th and 15-th fuel cycles) undoubtedly indicate for WWER-1000 Units (whose specific features are: Steam generators with austenitic stainless steel 08Cr18N10T tubing; Steam generators are with horizontal straight tubing and Fuel elements cladding material is Zr-1%Nb (Zr1Nb) alloy), that one realistic way for problemless implementation of 235 U high enriched fuel have been found. The main feature characteristics of this way are: Implementation of solid neutron burnable absorbers together with the dissolved in coolant neutron absorber - natural boric acid; Application of fuel cladding materials with enough corrosion resistance by the specific fuel cladding environment created by presence of SNB; Keeping of suitable coolant water chemistry which ensures low corrosion rates of core- and out-of-core- materials and limits in core (cladding) depositions and restricts out-of-core radioactivity buildup. The realization of this way in WWER-1000 Units in Kozloduy NPP was practically carried out through: 1) Implementation of Russian fuel assemblies TVSA which have as fuel cladding material E-110 alloy (Zr1Nb) with enough high corrosion resistance by presence of sub-cooled nucleate boiling (SNB) and use burnable absorber (Gd) integrated in the uranium-gadolinium (U-Gd 2 O 3 ) fuel (fuel rod with 5.0% Gd 2 O 3 ); 2) Development and implementation of water chemistry primary circuit guidelines, which require the relation between boric acid concentration and total alkalising agent concentrations to ensure coolant pH 300 = 7.0 - 7.2 values during the whole operation period. The above mentioned conditions by the passing of WWER-1000 Units in NPP Kozloduy to uranium fuel with 4.4% 235 U (TVSA fuel assemblies) practically ensured avoidance of the creation of the necessary conditions for AOA onset. The operational experience (2006-2009) of the

  15. Response and capacity evaluation of unit 1-2, Kozloduy NPP

    Kostov, M.; Stefanov, D.; Boncheva, H.

    1993-01-01

    Investigation described in this presentation was performed within the WANO Program for seismic safety assessment of Kozloduy NPP. The investigation is imposed by the necessity of seismic upgrading of the structures and equipment of the plant for the new design basic earthquake. Term of reference for this study was elaborated by experts of IAEA

  16. Approach to development and use of PSA Level 2 analysis for the Cernavoda nuclear power plant

    Turcu, I.; Deaconu, R.; Radu, G.

    1998-01-01

    This paper first describes the status of PSA activities for the Cernavoda NPP and the extension of the PSA work to include Level 2 PSA. Important characteristics of this reactor type for Level 2 PSA are outlined. Due to the specific layout of the CANDU reactor the evolution of severe accidents is considerably different to vessel type LWRs. Accidents can be roughly categorized into three categories, ''''severe accidents'''' which lead to the loss of core structural integrity, delayed loss of core structural integrity as a consequence of the loss of heat sinks, and fuel channel failures. The current work for modelling accident progression in the core region is described. The elements for the Level 2 PSA including definition of PDSs, probabilistic containment logic and source term calculation are outlined. It is pointed out that uncertainties have to be considered which are contained in the models to bridge knowledge gaps. For this purpose sensitivity studies will be carried out for key modelling assumptions. (author)

  17. Cernavoda nuclear power plant: Modifications in the fire protection measures of the CANDU 6 standard design

    Covalschi, V.

    1998-01-01

    Having as purpose the improvement of fire safety at the Cernavoda NPP - both in the prevention and the protection aspects in the case of fire - we implemented some modifications in the CANDU 6 standard design. These improvements are inspired, mainly, from two sources: the world-wide achievements in the field of fire protection techniques, introduced in nuclear power plants since the middle of 70's, when the CANDU 6 design was completed; the national practice and experience in fire protection, usually applied in industrial objectives (conventional power plants, in particular). The absence of any incident may be considered as a proof of the efficiency of the implemented fire preventing and protection measures. (author)

  18. A Preliminary Study on the Containment Integrity following BIT Removal for Kori NPP Unit 3,4

    Song, Dong Soo; Byun, Choong Sup [KEPRI, Nuclear Power Generation Laboratory, Daejeon (Korea, Republic of); Jo, Jong Young [ENERGEO Inc., Sungnam (Korea, Republic of)

    2008-05-15

    The Boron Injection Tank (BIT) is to provide high concentrated boric acid to the reactor in order to mitigate the consequences of postulated Main Steam Line Break accidents (MSLB). Although BIT plays an important role in mitigating the accident, high concentration of 20,000ppm causes valve leakage, pipe clog, precipitation and continuous heat tracing have to be provided. This paper is for the feasibility study of containment integrity using CONTEMPT code for BIT removal of Kori Nuclear Power Plant (NPP) Unit 3, 4.

  19. A Preliminary Study on the Containment Integrity following BIT Removal for Kori NPP Unit 3,4

    Song, Dong Soo; Byun, Choong Sup; Jo, Jong Young

    2008-01-01

    The Boron Injection Tank (BIT) is to provide high concentrated boric acid to the reactor in order to mitigate the consequences of postulated Main Steam Line Break accidents (MSLB). Although BIT plays an important role in mitigating the accident, high concentration of 20,000ppm causes valve leakage, pipe clog, precipitation and continuous heat tracing have to be provided. This paper is for the feasibility study of containment integrity using CONTEMPT code for BIT removal of Kori Nuclear Power Plant (NPP) Unit 3, 4

  20. Determining the Residual Lifetime of Qualified Electrical and I and C Equipment in Units 5 and 6 of Kozloduy NPP

    Radoslavov, Biser

    2012-01-01

    The proposed paper clarifies the environmental qualification and residual lifetime of installed equipment and electrical cables in operating WWER 1000 type units 5 and 6 of Kozloduy NPP. The qualification approach is a combination of analyses and tests in consideration of some specific features of WWER equipment. As a result of the study, selected equipment is divided in 26 groups. Qualification groups include similar types of equipment with equal resistance to foreign impacts, analogous critical parts, and same methods of control and estimation of residual lifetime. Qualification protocols were made for each group. (author)

  1. Automatic regulation of the feedwater turbo-pump capacity for the single-turbine 1000 MW NPP unit

    Pavlysh, O.N.; Garbuzov, I.P.; Reukov, Yu.N.

    1985-01-01

    A schematic of the flow regulators (FR) of feedwater turbo-pumps (FTP) for the single-turbine 1000 MW NPP unit is presented. The FR operate in response to feedwoter signals from FTP or in response to FTP rotor rotational speed and control automatic speed governars. The FR automatic regulation ensures limitation of FTP rotor maximum rotational speed at a feedwater flow rate excess equal to 3600 T/h. The transients in the automatic regulation system are considered. Production tests of FTP FR confirmed the FR operation reliability and the right choice of the regulator concept and structure

  2. Strategic maintenance plan for Cernavoda steam generators

    Cicerone, T.; Dhar, D.; VandenBerg, J.P.

    2002-01-01

    Steam generators are among the most important pieces of equipment in a nuclear power plant. They are required full time during the plant operation and obviously no redundancy exists. Past experience has shown that those utilities which implemented comprehensive steam generator inspection and maintenance programs and strict water chemistry controls, have had good steam generator performance that supports good overall plant performance. The purpose of this paper is to discuss a strategic Life Management and Operational-monitoring program for the Cernavoda steam generators. The program is first of all to develop a base of expertise for the management of the steam generator condition; and that is to be supported by a program of actions to be accomplished over time to assess their condition, to take measures to avoid degradation and to provide for inspections, cleaning and modifications as necessary. (author)

  3. The design preparation for radiation monitoring system in the frame of completion NPP Mochovce Units 3 and 4

    Sevecka, S.; Slavik, O.; Kapisovsky, V.

    2009-01-01

    In 1985 a Basic Design of Radiation Monitoring System (RMS) has been elaborated for Mochovce NPP unit 3 and 4 construction. Due to construction interruption in the following years this design solution became obsolete. A new solution of RMS have been developed with conception following that of original Basic Design accommodating also safety measures implemented in RMS of NPP EMO units 1 and 2, and based on modem instrumentation and computer technique. Following the updating of Basic Design documentation the preparation of elaboration of RMS detailed design was carried on. In the frame of this preparation a review of possible suppliers of instrumentation satisfying the conception of radiation monitoring system and the extension of required deliveries has been made. Also criteria on RMS suppliers selection have been determined. The types of monitoring systems and equipment, as well as their quantities, have been specified based on updated Basic Design requirements and production profiles and possibilities of potential suppliers. The required parameters of measurements (including measurement geometry) have been evaluated, as well as requirements of legislation and requirements of proposed RMS architecture. (authors)

  4. Methods, means and results from containment leakage decrease in unit 2 at Kozloduy NPP with international participation

    Demireva, E.; Grigorov, D.; Balabanov, E.

    1995-01-01

    A study of the Kozloduy NPP Unit 2 containment improvement has been carried out. The following objectives are identified: to assess confinement tightness (local tests); to improve tightness; to perform the most urgent repair works; to develop global test procedures including leak tightness at nominal and reduced pressure, structural integrity test and venting flaps reliability test. Nine groups of potential leakage paths have been determined. The ventilation system has been found as the major source of expected leakage having 60 penetrations with size above 250 mm. Proposed modifications of the ventilation system include reduction of the number of inflow and suction valves, replacement of some valves with a better quality ones and installation of isolating valves. It is planned to transfer the experience and results of this study to the other WWER-440 units. 1 ref

  5. Methods, means and results from containment leakage decrease in unit 2 at Kozloduy NPP with international participation

    Demireva, E; Grigorov, D; Balabanov, E [Energoproekt, Sofia (Bulgaria)

    1996-12-31

    A study of the Kozloduy NPP Unit 2 containment improvement has been carried out. The following objectives are identified: to assess confinement tightness (local tests); to improve tightness; to perform the most urgent repair works; to develop global test procedures including leak tightness at nominal and reduced pressure, structural integrity test and venting flaps reliability test. Nine groups of potential leakage paths have been determined. The ventilation system has been found as the major source of expected leakage having 60 penetrations with size above 250 mm. Proposed modifications of the ventilation system include reduction of the number of inflow and suction valves, replacement of some valves with a better quality ones and installation of isolating valves. It is planned to transfer the experience and results of this study to the other WWER-440 units. 1 ref.

  6. Three years re-use of low burned fuel assemblies from units 1 and 2 in core loading of units 3 and 4 WWER-440 at Kozloduy NPP

    Stoyanova, I.; Antov, A.; Spasova, V.

    2006-01-01

    At the end of 2002 Units 1 and 2 of Kozloduy NPP were shutdown before the end of their designed lifetime. This left a large number of assemblies yet with a significant energy resource. In 2003, 43 assemblies from Unit 1 and 55 assemblies from Unit 2 are loaded in the cores of Units 3 and 4 respectively. In 2004, new 49 assemblies from Unit 1 and new 55 assemblies from Unit 2 are loaded in the cores of Units 3 and 4 respectively. In 2005, the next new 25 assemblies from Unit 1 and 66 assemblies from Unit 2 are loaded in the cores of Units 3 and 4 respectively. The realized core loadings of Units 3 and 4 are illustrated. The large number of low burned assemblies after the shut down of Units 1 and 2 and their utilization during 4 consecutive cycles in the cores of Units 3 and 4 both do not permit to obtain in the last 3 cycles the typical mean burn up 35-36 MWd/kg U of 3.6% discharged assemblies

  7. Studying the dynamical characteristics of pumps in NPP unit auxiliary water system under operational conditions

    Belyaev, S.G.; Puzanov, A.I.; Belikov, V.P.; Dizik, B.S.

    1990-01-01

    Hydrodynamic loads appearing in the flow-through part of pump aggregates of the system of auxiliary water supply in NPP with variations in the operation modes are investigated. It is shown that during operation of centrifugal pumps the position of the mode on the pump characteristic plot must be controlled. When the mode point exceeds the limits of the working zone it results in a considerable increase of dynamic loads: pressure pulsation and vibration. As the flow rate increase the decrease in dynamic loads is recorded at low frequencies of about 2-4 Hz

  8. An approach for Periodic Safety Review (PSR) of units 5 and 6 of Kozloduy NPP

    Kichev, Emil

    2014-01-01

    Periodic Safety Reviews (PSR) is complementary to the routine and special safety reviews and does not replaced them. It determines the level of compliance with current safety requirements and covers all safety aspects of NPP operation and all equipment (SSCs) on site. Three levels of importance are defined for the documents in PSR (towards higher conservatism): Bulgarian documents; IAEA documents; Documents of manufactures and suppliers of the equipment (SSCs). The scope and activities consists of four stages and includes 14 safety factors (SF). Cooperation with external companies and organizations in areas with proved experience is used.

  9. Main results of the analysis of internal flooding in the reactor building of Kozloduy NPP Unit 6

    Demireva, E.; Goranov, S.; Horstmann, R.

    2004-01-01

    For modernization of Units 5 and 6 of Kozloduy NPP, a comprehensive analysis of internal flooding scenarios has been carried out for the reactor building outside the containment and for the turbine hall by FRAMATOME ANP and ENPRO Consult. The objective of the presentation is to provide information on the main results obtained in the flooding analysis of the reactor building (outside containment). The flooding analysis is being performed under application of the 'Methodology and boundary conditions'. Flooding calculations are provided for all of the rooms in the reactor building outside the containment in which the fluid systems, having the capacity for flooding, are mounted. The performed functional analysis shows whether the consequences of a postulated initial event are within the NPP design or could lead to situations which are not taken into account in the design. The proposals for overcoming of identified unacceptable situations and the possible strategy of room draining are also given. Several cases of leaks inside the sealed rooms in the restricted area lead to the situation that the rooms will get totally flooded. Even if this should be acceptable from the point of view of loss of system function, the water pressure effect on the structural elements, as walls and doors, does not allow such complete filling-up. The second relevant identified effect was spreading of humidity and high temperatures to adjacent rooms. Long-lasting effects of this type have to be avoided, in order to prevent potential common cause effects on safety system equipment (authors)

  10. Two managerial grids in NPP

    Zhao Hui

    2012-01-01

    Today, the nuclear power corporation (NPC) enjoys the profit of LCEP (the low carbon economic policy). at the same time, they also enduring more and more pressure. For example, the partner competition or the NPP potential occupational risk . The efficient counterplot of risk is the self-ability cultivation. It is essential to research the NPP managerial flow. The nuclear power plant (NPP) unit is a carrier of the NPC enterprise management system, and has taken on a new look 'pull one portion then the whole moving'. The NPP has three systematical characters, the security responsibility center, the man-machine system and the input-output system. The manufacturing system and the enterprise management system are the great constituents of the NPP managerial flows. Means of systems analysis, we can find out the truth of the NPP running interface. In CHINA, there are many operating experiences near 20 years. It indicates that the NPP manufacturing system and the enterprise system are the roots of the nuclear power corporation, the core of the all NPP systems must be based on it. So the ability cultivation is the work core to NPP. It is reliably to ensure the NPP to be up against problems, for instance, the security duty, the costing control and the man-machine system running harmoniously. This paper introduces the NPP managerial flow and the present state of QNPC, also come up with a proposal to refer for the NPC development actions of collective measure, specialization, standardization, fine. (author)

  11. Radioactive waste management at nuclear power plant Cernavoda

    Raducea, D.

    2002-01-01

    Many human activities generate waste, but people are worried about wastes produced in nuclear power plants (NPPs). Their concern is an unjustified fear toward the hazards from radioactive waste, probably because in any country generating electric power by NPPs a lot of attention is paid to relevant parties involved in radioactive waste management. Significant attention is also given to the management of radioactive waste at the Cemavoda NPP. The general approach required for the collection, handling, conditioning and storage of radioactive wastes, while maintaining acceptable levels of safety for workers, members of the public and the environment, is conceptually established. The overall programme provides the necessary facilities to adequately manage solid radioactive waste from Cemavoda NPP Unit 1 and will be capable of expansion when other units are brought into service. (author)

  12. Numerical Analysis of Loss of Residual Heal Removal System (RHRS) during Mid-Loop Operation for Hanul NPP Units 1 and 2

    Kim, Sook Kwan; Park, Seong Gyu; Han, Sang Koo [ACT Co., Daejeon (Korea, Republic of)

    2016-10-15

    As a part of supporting LPSD (Low Power and Shutdown) PSA (Probabilistic Safety Assessment) of Hanul NPP units 1 and 2, numerical analysis for a loss of RHRS (Residual Heat Removal system) during midloop operation was performed using RELAP5/MOD3.3 code. The one of main purpose of thermal hydraulic analysis for PSA work is to estimate times allowable for operation actions in each accident. A loss of RHRS during mid-loop operation may cause more significant results than during RCS full condition due to reduced RCS inventory. In order to perform this kind of analysis, it is particularly important to establish a steady state of mid-loop operational initial condition. Mid-loop operation corresponds to POS(Plant Operational State) 5 and 11 in the category of LPSD PSA at Hanul NPP units 1 and 2. RELAP5/MOD3.3 code was used to predict behaviors of RCS and fuels for the case of loss of RHRS during mid-loop operation at Hanul NPP units 1 and 2. The initial state of mid-loop operational condition was established by proper control of charging and letdown flow. Considering existing similar analysis results for this kind of accident, it can be concluded that RELAP5 code well predicts reasonably the behavior of RCS for loss of RHRS during mid-loop operation in Hanul NPP units 1 and 2. Thus the method developed in the analysis can be applied reasonably to support LPSD PSA.

  13. Methodology and boundary conditions applied to the analysis on internal flooding for Kozloduy NPP units 5 and 6

    Demireva, E.; Goranov, S.; Horstmann, R.

    2004-01-01

    Within the Modernization Program of Units 5 and 6 of Kozloduy NPP a comprehensive analysis of internal flooding has been carried out for the reactor building outside the containment and for the turbine hall by FRAMATOME ANP and ENPRO Consult. The objective of this presentation is to provide information on the applied methodology and boundary conditions. A separate report called 'Methodology and boundary conditions' has been elaborated in order to provide the fundament for the study. The methodology report provides definitions and advice for the following topics: scope of the study; safety objectives; basic assumptions and postulates (plant conditions, grace periods for manual actions, single failure postulate, etc.); sources of flooding (postulated piping leaks and ruptures, malfunctions and personnel error); main activities of the flooding analysis; study conclusions and suggestions of remedial measures. (authors)

  14. Treatment, conditioning and packaging for final disposal of low and intermediate level waste from Cernavoda: a techno-economic assessment

    Suryanarayan, S.; Husain, A. [Kinectrics Inc., Toronto, ON (Canada); Fellingham, L.; Nesbitt, V. [Nuvia Ltd., Didcot, Oxfordshire (United Kingdom); Toro, L. [Mate-fin, Bucharest (Romania); Simionov, V.; Dumitrescu, D. [Cernavoda Nuclear Power Plant, Cernavoda (Romania)

    2011-07-01

    National Nuclearelectrica Society (SNN) owns and operates two CANDU-6 plants at Cernavoda in Romania. Two additional units are expected to be built on the site in the future. Low and intermediate level short-lived radioactive wastes from Cernavoda are planned to be disposed off in a near-surface repository to be built at Saligny. The principal waste streams are IX resins, filters, compactable wastes, non-compactables, organic liquids and oil-solid mixtures. Their volumetric generation rates per reactor unit are estimated to be: IX resins (6 m{sup 3}/y), filters (2 m{sup 3}/y), compactables (23 m{sup 3}/y) and non-compactables (15 m{sup 3}/y). A techno-economic assessment of the available options for a facility to treat and condition Cernavoda's wastes for disposal was carried out in 2009 based on projected waste volumes from all four units. A large number of processes were first screened to identify viable options. They were further considered to develop overall processing options for each waste stream. These were then consolidated to obtain options for the entire plant by minimizing the number of unit operations required to process the various waste streams. A total of 9 plant options were developed for which detailed costing was undertaken. Based on a techno-economic assessment, two top ranking plant options were identified. Several scenarios were considered for implementing these options. Amongst them, a contractor run operation of a facility located on the Cernavoda site was considered to be more cost effective than operating the facility using SNN personnel. (author)

  15. Regulatory approach to NPP ageing in Bulgaria

    Vassilev, D.

    2000-01-01

    In this contribution summary information of Kozloduy NPP units is presented. The nuclear legislation, regulatory approach for managing safety aspects on NPP ageing, short term programme, complex programme PRG'97 ant other aspects of ageing management are discussed

  16. Some aspects of correction additions optimisation of water chemistry regime of Kozloduy NPP power units 3 and 4

    Topalova, I.

    2005-01-01

    Optimization of the water-chemistry regime is a major corrective measure for minimization of the corrosion processes of the nuclear power unit equipment. Research done in NPP Kozloduy III - IV power units concerning the migration of the corrosion products in the water of secondary circuit as well as the connection between corrosion processes and fluctuation in parameters of the applied water-chemistry regime are reported. Analysis of the dependences obtained lead to conclusions for optimization of the water chemistry regime of secondary circuit and minimization of the corrosion processes and improvement of corrosion condition of metal surfaces. The research is done for the circuit of each of the 8 turbines of the two power units for a period of 10 days. Data received is quantitatively representative /40-50 points/ for performing of analysis and reaching certain conclusions for the water chemistry regime and development of corrosion processes. Dependence of iron and copper concentration in the work medium on the pH, ammonia and hydrazine concentration as well as the dependence of pH on ammonia concentration in case of different quantity and composition of corrosion products on the different power units' equipment metal surfaces are shown. (author)

  17. Computer-aided design system for a complex of problems on calculation and analysis of engineering and economical indexes of NPP power units

    Stepanov, V.I.; Koryagin, A.V.; Ruzankov, V.N.

    1988-01-01

    Computer-aided design system for a complex of problems concerning calculation and analysis of engineering and economical indices of NPP power units is described. In the system there are means for automated preparation and debugging of data base software complex, which realizes th plotted algorithm in the power unit control system. Besides, in the system there are devices for automated preparation and registration of technical documentation

  18. Boat sampling and inservice inspections of the reactor pressure vessel weld No. 4 at Kozloduy NPP, Unit 1

    Cvitanovic, M.; Oreb, E.; Mudronja, V.; Zado, V.; Bezlaj, H.; Petkov, M.; Gledatchev, J.; Radomirski, S.; Ribarska, T.; Kroes, B.

    1999-01-01

    The paper deals with reactor pressure vessel (RPV) boat sampling performed at Kozloduy Nuclear Power Plant, Unit 1, from August to November 1996. Kozloduy NPP, Unit 1 has no reactor vessel material surveillance program. Changes in the material fracture toughness resulting from the fast neutron irradiation which cannot be monitored without removal of the vessel material. Therefore, the main objective of the project was to cut samples from the RPV wall in order to obtain samples of the RPV material for further structural analyses. The most critical area, i.e. weld No. 4 was determined as a location for boat sampling. Replication technique was applied in order to obtain precise determination of the weld geometry necessary for positioning of the cutting tool prior to boat sampling, and determination of divot depth left after boat sampling and grinding of sample sites. Boat sampling was performed by electrical discharge machining (EDM). Grinding of sample sites was implemented to minimize stress concentration effects on sample sites, to eliminate surface irregularities resulting from EDM process, and to eliminate recast layer on the surface of the EDM cut. Ultrasonic, liquid penetrant, magnetic particles, and visual examinations were performed after grinding to establish baseline data in the boat sampling area. The project preparation activities, apart from EDM process, and the site organization lead was entrusted to INETEC. The activities were funded by the PHARE program of the European Commission. (orig.)

  19. Preparation for Ignalina NPP decommissioning

    Medeliene, D.

    2004-01-01

    Latest developments of atomic energy in Lithuania, works done to prepare Ignalina NPP for final shutdown and decommissioning are described. Information on decommissioning program for Ignalina NPP unit 1, decommissioning method, stages and funding is presented. Other topics: radiation protection, radioactive waste management and disposal. Key facts related to nuclear energy in Lithuania are listed

  20. Safety assessment of multi-unit NPP sites subject to external events

    Samaddar, Sujit; Hibino, Kenta; Coman, Ovidiu

    2014-01-01

    This paper presents a framework for conducting a probabilistic safety assessment of multi-unit sites against external events. The treatment of multiple hazard on a unit, interaction between units, implementation of severe accident measures, human reliability, environmental conditions, metric of risk for both reactor and non-reactor sources, integration of risk and responses and many such important factors need to be addressed within the context of this framework. The framework facilitates the establishment of a comprehensive methodology that can be applied internationally to the peer review of safety assessment of multi-unit sites under the impact of multiple external hazards. In summary, it can be said that the site safety assessment for a multi-unit site will be quite complex and need to start with individual unit risk assessments, these need to be combined considering the interactions between units and their responses, and the fragilities of the installations established considering the combined demands from all interactions. Using newly established risk metric the risk can then be integrated for the overall site. Fig. 2 shows schematically such a proposal. Much work has to done and the IAEA has established a working group that is systematically establishing the structure and process to incorporate the many issues that are a part of a multi-unit site safety assessment. (authors)

  1. Change of secondary water regime of Paks NPP. Change of secondary water regime at Unit 2

    Doma, A.; Patek, G.; Pinter, T.; Bajari, M.; Tilky, P.

    2001-01-01

    The installation of high pH water regime during the 17th cycle of Unit 2 aimed to decrease the amount of transportation inlet of erosion-corrosion products (magnitude) in feedwater to SGs. The resolution of OAH-NBI permitting the installation ordained to make an evaluation of the process. The main conclusions and results are discussed. The high pH water regime proved to be adequate in the case of Unit 2 as well, similarly to Units 3, 4 and 1. (R.P.)

  2. Risk analysis of NPP in multi-unit site for configuration of AAC power source

    Kim, Myung Ki

    2000-01-01

    Because of the difficulties in finding new sites for nuclear power plants, more units are being added to the existing sites. In these multi-unit sites, appropriate countermeasures should be established to cope with the potential station blackout (SBO) accident. Currently, installation of additional diesel generator (DG) is considered to ensure an alternative AC power source, but it has not been decided yet how many DGs should be installed in a multi-unit site. In this paper, risk informed decision making method, which evaluates reliability of electrical system, core damage frequency, and site average core damage frequency, is introduced to draw up the suitable number of DG in multi-unit site. The analysis results show that installing two DGs lowered the site average core damage frequency by 1.4% compared to one DG in six unit site. In the light of risk-informed decisions in regulatory guide 1.174, there is no difference of safety between two alternatives. It is concluded that one emergency diesel generator sufficiently guarantees safety against station blackout of nuclear power plants in multi-unit site. (author)

  3. Analysis of Novo-Voronezh NPP unit 3 radiation lifetime of the WWER-440 reactor pressure vessel given samplings

    Kiselyov, V.; Korinets, A.; Maksimov, Yu.; Piminov, V.

    1997-01-01

    The analysis of the residual radiation lifetime of the Novo-Voronezh NPP Unit 3 reactor pressure vessel which had spherical samplings after annealing was performed for the spectrum of the 'worst' modes of the emergency situation category. For the residual radiation lifetime estimation within the given study, two approaches to determine stress intensity factors, K I , have been used simultaneously. The first approach included a direct numeric modelling of postulated cracks in the cut-out zone with the use of the 3D finite element method. The second approach included K 1 calculation using 3D weight functions calculated with the use of the boundary element method. For K I , calculation flaws have been postulated as surface longitudinal semielliptical flaws located in the deepest point of a cut-out. The results of K I calculations obtained using different methods were practically the same. The allowable critical brittleness temperature was determined as 175 C that permitted the extension of the radiation lifetime by up to 6 years after annealing. (orig.)

  4. Application of safety standards and rules in the Shelter Implementation Plan at the destroyed power unit of Chernobyl NPP

    Berthold, A.; Bogorinski, P.; Bykov, V.; Redko, V.; Erickson, L.; Kadkin, Ye.; Kondratiev, S.; Simonov, I.; Smyshliaieva, S.; Yesipenko, Yu.

    2002-01-01

    This report deals with the application of safety standards and rules to the Shelter Implementation Plan (SIP) measures. Since 1998 this plan is being implemented at the Chornobyl NPP destroyed unit (which is now known as the Shelter). It includes a set of various tasks whose performance will help partially achieve the established safety objectives. The Regulatory Authority should establish for the Shelter safety goals, principles, and criteria in general, while the Operator of the Shelter is free to independently select the optimum method for their implementation. The Operator of the Shelter must demonstrate (in safety analysis report) that established safety goals are achieved and safety principles and criteria are met. Safety goals, principles, and criteria established for radioactive waste management are reasonable to apply in measures provided for by SIP. However, due to the unique nature of the Shelter, some criteria should not be applied directly and in full scope. Norms and rules on radiation protection should be applied in full scope. The specifics of radiation protection during each Shelter-related activity are considered individually. Safety standards and rules related to technical aspects are reasonable only as a basis. Effective resolution of specific technical issues associated with safety assurance is achieved through interaction between the Operator and the Regulatory Authority during design of SIP structures and systems. Hence, effectiveness of the licensing process plays an important role in the success of the SIP.(author)

  5. Kozloduy NPP units 5 and 6 modernization program. Measures implementation in outages

    Naydenov, N.; Mignone, O.

    2004-01-01

    The units 5 and 6 modernization program is a highly demanding program composed by many plant modifications and studies about plant conditions. The program measures implementation during the units outages represents a challenge by the need to compromise shut down duration with the workload related to measures installation. The units shutdown duration should be kept to the planned duration. In parallel, contractors work has to be organized, planned and performed to allow successful measures completion. In accordance with the contract requirements, contractors prepare installation documents which comprise all activities to be performed during the installation and testing of the measures. The subcontractors complement these installation documents with the project organization and execution documents, which include the manpower skills, qualifications, work orders, and other important installation instructions and information. Contractors prepared detailed installation schedules, and these were integrated by Parsons E and C in the Integrated installation schedule. The integrated schedule proved to be useful to identify possible area usage conflicts and manpower overlapping, with appropriate results for electrical, instrumentation and control work, and for the utilization of the polar crane in the containment building. Contractors installation schedules were updated on a weekly basis, showing variances versus the target, and manpower histograms for the resource loading. Organization of contractors work was supported by KNPP plant outage meetings, in which status and problems were addressed, and solution and/or corrective actions defined for further implementation. KNPP meetings were planned on a daily basis for most relevant or critical measures, or on a weekly basis for less intensive measures. KNPP meetings proved to be an excellent communication tool for keeping the measures under control and monitoring KNPP defined personnel responsible for authorizing changes, in

  6. Renovation of the 'old' NPP units as an economically effective way of nuclear power development

    Zrodnikov, A.V.; Toshinsky, G.I.; Komlev, O.G.; Dragunov, Yu.G.; Stepanov, V.S.; Klimov, N.N.; Kopytov, I.I.; Krushelnitsky, V.N.

    2005-01-01

    In the process of nuclear power development there comes a phase when the old' power-units, which reactor installations have expired the designed and extended service lifetime are withdrawn from operating. At this phase in the case of the same annual investments into nuclear power, the increase of the total set up capacity of the nuclear power will be terminated because introduction of capacities due to construction of 'new' power-units only compensates for the reduction of capacities caused by withdrawing from operating the 'old' power-units. Along with this, taking into account a sizeable difference in the service lifetime of the nuclear steam supplying systems and the rest infrastructure of the nuclear power plants, it is an opportunity to find the solution to the problem of compensating for the withdrawn capacities without considerable increasing the annual investments. This opportunity is connected with use of the innovative nuclear power technology based on multipurpose small power modular fast reactors with lead-bismuth coolant for replacement of the withdrawn capacities (renovation of power-units). The features of the innovative nuclear power technology based on the SVBR-76/100 reactor installations, the results of the technical and economical investigations that demonstrate the high economical efficiency of use of the renovation technology using the SVBR-75/100 reactor modules are presented in the Paper. (author)

  7. Temelin NPP commissioning experiences

    Hanus, V.

    2002-01-01

    The Building Permit for the Temelin NPP with four VVER units was issued in 1986, which is a long time ago. Since then, however, was taken a route that is very different from what anybody imagined. Described are the legislative and design changes and given is a current condition of the power plant

  8. Modernization of electrical systems in NPP Kozloduy unit 5 and 6. Feedback of experience

    Stinshoff, H.

    2005-01-01

    In the frame of the modernization program for the nuclear power plant Kozloduy unit 5 and 6 Framatome ANP has implemented measures to increase the safety and availability of the electrical systems. The hardware installation is scheduled in the refueling outages of the years 2003 to 2005. In this paper the following items are presented: 1) an overview of the modernization measures; 2) some important technical features of the new equipment and diagnostic measures; 3) feedback of experience

  9. Assessment of the residual lifetime of the units 3 and 4 of the Kozloduy NPP

    Mojkinski, G.

    2011-01-01

    The purpose of the report is to present the methodology for the residual lifetime assessment for the buildings and facilities during the decommissioning. An analysis of the existing facilities and constructions is made and requirements for further exploitation are set. A quantitative assessment is made of the residual lifetime for the buildings and auxiliary objects for the units 3 and 4. A detailed analysis is made for the ventilation systems and other equipment. Recommendations are given for the extension of the equipment lifetime

  10. Dukovany NPP - Safely 16 TERA

    Vlcek, J.

    2008-01-01

    In this presentation increasing of power output of the Dukovany NPP is reviewed. To operate all Dukovany Units safely with the perspective of long-term operation (LTO) of 50 - 60 years it is proposed.

  11. Seismic safety review mission for the follow-up of the seismic upgrading of Kozloduy NPP (Units 1-4). Sofia, Bulgaria, 16-20 November 1992

    David, M.; Shibata, H.; Stevenson, J.D.; Godoy, A.; Gurpinar, A.

    1992-11-01

    A Seismic Safety Review Mission for the follow-up of the design and implementation of the seismic upgrading of Kozloduy NPP was performed in Sofia from 16-20 November 1992. This mission continued the second task of the follow-up activities of the design and implementation of the seismic upgrading (Phases 1 and 2), which is being carried out in Units 1 and 2 of the NPP. Thus the objectives of the mission was to assist the Bulgarian authorities in the technical evaluation of the design tasks defined for Phases 1 and 2 item HB of WANO 6 Month Programme, as follows: anchorage upgrades of low seismic capacity components; list of seismic safety related systems and components; detailed walkdown to assess seismic capacity of components and define priorities for the upgrading; determination of seismic structural capacity of pump house, diesel generator building and turbine building and design of required upgrades; liquefaction potential evaluation. Tabs

  12. Decommissioning of Kozloduy NPP units 1÷4 progress and challenges

    Kazakov, Momchil

    2016-01-01

    The process of decommissioning of Units 1 to 4 is under implementation according to the approved schedule and dismantling work in the TH is expected to be completed in due time, i.e. the end of 2018. Management of dismantled materials is difficult due to the lack of licensed sites for management of materials from the decommissioning activities, as well as due to the long free release procedures. In order to solve the above mentioned issues, measures have been taken concerning the design and construction of sites for management of materials from the decommissioning activities and in respect of the release of material from regulatory control. The preparation of the CA and auxiliary buildings for dismantling has started on schedule, as well as the dismantling of potentially contaminated equipment; Management and treatment of decommissioning RAM and RAW will be assisted by putting into operation of the Size Reduction and Decontamination Workshop (SRDW) and Plasma Melting Facility (PMF) which is scheduled for 2017; Management of RAW from the Mortuaries in the CA is another challenge for SERAW and in that regard a Feasibility Study for the Management of “Mogilnik” storages of KNPP Units 1-4 is first planned to be carried out and thereafter a management approach is to be selected; Regarding dismantling in the CA, SERAW is in the process of Elaboration of a Design for Dismantling of Equipment in the Controlled Areas of KNPP Units 1-4; Based on the selected option for dismantling, particularly the Reactor Pressure Vessel (RPV), reactor internals and the rest activated components, the Consultant shall justify by relevant analyses the requirement for temporary storage areas for activated equipment by complying with the best international practices

  13. Procedure for validating the life extension for the WWER-440 internals at NV NPP unit 3

    Filatov, V.M.; Evropin, S.V.

    2001-01-01

    The design lifetime (30 years) of the 1st generation WWER-440 reactor facilities is nearing completion in Russia. One of the major problems is to validate the life extension (LE) of the reactor internals ensuring the core arrangement and free passage of the control and protection system components during different operating modes, emergency modes included. The internals at the 1st generation units are designed so that to enable their replacement. But it requires a lot of funds and time. The work has been done to demonstrate that the internals may be further safely operated without their components being replaced provided their strength, longevity and serviceability are sufficiently validated. (author)

  14. Analysis of Depressurization Performance in Containment of Wolsong NPP Unit 1 through Containment Filtered Venting System

    Lee, Sunghan; Kim, Jinhyuck; Suh, Nam Duk; Cho, Songwon

    2014-01-01

    Containment filtered venting system (CFVS) is designed to open and to close isolation valves passively by an operator. CFVS is operated when the containment pressure exceeds the design pressure (225 kPa(a)) and is closed when the containment pressure decreases below 151 kPa(a). The aim of this study is to analyze the depressurization performance of Wolsong unit 1 through CFVS during SBO. The thermal-hydraulic behavior in containment of Wolsong unit 1 was evaluated using the MELCOR 1.8.6 code developed at Sandia National Laboratories (SNL) for the U.S. Nuclear Regulatory Commission (NRC). In addition, in order to evaluate the effects of the CFVS according to the venting area, a sensitivity study depending on different venting area of the CFVS was conducted. Finally, an analysis of the effects of filtering and scrubbing of radioactive material for CFVS is important but not treated in this paper. The SBO accident is chosen to analyze the thermal-hydraulic behavior of Wolsong unit 1. During SBO, the analysis of CFVS affecting on the depressurization of the containment was conducted using MELCOR 1.8.6 code. Also, a sensitivity study was carried out to evaluate the depressurization performance according to the venting area of CFVS. The results show that the containment pressure is considerably decreased and the integrity of the containment could be maintained in case of CFVS operating. Therefore, CFVS has the capacity to keep the containment pressure below the design pressure during SBO. In addition, there are large differences in the containment pressure depending on venting area. We found that the decreasing rate of the pressure in the containment and water level in CFVS depends on the venting area. In the future, a proper requirement for CFVS sizing criteria according to accident scenarios such as LBLOCA, SBLOCA and SGTR, etc. should be evaluated in order to review the licensing for CFVS. Finally, analyses of aerosols, fission product, and radioactive material

  15. Estimation of the radiation risks for population in the process of the BN-600 power unit operation at the Beloyarsk NPP

    Koltik, I.I.; Oshkanov, N.N.

    2005-01-01

    Dose burdens on the population are the main criterion in estimating the radiological risks during NPP operation. Results of analysis of annual dose burdens on the population in the period of the BN-600 unit operation are presented. Data on individual and collective doses due to gas-aerosol and liquid effluents of radionuclides from the BN-600 unit on critical groups of population are presented. Data on collective doses due to other types of reactors are provided. It is shown that the risks stemming from the BN type reactors are approximately 2 orderers below the risks of channel-type and WWER-reactors [ru

  16. Construction of the jet-vortex condenser at the Kozloduy NPP units 3 and 4

    Genovski, I.; Bonev, B.; Grigorov, A.; Sabinov, S.; Petlov, M.

    2003-01-01

    The paper present the behavior of the accident localization system in case of pipeline rupture in the primary circuit of the units 3 and 4 after the implementation of the modernization program. The program includes installation of a jet-vortex condenser. The cases with double rapture of a pipeline D y 200 mm and D y 500 mm are described. In the result of the program implementation the radiation consequences are significantly limited due to the condenser playing the role of a filter during the first second of the accident as well as due to the low values of the pressure during the whole accident. Thus the modernization program fulfills its purpose to assure non-exceeding of the radiation limits in case of double rupture of a main circulation pipeline

  17. Task 24: Dynamic analysis of Kozloduy NPP unit 5 structures: Reactor building

    Zola, M.

    1999-01-01

    This report refers to the activities of a sub-contract to the Project RER/9/046, awarded to ISMES by the International Atomic Energy Agency (IAEA) of Vienna, to compare the results obtained from the experimental activities performed under previous contract by ISMES with those coming from analytical studies performed in the framework of the Coordinated Research Programme (CRP) on 'Benchmark Study for the Seismic Analysis and Testing of WWER-type Nuclear Power Plants' by other Institutions, relevant to Kozloduy Unit 5 reactor building. After a brief introduction to the problem in Chapter 1, the identification of the comparison positions and reference directions is given in Chapter 3. A very quick description of the performed experimental tests is given in Chapter 4, whereas the characteristics of both experimental and analytical data are presented in Chapter 5. The data processing procedures are reported in Chapter 6 and some simple remarks are given in Chapter 7. (author)

  18. Safety evaluation for communication network software modifications of PCS in Ulchin NPP unit 3

    Ji, S. H.; Koh, J. S.; Kim, B. R.; Oh, S. H.

    1999-01-01

    On February 2, 1999, an incident occurred at the Ulchin Nuclear Power Plant Unit 3 which resulted in the corruption of data on Perform Net of Plant Control System. This incident was caused by the ASIC (Application Specific Integrated Circuit) chip on the Rehostable Module which is a part of Network Interface Module. Regarding this incident, we required that the utility should propose new algorithms to detect the hardware failure of ASIC chip and evaluated the appropriateness of network software modifications. As a result of this evaluation process, we required that the safety related interlock signals using data communication path be hardwired to make up for the vulnerability of the system architecture. In this paper, we will discuss the system architecture of PCS and fault analysis and evaluation findings

  19. Bohunice V1 NPP upgrading programme

    Kerak, J.

    2001-01-01

    The paper describes whole process of Bohunice V1 NPP nuclear safety and operational reliability level increase which has been performed since units commissioning (1. unit in 1978, 2. unit in 1980), continued Small Reconstruction (1991 -1993) and finished Gradual Upgrading(1994 -2000). The main purpose is to last stage -Gradual upgrading of Bohunice V1 NPP. (author)

  20. Upgrading the SPP-500-1 moisture separators-steam reheaters used in the Leningrad NPP turbine units

    Legkostupova, V. V.; Sudakov, A. V.

    2015-03-01

    The specific features of existing designs of moisture separators-steam reheaters (MSRs) and experience gained with using them at nuclear power plants are considered. Main factors causing damage to and failures of MSRs are described: nonuniform distribution of wet steam flow among the separation modules, breakthrough of moisture through the separator (and sometimes also through the steam reheater), which may lead to the occurrence of additional thermal stresses and, hence, to thermal-fatigue damage to or stress corrosion cracking of metal. MSR failure results in a less efficient operation of the turbine unit as a whole and have an adverse effect on the reliability of the low-pressure cylinder's last-stage blades. By the time the design service life of the SPP-500-1 MSRs had been exhausted in power units equipped with RBMK-1000 reactors, the number of damages inflicted to both the separation part and to the pipework and heating surface tubes was so large, that a considerable drop of MSR effectiveness and turbine unit efficiency as a whole occurred. The design of the upgraded separation part used in the SPP-500-1 MSR at the Leningrad NPP is described and its effectiveness is shown, which was confirmed by tests. First, efforts taken to achieve more uniform distribution of moisture content over the perimeter and height of steam space downstream of the separation modules and to bring it to values close to the design ones were met with success. Second, no noticeable effect of the individual specific features of separation modules on the moisture content was revealed. Recommendations on elaborating advanced designs of moisture separators-steam reheaters are given: an MSR arrangement in which the separator is placed under or on the side from the steam reheater; axial admission of wet steam for ensuring its uniform distribution among the separation modules; inlet chambers with an extended preliminary separation system and devices for uniformly distributing steam flows in the

  1. Decommissioning cost recovery in the United States: lessons learned from Connecticut Yankee NPP

    Joosten, J.

    1999-01-01

    The international audience at ICONE-7 is already familiar with the roles of the owner and the NRC in ensuring the technical and safety performance goals of nuclear plant decommissioning. This paper addresses the role of the economic regulator since the pursuit of technical and safety goals must necessarily carry with them -a price tag- and owners must be concerned with the recovery of those costs. Answers to questions about how to pay and who should pay for decommissioning can very often influence nuclear power plant owner's decision-making. In the United States, most nuclear power plants are privately owned. Nevertheless, their owners are not totally free to determine the plant's economics or profitability. Instead, plant owners must sell their electricity to consumers in a regulated market wherein the price of electricity and terms of sale are controlled by the government. Under this regulatory regime, utilities are generally allowed to recover their investment costs -including decommissioning costs- provided that such costs are prudently, incurred. However, when an owner retires the plant prematurely, the prudence of his actions -up to and including the shutdown- are likely to be challenged. In 1997, for example, the owners of the Connecticut Yankee reactor faced a stiff challenge to the recovery of decommissioning costs when they shut down the plant ten years before license expiration. The Connecticut Yankee case thus provides valuable insights into the role of economic regulation on a nuclear plant's decommissioning strategy. (author)

  2. Westinghouse experience in Kozloduy NPP units 5 and 6 I and C modernization

    Sechensky, B.

    2005-01-01

    The paper presents the background, current implementation approach and experience on the largest ever modernization program on operating units WWER 1000 (PWR) at Kozloduy Nuclear Power Plant in Bulgaria. The Modernization Program itself includes more than 212 measures. Westinghouse is modernizing the major I and C systems at WWER 1000. The major topics of the modernization program and specific approach described in this paper are as follows: 1) Design Approach and Feature; 2) Installation Approach; 3) Test Strategy; 4) Licensing Strategy, applicable codes and standards. At the end author summarized that: 1) Specific design solutions were required and developed in order to address the specific plant features. At each stage, representatives of the Client are being involved in the process of designing and testing of the equipment and systems; 2) Phase-by-phase installation efforts were developed and extensive installation design documentation was prepared to fit in the limited outage window and to successfully complete the installation activities; 3) Well-prepared, multi-phase testing strategy was developed and is being implemented to assure the proper and adequate operation of the equipment at the factory and at the real plant

  3. Development of performance analysis support modules in Younggwang NPP unit 3 and 4

    Heo, G. Y.; Lee, S. J.; Jang, S. H.; Choi, S. S.; Choi, Q. H.; Gee, M. H.; Heo, I.

    2003-01-01

    This paper covers the unmeasured parameter estimation module, the performance degradation estimation module, and the performance degradation diagnosis module that are the supporting modules of the thermal performance analysis program of Younggwang nuclear power plant unit 3 and 4, PERUPS (PERformance UPgrade System), which was developed by KHNP, KEPRI, Hoseo university, and ACT. The unmeasured parameter estimation module plays a role in the generation of estimated values for the parameters that are necessary but there are no sensors. The performance degradation estimation module shows the impact for electric gain and loss according to the parameters related to turbine cycle performance. The performance degradation diagnosis module provides the belief according degradation causes considering the measurement uncertainty, analysis uncertainty, and correlation among parameters. Reference data for the development of each module was prepared by a turbine cycle simulation tool, PEPSE. The unmeasured parameter estimation module and the performance degradation estimation module make the estimation correlations by the regression analysis using the reference data. In the performance degradation diagnosis module, Bayesian network is used for the modeling of uncertainty and knowledge-base. The validation of the developed modules was performed by the test data generated by PEPSE, and accomplished by the actual data again

  4. Assessment of the Zaporizhya NPP unit 1 reactor pressure vessel safety

    Podkopaev, V.; Popov, V.; Zaritsky, N.

    1997-01-01

    This emergency situation had occurred at the ZNPP unit 1 while its being under ''hot shutdown'' in natural coolant circulation mode. The main difference between emergency situation and mode with improper setting of PPPD described in the ''Technical Safety Substantiation (TSS) is that this mode is being considered in the TSS under rated power of reactor with main circulation pumps (MCP) under operation. This difference is a substantial one. For this reason a necessity appeared to asses an integrity of referred reactor pressure vessel (RPV) under given emergency situation to judge whether results obtained meet the ND requirements (safety assessment). Under operation such RPV elements are being mostly affected as upper cooling, lower cowling, weld No. 3 weld No. 4 situated in front of core. These elements materials ageing process is the most intense one. Thus, this work was aimed at investigation of structure material behavior and RPV integrity assessment under thermal shock conditions while PPPD improper setting. At that time the most attention was drawn to above mentioned upper and lower cowlings along with welds No. 3 and 4. 5 refs, figs, 10 tabs

  5. Assessment of the Zaporizhya NPP unit 1 reactor pressure vessel safety

    Podkopaev, V; Popov, V; Zaritsky, N [State Scientific and Technical Centre on Nuclear and Radiation Safety (SSTC NRS), Kiev (Ukraine)

    1997-09-01

    This emergency situation had occurred at the ZNPP unit 1 while its being under ``hot shutdown`` in natural coolant circulation mode. The main difference between emergency situation and mode with improper setting of PPPD described in the ``Technical Safety Substantiation (TSS) is that this mode is being considered in the TSS under rated power of reactor with main circulation pumps (MCP) under operation. This difference is a substantial one. For this reason a necessity appeared to asses an integrity of referred reactor pressure vessel (RPV) under given emergency situation to judge whether results obtained meet the ND requirements (safety assessment). Under operation such RPV elements are being mostly affected as upper cooling, lower cowling, weld No. 3 weld No. 4 situated in front of core. These elements materials ageing process is the most intense one. Thus, this work was aimed at investigation of structure material behavior and RPV integrity assessment under thermal shock conditions while PPPD improper setting. At that time the most attention was drawn to above mentioned upper and lower cowlings along with welds No. 3 and 4. 5 refs, figs, 10 tabs.

  6. Examination of steam generator alloy 800 NG tube from the Almaraz unit 2 NPP

    Diego, G. de; Gomez Briceno, D.; Maffiotte, C.; Baladia, M.; Arias, C.J.

    2015-01-01

    The steam generators of Almaraz Unit 2 were replaced in 1997 by the model 61W/D3 (Siemens) with Alloy 800NG steam generator tubes. Denting indications were firstly detected in 2006 in the SG-3. Crack indications were identified in 2009. At the end of 2011, three tubes were recovered from this steam generator to carry out destructive examination in order to identify the root cause of the tubes degradation. Analysis of deposits point out the existence of multiples elements in the removed OD (Outer Diameter) deposits as well as in the deposits at the free tube under sludge and at the transition zone. Deposits are more abundant at the transition zone than at free tube. About 10% Na concentration has been detected, whereas S and Cl appear in small concentrations. Si appears regularly and Cr, Ni concentrations in the deposits are similar. Multiple intergranular cracks have been detected at 3 mm above the last contact point between the tube and the TS (tube support), in a band of around 5 mm, practically in the whole perimeter of the tube. Fracture surface of crack-B was partially covered by a Si rich layer, whereas fracture surface of crack-A seems to be cleaner. However, no significant differences in composition, except higher amount of S in crack-B, were found in the deposits of both cracks. EDX mapping and Auger profiles point out Ni enrichment with slight Cr enrichment or depletion and Fe depletion. The comparison of Auger profiles with available results for Alloy 800 tested in caustic and acid sulfate environments seems to indicate that the environment inside the cracks detected in the tube R67C48 is neutral or moderately caustic

  7. The seismic reassessment Mochovce NPP

    Baumeister, P.

    2004-01-01

    The design of Mochovce NPP was based on the Novo-Voronez type WWER-440/213 reactor - twin units. Seismic characteristic of this region is characterized by very low activity. Mochovce NPP site is located on the rock soil with volcanic layer (andesit). Seismic reassessment of Mochovce NPP was done in two steps: deterministic approach up to commissioning confirmed value Horizontal Peak Ground Acceleration HPGA=0.1 g and activities after commissioning as a consequence of the IAEA mission indicate higher hazard values. (author)

  8. Start up physics tests of units 5 and 6 (WWER 1000) at Kozloduy NPP by comparison with the calculated neutron physics characteristics

    Antov, A.; Stoyanova, I.

    2008-01-01

    In conjunction with each refuelling shutdown of the reactor core, nuclear design calculations are performed to ensure that the reactor physics characteristics of the new core will be consistent with the safety limits. Prior to return to normal operation, a physics test program is required to determine if the operating characteristics of the core are consistent with the design predictions and to ensure that the core can be operated as designed. Successful completion of the physics test program is demonstrated when the test results agree with the predicted results within predetermined test criteria. Successful completion of the physics test program and successful completion of other tests, which are performed after each refuelling provides assurance that the plant can be operated as designed. The calculated neutron-physics characteristics values of Kozloduy NPP Unit 5 and Unit 6 (WWER 1000) obtained by the computer code package KASKAD are compared with the obtained results during the start up physics tests. The core fuel loading consists of 163 fuel assemblies (FAs). The calculated values are given according to actual experimental conditions of the reactor core during start up physics tests. The report includes comparisons between calculation results by code package KASKAD (BIPR7A) and experimental data values of main neutron-physics characteristics during start up physics tests in selected recent cycles of Kozloduy NPP Unit 5 and Unit 6. (authors)

  9. Start up physics tests of Units 5 and 6 (WWER-1000) at Kozloduy NPP by comparison with the calculated neutron physics characteristics

    Stoyanova, I.; Antov, A.

    2007-01-01

    In conjunction with each refuelling shutdown of the reactor core, nuclear design calculations are performed to ensure that the reactor physics characteristics of the new core will be consistent with the safety limits. Prior to return to normal operation, a physics test program is required to determine if the operating characteristics of the core are consistent with the design predictions and to ensure that the core can be operated as designed. Successful completion of the physics test program is demonstrated when the test results agree with the predicted results within predetermined test criteria. Successful completion of the physics test program and successful completion of other tests which are performed after each refuelling provides assurance that the plant can be operated as designed. The calculated neutron-physics characteristics values of Kozloduy NPP Unit 5 and Unit 6 (WWER 1000) obtained by the computer code package KASKAD are compared with the obtained results during the start up physics tests. The core fuel loading consists of 163 fuel assemblies. The calculated values are given according to actual experimental conditions of the reactor core during start up physics tests. The report includes comparisons between calculation results by code package KASKAD (BIPR7A) and experimental data values of main neutron-physics characteristics during start up physics tests in selected recent cycles of Kozloduy NPP Unit 5 and Unit 6 (Authors)

  10. Evaluation of specific tritium transfer parameters in equilibrium conditions for Cernavoda area

    Paunescu, N.; Galeriu, D.; Mocanu, N.; Margineanu, R.

    1998-01-01

    In Romania, a CANDU nuclear power plant with five reactors of 600 MWe is under construction. The first unit reached its criticality on April 1996 and became operational at full power on December 1996. The nuclear power plant is placed in Cernavoda area, in the S-E of Romania, between the Danube River and the Danube-Black Sea Canal. The prevalent local climate is continental and agricultural activity in the neighbourhood of the nuclear power plant is of intensive type. The routine atmospheric tritium release from the 3 GWe nuclear power plant is expected to be about 460 TBq/year and the aqueous release is expected to be 350 TBq/year. The aim of this study was to evaluate the environmental tritium reference level before commissioning the nuclear power plant. Representative samples for Cernavoda area were analysed: air humidity; water from Danube River, Danube-Black Sea Canal, lakes; drinking and ground water, rain (snow) water; soil at different depths; tissue free water tritium in vegetal and animal foodstuff relevant for human diet: cereals (wheat, maize, barley), vegetables (potato, tomato, cabbage, onion, bean), fruits, grapes, wine and milk; organically bound tritium in wheat and maize grains. The equipment and methods used were: Liquid scintillation analyzer of type TRICARB 1900 TR; scintillation cocktails of Instagel and Pico Fluor LLT type; sampling system for trapping the atmospheric tritium on molecular sieves; furnace; vacuum line and freeze trap (-60 deg. C); equipment for simple, fractionating and azeotropic distillation. The background level of tritium concentration was determined in environmental samples in Cernavoda area, in preoperational stage of nuclear power plant. The mean values determined during 1994-early 1996 are : (7.4±5.5) Bq/L in air humidity, (3.1±1.0) Bq/L in water, (3.53±0.4) Bq/L in tissue water from vegetable and (4.9±1.7) Bq/L in tissue water from cereals (grains). The values of tritium concentration in air, water, soil and

  11. Requalification of the steam supply systems of Units 3 and 4 of the Kozloduy NPP to a new model WWER-440/B-209M

    Iordanov, I.; Ourutchev, V.; Stoev, M.; Sabinov, S.

    2001-01-01

    In order to achieve significant advances in operational safety level, the project characteristics, the possibility of safety systems upgrading and operational conditions of Units 1 to 4 of the Kozloduy NPP were an object of very serious and in-depth analysis in the years 1990-2000. This systematic evaluation was initiated under the broad international concern resulted from the conclusions of IAEA missions held during 1990-1991 to assess the safety of the units. As a result of the efforts of the plant staff and many international experts the operational conditions, design safety and plant management were dramatically improved which resulted in bringing the plant to a new safety level. This review also developed such that the design safety features of Units 3 and 4 are significantly different from those units of the so-called V-230 group. The principle difference and advantages of Units 3 and 4 design were clarified and confirmed. A review process of the changed status of Units 3 and 4 safety was conducted in 1999-2000 with the help of IAEA experts and the experts of RISKAUDIT and WENRA. The process led to the conclusion that the significance of advantages of the safety level need to be encapsulated within a new safety case and the corresponding set of steps was combined as a 'Project for upgrading the Nuclear Steam Supply System of Units 3 and 4 of Kozloduy NPP to model WWER-440/B-209M'. The completion of the activities under this project is expected in 2002 following the major implementation phase during 2001/2002 units' outages. (author)

  12. The primary circuit materials properties results analysis performed on archive material used in NPP V-1 and Kola NPP Units 1 and 2

    Kupca, L.; Beno, P. [Nuclear Power Plants Research Institute Inc., Trnava (Slovakia)

    1997-04-01

    A very brief summary is provided of a primary circuit piping material properties analysis. The analysis was performed for the Bohunice V-1 reactor and the Kola-1 and -2 reactors. Assessment was performed on Bohunice V-1 archive materials and primary piping material cut from the Kola units after 100,000 hours of operation. Main research program tasks included analysis of mechanical properties, corrosion stability, and microstructural properties. Analysis results are not provided.

  13. Development and verification of a leningrad NPP unit 1 living PSA model in the INL SAPHIRE code format for prompt operational safety level monitoring

    Bronislav, Vinnikov

    2007-01-01

    The first part of the paper presents results of the work, that was carried out in complete conformity with the Technical Assignment, which was developed by the Leningrad Nuclear Power Plant. The initial scientific and technical information, contained into the In-Depth Safety Assessment Reports, was given to the author of the work. This information included graphical Fault Trees of Safety Systems and Auxiliary Technical Systems, Event Trees for the necessary number of Initial Events, and also information about failure probabilities of basic components of the nuclear unit. On the basis of this information and fueling it to the Usa Idaho National Laboratory (INL) SAPHIRE code, we have developed an electronic version of the Data Base for failure probabilities of the components of technical systems. Then, we have developed both the electronic versions of the necessary Fault Trees, and an electronic versions of the necessary Event Trees. And at last, we have carried out the linkage of the Event Trees. This work has resulted in the Living PSA (LPSA - Living Probabilistic Safety Assessment) Model of the Leningrad NPP Unit 1. The LPSA-model is completely adapted to be consistent with the USA INL SAPHIRE Risk Monitor. The second part of the paper results in analysis of fire consequences in various places of Leningrad NPP Unit 1. The computations were carried out with the help of the LPSA-model, developed in SAPHIRE code format. On the basis of the computations the order of priority of implementation of fire prevention measures was established. (author)

  14. Belene NPP

    Tsvetanov, P.

    1990-01-01

    The book presents the main results of the studies of the Bulgarian Academy of Sciences (BAS) on the construction of a new nuclear power plant at Belene on the Danube river. The programme of the studies comprises five areas: the socio-economic and energy development and the necessity of the commissioning; a technical project and design level of the equipment (safety, radioactivity control, waste disposal and economic efficiency of the power plant); the seismic properties of the construction site; the corresponding risk and design features of the plant; the ecological impacts of the NPP and public opinion. The studies in the different areas have been carried out by independent teams, fully responsible for the formulated topical conclusions. The general opinion of the BAS voiced in the book is that the construction of Belene NPP is not sufficiently substantiated and is considered unacceptable. 94 refs., 53 fig., 56 tabs. (R.Ts.)

  15. Safety assessment of Olkiluoto NPP units 1 and 2. Decision of the Radiation and Nuclear Safety Authority regarding the periodic safety review of the Olkiluoto NPP

    2010-02-01

    In this safety assessment the Radiation and Nuclear Safety Authority (STUK) has evaluated the safety of the Olkiluoto Nuclear Power Plant units 1 and 2 in connection with the periodic safety review. This safety assessment provides a summary of the reviews, inspections and continuous oversight carried out by STUK. The issues addressed in the assessment and the related evaluation criteria are set forth in the nuclear energy and radiation safety legislation and the regulations issued thereunder. The provisions of the Nuclear Energy Act concerning the safe use of nuclear energy, security and emergency preparedness arrangements, and waste management are specified in more detail in the Government Decrees and Regulatory Guides issued by STUK. Based on the assessment, STUK consideres that the Olkiluoto Nuclear Power Plant units 1 and 2 meet the set safety requirements for operational nuclear power plants, the emergency preparedness arrangements are sufficient and the necessary control to prevent the proliferation of nuclear weapons has been appropriately arranged. The physical protection of the Olkiluoto nuclear power plant is not yet completely in compliance with the requirements of Government Decree 734/2008, which came into force in December 2008. Further requirements concerning this issue based also on the principle of continuous improvement were included in the decision relating to the periodic safety review. The safety of the Olkiluoto nuclear power plant was assessed in compliance with the Government Decree on the Safety of Nuclear Power Plants (733/2008), which came into force in 2008. The decree notes that existing nuclear power plants need not meet all the requirements set out for new plants. Most of the design bases pertaining to the Olkiluoto 1 and 2 nuclear power plant units were set in the 1970s. Substantial modernisations have been carried out at the Olkiluoto 1 and 2 nuclear power plant units since their commissioning to improve safety. This is in line with

  16. Main features of buildings and structures important to safety of units V1 and V2 of Bohunice NPP

    David, M.

    1993-01-01

    The program of seismic upgrading of Bohunice NPPs has been started in the year 1989 (after finishing of new seismic input). Since that time the seismic upgrading of Main building of NPP V1 has already been realized, structural as well as technological parts. Beside that the designs of seismic upgrading of other structures of NPP V1 and V2 have been completed. It has been proved that the seismic upgrading of NPPs with reactors WWER 440 is very complicated, but still possible, even in the case with high seismic intensity. It would be not possible to fulfill this complicated task without the help of IAEA Missions. The activities of IAEA experts in the program of Bohunice NPPs upgrading are appreciated very much

  17. Modeling of the fatigue damage accumulation processes in the material of NPP design units under thermomechanical unstationary effects. Estimation of spent life and forecast of residual life

    Kiriushin, A.I.; Korotkikh, Yu.G.; Gorodov, G.F.

    2002-01-01

    Full text: The estimation problems of spent life and forecast of residual life of NPP equipment design units, operated at unstationary thermal force loads are considered. These loads are, as a rule, unregular and cause rotation of main stress tensor platforms of the most loaded zones of structural elements and viscoelastic plastic deformation of material in the places of stresses concentrations. The existing engineering approaches to the damages accumulation processes calculation in the material of structural units, their advantages and disadvantages are analyzed. For the processes of fatigue damages accumulation a model is proposed, which allows to take into account the unregular pattern of deformation multiaxiality of stressed state, rotation of main platforms, non-linear summation of damages at the loading mode change. The model in based on the equations of damaged medium mechanics, including the equations of viscoplastic deformation of the material and evolutionary equations of damages accumulation. The algorithms of spent life estimation and residual life forecast of the controlled equipment and systems zones are made on the bases of the given model by the known real history of loading, which is determined by real model of NPP operation. The results of numerical experiments on the basis of given model for various processes of thermal force loads and their comparison with experimental results are presented. (author)

  18. Beyond designed functional margins in CANDU type NPP. Radioactive nuclei assessment in an LOCA type accident

    Budu Andrei Razvan

    2015-01-01

    Full Text Available European Union's energy roadmap up to year 2050 states that in order to have an efficient and sustainable economy, with minimum or decreasing greenhouse gas emissions, along with use of renewable resources, each constituent state has the option for nuclear energy production as one desirable option. Every scenario considered for tackling climate change issues, along with security of supply positions the nuclear energy as a recommended option, an option that is highly competitive with respect to others. Nuclear energy, along with other renewable power sources are considered to be the main pillars in the energy sector for greenhouse gas emission mitigation at European level. European Union considers that nuclear energy must be treated as a highly recommended option since it can contribute to security of energy supply. Romania showed excellent track-records in operating in a safe and economically sound manner of Cernavoda NPP Units 1&2. Both Units are in top 10 worldwide in terms of capacity factor. Due to Romania's need to ensure the security of electricity supply, to meet the environmental targets and to move to low carbon generation technologies, Cernavoda Units 3&4 Project appears as a must. This Project was started in 2010 and it is expected to have the Units running by 2025. Cost effective and safety operation of a Nuclear Power Plant is made taking into consideration functional limits of its equipment. As common practice, every nuclear reactor type (technology used is tested according to the worse credible accident or equipment failure that can occur. For CANDU type reactor, this is a Loss of Cooling Accident (LOCA. In a LOCA type accident in a CANDU NPP, using RELAP/SCDAP code for fuel bundle damage assessment the radioactive nuclei are to be quantified. Recently, CANDU type NPP accidents are studied using the RELAP/SCDAP code only. The code formerly developed for PWR type reactors was adapted for the CANDU geometry and can assess the

  19. Simulating the transient regime for main condensate system at Cernavoda NPP

    Nita, Iulian; Gheorghiu, Mihai; Prisecaru, Ilie; Dupleac, Daniel

    2005-01-01

    The purpose of this project is to make a Thermal Hydraulic Analysis of Main Condensate System for getting real-time answer of installation during regimes occurring during normal and abnormal operation. To obtain the analyses the MMS code was used. The boundaries of the systems analysis are extended to Main Feedwater System in order to get a realistic response of Deaerator equipment which are situated between those two systems and have entrances from both systems. In this way we made a complex analysis with main condenser and steam generators as boundaries. We obtained a model for the entire chain of condensate and feedwater preheater with interface just turbine bleed steam. From that we could reduce the number of assumptions necessary to make the analysis. The analyses consist in hydraulics and thermal hydraulics analyses, respectively. For the first case analysed are: - the nominal operation regime with main condensate pumps; - start-up regime with total circulate of condensate to condenser; - 25% MCR (Maximum Continuous Rate) regime (this regime was used in designing the condensate regulating valves at low flow; - 40% MCR regime (with circulate of some condensate flow to condenser); - operating regime of 60% MCR with one main condensate pump operating; - operating regime with auxiliary condensate pump; - operating regime with discharging a condensate flow to condensate storage tank. The thermal hydraulic analyses deal with normal and abnormal operating regimes, respectively. In the first case analysed are the following regimes: - nominal operating regime with main condensate pump operating 100% MCR; - transient regime, 100-80% MCR; - transient regime, 100-80-60% MCR with two pumps in operation and 60 % MCR with one main condensate pump in operation; - transient regime, 100-80-60-60-40 % MCR; - shut-down regime; - start-up regime from Hot zero power to rated power regime. Finally, for the abnormal operating regimes the analyses concerned: - transient regime 100-90% MCR with by-pass of LP1 (low pressure heater) and CC (Condensate Cooler); - transient regime, 100-90% MCR with by-pass of LP2 and LP3; - turbine trip; - reactor trip; - loss of two main condensate pumps. The results were compared with Heat Balance made by General Electric (turbine supplier) for several stationary regimes. (authors)

  20. The impact of the internalisation of the decommissioning costs at Cernavoda NPP

    Metes, Mircea; Goicea, Andrei

    2004-01-01

    The 'decommissioning of the nuclear power plant' means to release the site where a nuclear installation has been operated in such manner that this site could be further used, without any restriction, by the present or future generations. This is an important and complex requirement related to sustainable development. The decommissioning is a complicated and costly process; therefore it is imperative to start its preparation as early as possible, to ensure the creation of the necessary financial resources and to carefully schedule all the phases to be performed after the plant's permanently shutdown. The paper presents different possible strategies for the decommissioning, recommended by the International Atomic Energy Agency-Vienna, as well as some elements of the decommissioning experience acquired in the world. Special attention is given to the issue of the financial resources which must be provided by the nuclear power plant, during its operational life, with the corresponding impact on the cost of the electrical energy delivered by the plant. The practice of the internalization of the decommissioning costs is worldwide accepted; it is an approach specific to nuclear sector, proving once more its compatibility with the environmental protection and sustainable development. The sustainable development consists in such solutions that are able to satisfy the needs of the present generation without hampering the ability of the future generations to satisfy their own needs. In the nuclear energy sector, sustainability is provided by the following specific features: (1) Nuclear energy was and shall be in the future an important factor in security of energy supply. Due to the availability of the primary energy resources (fissile and fertile materials), nuclear electricity is and shall be accessible at affordable price on a permanent and reliable basis. (2) Nuclear energy as a part of the energy mix can diminish non-renewable energy consumption, prevent the exhaustion of fossil energy resources and minimise long-term impacts of the energy industry on climate change. (3) Nuclear industry is committed to minimising environmental impacts, including the safe management of the radioactive wastes and spent fuel up to the final disposal, ensuring the safety and complying with social welfare. In this respect, all nuclear companies are committed to leave clean sites after permanently shutdown of the nuclear plants

  1. Preventive maintenance program of motorized operated valves (MOV) at Cernavoda NPP

    Groza, M.; Moldoveanu, Edy

    2001-01-01

    This is a Power Point presentation. The following objectives are addressed: A. Determine the target of MOV program; B. Define the strategy for MOV; C. Establish the MOV program execution phases; D. Identification of key parameters; E. Examples. The target of MOV program is to improve the safety by ensuring the adequacy of safety valves and the reliability of safety equipment and, subsequently, to ensure the economic operation of the plant. Consequences of MV malfunction are indicated. The strategy for MOV program development is both general, namely, to define the minimal requirements of preventive /corrective maintenance activities for all MOV's according to design/ manufacture specification and particular, namely to identify MV's specific problems and the need for increasing/decreasing the preventing maintenance tasks or frequency established in 'general' MOV program. Strategy for MOV program development implies: - Establish MOV program applicability; - Develop diagnostic strategy (define key parameters ); - Perform program for engineering review; - Establish program for preventive maintenance; - Revise procedures for operating and maintenance tests; - Dynamic evaluation of MOV. The program execution phases are listed as follows: 1. Perform risk assessment of the MOV's to determine criticality level (program applicability); 2. Collect data to fill in MOV Application Data Sheet; 3. Perform engineering review to determine functional parameters acceptable range and determine key parameters; 4. Analysis for maintenance tasks / frequencies selection and determination of implementing actions (engineer review); 5. Prepare work packages for availability confirmation; 6. Schedule and plan corrective actions or provide input to other programs; 7. Schedule and plan implementing actions in preparation for program field execution; 8. Program field implementation; 9. Program monitoring, evaluation and optimization. The criteria defining the key operational and maintenance parameters are presented. Examples are given for minimum periodic maintenance tasks as well as for mechanical inspections and I - C measurements. Diagnostic sheets are also presented

  2. Assessing the consequences in a nuclear accident scenario at Cernavoda NPP

    Margeanu, Sorin; Angelescu, Tatiana

    2004-01-01

    Having in view a possible nuclear incident, considerable planning is necessary to reduce at manageable levels the types of decisions leading to effective responses concerning the public protection. One of the most important parts of an emergency response plan is the computerized system which allows to predict the radiological impact of the accident and to provide information in a manageable and effective form for evaluating alternative countermeasure strategies in the various stages of the accident. In this paper the PC-COSYMA results for early containment failure of a CANDU reactor are presented. The deterministic health effects arising in nuclear accident situation are also presented. As source term we have used the core inventory obtained with ORIGEN computer code. The essential input parameters for PC-COSYMA computer code are also done. (authors)

  3. Chernobyl NPP accident. Overcoming experience. Acquired lessons

    Nosovskij, A.V.; Vasil'chenko, V.N.; Klyuchnikov, A.A.; Prister, B.S.

    2006-01-01

    This book is devoted to the 20 anniversary of accident on the Chernobyl NPP unit 4. History of construction, causes of the accident and its consequences, actions for its mitigation are described. Modern situation with Chernobyl NPP decommissioning and transferring of 'Ukryttya' shelter into ecologically safe system are mentioned. The future of Chernobyl site and exclusion zone was discussed

  4. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3G. Kozloduy NPP units 5/6: Analysis and testing. Working material

    1999-01-01

    In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

  5. WIMS-IST/DRAGON-IST side-step calculation of reactivity device and structural material incremental cross sections for Wolsong NPP Unit 1

    Dahmani, M.; McArthur, R.; Kim, B.G.; Kim, S.M.; Seo, H.-B.

    2008-01-01

    This paper describes the calculation of two-group incremental cross sections for all of the reactivity devices and incore structural materials for an RFSP-IST full-core model of Wolsong NPP Unit 1, in support of the conversion of the reference plant model to two energy groups. This is of particular interest since the calculation used the new standard 'side-step' approach, which is a three-dimensional supercell method that employs the Industry Standard Toolset (IST) codes DRAGON-IST and WIMS-IST with the ENDF/B-VI nuclear data library. In this technique, the macroscopic cross sections for the fuel regions and the device material specifications are first generated using the lattice code WIMS-IST with 89 energy groups. DRAGON-IST then uses this data with a standard supercell modelling approach for the three-dimensional calculations. Incremental cross sections are calculated for the stainless-steel adjuster rods (SS-ADJ), the liquid zone control units (LZCU), the shutoff rods (SOR), the mechanical control absorbers (MCA) and various structural materials, such as guide tubes, springs, locators, brackets, adjuster cables and support bars and the moderator inlet nozzle deflectors. Isotopic compositions of the Zircaloy-2, stainless steel and Inconel X-750 alloys in these items are derived from Wolsong NPP Unit 1 history dockets. Their geometrical layouts are based on applicable design drawings. Mid-burnup fuel with no moderator poison was assumed. The incremental cross sections and key aspects of the modelling are summarized in this paper. (author)

  6. Regulatory aspects of NPP safety

    Kastchiev, G.

    1999-01-01

    Extensive review of the NPP Safety is presented including tasks of Ministry of Health, Ministry of Internal Affairs, Ministry of Environment and Waters, Ministry of Defense in the field of national system for monitoring the nuclear power. In the frame of national nuclear safety legislation Bulgaria is in the process of approximation of the national legislation to that of EC. Detailed analysis of the status of regulatory body, its functions, organisation structure, responsibilities and future tasks is included. Basis for establishing the system of regulatory inspections and safety enforcement as well as intensification of inspections is described. Assessment of safety modifications is concerned with complex program for reconstruction of Units 1-4 of Kozloduy NPP, as well as for modernisation of Units 5 and 6. Qualification and licensing of the NPP personnel, Year 2000 problem, priorities and the need of international assistance are mentioned

  7. Comparison of the APA-H (Westinghouse) calculations with the operational data for ZpNPP unit 3 cycles 16-19

    Abdullayev, A. M.; Gorbachenko, O. V.; Ignatchenko, A.I.; Maryokhin, S.V.; Zhukov, A. I.

    2007-01-01

    The computer simulation of ZpNPP Unit 3 (WWER-1000) Cycles 16-19 core depletion has been performed on the basis of the operational data. The changes in reactor heat rate, lead bank position and inlet temperature during the core operation have been taken into account. These calculations were performed by using Westinghouse APA-H (ALPHA/PHOENIX/ ANC-H) code system. The main objectives of the calculations were the comparison with operational data for core loading with TVS-M (Cycle 16) and transition core loading with TVS-A (Cycle 17-19). The calculation results were compared with the results of Critical boric acid concentration vs. Cycle Burnup measurements and Start up Physics Test measurements (at HZP, BOC, NoXe core conditions). Additionally, the comparison between the results of assemblies power calculation performed by ANC-H and BIPR-7A codes is presented (Authors)

  8. Improvement of the reliability of the emergency diesel generators and their protections as a part of the modernization program for units 5 and 6 of the Kozloduy NPP

    Bogdanov, D.

    2003-01-01

    The measure 'Improvement of the reliability of the emergency diesel generators and their protections' 28411 is part of the modernization program for Units 5 and 6 of Kozloduy NPP. The scope of the measure includes complete change of the I and C system, the local control panels, the technological and electrical protections of the DG set, the excitation system and some of the power distribution switchboards. The new I and C system will be Teleperm XS type, produced by Framatome ANP, the power distribution switchboards type Sivacon, the excitation system Thyripart, and the electrical protection and synchronization system will be provided by Siemens. The purpose of the measure is to increase the availability, maintainability and to improve the reliability of the DG sets

  9. On the results of nuclear fuel temperature dynamics restoration at the Chornobyl NPP unit 4 during active phase of the accident

    O. V. Mikhailov

    2016-02-01

    Full Text Available Fuel temperature dynamics was reconstructed for active phase of the accident at the Chernobyl NPP Unit 4. Method of effective temperature calculation for uranium oxide is based on implementation of the CORSOR type mathematical codes and the model of lava-like fuel containing materials (LFCM formation from fragments of the former core (FFC in the room 305/2. Calculations were carried out according to release rate of 131I and 137Cs radionuclides during the period from April 26 until May 6, 1986. The rate of temperature drop during the FCM stage cooling bath silicate melt was estimated. It is shown that the main streams of LFCM could be formed at more moderate values of temperatures than it was performed previously. The results of the work are used to verify the “blast furnace” version of LFCM formation and formation of FCM with high uranium concentration.

  10. Determining permissible PT parameters in normal operating conditions for reactor pressure vessel of units 1-4 of NPP Kozloduy

    Batischev, M.; Yurukov, V.; Simovski, Ts.

    2000-01-01

    The main objective of the analysis is to verify the determined from the Main Designer P-T curves and to provide that permissible T values can be decreased even in case a lot of very conservative assumptions are taken into account. Detailed temperature and stress distributions are obtained using different 3D Finite Element Models. Then, assuming linear elastic behaviour and using these distributions onto models including cracks K I values are determined. From the K I values taking into account material characteristics and actual and prognostic neutron fluence of the most sensitive areas of the RPV, P-T curves are determined. Residual stresses in welds are also taken into account. Analysis has been performed independently following two different methodologies - one prescribed by Russian norms (PNAEh-G-7-002-86) and another, developed by the IAEA - 'Guidelines on PTS analysis for WWER NPP'. The obtained results using two methodologies are compared and the more severe are determined

  11. Strain measurement and analysis for the RPV of Qinshan NPP (unit I) at primary system hydrostatic test

    Qu Jiadi; Wang Peizhu; Xie Shiqiu; Chen Renchang; Sheng Xianke; Dou Yikang; Zhao Weiliang

    1994-01-01

    Hydrostatic test for RPV (Reactor Pressure Vessel) is not only a means to inspect the vessels and the associated systems but also an important way to verify the results of mechanical analysis. The loading obtained by measurement is useful for the establishment of loading spectrum. Some discussions on the shop hydrostatic test planning for the RPV of Qinshan NPP (Nuclear Power Plant) performed in Japan are presented. Comparisons between the results of hydrostatic test provided by vendor and those of primary system hydrostatic test conducted at Qinshan Site are also given. Some data obtained at Qinshan Site such as actual loading and technical data of the stud-bolt, are listed. The results of measurement for the flange rotation, important for the sealing characteristics of RPV, are specifically discussed. The authors point out some of the mistakes in the results of the shop hydrostatic test

  12. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3H. Kozloduy NPP units 5/6: Analysis and testing. Working material

    1999-01-01

    In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

  13. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3F. Kozloduy NPP units 5/6: Analysis and testing. Working material

    1999-01-01

    In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

  14. Assessment of the Internal Pressure Fragility of the Hanul NPP Units 3 and 4 Containment Building Using a Nonlinear Finite Element Analysis

    Park, Hyung Kui; Hahm, Dea Gi; Choi, In Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The sensitivity of the concrete strength is relatively higher compared to that of the steel strength. According to changes in the structure of the material, about 6-10% ultimate internal pressure differences occurred. Thirty sets of an FE model considering the material uncertainty of concrete and steel were composed for the internal pressure fragility assessment. From the internal pressure fragility assessment of the target containment building, the median capacity of liner leakage is estimated to be 116 psi. As can be seen from the Fukushima nuclear power plant accident, the containment building is the final protecting shield to prevent radiation leakage. Thus, a structural soundness evaluation for the containment pressure loads owing to a severe accident is very important. Recently, a probabilistic safety assessment has been commonly used to take into account the possible factors of uncertainty in a structural system. An assessment of the internal pressure fragility of the CANDU type containment buildings considering the correlation of structural material variables, and an assessment of the internal pressure fragility of the CANDU type containment buildings using a nonlinear finite element analysis, were also performed. However, for PWR type containment buildings, a fragility assessment has not been performed yet using a nonlinear finite element model (FEM) analysis. In this study, for the Hanul NPP units 3 and 4 containment building, the internal pressure fragility assessment was established using an FEM analysis. To do this, a three-dimensional finite element model, material property values, and a sensitive analysis were developed. A nonlinear finite element analysis of the Hanul NPP units 3 and 4 containment building was performed for a material sensitivity analysis and internal pressure fragility assessment.

  15. Assessment of the Internal Pressure Fragility of the Hanul NPP Units 3 and 4 Containment Building Using a Nonlinear Finite Element Analysis

    Park, Hyung Kui; Hahm, Dea Gi; Choi, In Kil

    2013-01-01

    The sensitivity of the concrete strength is relatively higher compared to that of the steel strength. According to changes in the structure of the material, about 6-10% ultimate internal pressure differences occurred. Thirty sets of an FE model considering the material uncertainty of concrete and steel were composed for the internal pressure fragility assessment. From the internal pressure fragility assessment of the target containment building, the median capacity of liner leakage is estimated to be 116 psi. As can be seen from the Fukushima nuclear power plant accident, the containment building is the final protecting shield to prevent radiation leakage. Thus, a structural soundness evaluation for the containment pressure loads owing to a severe accident is very important. Recently, a probabilistic safety assessment has been commonly used to take into account the possible factors of uncertainty in a structural system. An assessment of the internal pressure fragility of the CANDU type containment buildings considering the correlation of structural material variables, and an assessment of the internal pressure fragility of the CANDU type containment buildings using a nonlinear finite element analysis, were also performed. However, for PWR type containment buildings, a fragility assessment has not been performed yet using a nonlinear finite element model (FEM) analysis. In this study, for the Hanul NPP units 3 and 4 containment building, the internal pressure fragility assessment was established using an FEM analysis. To do this, a three-dimensional finite element model, material property values, and a sensitive analysis were developed. A nonlinear finite element analysis of the Hanul NPP units 3 and 4 containment building was performed for a material sensitivity analysis and internal pressure fragility assessment

  16. Principles of tariff determination for NPP electric power generation

    Ratnikov, B.E.; Gitel'man, L.D.; Artemov, Yu.N.; Fiantsev, V.S.

    1988-01-01

    Foundations of price-setting and order of accounting arrangement for NPP electric power are considered. NPP tariffs are established proceeding from standard costs of power generation. The standards are differentiated as to NPP groups, depending on technical, regional and natural geographic factors, taking into account the facility type, unit capacity and the number of similar NPP units. The conclusion is made that under conditions of NPP economic independence expansion and creation of prerequisites for going over to self-financing principles and also due to the qualitatively new stage of nuclear power generation development the level of efficiency, forseen by the tariffs, should be increased

  17. Dukovany NPP operation

    Vlcek, Jaroslav

    2010-01-01

    The topics discussed include: Dukovany NPP among CEZ Group power plants; International missions at the plant; Plant operation results; and Strategic goals and challenges. Historical data are presented in the graphical form, such as the unit capacity factor, unplanned capability loss factor, unplanned automatic scrams, fuel reliability, industrial safety accident rate, collective radiation exposure, WANO index, power generation data, and maximum achievable power by the end of year. Also discussed were the company culture and human resources, maintenance, power uprate, and related phenomena. (P.A.)

  18. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3I. Kozloduy NPP units 5/6: Analysis and testing. Working material

    1999-01-01

    In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

  19. NPP construction cost in Canada

    Gorshkov, A.L.

    1988-01-01

    The structure of capital costs during NPP construction in Canada is considered. Capital costs comprise direct costs (cost of the ground and ground rights, infrastructure, reactor equipment, turbogenerators, electrotechnical equipment, auxiliary equipment), indirect costs (construction equipment and services, engineering works and management services, insurance payments, freight, training, operating expenditures), capital per cents for the period of construction and cost of heavy water storages. It proceeds from the analysis of the construction cost structure for a NPP with the CANDU reactor of unit power of 515, 740 and 880 MW, that direct costs make up on the average 62%

  20. Decommissioning of NPP A-1

    Anon

    2009-01-01

    In this presentation the Operation history of A1 NPP, Project 'Decommissioning of A1 NPP' - I stage, Project 'Decommissioning of A1 NPP ' - II stage and Next stages of Project 'Decommissioning of A1 NPP ' are discussed.

  1. Lessons learnt from the resin release into the primary circuit of the Fessenheim NPP unit 1 in January 2004. Impact on the nuclear safety

    Georgescu, M.

    2004-01-01

    On January the 24 th , at the Fessenheim NPP unit 1, a human error was committed during a boron demineralizer line-up, caused by lack of preparation. Consequently, a quantity of resin estimated at about 300 liters was released from this demineralizer, through its safety valve, into the head-tank of the chemical and volume control (CVC) system and after that, into the primary circuit. The incident had a real impact on the unit: the CVC filters were clogged, the seal injection flow of the primary circuit main pumps was lost, the primary circuit main pump 2 tripped four days after the incident, as the rate of the recirculated seal leak flow (downstream the seal 1) increased up to the automatic trip set point, the shaft of the running primary circuit feed pump was found seized into the rear hydrostatic bearing following the pump stop (after ten days of successful operation), the thimble plugs were jammed into their guide tubes, the small diameter pipes were plugged. The unit shutdown for over five months was necessary to clean the primary circuit components, repair or replace the affected equipment items and carry out inspections and tests. The reinforced unit in-service monitoring program, set up during the unit start-up, confirms that, up to now, the unit operation has not been adversely affected by the residual amounts of resin which subsist in certain areas of the primary circuit. Nevertheless, it remains to verify that, in the long term, these deposits will have no negative chemical effect in the potential confined areas, such as the thermal barriers of the primary circuit main pumps. Finally, the occurrence of this incident underlines, once more, the importance of normal operating activity preparing and checking. It also reveals the implementation of an ''unforgiving'' design change allowing the installation of a boron demineralizer safety valve having its outlet connected to the primary circuit. (orig.)

  2. Brief review of 1995 events at Ukraine's NPPs. Report on the ChNPP unit 1 of November 27.1995 ''strict regime area premises contamination after reactor refuelling''

    Lomakin, V.

    1996-01-01

    In 1995 number of events at NPP had considerably decreased as compared with that for previous 1992-94, amounted in 87. In particular, as compared with 1994, events number had decreased by 36%. It characterizes a total improvement of current NPPs safety level during 1995. The most events number as recalculated per single unit was at the South Ukraine NPP - 8. The least - at the ChNPP - 4 in total, and 1,3 per unit. Decreasing of a total events number for 1995 did also accordingly reduce other quantitative system indices which reflect state of NPPs safety level. Among event root causes, as it was before, ''administrative management deficiencies'' and ''staff training deficiencies'' are still dominanting. ''Human factor'' issues are still pending for NPPs safety, despite of considerable efforts applied to improved efficiency of correcting measures aimed at their solution. Of sufficient importance for events system development in 1995 was the work implemented at the SSTC NRS/NRA as regards preparation of modern edition of the ''Regulation on order of NPP events investigation and account''. The IAEA/Nuclear Safety Division rendered a sufficient assistance for this work to be done through arrangement of advisory help to Ukrainian specialists from international experts. 2 figs, 8 diagrams

  3. Mochovce NPP simulator

    Ziakova, M.

    1998-01-01

    Mochovce NPP simulator basic features and detailed description of its characteristics are presented with its performance, certification and application for training of NPP operators as well as the training scenario

  4. Post-reconstruction full power and shut down level 2 PSA study for Unit 1 of Bohunice V1 NPP

    Kovacs, Z.

    2003-01-01

    The level 2 PSA model of the J. Bohunice V1 NPP was developed in the RISK SPECTRUM Professional code with the following objectives: to identify the ways in which radioactive releases from the plant can occur following the core damage; to calculate the magnitudes and frequency of the release; to provide insights into the plant behaviour during a severe accident; to provide a framework for understanding containment failure modes; the impact of the phenomena that could occur during and following core damage and have the potential to challenge the integrity of the confinement; to support the severe accident management and development of SAMGs. The magnitudes of release categories are calculated using: the MAAP4/VVER for reactor operation and shutdown mode with closed reactor vessel and the MELCOR code for shutdown mode with open reactor vessel. In this paper an overview of the Level 2 PSA methodology; description of the confinement; the interface between the level 1 and 2 PSA and accident progression analyses are presented. An evaluation of the confinement failure modes and construction of the confinement event trees as well as definition of release categories, source term analysis and sensitivity analyses are also discussed. The presented results indicate that: 1)for the full power operation - there is an 25% probability that the confinement will successfully maintain its integrity and prevent an uncontrolled fission product release; the most likely mode of release from the confinement is a confinement bypass after SGTM with conditional probability of 30%; the conditional probability for the confinement isolation failure probability without spray is 5%, for early confinement failure at the vessel failure is 4%, for other categories 1% or less; 2) for the shutdown operating modes - the shutdown risk is high for the open reactor vessel and open confinement; important severe accident sequences exists for release categories: RC5.1, RC5.2 and RC6.2

  5. The V-1 NPP and V-2 NPP upgrading

    1998-01-01

    A brief account of activities in the V-1 NPP and V-2 NPP upgrading as well as maintenance carried out by the Nuclear power plants Jaslovske Bohunice in 1997 is presented. The V-1 NPP applied the so called 'Small Backfitting Programme'covering 81 points of the Czechoslovak Atomic energy Commission Decree No 5/91. Continual upgrading continued after the Backfitting Programme completion with the Safety Report and following Nuclear Regulatory Authority of Slovak Republic (NRA SR) Decrees No 1/94 and 110/94 setting spheres and procedure for adopting and implementation of measures enabling the units to operate further on. Results of expert missions, analyses and assessments of components identified by Basic Engineering became the basis for the development of the Gradual Reconstruction Programme. The Programme outputs underwent economic and probabilistic assessing their contribution to nuclear safety. This process resulted in finalizing the Gradual Reconstruction Programme which started to be implemented in 1996 and will be completed in 1999. It is implemented by the REKON consortium and covers 17 areas including Instrumentation and Control, self-consumption emergency supply, leakage monitoring, emergency core cooling system, seismic reinforcement and radioactivity localisation. Both units will reach internationally acceptable safety standards for the remaining life-time period. The V-2 NPP Upgrading and Safety Enhancement Programme includes results of activities performed in the course of last years to define all important activities leading to enhancement of nuclear safety and performance reliability and effectiveness within the plant life-time period and to establish conditions for extending the life-time of these units for 40 years. The V-2 NPP Upgrading and Safety Enhancement Programme aims to assure safe operation with a probability of the core damages less than 10 -4 /reactor · year

  6. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3E. Kozloduy NPP units 5/6: Analysis/testing. Working material

    1996-01-01

    The Co-ordinated research programme on the benchmark study for the seismic analysis and testing of WWER-type nuclear power plants was initiated subsequent to the request from representatives of Member States. The conclusions adopted at the Technical Committee Meeting on Seismic Issues related to existing nuclear power plants held in Tokyo in 1991 called for the harmonization of methods and criteria used in Member States in issues related to seismic safety. The Consulltants' Meeting which followed resulted in producing a working document for CRP. It was decided that a benchmark study is the most effective way to achieve the principal objective. Two types of WWER reactors (WWER-440/213 and WWER-1000) were selected as prototypes for the benchmark exercise to be tested on a full scale using explosions and/or vibration generators. The two prototypes are Kozloduy Units 5/6 for WWER-1000 and Paks for WWER-440/213 nuclear power plants. This volume of Working material contains reports on data related to floor response spectra of Kozloduy NPP; calculational-experimental examination and ensuring of equipment and pipelines seismic resistance at starting and operating WWER-type NPPs; analysis of design floor response spectra and testing of the electrical systems; experimental investigations and seismic analysis Kozloduy NPP; testing of components on the shaking table facilities and contribution to full scale dynamic testing of Kozloduy NPP; seismic evaluation of the main steam line, piping systems, containment pre-stressing and steel ventilation chimney of Kozloduy NPP

  7. Radioactive contamination of the Belarus' territory causing to destruction of the building constructions of the 4th unit of the Chernobyl NPP

    Beskorovajnyj, V.P.; Kotovich, V.V.; Molodykh, V.G.; Skurat, V.V.; Stankevich, L.A.; Sharovarov, G.A.

    1995-01-01

    The adverse scripts of development of events, causing to destruction of object 'UKRYTIE' and to contamination of the territory of Republic of Belarus are considered. The number of designs of the 4th unit has visually observed damages. Also there are hypothetically unstable constructive elements, at installation of which in a conditions of 1986 the application of reliable welded or bolt connections was impossibly. Initial events of the considered hypothetical accident are earthquake or aircraft accident. Settlement data on contamination of territory for considered accident are indicated. The account was made for a moderate- stable condition of atmosphere by the Gauss model for process of the dust particles precipitation. In this case the radionuclide falling out will take place basically on already contaminated territory of Belarus. The additional contamination may be about 2 Ci/sq.km in the Mozyr' region and 20 Ci/sq.km in Chernobyl NPP territory. In case of imposing of acts of nature (the earthquake or tornado), the all dust fraction, which available in object, may be released in atmosphere. The total activity of the dust falling out will be about 1.3 MCi, that can lead to more powerful contaminated of the south part of Belarus. Despite the hypothetical character of the scripts, the probability of their realisation at long operation of object will increase. Thus, the transformation of object 'UKRYTIE' to a safe system is an urgent problem. 1 ref., 3 figs

  8. Leningrad NPP and energetics of north-western Russia

    Belov, I.

    2000-01-01

    Problems of Leningrad NPP operating units modernization, their design service life finishing by year of 2010, are discussed. To assure safe operation of unit 1 investments in the amount of 30 mln. dol are necessary. Estimations suggest economic efficiency of the measures, permitting saving of 300 mln. dol worth of gas. Unfortunately, without a rise in tariff for electric power produced by NPP it seems impossible. It is recommended that substantiated tariffs are set for electric power produced by NPP starting from January, 2000. The measure is indispensable for raising investment funds intended for operating NPP modernization [ru

  9. The Initial Test Programme Features for the Advanced Korean NPPs (Shin–Kori NPP Units 3&4)

    Sul, Y.S.

    2015-01-01

    Korea has developed the Advanced Power Reactor 1400 (APR1400), an evolutionary pressurised water reactor and has obtained the standard design approval in 2002. As of 2014, eight nuclear power plants (NPPs) are in preparation for operation or under construction, four in Korea (SKN 3&4, SUN 1&2) and four in UAE (BNPP 1, 2, 3&4), and four NPPs are in planning in Korea (SKN 5&6, SUN 3&4). Especially, SKN Units 3&4 are the first construction NPPs for the APR1400 and are currently in the final stage to get Operating Licence (OL). The initial test programme for NPPs begins as systems and components are turned over to the startup organization and ends with completion of the Power Ascension Tests (PATs). For SKN Unit 3, the Pre-core Hot Functional Testing has been successfully completed and the initial fuel loading would proceed after getting OL. The SKN Unit 4 is preparing for the CHT (Cold Hydrostatic Test). The SKN 3&4 has many new and advanced design features and so has developed the test programmes to demonstrate that those advanced design features can be safely operated and the performance levels can be maintained in accordance with approved safety requirements. Among those test programs, the examples of test programs, newly introduced ones compared to the previous NPPs are as follows; – SIT (Safety Injection Tank) Blowdown Test with FD (Fluidic Device) – IRWST (In-Containment Refueling Water Storage Tank) In-Plant Test – POSRV (Pilot Operated Safety Relief Valve) Test – Low Power Physics Testing and PAT considering FOAK (First Of A Kind) unit – Safe Shutdown Test with DCS (Distrubuted Control System) Fail and CMF (Common Mode Failure) for Safety Instrumentation and Control System. (author)

  10. Decommissioning of Brennilis NPP

    Baize, Jean-Marc

    1998-01-01

    This EDF press communique give information related to the decommissioning of the Brennilis NPP. The following five items are developed in this report: 1. the level-2 decommissioning operations at the Brennilis NPP; 2. the Brennilis NPP, a pilot operation from the commissioning up to the decommissioning; 3. history of the Brennilis NPP decommissioning; 4. the types of radioactive wastes generated by the Brennilis NPP decommissioning; 5. the Brennilis NPP - a yard management as a function of the wastes. The document contains also seven appendices addressing the following subjects: 1. the share of decommissioning assigned to EDF and the decommissioning steps; 2. the EDF installations in course of decommissioning; 3. the CEA decommissioned installations or in course of decommissioning; 4. regulations; 5. costs; 6. waste management - principles; 7. data on the decommissioning yard

  11. The supply model of the IandC system modernization at VVER 1000 units of the NPP Temelin

    Tomicek, L.

    1997-01-01

    The history of the instrumentation and control system of the Temelin nuclear power plant is briefly mentioned. An upgrading of this system was initiated, aimed at enhancement of nuclear safety and at increasing the economical effectiveness of electricity production. The final supplier of the new system is SKODA PRAHA, the Westinghouse Electric Co. being the sub-supplier. By modernization of the IandC system, conditions have been created for an up-to-date WWER-1000 type unit which copes with the current requirements on nuclear safety and operating economy. (A.K.)

  12. NPP life management (abstracts)

    Litvinskij, L.L.; Barbashev, S.V.

    2002-01-01

    Abstracts of the papers presented at the International conference of the Ukrainian Nuclear Society 'NPP Life Management'. The following problems are considered: modernization of the NPP; NPP life management; waste and spent nuclear fuel management; decommissioning issues; control systems (including radiation and ecological control systems); information and control systems; legal and regulatory framework. State nuclear regulatory control; PR in nuclear power; training of personnel; economics of nuclear power engineering

  13. Software development for simplified performance tests and weekly performance check in Younggwang NPP Unit 3 and 4

    Hur, K. Y.; Jang, S. H.; Lee, J. W.; Kim, J. T.; Park, J. C.

    2002-01-01

    This paper covers the current status of turbine cycle performance test in nuclear power plants and the software development which can solve some shortcomings related to performance tests. The software developed is for simplified performance tests and weekly performance checks in Yonggwang nuclear power plant unit 3 and 4. This software includes the requirements from the efficiency division for the consistency with actual performance analysis work and the usability of the collected performance test data. From the working survey, we identify the difference between the embedded performance analysis modules and the actual performance analysis work. This software helps operation or maintenance personnel to reduce work load, to support the trend analysis of essential parameters in a turbine cycle, and to utilize the correction curves for the decision-making in their work

  14. Current status of Chernobyl NPP decommissioning

    2009-01-01

    Strategy of Chernobyl NPP decommissioning with the decommissioning license 2002-2064 is presented. The main activities at the stage of ChNPP units shutdown (2002 - 2012) are: units maintenance in safe state; decommissioning infrastructure construction; unloading of SNF – main activity determining the stage duration; systems and elements final shutdown; decommissioning life-support systems reconstruction; Comprehensive engineering and radiation survey (CERS); dismantling of the reactor facilities external equipment; removal of RAW from units; decommissioning documentation development. The decommissioning activities main results are presented

  15. Safety analysis on Non-LOCA events for the revision of Wolsong NPP unit 2,3,4 sar

    Kim, Jong Hyun; Jin, Dong Sik; Ryu, Eui Seung; Kho, Dong Wook; Kim, Sung Min

    2015-01-01

    Korean Wolsong Nuclear Power Plant Units 2,3,4 (CANDU-6 Type) has prepared the revision of safety analysis report (Final Safety Analysis Report (FSAR) chapter 15) from the original performed in the year of 1990s, using the updated and state-of-the-art methodology and tools including IST safety analysis codes and more detail modelling. Compared with the original FSAR15, the revised FSAR15 has significant improvement in both the scope and the depth of safety analysis, which has demonstrated the safety analysis results have complied with the safety requirements(acceptance criteria). This paper will present the analysis scope for Non-LOCA events re-analyzed or added for the FSAR15 revision, methodologies applied such as codes and modelling and some important analysis results will be demonstrated with comparison to acceptance criteria. Application of more detail and near-realistic assumptions and method including Dev-PDO options and uncertainty related to the CHF correlations has altogether brought about more safety margin compared with the original FSAR15 with respect to SDS trip effectiveness etc. (author)

  16. Human reliability analysis approach to level 1 PSA - shutdown and low power operation of Mochovce NPP, Unit 1, Slovakia

    Stojka, Tibor; Holy, Jaroslav

    2003-01-01

    The paper presents general approach, used methods and form of documentation of the results as have been applied within the Human Reliability Analysis (HRA) task of the shutdown and low power PSA (SPSA) study for Mochovce nuclear power plant, Unit 1, Slovakia. The paper describes main goals of the HRA task within the SPSA project, applied methods and data sources. Basic steps of the HRA task and human errors (HE) classification are also specified in its first part. The main part of the paper deals with pre-initiator human errors, human-induced initiators and response to initiator human errors. Since the expert judgment method (SLIM) was used for the last type of human errors probability assessment, also related activities are described including preparation works (performance shaping factors (PSFs) selection, development of PSF classification tables, preparation of aid tools for interview with plant experts), qualitative analysis (sources of information and basic steps) and quantitative analysis itself (human errors classification for final quantification including criteria used for the classification, description of structure of the spreadsheet used for quantification and treatment with dependencies). The last part of the paper describes form of documentation of the final results and provides some findings. (author)

  17. Item 01: Peculiarities during installation of forced filtered venting system, units 3 and 4 of Kozloduy NPP

    Dinev, D.

    2005-01-01

    The Forced Filtered Venting System (FFV) is designated to minimize the uncontrolled and unfiltered release of activity to the environment due to untightness of the confinement in case of a severe accident. In this paper the flow diagram of FFV, Units 3 and 4 is shown and the main components of the system which are installed in RB, in Rooms A 031/2, A032/3, A031/4, at elevation 2.10 m are described. Calculation models of the pipelines of FFV were developed based on the requirements to the design and the input data, which were collected and analyzed. The graphic part of the model is presented at calculation schemes. The pipelines are checked according to the requirements of the ASME Code and the equations for calculation of the connected pipelines are stipulated in ASME NC-3650. The enclosed photos illustrate the most relevant positions of the modifications. In conclusion the positive aspects of the mounting experience for this unique installation are analyzed and the weak points are stated aiming at the improvement of the quality of preparation, organization and complete performance for similar facilities

  18. Changing NPP consumption patterns in the Holocene: from Megafauna "liberated" NPP to "ecological bankruptcy"

    Doughty, C.

    2015-12-01

    There have been vast changes in how net primary production (NPP) is consumed by humans and animals during the Holocene beginning with a potential increase in availability following the Pleistocene megafauna extinctions. This was followed by the development of agriculture which began to gradually restrict availability of NPP for wild animals. Finally, humans entered the industrial era using non-plant based energies to power societies. Here I ask the following questions about these three energy transitions: 1. How much NPP energy may have become available following the megafauna extinctions? 2. When did humans, through agriculture and domestic animals, consume more NPP than wild mammals in each country? 3. When did humans and wild mammals use more energy than was available in total NPP in each country? To answer this last question I calculate NPP consumed by wild animals, crops, livestock, and energy use (all converted to units of MJ) and compare this with the total potential NPP (also in MJ) for each country. We develop the term "ecological bankruptcy" to refer to the level of consumption where not all energy needs can be met by the country's NPP. Currently, 82 countries and a net population of 5.4 billion are in the state of ecologically bankruptcy, crossing this threshold at various times over the past 40 years. By contrast, only 52 countries with a net population of 1.2 billion remain ecologically solvent. Overall, the Holocene has seen remarkable changes in consumption patterns of NPP, passing through three distinct phases. Humans began in a world where there was 1.6-4.1% unclaimed NPP to consume. From 1700-1850, humans began to consume more than wild animals (globally averaged). At present, >82% of people live in countries where not even all available plant matter could satisfy our energy demands.

  19. Pilot Operation of Ex-core Neutron Sensors of Divers Shutdown System (DSS) Unit 2 Ignalina NPP

    Jakshtonis, Z.; Krivoshei, G.

    2006-01-01

    The Ignalina Safety Assessment, which was completed in December 1996, recommended the installation of a diverse shutdown system on the 2nd unit at Ignalina. During the PPR-2004 in the DSS project are created two independent shutdown systems by separating the absorber rods into two independent groups as follows: 1. One system (designated AZ) consists of the existing 24 BAZ rods and 49 AZ/BSM rods that together are used for reliable reactor shutdown (including Control and Protection System (CPS) circuit voiding accident). This system performs the emergency protection function. 2. The other system (designated BSM) comprises the remaining absorber rods and the 49 AZ/BSM rods. Thus 49 AZ/BSM rods are actuated from AZ initiating equipment as well as from BSM initiating equipment. The BSM system performs the normal reactor shutdown function and is able to ensure long-term maintenance of the reactor in the sub-critical state. Along with implementation of DSS was modernized existing Emergency Process Protection System, which was divided into two independent Sets of initiating equipment. The DSS is independent and diverse initiating equipment from the existing 1st Set equipment; with each set having its own independent in-core and ex-core sensors for measurement of neutron flux and process parameters. The 2nd Set of initiating equipment for measuring ex-core neutron flux, was modernized with new design of 4 Ex-Core detectors each have a single low level neutron flux detector and two high range neutron detectors. They are comprising: 1. A fission chamber which operates in pulse mode to cover the low flux levels. 2. A compensated ionisation chamber in current mode to operate at high flux level. This detector is doubled to give a measurement of the axial deviation. Two detectors are enough to produce the axial power deviation. The results of testing and analysis of pilot operation of ex-core neutron sensors of DSS will be shown on the Report. (author)

  20. Retrofitting of NPP Computer systems

    Pettersen, G.

    1994-01-01

    Retrofitting of nuclear power plant control rooms is a continuing process for most utilities. This involves introducing and/or extending computer-based solutions for surveillance and control as well as improving the human-computer interface. The paper describes typical requirements when retrofitting NPP process computer systems, and focuses on the activities of Institute for energieteknikk, OECD Halden Reactor project with respect to such retrofitting, using examples from actual delivery projects. In particular, a project carried out for Forsmarksverket in Sweden comprising upgrade of the operator system in the control rooms of units 1 and 2 is described. As many of the problems of retrofitting NPP process computer systems are similar to such work in other kinds of process industries, an example from a non-nuclear application area is also given

  1. Conference: Nuclear Safety at the Ignalina NPP - Achievements and Challenges

    1999-01-01

    Brief description of conference which took place in Vilnius on 8-9 April 1999 is presented. The aim of the international conference is to review the work carried out, to evaluate its influence on the nuclear safety, to get acquainted with the safety system of the Ignalina NPP. On December 31, the Ignalina NPP celebrated its 15 year anniversary. During that period the Ignalina NPP has produced more than 182 billion kWh of electricity. Nuclear power is not only immense economic benefit but also a syndrome of fear of an atomic bomb and the Chernobyl accident that has formed over the years. Numerous comprehensive international studies have been performed at the Ignalina NPP. After the Chernobyl accident many steps have been taken to improve the safety of the Ignalina NPP. The introduced changes guaranteed that the void coefficient remained negative in all possible circumstances. The Ignalina NPP is intensively preparing for licensing of unit 1

  2. Fuel leak testing performance at NPP Jaslovske Bohunice

    Slugen, V.; Krnac, S.; Smiesko, I.

    1995-01-01

    The NPP Bohunice VVER-440 fuel leak testing experience are relatively extensive in comparison with other VVER-440 users. As the first Europe NPP was adapted Siemens (KWU) in core-sipping equipment to VVER-440 units and since this time were have done these tests also for NPP Paks (Hungary) and NPP Dukovany (Czech Republic). The occurrence of leaking fuel assemblies in NPP is in the last 5 years relatively stabilised and low. A significant difference can be observed between type V-230 (31 leaks) and type V-213 (1 leak). None of of the indicated leaking fuel assemblies has been investigated in the hot cell. Therefore cannot be confirm the effective causes of leak occurrence. Nevertheless, the fuel failure rate and the performance of leak testing in NPP Bohunice are comparable to the world standard at PWR's. 1 tab., 2 figs., 3 refs

  3. Fuel leak testing performance at NPP Jaslovske Bohunice

    Slugen, V; Krnac, S [Slovak Technical Univ., Bratislava (Slovakia); Smiesko, I [Nuclear Powr Plant EBO, Jaslovske Bohuce (Slovakia)

    1996-12-31

    The NPP Bohunice VVER-440 fuel leak testing experience are relatively extensive in comparison with other VVER-440 users. As the first Europe NPP was adapted Siemens (KWU) in core-sipping equipment to VVER-440 units and since this time were have done these tests also for NPP Paks (Hungary) and NPP Dukovany (Czech Republic). The occurrence of leaking fuel assemblies in NPP is in the last 5 years relatively stabilised and low. A significant difference can be observed between type V-230 (31 leaks) and type V-213 (1 leak). None of of the indicated leaking fuel assemblies has been investigated in the hot cell. Therefore cannot be confirm the effective causes of leak occurrence. Nevertheless, the fuel failure rate and the performance of leak testing in NPP Bohunice are comparable to the world standard at PWR`s. 1 tab., 2 figs., 3 refs.

  4. Akkuyu NPP – the first Turkish NPP. The new history of the project

    Tzocheva, V.

    2012-01-01

    An overview is given to the Turkish energy sector and nuclear power plans. The project for the construction of the first NPP in Turkey is presented. The general parameters of the Project are: CAPEX: $ 20 bln; Project design: NPP-2006; (VVER- 1200); Number of units: 4; Total capacity: 4 800 MW; Construction period: 2014 – 2023; PPA period; 15 years, fixed price terms. An account of the activities during 2011, the Worley Parsons participation are presented and a tentative project schedule is given

  5. Integrated ageing management of Atucha NPP

    Ranalli, Juan M.; Marchena, Martin H.; Zorrilla, Jorge R.; Antonaccio, Elvio E.; Brenna, Pablo; Yllanez, Daniela; Cruz, Gerardo Vera de la; Luraschi, Carlos; Sabransky, Mario

    2013-01-01

    Atucha NPP is a two PHWR unit site located in Lima, Province of Buenos Aires, 120 km north of Buenos Aires, Argentina. Until recent, the site was split in Atucha I NPP, a 350 MW pressure vessel heavy water reactor in operation since 1974; and Atucha II, a similar design reactor, twice as big as Atucha I finishing a delayed construction. With the start-up of Atucha II and aiming to integrate the management of the plants, the Utility (Nucleolectrica Argentina Sociedad Anonima - NASA) has reorganized its operation units. Within this reorganization, an Ageing Management Department has been created to cope with all ageing issues of both Atucha I and II units. The Atomic Energy Commission of Argentina (Comision Nacional de Energia Atomica - CNEA) is a state-owned R and D organization that; among other functions such as designing and building research reactors, developing uranium mining and supplying radioisotopes to the medical market; is in charge of providing support and technological update to all Argentinean NPPs. The Ageing Management Department of Atucha NPP and the Ageing Management Division of CNEA has formed a joint working group in order to set up an Integrated Ageing Management Program for Atucha NPP following IAEA guidelines. In the present work a summary of the activities, documental structure and first outputs of the Integrated Ageing Management Program of Atucha NPP is presented. (author)

  6. Integrated Ageing Management of Atucha NPP

    Ranalli, J.M.; Marchena, M.H.; Zorrilla, J.R.; Sabransky, M.

    2012-01-01

    Atucha NPP is a two PHWR unit site located in Lima, Province of Buenos Aires, 120 km north of Buenos Aires, Argentina. Until recent, the site was split in Atucha I NPP, a 350 MW pressure vessel heavy water reactor in operation since 1974; and Atucha II, a similar design reactor twice as big as Atucha I finishing a delayed construction . With the start-up of Atucha II and aiming to integrate the management of the plants, the Utility (Nucleolectrica Argentina Sociedad Anonima - NASA) has reorganized its operation units. Within this reorganization, an Ageing Management Department has been created to cope with all ageing issues of both Atucha I and II units. The Atomic Energy Commission of Argentina (Comision Nacional de Energia Atomica - CNEA) is a state-owned R and D organization that; among other functions such as designing and building research reactors, developing uranium mining and supplying radioisotopes to the medical market; is in charge of providing support and technological update to all Argentinean NPPs. The Ageing Management Department of Atucha NPP and the Ageing Management Division of CNEA has formed a joint working group in order to set up an Integrated Ageing Management Program for Atucha NPP following IAEA guidelines. In the present work a summary of the activities, documental structure and first outputs of the Integrated Ageing Management Program of Atucha NPP is presented. (author)

  7. Integrated ageing management of Atucha NPP

    Ranalli, Juan M.; Marchena, Martin H.; Zorrilla, Jorge R.; Antonaccio, Elvio E.; Brenna, Pablo; Yllanez, Daniela; Cruz, Gerardo Vera de la; Luraschi, Carlos, E-mail: ranalli@cnea.gov.ar [Gerencia Coordinacion Proyectos CNEA-NASA, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Sabransky, Mario, E-mail: msabransky@na-sa.com.ar [Departamento Gestion de Envejecimiento, Central Nuclear Atucha I-II Nucleoelectrica Argentina S.A., Provincia de Buenos Aires (Argentina)

    2013-07-01

    Atucha NPP is a two PHWR unit site located in Lima, Province of Buenos Aires, 120 km north of Buenos Aires, Argentina. Until recent, the site was split in Atucha I NPP, a 350 MW pressure vessel heavy water reactor in operation since 1974; and Atucha II, a similar design reactor, twice as big as Atucha I finishing a delayed construction. With the start-up of Atucha II and aiming to integrate the management of the plants, the Utility (Nucleolectrica Argentina Sociedad Anonima - NASA) has reorganized its operation units. Within this reorganization, an Ageing Management Department has been created to cope with all ageing issues of both Atucha I and II units. The Atomic Energy Commission of Argentina (Comision Nacional de Energia Atomica - CNEA) is a state-owned R and D organization that; among other functions such as designing and building research reactors, developing uranium mining and supplying radioisotopes to the medical market; is in charge of providing support and technological update to all Argentinean NPPs. The Ageing Management Department of Atucha NPP and the Ageing Management Division of CNEA has formed a joint working group in order to set up an Integrated Ageing Management Program for Atucha NPP following IAEA guidelines. In the present work a summary of the activities, documental structure and first outputs of the Integrated Ageing Management Program of Atucha NPP is presented. (author)

  8. Romania - NPP PLiM Between Regulatory Requirement / Oversight and Operator Safety / Financial Interest

    Goicea, Lucian

    2012-01-01

    Cernavoda Unit 1 PLiM started in the first third of its design life, to develop as regulatory requirements of the components of standards and programmes and to benefit by earlier implementation of the measures for achieving maximum operating life. CNCAN regulatory present approach on the utility PLiM combines the regulatory requirements on management system, ageing management provisions of periodic safety review, detailed technical requirements of ageing programmes and different techniques focusing only on safety issues. (author)

  9. Safety upgrading program in NPP Mochovce

    Baumeister, P.

    1999-01-01

    EMO interest is to operate only nuclear power plants with high standards of nuclear safety. This aim EMO declare on preparation completion and commissioning of Mochovce Nuclear Power Plant. Wide co-operation of our company with International Atomic Energy Agency and west European Inst.ions and companies has been started with aim to fulfil the nuclear safety requirements for Mochovce NPP. Set of 87 safety measures was implemented at Mochovce Unit 1 and is under construction at Unit 2. Mochovce NPP approach to safety upgrading implementation is showed on chosen measures. This presentation is focused on the issues category III.(author)

  10. Licensing of the Ignalina NPP

    Kutas, S.

    1999-01-01

    Since 1991 State Nuclear Power Safety Inspectorate (VATESI) has regulated Ignalina NPP operation by issuing annual operating permits. Those have been issued following submission of specified documents by the Ignalina NPP that have been reviewed by VATESI. However, according to to the procedures that are now established in the Law on Nuclear Energy and subordinate regulations the use of nuclear energy in the Republic of Lithuania is subject to strict licensing. Therefore a decision about the licence for continued operation of unit 1 should be taken. Licence would be granted by VATESI in cooperation with the Ministry of Health, Ministry of Environment and the institutions of local authorities. Ignalina NPP presented to the VATESI safety analysis report (SAR) with other documents. SAR was made mainly by foreign experts and financed by European Bank for Reconstruction and Development (EBRD). VATESI in this process is supported by western regulators. A special project LAP - Licensing Assistance Project was launched to help VATESI perform licensing according western practices

  11. Estimation of the influence of the early termination of the operation of units 1- 4 in NPP Kozloduy on the greenhouse gas emissions and the obligations of Republic of Bulgaria regarding the Kyoto Protocol

    Christov, Chr.; Vasilev, Hr.

    2003-01-01

    The case of early termination of the operation of units 1 - 4 in NPP 'Kozloduy' would have a considerable impact on the greenhouse gas (GHG) emissions because in the structure of the electricity production the nuclear power plant occupies over 40%. Due to decrease of the share of the nuclear energy in the electricity production the share of the solid and gaseous fuels increases. They are a considerable source of GHG. Three scenarios for the development of the electric power sector until year 2015 have been studied for the case of early termination of the operation of units 1 - 4 in NPP: Scenario 1: Early termination of the operation of units 1 - 4 according to terms pointed out by the EU. Scenario 2: Decommissioning of units 1 - 4 according to term in the project design. Scenario 3: Early termination of the operation of units 1 - 2 according to terms pointed out by the EU and decommissioning of units 3 - 4 according to terms in the project design. Comparative calculations have been performed for the forecasted GHG emission quantities in the first commitment period of the Kyoto Protocol (2008 - 2012). The potential for possible quantities of GHG emissions that could be traded during the entire five-year period are estimated. At minimum possible price of the emissions 5 $US/tCO 2 the annual income will be at least 100 - 130 mill $US. The realistic estimation regarding the omitted benefits due to early termination of the operation of units 1 - 4 is about 900 mill $US for the five year period of Kyoto. The continued operation of units 3 - 4 to the end of the term defined in the project design could make it possible to fulfill an income of 700 mill to 1 billion $US from emission trading

  12. NPP service life management

    Elagin, Yu.P.

    2001-01-01

    Problems of NPP service life management and service life prolongation are reviewed. Methods for the prolongation of the French NPP service life are discussed, priority directions of nuclear block service life management in regard to aging in the context of the European program of investigation into the materials aging are identified. Questions of the provision of the 60 years service life of the Mihama 1 block (Japan) and decision of the problem of the control equipment aging in Great Britain are discussed. Situation with the prolongation of licenses on the NPP operation in the USA and Spain is considered [ru

  13. Optimal test intervals for shutdown systems for the Cernavoda nuclear power station

    Negut, Gh.; Laslau, F.

    1993-01-01

    Cernavoda nuclear power station required a complete PSA study. As a part of this study, an important goal to enhance the effectiveness of the plant operation is to establish optimal test intervals for the important engineering safety systems. The paper presents, briefly, the current methods to optimize the test intervals. For this reason it was used Vesely methods to establish optimal test intervals and Frantic code to survey the influence of the test intervals on system availability. The applications were done on the Shutdown System no. 1, a shutdown system provided whit solid rods and on Shutdown System no. 2 provided with injecting poison. The shutdown systems receive nine total independent scram signals that dictate the test interval. Fault trees for the both safety systems were developed. For the fault tree solutions an original code developed in our Institute was used. The results, intended to be implemented in the technical specifications for test and operation of Cernavoda NPS are presented

  14. A dose assessment for final low level waste disposal located at Cernavoda

    Moldoveanu, E.

    1995-01-01

    This paper presents the first step in the radiological effect evaluation of the low radioactive wastes disposal which will be located in Cernavoda's area. The calculations are done with some approximations based on pessimistic hypotheses. In this sense, the primary step of the accident scenario is a total failure of the wastes disposal and a total emission of radioactive wastes in the environment. The results are estimated versus the time in which radioisotopes migrate through geological formations until they arrive at the underground water. It is considered that for Cernavoda, a town situated in the vicinity of the disposal, the water is contaminated with all radioisotopes arising in this way, and people ingest this water (2 l/day). The results are presented in tables and figures. (author)

  15. Modernization and safety improvement project of the NPP V-2 Jaslovske Bohunice

    Michal, V.; Losonsky, B.; Magdolen, J.

    2000-01-01

    This contribution deals with the form, present state, and results of the Nuclear Power Plants Research Institute (the Slovak acronym is VUJE - Vyskumny Ustav Jadrovych Elektrarni) participation in the NPP V-2 Jaslovske Bohunice Modernization and Safety Improvement Project. A short description of VUJE history, activity, and results is also presented as well as NPPs Jaslovske Bohunice characterization. VUJE was established in 1977 and deals with scientific and research needs of nuclear power plants, such as design, construction, commissioning and operation. The next fields of VUJE activity are, NPP reconstruction, NPP personnel training, radioactive waste management technology, and NPP decommissioning. The nuclear power plant, Jaslovske Bohunice, is situated approximately 15 km from the district town of Trnava in the southwestern region of the Slovak Republic. The construction of the first Czechoslovak NPP A-1 began on this site in 1957 .The construction of the double-unit NPP V-1 with WWER-440 (type V-230) reactor began in 1972. The first unit of NPP V-1 began operation in 1978 and the second in 1980. NPPs construction on the Bohunice site continued with NPP V-2, which has two units with WWER-440 (type V-213) reactors. Unit 1 and Unit 2 of NPP V-2 were commissioned in 1984 and 1985, respectively. Slovak electric utility Slovenske elektrarne (SE) is the owner/commissioner of NPP V-2. This NPP is responsible for more than 20% of the total electrical energy production of SE, making it an essential supporter of the Slovak economy. (authors)

  16. Regulatory approach to NPP ageing in Romania

    Benescu, C.G.; Hossu, A.

    2000-01-01

    In this paper the Romanian requirements for ageing management of systems and components important to safety of Cernavoda nuclear power plant (one Candu type reactor, heavy water moderated power reactor) are presented

  17. Maintenance training centre at NPP Paks, Hungary

    Babos, K.

    1996-01-01

    The lecture shows the feature of WWER-440/213 units maintenance, the existing maintenance training system, the necessity of the change in maintenance training system at NPP Paks. The author introduces the would-be maintenance training centre, the training facilities and the main tasks related to the maintenance training. (author)

  18. Gamma irradiation tests of concrete material recommended for storage casks of spent nuclear fuel arising from Cernavoda NPP

    Dulama, M.; Deneanu, N.; Dulama, C.; Baboescu, E.

    2001-01-01

    Considerable effort is being devoted to the Romania's Nuclear Spent Fuel and Waste Management R and D Program to develop engineered barriers for the containment of nuclear fuel waste under conditions of deep geological disposal. Engineering practice suggests that the concrete should fulfil the requirements of long term physical stability and resistance to radiation. With an appropriate system of metal reinforcement, it should be possible to obtain the tensile and impact strength required, avoiding the risk of mechanical damage during handling and emplacement. In accordance with the concept developed by CITON-Bucharest, presently, the dry storage of spent nuclear fuel is thought by two choices: - The alternative of dry storage type MMB3; - The alternative of dry storage type TRANSTOR. By using ORIGEN and PELSHIE computer codes, we evaluated the gamma radiation dose absorbed by the concrete walls of the storage vault both in MMB3 and in TRANSTOR designing variants. The irradiation tests were performed at the Gamma Irradiation Facility of the Institute for Nuclear Research. (authors)

  19. Qualified operator training in the simulated control room environment

    Ionescu, Teodor; Studineanu, Emil; Radulescu, Catalina; Bolocan, Gabriel

    2005-01-01

    Full text: Mainly designed for the training of the Cernavoda NPP Unit 2 operators, the virtual simulated environment allows the training of the already qualified operators for Cernavoda NPP Unit 1, adding to the already trained knowledge, the differences which has occurred in the Unit 2 design. Using state-of-the-art computers and displays and qualified software, the virtual simulated panels could offer a viable alternative to classic hardware-based training. This approach allows quick training of the new procedures required by the new configuration of the re-designed operator panels in the main control room of Cernavoda NPP Unit 2. (authors)

  20. Qualified operator training in the simulated control room environment

    Ionescu, Teodor; Studineanu, Emil; Radulescu, Catalina; Bolocan, Gabriel

    2005-01-01

    Mainly designed for the training of the Cernavoda NPP Unit 2 operators, the virtual simulated environment allows the training of the already qualified operators for Cernavoda NPP Unit 1, adding to the already trained knowledge, the differences which have occurred in the Unit 2 design. Using state-of-the-art computers and displays and qualified software, the virtual simulated panels could offer a viable alternative to classic hardware-based training. This approach allows quick training of the new procedures required by the new configuration of the re-designed operator panels in the main control room of Cernavoda NPP Unit 2. (authors)

  1. The settlement Cernavoda III culture on the site Bubanj near Niš

    Milanović Dragan

    2011-01-01

    Full Text Available Archaeological investigations carried out between 2008 and 2010 in the east sector of site Bubanj near Niš (Plan 1; Figs. 1-3 confirmed the existence of horizon of the Cernavoda III culture. In features 22, 23 and 31, which are the remains of settlement buildings, have been found archaeological material mostly pottery vessels, which according to style of decoration, technological and morphological characteristics could be ascribed to the initial period of late Eneolithic. Also, the dwelling structures of Krivodol-Salcuþa-Bubanj cultural complex have been recorded in the layer of brown soil with the remains of above mentioned Cernavoda III buildings. In the vertical stratigraphy of trench I (Fig. 4 the mentioned layer was encountered immediately under the layer of whitish/gray ashy soil and thin layer of compact soil of gray color (Fig. 5, which date from the advanced phases of the late Eneolithic and above the early Eneolithic layers. The settlement features recorded during 2009 excavations are parts of the structures from the settlement of Cernavoda III culture (Fig. 6; T. I-III. Feature 22 is section of devastated probably aboveground building, feature 23 is shallow pit and feature 31 is most probably the rubbish pit. Very similar stratigraphy of the site had been recorded by investigations of M. Garašanin in 1954. In the layer of brown soil, the material of Cernavoda III culture was discovered in level III, and in level IV both Cernavoda III and the material of the earlier Krivodol-Salcuþa-Bubanj cultural complex was recorded. These building horizons are at different depths within approximately same area of the trench and have been identified on the basis of considerable amount of daub and stone, two floor levels, wooden building material and fragmented pottery vessels (T. IV-VI. Despite the lack of technical field documentation remains of one above ground structure could be identified at level III according to descriptions from field

  2. Reactor plant for Belene NPP completion

    Dragunov, Yu. G.; Ryzhov, S. B.; Ermakov, D. N.; Repin, A. I.

    2004-01-01

    Construction of 'Belene' NPP was started at the end of 80-ties using project U-87 with V-320 reactor plant, general designer of this plant is OKB 'Gidropress'. At the beginning of 90-ties, on completing the considerable number of deliveries and performance of civil engineering work at the site the NPP construction was suspended. Nowadays, considering the state of affairs at the site and the work performed by Bulgarian Party on preservation of the equipment delivered, the most perspective is supposed to be implementation of the following versions in completing 'Belene' NPP: for completion of Unit 1 - reactor plant VVER-1000 on the basis of V-320 reactor with the maximum use of the delivered equipment (V-320M) having the extended service life and safety improvement; for Unit 2 - advanced reactor plant VVER-1000. For the upgraded reactor plant V-230M the basic solutions and characteristics are presented, as well as the calculated justification of strength and safety analyses, design of the reactor core and fuel cycle, instrumentation and control systems, application of the 'leak-before break' in the project and implementation of safety measures. For the modernised reactor plant V-392M the main characteristics and basic changes are presented, concerning reactor pressure vessel, steam generator, reactor coolant pump set. Design of NPP with the modernized reactor plant V-320M meets the up-to-date requirements and can be licensed for completion and operation. In the design of NPP with the advanced reactor plant the basic solutions and the equipment are used that are similar to those used in standard reactor plant V-320 and new one with VVER-1000 under construction and completion in Russia, and abroad. Compliance of reactor design with the up-to-date international requirements, considering the extended service life of the main equipment, shows its rather high potential for implementation during completion of 'Belene' NPP

  3. Project No. 10 - Partial restoration of Ignalina NPP territory

    2000-01-01

    At present Ignalina NPP territory makes a total of 2544 ha of land. Due to termination of construction activity development and due to the decision taken to shutdown unit 1 the need in such a territory fell off. For normal and safe operation of Ignalina NPP 1440 ha is enough, including 1237 ha for of Ignalina NPP administrative area and 203 ha for auxiliary objects. Ignalina NPP will have to rearrange territory, forestry that was damaged during the construction activities of the plant and to restore the damaged farmlands and to pass the rearranged forestry that belonged to the Ignalina NPP to the Ministry of Forestry. The total estimated cost of the project is about 1.042 M EURO

  4. The dependence level analysis between the human actions in NPP Operation

    Farcasiu, M.; Nitoi, M.; Apostol, M.; Florescu, G.; Prisecaru, Ilie

    2009-01-01

    The Human Reliability Analysis (HRA) is an important method in Probabilistic Safety Assessment (PSA) studies and offers desirability for concrete improvement of the man - machine - organization interfaces, reliability and safety. An important step in HRA is the dependence level analysis between the human actions performed by the same person or between the actions performed by different persons, step in quantitative analysis of the human errors probabilities. The purpose of this paper is to develop a model to analyze the dependence level between human actions for Nuclear Power Plant (NPP) operation. The model estimates the conditional human error probabilities (CHEP) and joint human error probabilities (JHEP). The achieved sensitivity analyses determine human performance sensibility to systematic variations for dependence level between human actions. The human error probabilities estimated in this paper are adequate values for integration both in HRA and in PSA realized for NPP. This type of analysis helps in finding and analyzing the ways of reducing the likelihood of human errors, so that the impact of human factor to systems availability, reliability and safety can be realistically estimated. In order to demonstrate the usability of this model an analysis is performed upon the dependences between the necessary human actions in mitigating the consequences of LOCA events, particularly for the case of Cernavoda NPP. (authors)

  5. NPP electrical price and tariff in the world

    Mochamad Nasrullah and Sriyana

    2010-01-01

    Construction of a Nuclear Power Plant (NPP) is always become a controversial issue. Nuclear utility and other party which support the NPP present a calculation of NPP electricity cost too optimistic. However for utility and other party that contra to nuclear present a calculation of NPP electricity cost too pessimistic. This study present to reduce the controversy of nuclear cost. In this study, capital cost (Engineering Procurement Construction, EPC) was taken from Asian, America and Europe, operating and maintenance cost uses experience data of PLN, and nuclear fuel cost uses data year of 2008 with high price, low price and average price scenario. The methodological tools used to compare electricity generation cost was LEGECOST, a program developed by IAEA (International Atomic Energy Agency), while for electricity tariff- price calculation using a program developed by PLN research and development center. With the discount rate 10%, the result shows that the cheapest electricity generation cost of NPP is less than 40 mills/kWh, and average electricity tariff was 55 mills/kWh. In the Europe countries the electricity tariff more expensive than NPP in Asia. However generating cost and electricity tariff of NPP in United Stated of America (USA) less competitive because investment cost more expensive. Generating cost and electricity tariff was different at each country depend on salary, labor wage, materials price, construction specification, regulation related to NPP and environment aspect. (author)

  6. The responses of net primary production (NPP) and total carbon storage for the continental United States to changes in atmospheric CO{sub 2}, climate, and vegetation

    McGuire, D.A. [Marine Biological Lab., Woods Hole, MA (United States)

    1995-06-01

    We extrapolated 3 biogeochemistry models (BIOME-BGC, CENTURY, and TEM) across the continental US with the vegetation distributions of 3 biogeography models (BIOME2, DOLY, and MAPSS) for contemporary climate at 355 ppmv CO{sub 2} and each of 3 GCM climate scenarios at 710 ppmv. For contemporary conditions, continental NPP ranges from 3132 to 3854 TgC/yr and total carbon storage ranges from 109 to 125 PgC. The responses of NPP range from no response (BIOME-BGC with DOLY or MAPSS vegetations for UKMO climate) to increases of 53% and 56% (TEM with BIOME2 vegetations for GFDL and OSU climates). The responses of total carbon storage vary from a decrease of 39% (BIOME-BGC with MAPSS vegetation for UKMO climate) to increases of 52% and 56% (TEM with BIOME2 vegetations for OSU and GFDL climates). The UKMO responses of BIOME-BGC with MAPSS vegetation are caused by both decreased forest area (from 44% to 38%) and photosynthetic water stress. The OSU and GFDL responses of TEM with BIOME2 vegetations are caused by forest expansion (from 46% to 67% for OSU and to 75% for GFDL) and increased nitrogen cycling.

  7. EMAS at Doel NPP

    Nolan, Peter; Thoelen, Els

    1998-01-01

    In October 1995, Doel NPP of Electrabel, Belgium opted to seek registration under the EC Eco-management and Audit Scheme (EMAS). A comprehensive environmental management system (EMS) has been introduced and implemented, encompassing all four PWRs and the supporting departments. A critical step was to seek certification from an accredited environmental auditing body against the International Standard ISO 14001. This provided the foundation for the publicly available environmental statement required by EMAS. The complications of achieving EMAS at a time when national and international standards were being re-formulated were successfully overcome and Doel NPP passed its EMAS audit in June 1997. (author)

  8. Modernization of the oldest Swedish NPP

    Hagberth, Ronald

    1998-01-01

    OKG operates three BWR units of ABB design: Oskarshamn 1 with a net capacity of 440' MW, Oskarshamn 2 of 600 MW and Oskarshamn 3 of 1160 MW. Oskarshamn 1 NPP was commissioned in 1972 as the first commercial nuclear unit in Sweden. After more than twenty years of successful operation, the unit is now also the first reactor in Sweden to undergo a large safety modernization program. In the year 2000 the Oskarshamn 1 NPP will be modernized to a high level of safety standard and ready for operation for another period of at least 20 years. Experience gained can be used when modernizing other NPPs. The investment program for life extension is reasonable and shows that NPPs can be operated with an expected life span of more than 40 years at an ever-increasing safety level and still be very competitive in a deregulated market. (author)

  9. Chernobyl NPP decommissioning efforts - Past, Present and Future. Decommissioning Efforts on Chernobyl NPP site - Past, Present

    Kuchinskiy, V.

    2017-01-01

    Two unique large-scale projects are underway at the moment within the Chernobyl - Exclusion zone - Shelter object transformation into ecologically safe system and the decommissioning of 3 Chernobyl NPP Units. As a result of beyond design accident in 1986 the entire territory of the industrial site and facilities located on it was heavily contaminated. Priority measures were carried out at the damaged Unit under very difficult conditions to reduce the accident consequences and works to ensure nuclear and radiation safety are continuous, and the Unit four in 1986 was transformed into the Shelter object. Currently, works at the Shelter object are in progress. Under assistance of the International Community new protective construction was built above the existing Shelter object - New Safe Confinement, which will ensure the SO Safety for the long term - within up to 100 years. The second major project is the simultaneous decommissioning of Chernobyl NPP Units 1, 2 and 3. Currently existing Chernobyl NPP decommissioning Strategy has been continuously improved starting from the Concept of 1992. Over the years the following was analyzed and taken into account: the results of numerous research and development works, international experience in decommissioning, IAEA recommendations, comments and suggestions from the governmental and regulatory bodies in the fields of nuclear energy use and radioactive waste management. In 2008 the final decommissioning strategy option for Chernobyl NPP was approved, that was deferred gradual dismantling (SAFSTOR). In accordance with this strategy, decommissioning will be carried out in 3 stages (Final Shutdown and Preservation, Safe Enclosure, Dismantling). The SAFSTOR strategy stipulates: -) the preservation of the reactor, the primary circuit and the reactor compartment equipment; -) the dismantling of the equipment external in relation to the reactor; -) the safe enclosure (under the supervision); -) the gradual dismantling of the primary

  10. Construction of large-thickness sand cushions for NPP foundations

    Krantsfel'd, Ya.L.; Losievskaya, I.K.; Kovalenko, R.P.; Mutalipov, A.

    1982-01-01

    A study is made on some technological peculiarities of preparation of NPP foundations and control methods of foundation density. As an example the experience of cement-sand foundation construction for two 900 MW power-units at the Koeberg South Africa NPP is briefly described. The experience of artificial foundation construction at this NPP indicates both the possibility of obtaining the required quality of cement-sand cushions and commercial construction of large volume of such cushions by acceptable rates and the necessity of unification of work quality characteristics

  11. Dukovany NPP maintenance management

    Siegel, F.

    2005-01-01

    Maintenance planning and management for the technological equipment of the Dukovany NPP are described. A Maintenance Control and Evaluation System has been developed and is in use to help manage the complex maintenance issue. Practical examples of outputs of the System, with a comprehensive use of the cost, reliability and safety related data, are presented. (author)

  12. NPP Krsko decommissioning concept

    Novsak, M.; Fink, K.; Spiler, J.

    1996-01-01

    At the end of the operational lifetime of a nuclear power plant (NPP) it is necessary to take measures for the decommissioning as stated in different international regulations and also in the national Slovenian law. Based on these requirements Slovenian authorities requested the development of a site specific decommissioning plan for the NPP KRSKO. In September 1995, the Nuklearna Elektrarna Krsko (NEK) developed a site specific scope and content for decommissioning plan including the assumptions for determination of the decommissioning costs. The NEK Decommissioning Plan contains sufficient information to fulfill decommissioning requirements identified by NRC, IAEA and OECD - NEA regulations. In this paper the activities and the results of development of NEK Decommissioning Plan consisting of the development of three decommissioning strategies for the NPP Krsko and selection of the most suitable strategy based on site specific, social, technical, radiological and economical aspects, cost estimates for the strategies including the costs for construction of final disposal facilities for fuel/high level waste (fuel/HLW) and low/intermediate level waste (LLW/ILW) and scheduling all activities necessary for the decommissioning of the NPP KRSKO are presented. (author)

  13. NPP Krsko decommissioning concept

    Novsak, M.; Fink, K.; Spiler, J.

    1996-01-01

    At the end of the operational lifetime of a nuclear power plant (NPP) it is necessary to take measures for the decommissioning as stated in different international regulations and also in the national Slovenian law. Based on these requirements Slovenian authorities requested the development of a site specific decommissioning plan for the NPP Krsko. In September 1995, the Nuklearna Elektrarna Krsko (NEK) developed a site specific scope and content for a decommissioning plan including the assumptions for determination of the decommissioning costs. The NEK Decommissioning Plan contains sufficient information to fulfill the decommissioning requirements identified by NRC, IAEA and OECD - NEA regulations. In this paper the activities and results of development of NEK Decommissioning Plan consisting of the development of three decommissioning strategies for the NPP Krsko and selection of the most suitable strategy based on site specific, social, technical, radiological and economic aspects, cost estimates for the strategies including the costs for construction of final disposal facilities for fuel/high level waste (fuel/HLW) and low/intermediate level waste (LLW/ILW) and scheduling of all activities necessary for the decommissioning of the NPP Krsko are presented. (author)

  14. Arrangement and statistics of storage containers of spent fuel for assemblies of the SFP of NPP-L V, Unit 1

    Mijangos D, Z. E.; Vargas A, A. F.; Amador C, C.

    2014-10-01

    This work presents the determination of assemblies of the spent fuel pool (SFP) of the nuclear power plant of Laguna Verde (NPP-L V) which are candidates to be assigned to storage containers of independent spent fuel, with the objective of liberating decay heat and to have more space in the SFP, for the store of retired assemblies of the reactors in future reloads of NPP-L V, besides that the removed assemblies of the SFP should be stored in specific containers to guarantee the physical safety of them, as well as the radiological protection to the population and the environment. The design of the containers considered in this work is to store a maximum of 69 assemblies; it has a thermal capacity of 26 kilowatts and allows storing assemblies with a minimum of 5 years of have been extracted of the reactor core. Is considered that in 2016 start the storage of the spent assemblies on the containers, the candidates assemblies to store cover from the first reload in 1991, until the assemblies deposited in the SFP in the 14 reload in 2010; therefore in 2016, such assemblies will have fulfilled with the criteria of 5 years of have been removed of the Reactor, also the 69 assemblies assigned to each container will have a resulting decay heat that does not exceed the thermal capacity of the container, but that in great percentage approximates to the same one, and this way to take full advantage of their storage capacity and thermal capacity for each container. This work also contains the arrangement to accommodate the assemblies in the containers; such arrangement is constituted by areas according to the decay heat of each assembly. (Author)

  15. Plant level of automated control system at a NPP with RBMK reactor

    Vorob'ev, V.P.; Gorbunov, V.P.; Dmitriev, V.M.; Litvin, A.S.

    1987-01-01

    The functional structure of plant level automated control system (ACS) at NPP with RBMK-1000 reactors, its binding with the on-line control system of higher and lower levels, as well as engineering requirements to software and recommendations on composition of hardware components, are considered. NPP ACS is an organizational-engineering system consisting of computer facilities and binding aimed at solving management, economical, organizational and physical-engineering problems to control NPP more effectively. The system carries out data acquisition, preliminary processing, analysis, transmission and representation for users to accept solutions for NPP operation by operative and management personnel. The main aim of integrated NPP ACS is the control development and increase of NPP economical efficiency, the increase of electric and heat energy production, the optimization of the production distribution between units, the development of production and economic NPP control

  16. Preparation of Long Term Operation in Dukovany NPP, Czech Republic

    Krivanek, R.; Sabata, M.

    2012-01-01

    Dukovany NPP in the south-east of the Czech Republic operates four VVER 440/213 type units. The first unit was commissioned in 1985 and the last one in 1987. The operational results of the whole NPP have been excellent and NPP permanently belongs between the first quartile of the best operated NPPs in the world in accordance with WANO factors. Large safety improvement programme have been implemented in last 15 years. The original design lifetime of main components is 30 years which means till 2015 and it is understandable that NPP is preparing for long-term operation (LTO). The paper is describing activities carried out and planned for safe and successful LTO. (author)

  17. Design safety improvements of Kozloduy NPP

    Hinovski, I.

    1999-01-01

    Design safety improvements of Kozloduy NPP, discussed in detail, are concerned with: primary circuit integrity; reactor pressure vessel integrity; primary coolant piping integrity; primary coolant overpressure protection; leak before break status; design basis accidents and transients; severe accident analysis; improvements of safety and support systems; containment/confinement leak tightness and strength; seismic safety improvements; WWER-1000 control rod insertion; upgrading and modernization of Units 5 and 6; Year 2000 problem

  18. The main steps of the Romanian nuclear power program development - Accumulated experience

    Chirica, T.; Popescu, D.; Condu, M.; Vatamanu, M.

    1998-01-01

    The paper presents a historical summary of the Romanian Nuclear Power Program development, providing details for the main criteria and principles the Program was based upon, the contracts signed with the foreign partners to implement it, and the national participation (site contractors, suppliers and design organizations). The effect of the equipment assimilation program on the NPP Cernavoda (5x700 MWe) and especially on Unit 1 schedule and performance is analyzed. Further on the impact of the transition from centralized to a market economy over the Romanian Nuclear Power Program development is analyzed, providing information's on its actual status and perspectives for the next 20 years. A description of the NPP Cernavoda Unit 1 actual progress and of the main steps performed by RENEL to get finance to complete NPP Cernavoda Unit 2 is included. Finally there is summarized the accumulated experience, and its feed back on RENEL strategy to complete NPP Cernavoda Unit 2. (author)

  19. Baltic NPP Project specifics and current status

    2011-01-01

    Project overview: 2 x 1194 MW Units (AES-2006 series); Location in Kaliningrad region of the; Russian Federation; Operation dates: Unit 1 – Oct 2016; Unit 2 – Apr 2018; Site preparatory works ongoing. This is first NPP project in the Russian Federation providing opportunity for participation of foreign investors. Foreign investors may acquire up to 49% share. Cross-border transmission lines developed under separate project with participation of foreign investors. Conclusion: At the selected set of assumptions, the project is financially feasible in all scenarios

  20. The performance shaping factors influence analysis on the human reliability for NPP operation

    Farcasiu, M.; Nitoi, M.; Apostol, M.; Florescu, G.

    2008-01-01

    The Human Reliability Analysis (HRA) is an important step in Probabilistic Safety Assessment (PSA) studies and offers an advisability for concrete improvement of the man - machine - organization interfaces, reliability and safety. The goals of this analysis are to obtain sufficient details in order to understand and document all-important factors that affect human performance. The purpose of this paper is to estimate the human errors probabilities in view of the negative or positive effect of the human performance shaping factors (PSFs) for the mitigation of the initiating events which could occur in Nuclear Power Plant (NPP). Using THERP and SPAR-H methods, an analysis model of PSFs influence on the human reliability is performed. This model is applied to more important activities, that are necessary to mitigate 'one steam generator tube failure' event at Cernavoda NPP. The results are joint human error probabilities (JHEP) values estimated for the following situations: without regarding to PSFs influence; with PSFs in specific conditions; with PSFs which could have only positive influence and with PSFs which could have only negative influence. In addition, PSFs with negative influence were identified and using the DOE method, the necessary activities for changing negative influence were assigned. (authors)

  1. Optimization of radiation protection at Bohunice NPP

    Dobis, L.; Svitek, J.

    2003-01-01

    Bohunice Nuclear Power Plant is situated in south - western part of Slovakia about 50 km away from Bratislava. There are four PWR reactors 440 MW e each - two units with reactors WWER - 230 (V1 NPP) and two units with WWER - 213 (V2 NPP). requirements for the optimization process are given in the mentioned Code No.12 of Ministry of Health. Code 12 stipulates the technical and organizational requirements for proving the Rational Achievable Level (RAL) of radiation protection. This level can be proved by means of the comparison of the dose distribution to the costs of protection. An example of two figures of dose constraints is: collective dose 20 man mSv for the specific task; individual exposure 1 mSv per day. The values of the financial equivalents of personal exposure - so called the alpha coefficients - are used for the calculation of the benefit of proposed measures. Impact of legislative changes into Bohunice NPP and optimization process are presented. Apparently the new law and the associate code created a base of transparent and understandable policy of radiation protection and optimization in Slovak Republic. The radiation protection legislative was implemented into the praxis and persons became familiar with it. Defining clear and unambiguous terms facilitated the communication between users and the regulatory body - State Health Institute. Optimization was generally accepted by the workers and managers and began to be a part of safety culture of operation at nuclear power plants. (authors)

  2. SAT for NPP personnel training in USA

    Spinney, R.

    1995-01-01

    This discussion addressed the experience with the application of SAT at USA NPPs. In particular, the transition of NPP training processes, staff composition, and reporting structure from the TMI accident to present. As well, oversight and guidance activities of the INPO and more intensive inspection by the NRC began during this period. The average NPP training staff grew to 30-40 per unit, along with a change in reporting line from plant to corporate management. With the reduction of resources occurring in the late 1980s, overall training staff size decreased, the composition changed, and reporting line reverted to plant management. The overall lessons-learned for application of the SAT consisted of the need for simplification, management involvement, and exploitation of the technology

  3. Russian normative approach to the question of management of NPP life time

    Karpunin, N.I.

    2002-01-01

    Full text: In Russia, the designated service life of a nuclear power plant (NPP) is 30 years. During the period 2001-2010, 15 Russian NPP units will reach the end of their service life. The 'Basic Provisions of NPP Safety Assurance', OPB-88/97, Item 5.1.14, provide for a possible extension of NPP operation beyond the designated service life. For such an extension, the NPP operating organization must apply for a license renewal to Gosatomnadzor, which needs to specify the relevant requirements. GAN is developing regulatory documents to provide a basis for NPP license renewal/extension of NPP operation, which would benefit from international experience. In accordance with 'The program of Atomic Energy Development in the Russian Federation for 1998-2005 and up to 2010' adopted by Decree No. 815 of the Government of the Russian Federation on 21 July 1998, priority is placed on the preparation of NPPs for extension of service life and on ensuring safety in the extended operating period. The length of the extension beyond the designated service life is to be determined on the basis of a range of technical and economic considerations, including: The ability to ensure and maintain operational safety; Sufficient residual service life of the unit's non-repairable components; The availability of temporary storage facilities for the additional spent nuclear fuel and radioactive waste, or the possibility of its transport off-site; The ability to ensure safe handling of the radioactive waste generated during the extension period; To extend the lifetime of an NPP unit, the plant Operator is required to perform the following tasks: Carry out a comprehensive survey of the NPP unit; Draw up a programme of preparation for lifetime extension; Prepare the NPP unit for operation in the extended period; Carry out the necessary tests. There are also some normative documents, which regulate management of NPP life time. (author)

  4. Operation safety at Ignalina NPP

    Zheltobriukh, G.

    1999-01-01

    An improvement of operational safety at Ignalina NPP covers: improvement of management structure and safety culture; symptom-based emergency operating procedures; staff training and full scope simulator; program of components ageing; metal inspection; improvement of fire safety. The first plan of Ignalina NPP Safety culture development for 1997 purposed to the SAR recommendation implementation was prepared and approved by the General Director

  5. Assessment of the cryogenic distillation system in Cernavoda tritium removal facility

    Pasca, Gheorghe; Draghia, Mirela; Porcariu, Florina; Ana, George

    2010-01-01

    Full text: This paper aims at presenting an assessment of the Cryogenic Distillation system (CD) in the Cernavoda Tritium Removal Facility (CTRF). The cryogenic distillation system is one of the key components of the CTRF which comprises other systems as: the liquid phase catalytic exchange system, designed to transfer tritium from heavy water to a deuterium stream to be fed into the CD system; the atmosphere detritiation system; the tritium recovery system; the tritium/hydrogen monitoring system; the central interlocking system; the tritium extraction and storage system. Thus, the need to build a tritium separation and recovery system results from economic opportunities offered both by heavy water reuse and tritium production, but, at the same time, it offers an alternative for the storage of tritiated heavy water as radioactive waste. (authors)

  6. Influence of the crustal and subcrustal Vrancea seismic sources on Cernavoda nuclear power plant site

    Marmureanu, Gheorghe; Popescu, Emilia; Mircea Radulian

    2002-01-01

    The basis of the seismic hazard assessment in different geographical regions with dense-populated areas and strategic objectives (dams, nuclear power plants, etc.) is the study of seismicity of the seismogenic sources which affect these sites. The purpose of this paper is to provide a complete set of information relative to the Vrancea seismic source (in the crust and the intermediate depth domains) that is fundamental for the seismic hazard evaluation at Cernavoda nuclear power plant site. The analysis that we propose has to deal with the following items: (1) geometrical definition of the seismic sources; (2) setting the earthquake catalog associated to each seismic source; (3) estimation of the maximum possible magnitude; (4) estimation of the frequency - magnitude relationship; (5) computation of the distribution function for focal distance; (6) correlation between focal depth and magnitude; (7) attenuation law. We discuss also the implications of the model parameters on the seismic hazard level. (authors)

  7. Fuel handling at Cernavoda 1 N.P.S. - commissioning and training philosophy

    Standen, G W [AECL-Ansaldo Consortium, Cernavoda (Romania); Tiron, C; Marinescu, S [Regia Nationala de Electricitate (RENEL), Cernavoda (Romania); [Filiala Centrala Nuclearo Electrica (FCNE), Cernavoda (Romania)

    1997-12-31

    Efficient operation of a Candu nuclear power plant depends greatly on the reliable and safe operation of the fuel handling system. Successful commissioning of the system is obviously a key aspect of the reliability of the system and this coupled with a rigorous training programme for the fuel handling staff will ensure the system`s safe operation. This paper describes the philosophy used at Cernavoda 1 N.P.S. for the commissioning of the fuel handling systems and for the training of staff for operation and maintenance of these systems. The paper also reviews the commissioning programme, describing the milestones achieved and discussing some of the more interesting technical aspects which includes some unique Romanian input. In conclusion the paper looks at the organization of the mature fuel handling department from the operations, maintenance and technical support points of view and the long term plans for the future. (author). 1 fig.

  8. Fuel handling at Cernavoda 1 N.P.S. - commissioning and training philosophy

    Standen, G.W.; Tiron, C.; Marinescu, S.

    1996-01-01

    Efficient operation of a Candu nuclear power plant depends greatly on the reliable and safe operation of the fuel handling system. Successful commissioning of the system is obviously a key aspect of the reliability of the system and this coupled with a rigorous training programme for the fuel handling staff will ensure the system's safe operation. This paper describes the philosophy used at Cernavoda 1 N.P.S. for the commissioning of the fuel handling systems and for the training of staff for operation and maintenance of these systems. The paper also reviews the commissioning programme, describing the milestones achieved and discussing some of the more interesting technical aspects which includes some unique Romanian input. In conclusion the paper looks at the organization of the mature fuel handling department from the operations, maintenance and technical support points of view and the long term plans for the future. (author). 1 fig

  9. Analysis of the failed threaded rod from the support of the pipelines from CNE Cernavoda

    Fulger, M.; Mihalache, M.; Velciu, L.; Nitu, A.; Puscasu, C.

    2016-01-01

    The goal of the current study was analysis of one threaded rod from the support of pipelines from CNE Cernavoda raw water cooling system (RCW) to identify the causes of its breakage. For the failure analysis, were used following techniques: optical microscopy, scanning electron microscopy/ energy dispersive X - ray spectrometry (EDS) and mechanical tries (Brinell hardness). The conclusion was the failure had been caused by improper mounting of the rod in the spring guide system. Thus, a complex distribution of tensions emerged, rather than the vertical distribution as designed for the guide with spring. On the other hand, the presence of a hard impurity (titanium carbide), in the threaded region and the usage of a material with greater hardness and with higher chrome composition than specified in the project, had favored the appearance of a fatigue fissure, leading to a tear in the rod. (authors)

  10. Danube quality water assessment from the microbiological point of view in Cernavoda nuclear plant area

    Sundri, Mirela Iuliana

    2003-01-01

    Herein are analysed the following microbiological parameters: total viable count, total coliforms and faecal coliforms, which represent a standard indicator for water quality. The study has been done during 1998-2002 upon the water in the Danube River and in the channels for cooling water used by Cernavoda Nuclear Power Plant condensers. In this area, based on these values of evaluated parameters, the water feature is placed in the quality classes II and III (moderate and critical pollution), in conformity with European Community Directives. Bacterial communities, component part of aquatic biocenoses, are very important for matter and energy flux. Their contribution to self-purification processes of rivers is of great interest related to the water quality assessment. Microorganisms are ideal sensors, because they respond fast to the fluctuation of environmental conditions by specific changes, detectable physiologically and metabolically. The temperature is a major factor, which directly affects the intensity of all microbial processes. Because the microorganisms are interconnected with the other living organisms, the qualitative or quantitative changes of their activity will affect the functions of the whole ecosystem. Bacterial indicators such as total viable count (colony count), total coliforms or faecal coliforms (thermo-tolerant coliforms) are widely applied to the assessment of water quality. Because of their mostly allochthonus origin, these are used as indicators of changes in the natural water conditions; they point out an organic matter or faecal water pollution. Although the water quality can be considered acceptable from the chemical or biological point of view, the bacteriological parameters might be detected in critical concentration. The objectives of this microbiological assessment are analysis of the variation of bacteriological indicators in some sampling points of Cernavoda aquatic ecosystems area, and monitoring the manner of using the water by

  11. Human Resources Training Requirement on NPP Operation and Maintenance

    Nurlaila; Yuliastuti

    2009-01-01

    This paper discussed the human resources requirement on Nuclear Power Plant (NPP) operation and maintenance (O&M) phase related with the training required for O&M personnel. In addition, this paper also briefly discussed the availability of training facilities domestically include with some suggestion to develop the training facilities intended for the near future time in Indonesia. This paper was developed under the assumptions that Indonesia will build twin unit of NPP with capacity 1000 MWe for each using the turnkey contract method. The total of NPP O&M personnel were predicted about 692 peoples which consists of 42 personnel located in the head quarter and the rest 650 people work at NPP site. Up until now, Indonesia had the experience on operating and maintaining the nonnuclear power plant and several research reactors namely Kartini Reactor Yogyakarta, Triga Mark II Reactor Bandung, and GA Siwabessy Reactor Serpong. Beside that, experience on operating and maintaining the NPP in other countries would act as one of the reference to Indonesia in formulating an appropriate strategy to develop NPP human resources particularly in O&M phases. Education and training development program could be done trough the cooperation with vendor candidates. (author)

  12. MCNP calculation of the critical H_3BO_3 concentrations for the first fuel loading into the reactor core of NPP MO-3-4 units

    Vrban, B.; Lueley, J.; Farkas, G.; Hascik, J.; Hinca, R.; Petriska, M.; Slugen, V.

    2012-01-01

    The purpose of the analysis was the determination of critical H_3BO_3 concentrations for the first fuel loading into the reactor core of MO34 units using 2"n"d generation fuel during the first start-up of new unit using calculation code MCNP 1.60. H_3BO_3 concentrations were computed for the given temperature of the primary circuit and position of the 6"t"h safety control rod group. Because of the very first start-up of these units, detailed analyses of active-core parameters are required by National Regulatory Authority and needed for safe operation of nuclear facility. (authors)

  13. International benchmark for coupled codes and uncertainty analysis in modelling: switching-Off of one of the four operating main circulation pumps at nominal reactor power at NPP Kalinin unit 3

    Tereshonok, V. A.; Nikonov, S. P.; Lizorkin, M. P.; Velkov, K; Pautz, A.; Ivanov, V.

    2008-01-01

    The paper briefly describes the Specification of an international NEA/OECD benchmark based on measured plant data. During the commissioning tests for nominal power at NPP Kalinin Unit 3 a lot of measurements of neutron and thermo-hydraulic parameters have been carried out in the reactor pressure vessel, primary and the secondary circuits. One of the measured data sets for the transient 'Switching-off of one Main Circulation Pump (MCP) at nominal power' has been chosen to be applied for validation of coupled thermal-hydraulic and neutron-kinetic system codes and additionally for performing of uncertainty analyses as a part of the NEA/OECD Uncertainty Analysis in Modeling Benchmark. The benchmark is opened for all countries and institutions. The experimental data and the final specification with the cross section libraries will be provided to the participants from NEA/OECD only after official declaration of real participation in the benchmark and delivery of the simulated results of the transient for comparison. (Author)

  14. Impact of nuclear information on the public acceptance. Case study for young people in Cernavoda and Pitesti towns

    Constantin, Marin; Diaconu, Daniela

    2007-01-01

    The general objective of this work was to investigate the impact of nuclear information on young people's knowledge and attitudes by using different Methods/Participatory Tools in an Educational Programme. The investigation started with a baseline survey of six groups of youngsters, three each from Pitesti and Cernavoda, which was completed early in 2005. After analysing the results an Educational Programme was proposed and developed following the FP6- COWAM2 Annual Seminar at Ljubljana. The Programme was produced by November 2005 and three methods were selected: classical methods usually used for school teaching, the discovery method, and a method involving simulation of a Local Committee. Three groups from Pitesti and four from Cernavoda attended the Programme, which was followed by a new questionnaire-based measurement (May 2006). (authors)

  15. NPP Prevlaka - Preparation of construction

    Bojic, K.

    1984-01-01

    On the basis of study 'Optimal electricity generation structure till the year 2000' production of 3 x 500 MWe in nuclear power plants has been anticipated. Second Croatian-Slovenian NPP project will be based on the same principles the first one (NPP Krsko) was based on. Preconstruction investigation studies are performed at site Prevlaka on river Sava downstream of Zagreb. Licensing procedure has started with republic Urban countryside planning activities. Preconstruction activities are planned to be finished by the end of 1986. while the construction is expected to start during 1987. Parallel to investigation studies for NPP Prevlaka, evaluation of nuclear technology and reactor type is planned to be made. (author)

  16. System approach as a tool for optimization of the dismantling technological process of NPP decommissioning

    Bylkin, B.K.; Shpitser, V.Ya.

    1994-01-01

    The concept of NPP unit decommissioning has been considered. Special attention was paid to the stage of dismantling of NPP unit equipment. Employment of systematic approach as a tool for optimization of dismantling processes permits formalizing manipulations with certified indices of quality and it permits an objective assessment of the dismantling technology level attained during designing as compared with the basic one. It seems appropriate to develop a basic project of NPP unit decommissioning as a technical means of planning, predicting and evaluating ecological and social aftereffects

  17. Technology for NPP decantate treatment realized at Kola NPP

    Stakhiv, Michael; Avezniyazov, Slava; Savkin, Alexander; Fedorov, Denis; Dmitriev, Sergei; Kornev, Vladimir

    2007-01-01

    At Moscow SIA 'Radon' jointly with JSC 'Alliance Gamma', the technology for NPP Decantate Treatment was developed, tested and realized at Kola NPP. This technology consists of dissolving the salt residue and subsequent treatment by ozonization, separation of the deposits formed from ozonization and selective cleaning by ferro-cyanide sorbents. The nonactive salt solution goes to an industrial waste disposal site or a repository specially developed at NPP sites for 'exempt waste' products by IAEA classification. This technology was realized at Kola NPP in December 2006 year. At this time more than 1000 m 3 of decantates log time stored are treated. It allows solving very old problem to empty decantates' tanks at NPPs in environmentally safe manner and with high volume reduction factor. (authors)

  18. NPOESS Preparatory Project (NPP) Science Overview

    Butler, James J.

    2011-01-01

    NPP Instruments are: (1) well understood thanks to instrument comprehensive test, characterization and calibration programs. (2) Government team ready for October 25 launch followed by instrument activation and Intensive Calibration/Validation (ICV). NPP Data Products preliminary work includes: (1) JPSS Center for Satellite Applications and Research (STAR) team ready to support NPP ICV and operational data products. (2) NASA NPP science team ready to support NPP ICV and EOS data continuity.

  19. Workflow in Almaraz NPP

    Gonzalez Crego, E.; Martin Lopez-Suevos, C.

    2000-01-01

    Almaraz NPP decided to incorporate Workflow into its information system in response to the need to provide exhaustive follow-up and monitoring of each phase of the different procedures it manages. Oracle's Workflow was chosen for this purpose and it was integrated with previously developed applications. The objectives to be met in the incorporation of Workflow were as follows: Strict monitoring of procedures and processes. Detection of bottlenecks in the flow of information. Notification of those affected by pending tasks. Flexible allocation of tasks to user groups. Improved monitoring of management procedures. Improved communication. Similarly, special care was taken to: Integrate workflow processes with existing control panels. Synchronize workflow with installation procedures. Ensure that the system reflects use of paper forms. At present the Corrective Maintenance Request module is being operated using Workflow and the Work Orders and Notice of Order modules are about to follow suit. (Author)

  20. Role of the Property Engineering in the units' construction of the Cernavoda nuclear power plant

    Esteban-Zazo Gomez, J. A.; Varas Suarez, M. I.; Dehalu, J. M.; Giura, A.

    2010-01-01

    The engineering of the property acts as owner's representative to ensure that the technical execution of the work is done according to the specifications. Normally, his paper complements the role of project management often tends to be more focused on the monitoring and supervision of commercial and financial aspects of it.

  1. Room 305/2 of the unit 4 of the Chernobyl ChNPP: its condition, evaluation of the fuel bulk

    Borovoj, A.A.; Pazukhin, Eh.M.; Lagunenko, A.S.

    1998-01-01

    The question on the bulk of the spent nuclear fuel in the room 305/2 of the Unit 4 has been given consideration. On the basis of the results of direct observations, tele- and photo shooting, data of chemical analysis of samples and measurement of the maximum exposure dose rate on drilling detailed model of the main elements relative position in the former core has been developed. Minimum fuel bulk in the room 305/2 has been evaluated

  2. Shock absorber in Ignalina NPP

    Bulavas, A.; Muralis, J.

    1996-09-01

    Theoretical calculation and experimental analysis of models of shock absorber in Ignalina NPP is presented. The results obtained from the investigation with model of shock absorber coincide with the theoretical calculation. (author). 2 figs., 3 refs

  3. Selection of NPP for Kazakhstan

    Zhotabaev, Zh.R.

    2003-01-01

    Commercial NPP for Kazakhstan should to meet to several main requirements: 1). Safety operation (accident probability not more than 10 -6 1/p. year). 2). High efficiency > 40 %. 3). Possibility of use for high-temperature chemistry and hydrogen production. 4). Possibility for manufacturing of considerable part of equipment in Kazakhstan. 5). Possibility for fuel production and reprocessing in Kazakhstan. 6). Independence from existence of large water-supply sources. Comparative analysis of several NPP with different reactors (WWR-1000, Candu, BREST, VG-400; graphite molten salt reactor) shows that NPP with the graphite molten salt reactor meets to all above requirements, but hydrogen production it is possible by more complete 4-stage technology, since coolant temperature is 800 Deg. C. The principle advantage is possibility of manufacturing of main equipment and fuel in Kazakhstan that reduce the cost of NPP construction and operation

  4. Modernization programme at Dukovany NPP

    Trnka, M.

    2000-01-01

    The main goal of each NPP is to produce electricity safely, economically and without influence to environment. For Dukovany NPP it means to upgrade all documentation and perform the Equipment Upgrading Programme. All these activities are time and money consuming and therefore the determination of priority of all items was necessary. In the presentation there are mentioned some important changes in documentation, results of PSA studies and reason for Equipment Upgrading Programme performance. It was selected the most important item from the list of Equipment Upgrading Programme the I and C upgrading. Management has decided that Dukovany NPP will become among the best NPPs with WWER type of reactor. It seems this decision is the best way how to extend lifetime of the NPP. (author)

  5. Suomi NPP Ground System Performance

    Grant, K. D.; Bergeron, C.

    2013-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, was launched on 28 October 2011, and is currently undergoing product calibration and validation activities. As products reach a beta level of maturity, they are made available to the community through NOAA's Comprehensive Large Array-data Stewardship System (CLASS). CGS's data processing capability processes the satellite data from the Joint Polar Satellite System satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to NOAA and Department of Defense (DoD) processing centers operated by the United States government. CGS is currently processing and delivering SDRs and EDRs for Suomi NPP and will continue through the lifetime of the Joint Polar Satellite System programs. Following the launch and sensor activation phase of the Suomi NPP mission, full volume data traffic is now flowing from the satellite through CGS's C3, data processing, and data delivery systems. Ground system performance is critical for this operational system. As part of early system checkout, Raytheon measured all aspects of data acquisition, routing, processing, and delivery to ensure operational performance requirements are met, and will continue to be met throughout the mission. Raytheon developed a tool to measure, categorize, and

  6. Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 7. Part 1. Localization of accident consequences at the 4th power unit, operating site of the Chernobyl NPP and adjoining territories

    Ignatenko, E.I.

    1989-01-01

    The next data on the accident consequence elimination are presented: temperature monitoring results, gamma radiation exposure dose rates, neutron and gamma fields, aerosol disperse composition. The information system for scientific researches FINISH and automatic subsystems for radiation control and the Ukrytie object diagnostics are described. Decontamination of the Chernobyl' NPP territory, equipment and rooms is described too

  7. Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 7. Part 2. Localization of accident consequences at the 4th power unit, operating site of the Chernobyl' NPP and adjoining territories

    Ignatenko, E.I.

    1989-01-01

    The next data on the accident consequence elimination are presented: temperature monitoring results, gamma radiation exposure dose rates, neutron and gamma fields, aerosol disperse composition. The information system for scientific researches FINISH and automatic subsystems for radiation control and the Ukrytie object diagnostics are described. Decontamination of the Chernobyl' NPP territory, equipment and rooms is described too

  8. Irradiation Embrittlement Monitoring Programs of RPV's in the Slovak Republic NPP's

    Kupca, Ludovik

    2006-01-01

    Four types of surveillance programs were (are) realized in Slovak NPP's: 'Standard Surveillance Specimen Program' (SSSP) was finished in Jaslovske Bohunice V-2 Nuclear Power Plant (NPP) Units 3 and 4, 'Extended Surveillance Specimen Program' (ESSP), was prepared for Jaslovske Bohunice NPP V-2 with aim to validate the SSSP results, For the Mochovce NPP Unit 1 and 2 was prepared completely new surveillance program 'Modern Surveillance Specimen Program' (MSSP), based on the philosophy that the results of MSSP must be available during all NPP service life, For the Bohunice V-1 NPP was finished 'New Surveillance Specimen Program' (NSSP) coordinated by IAEA, which gave arguments for prolongation of service life these units for minimum 20 years, New Advanced Surveillance Specimen Program (ASSP) for Bohunice V-2 NPP (units 3 and 4) and Mochovce NPP (units 1, 2) is approved now. ASSP is dealing with the irradiation embrittlement of heat affected zone (HAZ) and RPV's austenitic cladding, which were not evaluated till this time in surveillance programs. SSSP started in 1979 and was finished in 1990. ESSP program started in 1995 and will be finished in 2007, was prepared with aim of: increasing of neutron fluence measurement accuracy, substantial improvement the irradiation temperature measurement, fixed orientation of samples to the centre of the reactor core, minimum differences of neutron dose for all the Charpy-V notch and COD specimens, the dose rate effect evaluation. In the year 1996 was started the new surveillance specimen program for the Mochovce RPV's unit-1 and 2, based on the fundamental postulate - to provide the irradiation embrittlement monitoring till the end of units operation. The 'New Surveillance Specimen Program' (NSSP) prepared in the year 1999 for the Bohunice V-1 NPP was finished in the year 2004. Main goal of this program was to evaluate the weld material properties degradation due to the irradiation and recovery efficiency by annealing too. The

  9. Psychology of NPP operation safety

    Tret'yakov, V.P.

    1993-01-01

    The book is devoted to psychologic investigations into different aspects of NPP operative personnel activities. The whole set of conditions on which successful and accident-free personnel operation depends, is analysed. Based on original engineering and socio-psychologic investigations complex psychologic support for NPP personnel and a system of training and upkeep of operative personnel skills are developed. The methods proposed have undergone a practical examination and proved their efficiency. 154 refs., 12 figs., 9 tabs

  10. Chernobyl NPP accident: a year later

    Asmolov, V.G.; Borovoj, A.A.; Demin, V.F.

    1988-01-01

    Consideration is being given to measures on liquidation of Chernobyl accident aftereffects, conducted since August, 1986. One of the most important measures lay in construction of the ''shelter'', which must provide long-term conservation of accidental unit. Works on decontamination of reactor area and contaminated populated regions were continued. Measures on providing safety of population and its health protection were performed. An attention was paid to long-term investigations on studying delayed aftereffects of the accident, monitoring of invironment, development and introduction of measures on improving NPP safety. Prospects of further development of nuclear power engeneering and possibilities of improving its safety are considered

  11. Demands on project management of comprehensive modernization projects in the electrical systems area. Example of modernization of electrical systems of Kozloduy NPP Unit 5 and 6

    Stinshoff, Helmut; Weber, Patrick

    2006-01-01

    In nuclear power plants, station supply with electric energy must be guaranteed any time. This applies in particular also during the implementation of complex electrical systems modernization projects. Highest demands on the project management, extensive experience and system knowledge are required. In the frame of the Modernization Program for the nuclear power plant Kozloduy unit 5 and 6 in Bulgaria Framatome ANP has approved its ability to implement a large scope of modernization measures during the refueling outages of the years 2003 to 2005. The Contract of the Modernization Program for the European Consortium Kozloduy (Framatome ANP, Atomenergoexport) was signed in July 1999 and became effective in June 2001. The project will be finished by May 2006, with the approval of the Updated Final Safety Analysis Report. The scope of hardware work has been implemented within 6 plant outages during the years 2002 to 2005. The focus of the Modernization Program is mainly oriented to nuclear safety aspects, with the aim of upgrading of the Units to a high safety level in compliance with international practice. A further section of the project is dedicated to upgrading of operational equipment. Framatome ANP personnel have shown that besides the technical challenges which had to be faced, also the intercultural and language barriers were successfully overcome. The good teamwork between the partners of the Consortium ECK, its Bulgarian subcontractors and with Kozloduy plant personnel has been an important success factor. (authors)

  12. Welding of large-size embelled fittings in NPP construction

    Semenov, N.A.; Savinov, O.A.

    1988-01-01

    Drawbacks of the accepted technology for peoducing embedded fittings are considered. Activities on modernization of the standard ADF-2001 automatic welding machine are described. Results of testing the samples of welded joints performed using the modernized automatic welding machine, and economic effect caused by its introduction at the balakovo NPP second unit construction are presented

  13. The post-accidents exploitation of Chernobyl NPP

    Nosovskij, A.V.

    1996-01-01

    Problems facing the Chernobyl NPP personnel since its commissioning and during its post-accident operation are considered. The accomplished measures on improving the power units safety, normalization of the radiation situation as well as the impact of psychological factor at the safety culture level are discussed

  14. Device to measure level in a steam drum of NPP

    Vinogradov, Yu.A.

    1988-01-01

    Gravitation-hydrostatic device for measuring coolant level in a steam drum of NPP is described. The device enables to improve the accuracy and sensitivity of measuring coolant level above and below the submerged perforated sheet of the steam drum and decrease the amount of levelling vessels in the unit by 50%. 1 fig

  15. On improving the NPP construction long-term planning

    Solov'ev, M.M.

    1980-01-01

    General approaches to solving the problems of long-term planning of the construction-mounting work volume and introduction of power capacities at different paces of power unit commission and norms of construction time are considered. Problems associated with location and development of subsidiary industries providing NPP construction are discussed. It is shown that decrease of WWER-1000 reactor type NPP construction time from 24 to 12 months results in reduction of required high-skilled engineers, managerial staff, unique construction mechanisms and engines as well as in improvement of conditions for conducting measures on work arrangement during preparation of construction industry and mounting of the first assemblies

  16. NPP Temelin instrumentation and control system upgrade and verification

    Ubra, O.; Petrlik, J.

    1998-01-01

    Two units of Ver 1000 type of the Czech nuclear power plant Temelin, which are under construction are being upgraded with the latest instrumentation and control system delivered by WEC. To confirm that the functional design of the new Reactor Control and Limitation System, Turbine Control System and Plant Control System are in compliance with the Czech customer requirements and that these requirements are compatible with NPP Temelin upgraded technology, the verification of the control systems has been performed. The method of transient analysis has been applied. Some details of the NPP Temelin Reactor Control and Limitation System verification are presented.(author)

  17. Problems of complex automation of process at a NPP

    Naumov, A.V.

    1981-01-01

    The importance of theoretical investigation in determining the level and quality of NPP automation is discussed. Achievements gained in this direction are briefly reviewed on the example of domestic NPPs. Two models of the problem solution on function distribution between the operator and technical means are outlined. The processes subjected to automation are enumerated. Development of the optimal methods of power automatic control of power units is one of the most important problems of NPP automation. Automation of discrete operations especially during the start-up, shut-down or in imergency situations becomes important [ru

  18. Corrosion strength monitoring of NPP component residual lifetime

    Denisov, V.G.; Belous, V.N.; Arzhaev, A.I.; Shuvalov, V.A.

    1994-01-01

    Importance of corrosion and fatigue monitoring; types of corrosion determine the NPP equipment life; why automated on-line corrosion and fatigue monitoring is preferable; major stages of lifetime monitoring system development; major groups of sensors for corrosion and strength monitoring system; high temperature on-line monitoring of water chemistry and corrosion; the RBMK-1000 NPP unit automatic water chemistry and corrosion monitoring scheme; examples of pitting, crevice and general corrosion forecast calculations on the basis of corrosion monitoring data; scheme of an experimental facility for water chemistry and corrosion monitoring sensor testing. 2 figs., 4 tabs

  19. The evolution of the fuel cycle in the Dukovany NPP

    Bajgl, J [Jaderna Elektrarna, Dukovany (Czech Republic)

    1994-12-31

    The ten-year operational experience of four WWER-440 units in Dukovany NPP with a total number of 35 cycles is outlined. The strategy of fuel reloading has been changed from out-in schemes to low-leakage patterns. The linear pin power limitation will be introduced. The main physical limits and conditions for the NPP operation are listed. The main goal is to go to a full 4-year fuel cycle in which the burnup will be about 40 Mwd/kg U. 6 tabs.

  20. Modernization of Unit 2 at Oskarshamn NPP- Main Objectives, Experience from Design, Separation of Operational and Nuclear Safety Equipment - Lessons Learned

    Kanaan, Salah K.

    2015-01-01

    This paper aims to give a picture of Oskarshamn Nuclear Power Plant (OKG) experience from design for one of the biggest modernization project in the world and focuses on what was learned that is specific to robustness of electrical power systems, especially through Fukushima Station Blackout (SBO). The planning for unit 2 at OKG was initiated in 1967 and the plant was completed on time and was synchronized to the grid October 2, 1974 and is of type BWR. Unit 2 was originally on 580 MW. In 1982 a thermal power up-rate was performed, from 1700 MWh to 1800 MWh (106% reactor output). A decision was made to perform a modernization and a new power up-rate to 850 MW and there were several reasons for this decision; New safety regulations from Swedish Radiation Safety Authority (SSM), Ageing of important components and the initial focus was on safety and availability - Project Plant Life Extension (Plex) was established and became the largest nuclear power modernization in the world. The modernization will lead to: - New safety concept with 4 divisions instead for existing 2 with 2 new buildings South Electrical Building (SEB) and North Electrical Building (NEB); - Completely new software - based equipments for monitoring, control and I and C; - New Low Pressure Turbine, new generator and main transformer; - New MCR and simulator; - Compliance with modern reactor safety requirements; - Redundancy, Separation, Diversification, Earthquake; - Reinforcement of existing safety functions; - New Electricity - I and C (electric power incl. reinforced emergency power and control systems); - New buildings for Electricity - I and C; - Reinforcement of existing process systems as well as installation of new ones. Based on studies and good experiences on how to separate the operational and the safety equipment, the project led to a completely new safety concept. The safety concept is based on fully understanding the safety system that shall encompass all of the elements required to

  1. Evaluation of cost of radioactive waste management during the Chernobyl NPP decommissioning

    Gavrish, V.M.; Tkachev, D.A.

    2009-01-01

    The article presents the results of calculations on evaluation of radioactive waste volumes, the required financing, and the labor expenses for management of radioactive waste that may arise during the decommissioning of Chernobyl NPP Units 1, 2, 3

  2. Main principles of the Chernobyl' NPP zone development

    Ignatenko, E.I.; Komarov, V.I.; Zverkov, V.V.; Proskuryakov, A.G.

    1989-01-01

    It is suggested to divide the Chernobyl' NPP zone into two parts, which are the alienation and evacuation (buffer) zones. The alienation zone includes the areas with greatest contamination around the Chernobyl' NPP. The population residence in this zone is forbidden. The watching method of working with short-time personnel residence is suggested to be used in this zone. The buffer zone is the territory out of the alienation zone boundaries including all settlements, from which the population is evacuated. Constant residence is permitted in the buffer zone for persons 50 and more years old with introduction of restrictions for diet and residence organization. The production activity in this zone includes operation of three units of the Chernobyl' NPP, works with the Ukrytie object and researches. Operations connected with radioactive waste processing and redisposal from places of storage is not recommended to be done. It is suggested to develop methods for local radioactive waste processing

  3. Construction of Belene NPP in Bulgaria

    JSC Atomstroyexport

    2010-01-01

    Presentations concluding remarks: ASE has performed its scope of responsibilities under the Agreement of 29.11.2006 and has achieved great results regarding both the Technical part of the Project and its organization; Though there is a number of unsettled issues under the Project, in particular, the issue related to financing, ASE is willing to continue the Project and works on its development; The Russian Party believes that in case the activities under the Project are continued, Belene NPP will be constructed with high quality and within the time limits prescribed in the Agreement of 29.11.2006: 59 months before Unit 1 take-over into operation and 71 month before Unit 2 take-over into operation, starting from concreting of foundation slab of Unit 1 Reactor building

  4. Development status of the cryogenic distillation system in Cernavoda Tritium Removal Facility

    Draghia, Mirela; Ana, George; Pasca, Gheorghe; Porcariu, Florina

    2009-01-01

    Full text: The reference design technology for the heavy water detritiation plant of Cernavoda CANDU station is based on combination of Liquid Phase Catalytic Exchange (LPCE) and Cryogenic Distillation (CD) processes. Based on this technology, tritium is transferred from the heavy water to a deuterium stream in the catalyzed isotopic exchange process, LPCE, followed by a final enrichment within the cryogenic distillation cascade. The final step is the tritium storage on metallic hydride. The basic function of the Cryogenic Distillation System (CDS) is the separation of tritium from the tritiated deuterium coming from the LPCE column in the following conditions: - the final product has to be tritium with a concentration of at least 99%; - it must be provided a detritiation factor of at least 100 (the ration between the tritium concentration in the deuterium stream fed to the CD system and the tritium concentration in the returned stream to the LPCE); - the deuterium must be enriched up to 99.995%, by removing the protium; - provisions for safe discharge of the entire inventory of the CD cascade into buffer vessels shall be implemented. To summarize, the present status of the project consists of technical documentation for all the components of CDS, including the P and ID (Pipping and Instrumentation Diagram), preliminary data sheets, technical specifications, drawings for the major components as the buffer vessels, coldbox, etc, and 3D models as well for almost all the components. (authors)

  5. The role of the international Chornobyl Center in coordinating and conducting the work related to Chornobyl NPP closure and creation the new employment opportunities in Slavutych

    Nosovskij, A.V.

    2001-01-01

    The Slavutych division of the international Chornobyl Center (ICC) actively conducts its work in Slavutych from 1997. The following work was conducted during the last years: Documentation on the ChNPP 1-st Unit and 2-nd Unit decommissioning was developed. Comprehensive engineering and radiation survey of the 1-st Unit was conducted. Decommissioning database was created. On demand of Chornobyl NPP, the work on development the following documents was conducted: The 3-rd Unit shutdown program. Comprehensive program on ChNPP decommissioning. ChNPP personnel and Slavutych residents social protection program

  6. Spain in South Ukraine NPP

    Ibanez, M.

    1994-01-01

    A Technical Assistance Protocol was signed between the Governments of the GIS and the Commission of the European Union (CEU) on August 2, 1991 and this was the starting point of the TACIS program. In this article, the activities described are those related to the TACIS-92/93/94 on site technical assistance to South Ukraine NPP (SUK NPP). Within the scope of the TACIS 92 Program the CEU and the Ukrainian Authorities agreed a list of projects to be implemented at South Ukraine NPP with the aim to improve the operational safety of the plant. This part of the program is called TACIS 92 on-site activities. The total budget allocated to these projects is a MECU. The European Union ''utility'' selected to lead this program at South Ukraine NPP was UNESA and the first contract to cover our activities was signed in July 1993 between the CEU (Mr. Pablo Benavides) and UNESA (Mr. Pedro Rivero). The projects will be implemented at SUK NPP but according to the contract UNESA is ''The Consultant'' and GOSKOMATON (The Ukrainian Sate Committee on Nuclear Power Utilization) is the ''Recipient Institution''. (Author)

  7. Emergency preparedness at Ignalina NPP

    Kairys, A.

    1998-01-01

    Brief review of Ignalina NPP safety upgrading and personnel preparedness to act in cases of accidents is presented. Though great activities are performed in enhancing the plant operation safety, the Ignalina NPP management pays a lot of attention to preparedness for emergency elimination and take measures to stop emergency spreading. A new Ignalina NPP emergency preparedness plan was drawn up and became operational. It is the main document to carry out organizational, technical, medical, evacuation and other activities to protect plant personnel, population, the plant and the environment from accident consequences. Great assistance was rendered by Swedish experts in drawing this new emergency preparedness plan. The plan consists of 3 parts: general part, operative part and appendixes. The plan is applied to the Ignalina NPP personnel, Special and Fire Brigade and also to other contractor organizations personnel carrying out works at Ignalina NPP. There are set the following emergency classes: incident, emergency situation, alert, local emergency, general emergency. Separate intervention level corresponds to each emergency class. Overview of personnel training to act in case of an emergency is also presented

  8. Some problems of NPP personnel training

    Vajshnis, P.P.; Kumkov, L.P.; Omel'chuk, V.V.

    1984-01-01

    Shortcomings of NPP personnel training are discussed. Development of full-scale training systems is necessary for qualitative training operative personnel. Primary problems that should be necessarily solved for ensuring effective training NPP personnel are considered

  9. Individual protection of NPP personnel

    Koshcheev, V.S.; Gol'dshtejn, D.S.; Chetverikova, Z.S.

    1983-01-01

    Specific features of NPP personnel individual protection are considered, mainly with respect to maintenance and repair works on various type reactors. The major concern is given to the selection and application reglamentations of the individual protection system (IPS), employment of sanitary locks, the organization of individual protection under the conditions of a heating microclimate. The ways are specified to the development and introduction of the most effective IPS and improvement of the entire NPP personnel individual protection system with respect to providing the necessary protection effect for maintaining high working capability of the personnel and minimizing the IPS impact on human organism functional systems. The accumulated experience in the personnel individual protection can be applied during construction and operation of NPP's in CMEA member-countries [ru

  10. Safety culture at Mochovce NPP

    Markus, Jozef; Feik, Karol

    2002-01-01

    This article presents the approach of Mochovce NPP to the Safety culture. It presents activities, which have been taken by Mochovce NPP up to date in the area of Safety culture enhancement with the aim of getting the term into the subconscious of each employee, and thus minimising the human factor impact on occurrence of operational events in all safety areas. The article furthermore presents the most essential information on how the elements characterising a continuous progress in reaching the planned Safety culture goals of the company management have been implemented at Mochovce NPP, as well as the management's efforts to get among the best nuclear power plant operators in this area and to be an example for the others. (author)

  11. Dynamic model for tritium build-up at NPP with RBMK type reactors and its enviromental beraviour

    Badyaev, V.V.; Egorov, Yu.A.; Ivanov, E.A.; Stegachev, G.F.; Tolstykh, V.D.

    1982-01-01

    A model of tritium production dynamics for a high power NPP with RBMK type reactors is proposed and investigated. The main ''skeleton'' model structure for forecasting tritium buildup at a NPP and its exchange with the environment has been singled out at a heuristic level. Decomposition and layout of the units have been performed by global functional relations of the investigated objects (NPP and environment). the model accounts for only oxidized tritium forms. Water exchange between the NPP subsystems and environment is the main mechanism for tritium migration. The model does not account for scheduled periodic maintenance work effects, presence of stagnant zones in the station circuits, fuel burn-up, etc. The parametric identification method applied in the model makes the model adaptable to particular situations and considered systems of the NPP and environment. Completing the model with necessary and sufficient experimental data one can pass to certain forecasting problems and to NPP control as a tritium source in the environment

  12. Radioactive wastes management of NPP

    Klyuchnikov, A.A.; Pazukhin, Eh.M.; Shigera, Yu. M.; Shigera, V.Yu.

    2005-01-01

    Modern knowledge in the field of radiation waste management on example of the most serious man-made accident at Chernobyl NPP are illuminated. This nuclear power plant that after accident in 1986 became in definite aspect an experimental scientific ground, includes all variety of problems which have to be solved by NPP personnel and specialists from scientific organizations. This book is aimed for large sphere of readers. It will be useful for students, engineers, specialists and those working in the field of nuclear power, ionizing source and radiation technology use for acquiring modern experience in nuclear material management

  13. NPP Krsko secondary side analysis

    Fabijan, Lj.

    1987-01-01

    The purpose of this work is to analyze secondary side thermohydraulics response on steam generator tube plugging in order to ensure nominal NPP power. We had established that the additional opening of the governing valve No. 3 and 4 can compensate pressure drop caused by steam generator tube plugging. Two main steam flows with four governing valves were simulated. Steam expansion in turbine and feed water system was modeled separately. All important process point and steam moisture changes impact on nominal NPP power were analysed. (author)

  14. Concreting organization during Chernobylsk NPP construction

    Lysyuk, R.I.; Kareva, A.P.

    1984-01-01

    Conreting organization during the Chernobylsk NPP construction is described. Processes of extra heavy concrete production and placement, which specific mass constitutes 4t/m 3 at the age of 28 days wiath metallic aggregates and 3.3-3.5 t/m 3 at the same age without aggregates, are considered in short. Basic characteristics of this concrete are presented. At the 4th power unit labour contents for construction works were a 1.5 times lower as compared to the 3rd power unit erection. This progress was achieved by round-the-clock operation of the concrete plant with the 800 m 3 /day output and also by utilization of special equipment for mechanized concrete placement: concrete pumps, automatic concrete mixer, manipulators and concrete pipelines

  15. The Chernobyl NPP decommissioning: Current status and alternatives

    Mikolaitchouk, H.; Steinberg, N.

    1996-01-01

    After the Chernobyl accident of April 26, 1986, many contradictory decisions were taken concerning the Chernobyl nuclear power plant (NPP) future. The principal source of contradictions was a deadline for a final shutdown of the Chernobyl NPP units. Alterations in a political and socioeconomic environment resulted in the latest decision of the Ukrainian Authorities about 2000 as a deadline for a beginning of the Chernobyl NPP decommissioning. The date seems a sound compromise among the parties concerned. However, in order to meet the data a lot of work should be done. First of all, a decommissioning strategy has to be established. The problem is complicated due to both site-specific aspects and an absence of proven solutions for the RBMK-type reactor decommissioning. In the paper the problem of decommissioning option selection is considered taking into account an influence of the following factors: relevant legislative and regulatory requirements; resources required to carry out decommissioning (man-power, equipment, technologies, waste management infrastructure, etc.); radiological and physical status of the plant, including structural integrity and predictable age and weather effects; impact of planned activities at the destroyed unit 4 and within the 30-km exclusion zone of the Chernobyl NPP; planed use of the site; socio-economic considerations

  16. Equipment maintenance as a tool for raising of safety and efficiency of the NPP'Kozloduy' operation

    Kichev, E.

    1999-01-01

    The role of the maintenance in the NPP management is discussed. The main links in the management are: NPP executives and their position; maintenance; quantitative characteristics of the maintenance. The described management process gives the opportunity the maintenance optimization on different levels: component, system, unit, plant. The results are valid for other areas with high safety requirements

  17. Nuclear Oversight Function at Krsko NPP

    Bozin, B.; Kavsek, D.

    2010-01-01

    industry experience (events, good practice etc.) in its assessment. That becomes most important in small utilities (with one nuclear unit only) such as the Krsko NPP. Involvement in international organizations is therefore a must and not an option for such organization. The Krsko NPP is today widely involved in various international organizations. Both sides are deriving substantial benefits from such cooperation.(author).

  18. Implementation of the KASKAD computer code system for WWER-440 at Kozloduy NPP

    Antonov, A.; Georgieva, N.; Spasova, V.

    2003-01-01

    Since 2002 at Kozloduy NPP - EP1 the code package KASKAD is used for WWER-440 reactor core calculations. The main codes entering this package are: BIPR-7A: 3-D diffusion and core analysis code; PERMAK-A: 2-D fine mesh diffusion code. The burnup calculations were performed for all cycles of the Kozloduy NPP Unit 1, Unit 2, Unit 3 and Unit 4. For the last 4-5 cycles of the Units were calculated control rods worth, critical boron concentration at zero power, reactivity coefficients and linear power. These results were analysed and were compared with experimental data. Some results were given in this paper

  19. Can the Ignalina NPP be safe?

    Kutas, S.

    1999-01-01

    Many countries started using nuclear power before Lithuania, the IAEA and NEA were established and have been functioning efficiently, numerous conventions have been signed that control nuclear activities, nuclear safety regulations and standards have been set. Lithuania which is striving to integrate into the West European structures and to become a member of the 'club' of the world's nuclear states, has become a full and equal member of the IAEA and recognises its recommendations. Furthermore, it has signed or joined international conventions and is doing its best to introduce the practice of controlling nuclear safety applied in western countries. Nuclear safety cannot be taken as something finite that does not change. The requirements of nuclear and radiation safety are continuously redefined taking into consideration scientific discoveries and inventions as well as technical progress. Safety assurance can be the only criterion that should determine whether the nuclear power plant can be operated in Lithuania. The safety analysis report confirmed that the Ignalina NPP can be safely operated until the channel-graphite gap closes. The experiments conducted to date have convincingly shown that by the year 2000 the gap will not close in any of the fuel channels of unit 1. It can be hoped that the submitted studies, analyses and assessments will confirm that the Ignalina NPP meets Lithuania's nuclear safety requirements that have been drawn up in compliance with the recommendations of IAEA

  20. Feed water distribution pipe replacement at Loviisa NPP

    Savolainen, S.; Elsing, B. [Imatran Voima Loviisa NPP (Finland)

    1995-12-31

    Imatran Voima Oy operates two WWER-440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of feed water distribution (FWD) pipe were observed in 1989. The FWD-pipe T-connection had suffered from severe erosion corrosion damages. Similar damages have been been found also in other WWER-440 type NPPs. In 1989 the nozzles of the steam generator YB11 were inspected. No signs of the damages or signs of erosion were detected. The first damaged nozzles were found in 1992 in steam generators of both units. In 1992 it was started studying different possibilities to either repair or replace the damaged FWD-pipes. Due to the difficult conditions for repairing the damaged nozzles it was decided to study different FWD-pipe constructions. In 1991 two new feedwater distributors had been implemented at Dukovany NPP designed by Vitckovice company. Additionally OKB Gidropress had presented their design for new collector. In spring 1994 all the six steam generators of Rovno NPP unit 1 were replaced with FWD-pipes designed by OKB Gidropress. After the implementation an experimental program with the new systems was carried out. Due to the successful experiments at Rovno NPP Unit 1 it was decided to implement `Gidropress solution` during 1994 refueling outage into the steam generator YB52 at Loviisa 2. The object of this paper is to discuss the new FWD-pipe and its effects on the plant safety during normal and accident conditions. (orig.).

  1. Feed water distribution pipe replacement at Loviisa NPP

    Savolainen, S; Elsing, B [Imatran Voima Loviisa NPP (Finland)

    1996-12-31

    Imatran Voima Oy operates two WWER-440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of feed water distribution (FWD) pipe were observed in 1989. The FWD-pipe T-connection had suffered from severe erosion corrosion damages. Similar damages have been been found also in other WWER-440 type NPPs. In 1989 the nozzles of the steam generator YB11 were inspected. No signs of the damages or signs of erosion were detected. The first damaged nozzles were found in 1992 in steam generators of both units. In 1992 it was started studying different possibilities to either repair or replace the damaged FWD-pipes. Due to the difficult conditions for repairing the damaged nozzles it was decided to study different FWD-pipe constructions. In 1991 two new feedwater distributors had been implemented at Dukovany NPP designed by Vitckovice company. Additionally OKB Gidropress had presented their design for new collector. In spring 1994 all the six steam generators of Rovno NPP unit 1 were replaced with FWD-pipes designed by OKB Gidropress. After the implementation an experimental program with the new systems was carried out. Due to the successful experiments at Rovno NPP Unit 1 it was decided to implement `Gidropress solution` during 1994 refueling outage into the steam generator YB52 at Loviisa 2. The object of this paper is to discuss the new FWD-pipe and its effects on the plant safety during normal and accident conditions. (orig.).

  2. Preparation for Early Termination of Ignalina NPP Operation

    Poskas, P.; Poskas, R.

    2003-01-01

    Seimas (Parliament of Lithuania) approved updated National Energy strategy where it is indicated that first Unit will be shutdown before the year 2005 and second Unit in 2009 if funding for decommissioning is available from EU and other donors. In accordance to Ignalina NPP Unit 1 Closure Law the Government of Lithuania approved the Ignalina NPP Unit 1 Decommissioning Program until year 2005. For enforcement of this program, the plan of measures for implementation of the program was prepared and approved by the Minister of Economy. The plan consists of two parts, namely technical- environmental and social-economic. Technical-environmental measures are mostly oriented to the safe management of spent nuclear fuel and operational radioactive waste stored at the plant and preparation of licensing documents for Unit 1 decommissioning. Social-economic measures are oriented to mitigate negative social and economic impact on Lithuania, inhabitants of the region, and, particularly, o n the staff of Ignalina NPP by means of creating favorable conditions for a balanced social and economic development of the region. In this paper analysis of planned activities, licensing requirements for decommissioning, progress in preparation of the Final Decommissioning Plan is discussed

  3. Safety aspects of NPP ageing

    1995-01-01

    Preparation of safety practices on assessment and management of aging of major NPP components important to safety, CRP on management of aging of concrete containment buildings, CRP on management of aging of in-containment instrumentation and control cables are outlined

  4. Qualification of NPP operations personnel

    Wang Jiao.

    1987-01-01

    Competence of personnel is one of the important problems for safety operation of nuclear power plant. This paper gives a description of some aspects, such as the administration of NPP, posts, competence of personnel, training, assessing the competence and personnel management

  5. Detection of primary coolant leaks in NPP

    Slavov, S.; Bakalov, I.; Vassilev, H.

    2001-01-01

    The thermo-hydraulic analyses of the SG box behaviour of Kozloduy NPP units 3 and 4 in case of small primary circuit leaks and during normal operation of the existing ventilation systems in order to determine the detectable leakages from the primary circuit by analysing different parameters used for the purposes of 'Leak before break' concept, performed by ENPRO Consult Ltd. are presented. The following methods for leak detection: measurement of relative air humidity in SG box (can be used for detection of leaks with flow rate 3.78 l/min within one hour at ambient parameters - temperature 40 0 - 60 0 C and relative humidity form 30% to 60%); measurement of water level in SG box sumps (can not be used for reliable detection of small primary circuit leakages with flow rate about 3.78 l/min); measurement of gaseous radioactivity in SG box( can be used as a general global indication for detection of small leakages from the primary circuit); measurement of condensate flow after the air coolers of P-1 venting system (can be used for primary circuit leak detection) are considered. For determination of the confinement behaviour, a model used with computer code MELCOR has been developed by ENPRO Consult Ltd. A brief summary based on the capabilities of the different methods of leak detection, from the point of view of the applicability of a particular method is given. For both Units 3 and 4 of Kozloduy NPP a qualified complex system for small leak detection is planned to be constructed. Such a system has to unite the following systems: acoustic system for leak detection 'ALUS'; system for control of the tightness of the main primary circuit pipelines by monitoring the local humidity; system for primary circuit leakage detection by measuring condensate run-off in collecting tank after ventilation system P-1 air coolers

  6. Experience in NPP operation and prospects of nuclear power development in France

    Lekler, Zh.

    1986-01-01

    Main results and perspectives of nuclear power development in France are analysed. Data characterizing operation of NPPs with PWR reactors in France and leading capitalist countries are given. Problems related to the organization of works on control of NPP operation and its maintenance are discussed. Power utilization factor for french power units amounted to 75% in 1984. NPP share of all electric power generated in the country constituted 59%. Emergency reactor shut-downs took 5% of calendar time in 1984

  7. Analysis of NPP protection structure reliability under impact of a falling aircraft

    Shul'man, G.S.

    1996-01-01

    Methodology for evaluation of NPP protection structure reliability by impact of aircraft fall down is considered. The methodology is base on the probabilistic analysis of all potential events. The problem is solved in three stages: determination of loads on structural units, calculation of local reliability of protection structures by assigned loads and estimation of the structure reliability. The methodology proposed may be applied at the NPP design stage and by determination of reliability of already available structures

  8. Use of operator training and simulating complexes for development of NPP APCS

    Malkin, S.D.; Rakitin, I.D.; Sivokon', V.P.

    2002-01-01

    The evolution of NPP educational facilities - from systems of training of personnel to power simulating systems for the development of Automatic Process Control System (APCS) and safety analysis is followed. High efficiency of simulating systems application for the development of NPP APCS including optimization of man-machine system interface was shown by experiments of USA, France, Japan, United Kingdom, conforming examples were given [ru

  9. Preventing degradation and in-service inspection of NPP steam generator

    Ding Xunshen

    1999-01-01

    The author describes the degradation of steam generator tubes in initial operating stage of France NPP. The author emphatically presents the preventive measures to tackle degradation and In-service inspection of Daya Bay NPP 1 unit as a guarantee of safety operation, including secondary side water chemistry monitoring and controlling, leakage rate monitoring, eddy-current inspection, mechanical cleaning, cleanliness inspection, foreign objects removal and etc

  10. Low level radioactive waste disposal in Kozloduy NPP in Bulgaria

    Stanchev, V.

    2001-01-01

    Kozloduy NPP is the biggest power plant in the Republic of Bulgaria. It is in operation since 1974 and for the past 25 years it has generated over 263 billion kWh electric power. The NPP share in the total electric production in 1998 was about 50%. It has six units in operation - four WWER 440 B-230 and two WWER 1000 B-320. In the nuclear reactor operation the generation of radioactive waste (RAW) is an inevitable process. The waste must be conditioned, stored and disposed of in a safe manner. There are no national radioactive waste disposal facilities, for waste generated by an NPP, in Bulgaria to the moment. This situation necessitates the storage of operational RAW to be carried out on site for a long period of time (30 to 50 years). Following the principle for protection of human health and environment now and in the future, Kozloduy NPP adopted the concept for conditioning the RAW to a stable solid form and placing the waste in a package which should keep its features for a sufficiently long term so that the package can be safely transported to the disposal site. (author)

  11. Implementation of the II. Stage decommissioning of A1 NPP

    Ficher, T.

    2015-01-01

    Presentation is focused on the implementation of the II. stage decommissioning of A1 NPP. Introductory part focuses on brief characteristics of the power plant with a history of operation, basic technical parameters and actions that were made after operation. The next section describes the basic schedule for decommissioning, structure of management and implementation of the II. stage decommissioning of the A1 NPP and objectives of the individual stages. The last and largest part of the presentation is devoted to detailed description of the II. stage decommissioning of the A1 NPP, its individual tasks and verbal and visual description of the activities that were performed. Presented is decommissioning of the technology and construction of external objects NPP A1 including storage tanks for liquid RAW, next are presented activities carried out in the Main Production Unit - decommissioning of non-operating technologies in various places/rooms, management of waste arising from these activities, treatment of case of A1 long-term spent fuel storage and long-term spent fuel storage. The subsequent section is devoted to the management and handling of contaminated soil, concrete and construction waste, including management of VLLW. (authors)

  12. Nuclear fuel utilization at the Kozloduy NPP

    Boyadzhiev, Z [Kombinat Atomna Energetika, Kozloduj (Bulgaria); Kharalampieva, Ts; Pejchinov, Ts

    1996-12-31

    Data on core loading and operation conditions during past fuel cycles of the Units 1 to 6 at the Kozloduy NPP are presented. The Units 1 and 2 have reached average discharge fuel burn-up of 31 MW d/kg U, the Unit 3 - 34 MW d/kg U and the Unit 4 - 36.5 MW d/kg U. By use of dummies and low-leakage core loading patterns for WWER-440 cores an effective reduction in reactor pressure vessel irradiation is obtained. By increasing the enrichment level and improving the characteristics of the Units 3 and 4, a design fuel cycles duration has been reduced by 5-10% in number of assemblies. Core loading design has been modelled using computer codes SPPS-1, BIPR-7, ALBOM, PROROC. A 3-year fuel cycle utilizing 4.4% enriched fuel proved to be more efficient for WWER-1000 by 15% reduction in fuel cost compared to the 2-year cycle. Future developments include improvements of the in-core monitoring system and process on-line simulation based on more accurate computer codes. 7 refs., 6 figs., 10 tabs.

  13. The role of research programs and commercial contracts for increase of economic competitiveness and development at INR Pitesti

    Petra, Nicoleta Mihaela; Ionila, Maria; Datcu, Mirela; Balan, Iosif Bogdan; Cretu, Ileana

    2008-01-01

    In the period in which globalization is increasing, one of the strategic objectives of the institute is to focus on those activities which help developing of services, products and technologies, applicable in nuclear industry, environment protection and medicine. One way to sustain INR activity is the technological transfer which ensures availability of research results by carrying out of R and D contracts in priority areas and of contracts with economical agents for the supply of services, products, technologies, such as: - Materials irradiation for medicine, industry and research; - Neutron Activation Analysis (NAA) and prompt gamma spectrometry for Cernavoda NPP - Unit 1; - Control and testing: non-destructive examination, functional tests of samples and equipment from Cernavoda NPP - Unit 1; - Characterization, conditioning and treatment of radioactive wastes for NPP- Cernavoda, Unit 1, Nuclear Fuel Plant (FCN) - Pitesti; - Measurement of isotopes concentration in environmental samples; -Corrosion experiments in static autoclaves and experiments regarding microbial corrosion for NPP Cernavoda Unit 1 and FCN Pitesti; - Nuclear consultancy for Cernavoda NPP - Unit 1 and Unit 2; - Stainless steel casks for radwaste; - Containers for heavy water; - Training and practice for students at the Universities of Pitesti, Bucuresti, Brasov. The paper presents the main areas where the results obtained in R and D programs can be applied, their implementation can be done, and the status of contracts and their importance for INR Pitesti and Romanian society development, as well. (authors)

  14. Experience of TVSA fuel implementation at Kozloduy NPP

    Kamenov, K.; Kamenov, AI.; Hristov, D.

    2011-01-01

    The base design of the Russian fuel assemblies TVSA have been under operation at Kozloduy NPP WWER-1000 reactors since 2004. The old type fuel assemblies TVS-M were gradually substituted till 2008. The TVSA assembly distinguishes itself with much stronger construction. As a burnable absorber it has a mixture of uranium and uniformly distributed Gd in 6 or more fuel rods. This enables to increase the safety and effectiveness of fuel cycles. The experience gained during TVSA fuel implementation on units 5 and 6 and KASKAD code package validation was presented at the eightieth International conference on WWER 'Fuel performance, modelling and experimental support in 2009'. Additional information about TVSA fuel implementation at Kozloduy NPP WWER-1000 units in a 4-year fuel cycle with 42 and 48 fresh fuel assemblies reloading scheme is presented in the paper. (Authors)

  15. Challenges of Ignalina NPP Decommissioning - View of Lithuanian Operator

    Aksionov, P.

    2017-01-01

    The state enterprise Ignalina Nuclear Power Plant (INPP) operates 2 similar design units of RBMK-1500 water-cooled graphite-moderated channel-type power reactors (1500 MW electrical power). INPP is carrying out the decommissioning project of the 2 reactors which includes: -) the retrieval of the spent nuclear fuel from the power units and its transportation into the Interim Spent Fuel Storage Facility; -) equipment and building decontamination and dismantling; -) radioactive waste treatment and storage; and -) the operation of key systems to ensure nuclear, radiation and fire protection. Ignalina NPP decommissioning project is planned to be completed by 2038. The presentation will be focused on the ongoing decommissioning activities at Ignalina NPP. The overview of main aspects and challenges of INPP decommissioning will be provided

  16. Simulators for NPP operators

    Yuzhakov, A.Yu.

    2010-01-01

    The author reports on the application of full-scale simulators for training and maintaining proficiency of unit control room operators that is an essential element of Russian NPPs personnel education system. The existing simulators for the unit control room operating personnel are listed. The integrated approach to developing and maintaining the training hardware is described. The integrated approach is being implemented on the basis of observance of the existing requirements to training hardware, improvement of regulations, control from a single centre responsible for the provision of support to the activities, inclusion into the plans of simulators for development of skills for operating control over equipment and systems, as well as control from local boards [ru

  17. Quality assurance during construction and mounting of the Balakovo NPP

    Savkin, A.I.; Vorob'ev, N.G.; Kugrysheva, M.A.

    1984-01-01

    Measures directed at opportune comissioning of the first unit of Balakovo NPP with the caracity 1000 MW(el.) are briefly described. A high quality of construction and mounting works is achieved due to a high level of engeneering preparation in the industry, organization of daily control over the works implementation and quality of products and materials supplied, by the improvement of automation and introduction of progressive forms of organization and remuneration

  18. Primary circuit water chemistry during shutdown period at Kalinin NPP

    Gorbatenko, S.; Otchenashev, G.; Yurmanov, V.

    2005-01-01

    The primary circuit water chemistry feature at Kalinin NPP is using of special up-dated regime during the period of unit shutdown for refueling. The main objective of up-dated regime is removing from the circuit long time living corrosion products on SVO-2 ion exchange filters with the purpose of dose rates reduction from the equipment and in such a way reduction of maintenance personnel overexposure. (N.T.)

  19. ASSET experience at Paks NPP

    Szabo, I.

    1997-01-01

    At Paks NPP special attention has been paid to international reviews since the very beginning of operation. Several international teams visited Paks in order to provide independent assessment of plant performance, conditions and safety. Paks NPP Management has the further intention to invite international reviews regularly (yearly) in the future as well. The experience gained during these reviews helped to establish a unified process of preparation for the reviews, performing them and handling the results. The Safety Department is in charge of organization of the whole process. All these reviews have their specific features and they are focused on different areas. The ASSET reviews provides the assessment of plant performance and safety through the analysis of safety significant events, which have occurred at the nuclear power plant. This approach makes this review specific and different from the other ones

  20. ASSET experience at Paks NPP

    Szabo, I [Operational Safety Dept., Paks NPP, Paks (Hungary)

    1997-10-01

    At Paks NPP special attention has been paid to international reviews since the very beginning of operation. Several international teams visited Paks in order to provide independent assessment of plant performance, conditions and safety. Paks NPP Management has the further intention to invite international reviews regularly (yearly) in the future as well. The experience gained during these reviews helped to establish a unified process of preparation for the reviews, performing them and handling the results. The Safety Department is in charge of organization of the whole process. All these reviews have their specific features and they are focused on different areas. The ASSET reviews provides the assessment of plant performance and safety through the analysis of safety significant events, which have occurred at the nuclear power plant. This approach makes this review specific and different from the other ones.

  1. Nuclear Fuel in Cofrentes NPP

    2002-01-01

    Fuel is an essential in the nuclear power generating business because of its direct implications on safety, generating costs and the operating conditions and limitations of the facility. Fuel management in Cofrentes NPP has been targeted at optimized operation, enhanced reliability and the search for an in-depth knowledge of the design and licensing processes that will provide Iberdrola,as the responsible operator, with access to independent control of safety aspects related to fuel and free access to manufacturing markets. (Author)

  2. NPP Krsko Living PSA Concept

    Vrbanic, I.; Spiler, J.

    2000-01-01

    NPP Krsko developed PSA model of internal and external initiators within the frame of the Individual Plant Examination (IPE) project. Within this project PSA model was used to examine the existing plant design features. In order to continue with use of this PSA model upon the completion of IPE in various risk-informed applications in support of plant operation and evaluations of design changes, an appropriate living PSA concept needed to be defined. The Living PSA concept is in NPP Krsko considered as being a set of activities pursued in order to update existing PSA model in a manner that it appropriately represents the plant design, operation practice and history. Only a PSA model which is being updated in this manner can serve as a platform for plant-specific risk informed applications. The NPP Krsko living PSA concept is based on the following major ponts. First, the baseline PSA model is defined, which is to be maintained and updated and which is to be reference point for any risk-informed application. Second, issues having a potential for impact on baseline PSA model are identified and procedure and responsibilities for their permanent monitoring and evaluation are established. Third, manner is defined in which consequential changes to baseline PSA model are implemented and controlled, together with associated responsibilities. Finally, the process is defined by which the existing version of baseline PSA model is superseded by a new one. Each time a new version of baseline PSA model is released, it would be re-quantified and the results evaluated and interpreted. By documenting these re-quantifications and evaluations of results in a sequence, the track is being kept of changes in long-term averaged risk perspective, represented by long-term averaged frequencies of core damage and pre-defined release categories. These major topics of NPP Krsko living PSA concept are presented and discussed in the paper. (author)

  3. Welding facilities for NPP assembling

    Rojtenberg, S.S.

    1987-01-01

    Recommendations concerning the choice of equipment for welding in pre-assembling work shops, in the enlarging assembling shops and at the assembling site, are given. Advanced production automatic welders and semiautomatic machines, applied during the NPP equipment assembling as well as automatic machines specially produced for welding the main reactor components and pipelines are described. Automatic and semiautomatic machine and manual welding post supply sources are considered

  4. Lessons learnt from Ignalina NPP decommissioning project

    NAISSE, Jean-Claude

    2007-01-01

    The Ignalina Nuclear Power Plant (INPP) is located in Lithuania, 130 km north of Vilnius, and consists of two 1500 MWe RBMK type units, commissioned respectively in December 1983 and August 1987. On the 1. of May 2004, the Republic of Lithuania became a member of the European Union. With the protocol on the Ignalina Nuclear Power in Lithuania which is annexed to the Accession Treaty, the Contracting Parties have agreed: - On Lithuanian side, to commit closure of unit 1 of INPP before 2005 and of Unit 2 by 31 December 2009; - On European Union side, to provide adequate additional Community assistance to the efforts of Lithuania to decommission INPP. The paper is divided in two parts. The first part describes how, starting from this agreement, the project was launched and organized, what is its present status and which activities are planned to reach the final ambitious objective of a green field. To give a global picture, the content of the different projects that were defined and the licensing process will also be presented. In the second part, the paper will focus on the lessons learnt. It will explain the difficulties encountered to define the decommissioning strategy, considering both immediate or differed dismantling options and why the first option was finally selected. The paper will mention other challenges and problems that the different actors of the project faced and how they were managed and solved. The paper will be written by representatives of the Ignalina NPP and of the Project Management Unit. (author)

  5. On the NPP structural reliability

    Klemin, A.I.; Polyakov, E.F.

    1980-01-01

    Reviewed are the main statements peculiarities and possibilities of the first branch guiding technical material (GTM) ''The methods of calculation of structural reliability of NPP and its systems at the stage of projecting''. It is stated, that in GTM presented are recomendations on the calculation of reliability of such specific systems, as the system of the reactor control and protection the system of measuring instruments and automatics and safe systems. GTM are based on analytical methods of modern theory of realibility with the Use of metodology of minimal cross sections of complex systems. It is stressed, that the calculations on the proposed methods permit to calculate a wide complex of reliability parameters, reflecting separately or together prorerties of NPP dependability and maintainability. For NPP, operating by a variable schedule of leading, aditionally considered are parameters, characterizing reliability with account of the proposed regime of power change, i.e. taking into account failures, caused by decrease of the obtained power lower, than the reguired or increase of the required power higher, than the obtained

  6. Solid radioactive waste processing facility of the NPP Leningrad

    Weichard, Swetlana

    2008-01-01

    On behalf of the Russian Company Rosenergoatom NUKEM Technologies GmbH is planning and constructing a complete facility for the processing of solid low- and medium-active radioactive wastes. The NPP Leningrad comprises 4 units of RBMK-1000 reactors, the plant life has been extended by 15 years, the first unit is to be decommissioned in 2018. The construction of four new units is planned. NUKEM is in charge of planning, manufacture, construction and startup of the following facilities: sorting, internal transport, combustion and waste gas cleaning, emission surveillance, compacting, packaging and radiological measurement.

  7. Report of the review of the safety improvement programme for South Ukraine NPP units 1 and 2 and to identify the safety issues of ''small series'' WWER-1000 NPPs. South Ukraine Yuzhnoukrainsk, Nikolaev Region Ukraine, 8 to 19 July 1996. Draft

    Bastin, S.; Hoehn, J.; Lin, C.; Taylor, R.; Benitez, F.; Dale, H.; Mueller, B.; Rieg, C.Y.

    1996-10-01

    According to the Ukrainian request the purpose of the IAEA experts' mission was to review the safety improvement programme for South Ukraine NPP Units 1 and 2 in order to advise on the completeness and adequacy of safety improvements implemented and/or proposed. Another purpose of the mission was to identify major design and operational deficiencies as a basis to compile a consolidated list of generic safety issues for the units of the 'small series'' of WWER-1000 reactors (''Issue Book for ''small series'' WWER-1000 NPPs). Conclusions and recommendations from the IAEA mission are based on the combined expertise of the international group of experts who composed the team. They are intended to assist national authorities and plant operators who have the sole responsibilities for the regulation and safe operation. tabs

  8. Probabilistic safety analysis of the Kozloduy NPP units 1-4 (WWER-440/230) using independent emergency feedwater system; Veroyatnostnyj analiz bezopasnosti I-IV blokov AEhS `Kozloduy` s reaktorami tipa WWER-440 (V 230) pri vklyuchenii nezavisimoj sistemy avarijnoj podpitki PG

    Kalchev, B; Marinov, M; Dimitrov, B; Avdzhiev, K [Energoproekt, Sofia (Bulgaria)

    1996-12-31

    The safety of the Kozloduy NPP is being promoted by backfitting and improved operational practice. Special measures mitigating potential severe accidents consequences are needed because of some deficiencies in the original design of the four WWER-440 units. In conditions of a total LOCA (Loss Of Coolant Accident) it is impossible to ensure decay heat removal using the existing safety system. In such cases an extra emergency feedwater system independent of the plant`s other systems has been introduced which offers a new alternative means of removing the residual heat from the reactor. A probabilistic safety analysis is carried out using the method of event trees. A comparison between the existing safety system and the newly proposed is made. The simulation results of the unit behaviour prove that the damage frequency of the active zone is lower with the new system. 3 refs., 3 tabs., 2 figs.

  9. Polish media and public opinion on NPP Mochovce commissioning

    Latek, Stanislaw

    1999-01-01

    The so called 'Mochovce Problem' was one of the major topics in Polish media in the period from May to July 1998. The nuclear power plant commissioning caused an unexpectedly strong reaction, especially in the newspapers, slightly less so in electronic media. Faced with clearly hostile media reaction to Mochovce NPP, the National Atomic Energy Agency representatives, together with atomic and nuclear experts, undertook to change these attitudes. In numerous interviews, letters to the editors and talks with journalists, they attempted to correct the mistakes, explain the true safety situation in the nuclear power plant, by whom it was constructed, who supervised and tested the systems and so on. The completion of Mochovce NPP construction improved significantly the electricity balance in Slovakia, thus decreasing the pressure for continuing the operation of older Bohunice V1 units beyond their design lifetime. For this reason, as well as in view of striving for improvement in environmental factors beyond Polish southern border, especially after Kyoto/97 decisions on greenhouse gases emissions, the public opinion in Poland should support the Mochovce NPP construction. In 1996 Poland has signed with Slovakia a bilateral inter-governmental agreement on the prompt notification on nuclear accidents and on the cooperation in the nuclear safety and radiological protection matters. On the basis of this agreement the experts from Polish National Atomic Energy Agency are in perpetual contact with Slovakian Nuclear Regulatory Body and in each and every moment can obtain full and comprehensive information on the plant parameters iportant for nuclear safety. The experts explanations, together with the NAEA top management visit to the plant itself, brought some results. The media became less aggressive, and Polish public and authorities - contrary to the Austrians - do not protest loudly against the commissioning of this newest European NPP. Now, in December 1998, the tune of

  10. Testing of components on the shaking table facilities of AEP and contribution to full scale dynamic testing of Kozloduy NPP. Final report

    Ambriashvili, Y.

    1999-01-01

    Units 5 and 6 of the Kozloduy NPP were designed as a standardized WWER-1000 on the basis standardized scheme designs, including building structures and reactor building. The accelerograms and response spectrum were adopted based on seismological, geological, geophysical and other conditions of the region where the NPP is expected to be located. This paper presents the results design floor response spectra analysis as well as method and some results of the tests of electrical equipment as identified by the Kozloduy NPP staff

  11. Metamorphosis of NPP A1, V1, V2

    Dobak, D.; Moncekova, M.

    2005-01-01

    In this book the history of construction, commissioning and exploitation of NPP A1, NPP V1 and NPP V2 in Jaslovske Bohunice is presented on documentary photos. Vicinity around of these NPPs is presented, too

  12. Ignalina NPP: living and working conditions

    Chiuzhas, A.

    1998-01-01

    The conference was devoted to discuss the social problems related with the operation of Ignalina NPP. The main topics are the following: analysis of public opinion of surrounding region of Ignalina NPP including neighbouring Daugavpils district in Latvia, environment impact evaluation of Daugavpils district, assessment of the influence of Ignalina NPP operation to the development of business in the region, investigation of problems of Visaginas town - residence of Ignalina NPP personnel. The specificity of Visaginas (former Sniechkus) is defined by the majority of non-native Lithuanians living there. Cultural transformation and political organization of the region were surveyed as well

  13. NPP backfitting and services

    Pauli, W.; Blumer, U.; Edelmann, X.

    1988-01-01

    The Swiss nuclear power stations are not only of different design (PWR, BWR), but also have been built by several system suppliers over the last 20 years. Consequently, an individual approach has to be adopted for the backfitting and services for each of the five units in operation. Part of the ongoing maintenance effort for nuclear power plants currently in operation is the idea to extend their operating lifetime as long as it appears economic. Although many of the components have been designed for a life of 40 years, their operating period may be extended considerably, provided that proper measures are taken to keep the plants in optimal conditions for this goal. Such measures for a plant life extension program are: assessment of records of actual operating history; additional monitoring where necessary for temperatures, stress, strain, etc.; non-destructive examination techniques; destructive examination of samples removed from service; thermohydraulic and structural analysis for fatigue and fracture; preventive maintenance; repairs; replacement with components of better design and/or material; installation of additions and redundancies where safety is important. 2 refs

  14. Nuclear fuel utilization in Kozloduy NPP

    Boyadzhiev, Z; Kharalampieva, Ts; Pejchinov, Ts [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

    1994-12-31

    An assessment of fuel utilization in Kozloduy NPP units 1-6 is made on the basis of operational data obtained for a total of 62 fuel cycles. Basic characteristics of core loading and operation conditions are given. SPPS-1 and BIPR-7 codes are used to calculate assembly-wise power distributions for different full power days of a given cycle and unit. The data are compared with the measured values of these quantities. The analysis performed shows that the core loading option chosen has led to efficient fuel utilization without violation of the nuclear safety criteria. For WWER-440 (Units 1 - 4) this is expressed in effective reduction of the reactor vessel irradiation, maintaining the design duration of the fuel cycles at a reduced number of assemblies by a factor 5 - 5-10%, utilizing fuel with higher enrichment and implementing the 4-year fuel cycle. For WWER-1000 the improvements lead to: adoption of the 3-year fuel cycle utilizing fuel with 4.4% initial enrichment, implementation of improved fuel with a new type of absorbers and more effective low-leakage core loading patterns. 10 tabs., 6 figs., 7 refs.

  15. NPP Evaluation, backfitting and life extension. An engineering viewpoint

    Gonzalez Lopez, A.

    1993-01-01

    During the decade of the 80s, the Owners of the two oldest operating plants in Spain designed and built during the 60s - namely, Jose Cabrera NPP, a Westinghouse PWR, and Santa Maria de Garona NPP, a GE BWR- undertook the following important programs: 1. A far-reaching Systematic Evaluation Program (SEP) for the Jose Cabrera NPP consisting in the systematic safety review of the plant design, followed by the necessary hardware modifications, to upgrade it and make it comply with current safety criteria, and a Plant Upgrading Program for the Garona Nuclear Station focusing on specific topics affecting GE BWR Mark-I type plants of the same vintage. 2. A Remaining Life Management Program to ensure that the units, after extensive backfittings and high capital investment, would complete their design life, leaving open the option for plant life extension. These two units are today considered by the Spanish nuclear industry as the pilot plants for Plant Life Extension (PLEX) programs for PWRs and BWRs in our country The purpose of this paper is to summarize the principal lessons learned from EMPRESARIOS AGRUPADOS' participation as an architect-engineering organization in the engineering, design and implementation of these Programs. They are practical examples of positive experience which could be considered as a reference when carrying out similar programs for other plants. (author)

  16. NPP Evaluation, backfitting and life extension. An engineering viewpoint

    Gonzalez Lopez, A [Empresarios Agrupados, A.I.E., Madrid (Spain)

    1993-12-15

    During the decade of the 80s, the Owners of the two oldest operating plants in Spain designed and built during the 60s - namely, Jose Cabrera NPP, a Westinghouse PWR, and Santa Maria de Garona NPP, a GE BWR- undertook the following important programs: 1. A far-reaching Systematic Evaluation Program (SEP) for the Jose Cabrera NPP consisting in the systematic safety review of the plant design, followed by the necessary hardware modifications, to upgrade it and make it comply with current safety criteria, and a Plant Upgrading Program for the Garona Nuclear Station focusing on specific topics affecting GE BWR Mark-I type plants of the same vintage. 2. A Remaining Life Management Program to ensure that the units, after extensive backfittings and high capital investment, would complete their design life, leaving open the option for plant life extension. These two units are today considered by the Spanish nuclear industry as the pilot plants for Plant Life Extension (PLEX) programs for PWRs and BWRs in our country The purpose of this paper is to summarize the principal lessons learned from EMPRESARIOS AGRUPADOS' participation as an architect-engineering organization in the engineering, design and implementation of these Programs. They are practical examples of positive experience which could be considered as a reference when carrying out similar programs for other plants. (author)

  17. Enhancing NPP Safety Through an Effective Dependability Management

    Vieru, G., E-mail: g_vieru@yahoo.com [AREN, Bucharest (Romania)

    2014-10-15

    Taking into account the importance of the continuous improvement of the performance and reliability of a NPP and practical measures to strengthen nuclear safety and security, it is to be noted that a good management for a nuclear power reactor involves a ''good dependability management'' of the activities, such as: Reliability, Availability, Maintainability (RAM) and maintenance support. In order to evaluate certain safety assessment criteria intended to be applied at the level of the nuclear reactor unit management, equipment dependability indicators and their impact over the availability and reactor safety have to be evaluated. Reactor equipment dependability indicators provide a quantitative indication of equipment RAM performances (Reliability, Availability and Maintenance). One of the important benefits of maintenance and failure data gathering is that it can be used as a support of probabilistic safety assessment (PSA). Also, a good dependability management implementation may be used to complement reactor level unit performance indicators in the field of safe operation, maintenance and improving operating parameters, as well as for Strengthening Safety and Improving Reliability of a NPP. This paper underlines the importance of nuclear safety and security as prerequisites for nuclear power. In addition, it demonstrates how different technical aspects, through implementation of a good dependability management, contribute to a strengthened safety and an improvement of availability of the NPP through dependability indicators determination and evaluation. (author)

  18. Experience from the Inspection of Licensees' Outage Activities, Including Fire Protection Programmes, Event Response Inspections, and the Impact of the Fukushima Daiichi NPP Accident on Inspection Programmes. Workshop Proceedings, Chattanooga, Tennessee, United States, 7-10 April 2014

    2014-10-01

    The main purpose of the workshop was to provide a forum of exchange of information on the regulatory inspection activities. Participants had the opportunity to meet with their counterparts from other countries and organisations to discuss current and future issues on the selected topics. They developed conclusions regarding these issues and hopefully, identified methods to help improve their own inspection programmes. The NEA Committee on Nuclear Regulatory Activities (CNRA) believes that an essential factor in ensuring the safety of nuclear installations is the continuing exchange and analysis of technical information and data. To facilitate this exchange the Committee has established working groups and groups of experts in specialised topics. The Working Group on Inspection Practices (WGIP) was formed in 1990 with the mandate '..to concentrate on the conduct of inspections and how the effectiveness of inspections could be evaluated..'. The WGIP facilitates the exchange of information and experience related to regulatory safety inspections between CNRA member countries. These proceedings cover the 12. International Workshop held by WGIP on regulatory inspection activities. This workshop, which is the twelfth in a series, along with many other activities performed by the Working Group, is directed towards this goal. The consensus from participants at previous workshops, noted that the value of meeting with people from other inspection organisations was one of the most important achievements. The focus of this workshop was on experience gained from regulatory inspection activities in three areas: - Inspection of Outage Activities Including Fire Protection Programmes. - Event Response Inspections. - The Impact of Inspection Programmes of the Fukushima Daiichi Nuclear Power Plant (NPP) Accident. The main objectives of the WGIP workshops are to enable inspectors to meet with inspectors from other organisations, to exchange information regarding regulatory inspection

  19. Consideration for a tritium removal facility at the Cernavoda Nuclear Power Station

    2006-01-01

    Full text: A pre-feasibility study considering process options for a Tritium Removal Facility at the Cernavoda Nuclear Power Station has been completed by ICIT and AECL. Three different process options were considered. These three options differ in the front-end process used to transfer tritium from heavy water to deuterium gas. All three options use cryogenic distillation (CD) as a back end process to extract tritium from the deuterium gas stream and concentrate it into a small volume stream of pure DT or T 2 that can be immobilized on a titanium sponge. The first option for the front-end process is Liquid Phase Catalytic Exchange (LPCE). The LPCE column is used to transfer the tritium from the heavy water to a recirculating stream of deuterium gas. The separation of hydrogen isotopes takes place in the cryogenic distillation column. Tritium-depleted deuterium gas from the CD system is fed back to the LPCE column. The cryogenic distillation system concentrates the tritium into a small volume of elemental tritium for storage. Tritiated heavy water that has been purified to remove catalyst poisons is fed to the top of the LPCE column. The heavy water leaving the column is depleted in deuterium. Both existing detritiation plants built to detritiate CANDU reactors (the Darlington TRF in Canada and the Wolsung TRF in Korea) use variations of the LPCE-CD process. The second option uses electrolysis to convert tritiated heavy water into oxygen and tritiated deuterium gas. The deuterium gas is sent to the Cryogenic Distillation system to extract and concentrate the tritium. The tritium depleted deuterium gas is recombined with the electrolytic oxygen to give a tritium-depleted heavy water product. The third option uses a Combined Electrolysis and Catalytic Exchange (CECE) front end. A CECE process concentrates the tritium in the water and, using water electrolysis, converts the concentrated tritium into deuterium gas. An overhead catalytic recombiner converts the

  20. Specific problems in Kozloduy municipality, concerning NPP operation and decommissioning

    Pironkova, L.

    2000-01-01

    The only nuclear power plant in Bulgaria, which operates for 25 years is located in Kozloduy. Kozloduy municipality is situated in the northern part of Danube plane, includes the administrative center and four villages. It is 200 km far from Sofia and 80 km from the regional center Vratza. The Kozloduy NPP operates 6 units of total capacity 3760 MW, producing more than 40% of the electricity needs in Bulgaria. Settled and recurring problems of the municipality are related to economic, geographical, demographic and administration issues. Future problems will be related to forthcoming reactor shutdown and decommissioning. This involves economic problems, possible bankruptcies of local firms servicing the NPP, decreasing budget and living standard, expected restrictions of social programs, increasing unemployment, possible changes in demographic structure of population

  1. Seismic safety of building structures of NPP Kozloduy III

    Varbanov, G.I.; Kostov, M.K.; Stefanov, D.D.; Kaneva, A.D.

    2005-01-01

    In the proposed paper is presented a general summary of the analyses carried out to evaluate the dynamic behavior and to assess the seismic safety of some safety related building structures of NPP Kozloduy. The design seismic loads for the site of Kozloduy NPP has been reevaluated and increased during and after the construction of investigated Units 5 and 6. Deterministic and probabilistic approaches are applied to assess the seismic vulnerability of the investigated structures, taking into account the newly defined seismic excitations. The presented results show sufficient seismic safety for the studied critical structures and good efficiency of the seismic upgrading. The applicability of the investigated structures at sites with some higher seismic activities is discussed. The presented study is dealing mainly with the civil structures of the Reactor building, Turbine hall, Diesel Generator Station and Water Intake Structure. (authors)

  2. Safety reassessment of the Paks NPP (the AGNES project)

    Gado, J [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics; Bajsz, J; Cserhati, A; Elter, J [Paksi Atomeroemue Vallalat, Paks (Hungary); Hollo, E [Energiagazdalkodasi Intezet, Budapest (Hungary); Kovacs, K [EROTERV Engineering and Contractor Co (Hungary); Maroti, L [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics; Miko, S [Paksi Atomeroemue Vallalat, Paks (Hungary); Techy, Z [Energiagazdalkodasi Intezet, Budapest (Hungary); Vidovszky, I [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics

    1996-12-31

    The reassessment of the Paks NPP safety according to internationally recognized criteria of the Advanced General and New Evaluation of Safety (AGNES) project is outlined. The Paks NPP consists of four WWER-440/V-213 units. The following groups of analysis have been performed: system analysis and description; analysis of design basis accidents; severe accidents analysis; level 1 probabilistic safety analysis. Postulated accidents (PA) and Anticipated Operational Occurrences (AOO) are estimated in detail for the following initiating events: increase/decrease in secondary heat removal; decrease in primary coolant inventory; increase/decrease of reactor coolant inventory; reactivity and power distribution anomalies; analysis of transients with the failure of reactor scram (ATWS); pressurized thermal shock analyses. Severe accident analysis was made for the accidents on in-vessel phase and containment phase, for radioactive release and for accident management.

  3. 'Kozloduy' NPP geological environment as a barrier against radionuclide migration

    Antonov, D.

    2000-01-01

    The aim of this report is to present an analysis of the geological settings along Kozloduy NPP area from the viewpoint of a natural, protective barrier against unacceptable radionuclides migration in the environment. Possible sources of such migration could be an eventual accident in an active nuclear plant; radioactive releases from decommissioned Power Units or from temporary or permanent radioactive waste repositories. The report is directed mainly to the last case, and especially to the site selection for near surface short lived low and intermediate level (LILW) radioactive repository. The main conclusion of the geological settings assessment and of the many years monitoring is that the Kozloduy NPP area offers good possibilities for site selection of LILW repository. (author)

  4. Safety reassessment of the Paks NPP (the AGNES project)

    Gado, J.; Hollo, E.; Kovacs, K.; Maroti, L.; Techy, Z.; Vidovszky, I.

    1995-01-01

    The reassessment of the Paks NPP safety according to internationally recognized criteria of the Advanced General and New Evaluation of Safety (AGNES) project is outlined. The Paks NPP consists of four WWER-440/V-213 units. The following groups of analysis have been performed: system analysis and description; analysis of design basis accidents; severe accidents analysis; level 1 probabilistic safety analysis. Postulated accidents (PA) and Anticipated Operational Occurrences (AOO) are estimated in detail for the following initiating events: increase/decrease in secondary heat removal; decrease in primary coolant inventory; increase/decrease of reactor coolant inventory; reactivity and power distribution anomalies; analysis of transients with the failure of reactor scram (ATWS); pressurized thermal shock analyses. Severe accident analysis was made for the accidents on in-vessel phase and containment phase, for radioactive release and for accident management

  5. Reactor building seismic analysis of a PWR type - NPP

    Kakubo, Masao

    1983-01-01

    Earthquake engineering studies raised up in Brazil during design licensing and construction phases of Almirante Alvaro Alberto NPP, units 1 and 2. State of art of soil - structure interaction analysis with particular reference to the impedance function calculation analysis with particular reference to the impedance function calculation of a group of pile is presented in this M.Sc. Dissertation, as an example the reactor building dynamic response of a 1325 MWe NPP PWR type is calculated. The reactor building is supported by a pile foundation with 2002 end bearing piles. Upper and lower bound soil parameters are considered in order to observe their influence on dynamic response of structure. Dynamic response distribution on pile heads show pile-soil-pile interaction effects. (author)

  6. Simulator training and human factor reliability in Kozloduy NPP, Bulgaria

    Stoychev, Kosta

    2007-01-01

    This is a PowerPoint presentation. Situated in North Bulgaria, in the vicinity of the town of Kozloduy, near the Danube River bank, there is the Bulgarian Kozloduy Nuclear Power plant operating four WWER-440 and two WWER-1000 units. Units 1 and 2 were commissioned in July, 1974 and November, 1975, respectively. These were shut down at the end of 2003. Units 3 and 4 were commissioned in December, 1980 and May, 1982. They were shut down at the end of 2006 as a precondition for Bulgaria's accession to the European Union. The 1000 MW units 5 and 6 of Kozloduy NPP were commissioned in September, 1988 and December, 1993, respectively. Large-scale modernization have been implemented and now the units meet all international safety standards. The paper describes the multifunctional simulator Kozloduy NPP for the operational staff training. The training stages are as follows: - Preparatory; -Theoretical studies; - Training at the Training Centre by means of technical devices; - Preparation and sitting for an exam before a Kozloduy NPP expert commission; - Simulator training ; - Preparation to obtain a permit for a license, corresponding to the position to begin work at the NPP; - Exams before the Nuclear Regulatory Agency (NRA) and licensing; - Shadow training at the working place; - Permission for unaided operation. The following positions are addressed by the simulator training: - Chief Plant Supervisor; - Shift Unit Supervisor; - Senior Reactor Operator; - Simulator Instructor; - Controller physicist; -Senior Turbine Operator; - Senior Operator of Turbine Feedwater Pumps of Kozloduy NPP. Improving of training method led to a reduction of number of significant events while worldwide practice proves that improvement of engineering resulted in an increase in the percentage of events, related to human factor. Analysis of human reliability in 2005 and 2006 in cooperation with representatives from Great Britain and the Technical University in Sofia were worked on the DTI NSP B

  7. Water chemistry of secondary circuit and SG currently status NPP 'Kozloduy' 3

    Minkova, K. [Kozloduy NPP (Bulgaria)

    2002-07-01

    The author gives a historical review of the secondary water chemistry regimes of NPP Kozloduy Unit 3. Results of eddy current inspection on the steam generator of Unit 5 and quantity of the deposits on the surfaces of steam generator during 1989-2001 inspections are given. (uke)

  8. Radiation monitoring in the NPP environment, control of radioactivity in NPP-environment system

    Egorov, Yu.A.

    1987-01-01

    Problems of radiation monitoring and control of the NPP-environment system (NPPES) are considered. Radiation control system at the NPP and in the environment provides for the control of the NPP, considered as the source of radioactive releases in the environment and for the environmental radiation climate control. It is shown, that the radiation control of the NPP-environment system must be based on the ecological normalization principles of the NPP environmental impacts. Ecological normalization should be individual for the NPP region of each ecosystem. The necessity to organize and conduct radiation ecological monitoring in the NPP regions is pointed out. Radiation ecological monitoring will provide for both environmental current radiation control and information for mathematical models, used in the NPPES radiation control

  9. Display systems for NPP control

    Rozov, S.S.

    1988-01-01

    Main trends in development of display systems used as the means for image displaying in NPP control systems are considered. It is shown that colour display devices appear to be the most universal means for concentrated data presentation. Along with digital means the display systems provide for high-speed response, sufficient for operative control of executive mechanisms. A conclusion is drawn that further development of display systems will move towards creation of large colour fields (on reflection base or with multicolour gas-discharge elements)

  10. Emergency preparedness at Barsebaeck NPP in Sweden

    Olsson, R.; Lindvall, C.

    1998-01-01

    On-site emergency preparedness plan at Barsebaeck NPP is presented. In an emergency the responsibility of the NPP is to alarm the emergency organizations, spend all efforts to restore safe operation, assess the potential source term as to size and time, protect their own personnel, inform personnel and public. Detailed emergency procedures overview is provided

  11. Safety culture in Ignalina NPP, regulatory view

    Maksimovas, G [VATESI (Lithuania)

    1997-09-01

    The presentation describes how success on the way to a high level Safety Culture in Ignalina NPP may be achieved by daily, well motivated activities with good attitude and proper management participation, ensuring the development and proper implementation of Safety Culture principles within the activities of Operational organization of Ignalina NPP.

  12. Safety culture in Ignalina NPP, regulatory view

    Maksimovas, G.

    1997-01-01

    The presentation describes how success on the way to a high level Safety Culture in Ignalina NPP may be achieved by daily, well motivated activities with good attitude and proper management participation, ensuring the development and proper implementation of Safety Culture principles within the activities of Operational organization of Ignalina NPP

  13. Constructive approaches to the space NPP designing

    Eremin, A.G.; Korobkov, L.S.; Matveev, A.V.; Trukhanov, Yu.L.; Pyshko, A.P.

    2000-01-01

    An example of designing a space NPP intended for power supply of telecommunication satellite is considered. It is shown that the designing approach based on the introduction of a leading criterion and dividing the design problems in two independent groups (reactor with radiation shield and equipment module) permits to develop the optimal design of a space NPP [ru

  14. NPP Bohunice experience with ASSET services

    Klimo, J.

    1996-01-01

    The general description of Bohunice NPP ASSET experience history was given at the last annual workshop in 1995. In my short presentation I would like to pay attention to the progress in this area which was achieved at our NPP during the last year. (author)

  15. NPP Bohunice experience with ASSET services

    Klimo, J [Bohunice NPP (Slovakia)

    1997-12-31

    The general description of Bohunice NPP ASSET experience history was given at the last annual workshop in 1995. In my short presentation I would like to pay attention to the progress in this area which was achieved at our NPP during the last year. (author).

  16. Experience of Bohunice V-1 NPP

    Dobik, Dobroslav

    2000-01-01

    Slovakia remains significantly dependent on imports of primary energy sources, which represent as much as 80% of the demand. Of the total consumption of electricity in Slovakia, 40% was generated in nuclear power plant units in 1998. Slovakia operates 6 units with WWER 440 nuclear reactors. Slovakia is the signatory of all important international agreements and conventions in the field of nuclear energy, and its legislation is in an advanced stage of approximation to European Union law. This is a very important aspect, showing Slovakia's approach to nuclear safety. In 1993 Slovakia accepted the commitments of the UN Convention on Climate Changes, including a reduction of greenhouse gases to 1990 levels by the year 2000. Moreover, as an internal target Slovakia has set the reaching of the 'Toronto Objective', i.e. 20% reduction in CO x , emissions through the year 2005 as compared to 1988. In our opinion, this is not possible without nuclear energy. Time has shown, that the political aspects are more powerful, especially if you underestimate their importance over the than the technical ones. In the case of Bohunice V-1 NPP the political aspects were on the following levels: 1. Slovak republic (Czechoslovakia), political changes, decisions of the government; 2. European Union - Agenda 2000, Accession criteria, nuclear safety criteria, EBRD; 3. Austria as a neighbouring country. Starting with year 1990, 23 expert missions took place at Bohunice V-1 NPP by now. The only criteria for further operation should have been Nuclear safety, which is supervised by NRA SR. It was fully in compliance with EU policy, each country is solely responsible for its energy sector and for nuclear energy use. Our satisfaction lasted not too long. Following negotiation with EU on the highest political level, driven by willingness to be invited for negotiation of accession on the Helsinki Summit, the Slovak government decided on September 14th, on Bohunice V-1 Units shutdown in 2006 and 2008

  17. Role of PRA in new NPP projects

    Julin, A.; Sandberg, J.; Virolainen, R.

    2012-01-01

    In Finland, a plant specific, Level 1 and 2 Probabilistic Risk Analysis (PRA) is required as a prerequisite for issuing the construction license and operating license. The use of PRA in various applications and the main insights are presented. These applications include e.g. PRA support to the design of SSCs (Systems, Structures and Components), definition of pre-service and in-service inspection programs, evaluation of the safety classification of SSCs, development of procedures, training and in definition of risk informed technical specifications, periodic testing and on-line preventive maintenance programs. In addition, PRA shall be used to assess the adequacy and coverage of the phase and system commissioning programs. Also the potential risks related to commissioning tests during nuclear test phase, shall be assessed with the help of PRA. In OL3 project, risk informed approach has been applied on a large scale for the first time in the design, construction and commissioning of a new NPP unit. Pre-nuclear commissioning tests have started at OL3 site and the plant is foreseen to begin commercial operation in 2013. Decisions have been made to launch new NPP projects. Teollisuuden Voima Oyj (TVO) is planning to build a new unit (OL4) at Olkiluoto site and a new utility, Fennovoima, is planning to build one unit at one of two alternative green field sites in Northern parts of Finland. Insights from PRAs of operating NPPs have been used in the evaluation of possible new sites to ensure that the site specific concerns and environmental conditions are adequately taken into account in the design of SSCs. Although the seismic activity at the Olkiluoto site is low, a comprehensive seismic risk analysis is being conducted. Its results support the review of the deterministic seismic design. For new sites, a probabilistic seismic hazard analysis has been carried out for the determination of the design earthquake. Experiences from OL3 licensing have been utilized in the

  18. Barsebaeck NPP in Sweden - Decommissioning Project

    Hakan, Lorentz

    2009-01-01

    Barsebaeck 1 and 2, type BWR (Boiling Water Reactor) with a capacity of 615 MWe was closed down permanently on 30 November 1999 respective 31 May 2005 due to political decision. Both units together have been in Service operation (Care and maintenance) since 1 December 2006. Barsebaeck NPP will stay in Service operation until beginning of 2018 when Dismantling operation begins with the aim of a free-realized site in the beginning of 2025. That means that the remaining buildings, including equipment should be declared free-released or dismantled. It would then be up to the owner, E.ON Kaernkraft Sverige AB (EKS) to decide what is to be done with the site in the future. There was a re-organisation at Barsebaeck Kraft AB (BKAB) in 1 January 2007 and the company is organised in the following areas of function: site service operation, decommissioning planning, new business and BO replacement. The Organisation at BKAB has gone down from 450 during operation of Barsebaeck 1 and 2 to 50 employees (2009-01-01) involved in Service operation of both units. But still there are in total 250 persons placed at Barsebaeck NPP with different kinds of job assignments. A lot of activities have been carried out since 2000 and up to now for example: - All nuclear fuel has been transported away to interim storage at CLAB in Oskarshamn. - BKAB have built up contact nets and competence by taking part in different kinds of national and international organisations (SKB, IAEA, OECD/NEA TAG, WNA, ENISS, WANO, EPRI etc) commissions. - The Electrical and operational systems have been rebuilt for the actual demands and requirements for the Service operation. - The central control room is unattended since 17 December 2007 and the supervision of the Service operation is handled by a system of VDI (duty engineers) and LOP (alarm operators). - Full system decontamination on unit 1 and 2. Barsebaeck's approach today and for the future dismantling are: - Safer; - Faster; - Cost effective. BKAB

  19. Seismic characterization of the NPP Krsko site

    Obreza, J.

    2000-01-01

    The goal of NPP Krsko PSA Project Update was the inclusion of plant changes (i.e. configuration/operational related) through the period January 1, 1993 till the OUTAGE99 (April 1999) into the integrated Internal/External Level 1/Level 2 NPP Krsko PSA RISK SPECTRUM model. NPP Krsko is located on seismotectonic plate. Highest earthquake was recorded in 1917 with magnitude 5.8 at a distance of 7-9 km. Site (founded) on Pliocene sediments which are as deep as several hundred meters. No surface faulting at the Krsko site has been observed and thus it is not to be expected. NPP Krsko is equipped with seismic instrumentation, which allows it to complete OBE (SSE). The seismic PSA successfully showed high seismic margin at Krsko plant. NPP Krsko seismic design is based on US regulations and standards

  20. NPP lifetime philosophy: the transatlantic difference

    Mowry, Christofer

    1998-01-01

    Fundamental institutional and cultural differences in the transatlantic nuclear power industries, and in particular those between the Nordic countries and the United States, have driven divergent plant life management strategies -strategies resulting in distinctly different plant performance. Recognition of the linkage between three key components of overall Nuclear Power Plant (NPP) performance - yearly O and M costs, safety, and effective plant lifetime -is based on different institutional perspectives. In the Nordic countries, explicit recognition of this linkage has been historically translated into an integrated approach to plant performance. American NPPs, however, have been forced to focus primarily on near term O and M performance and regulatory mandated investment. While Nordic NPPs view capital investment in plant lifetime management and modernization as necessary to avoid declining plant performance and the cost of replacement power, American NPPs exhibit reluctance for such investments due to the difficulty of justifying the associated short-term costs. The diverging histories of two NPPs of the same vintage and design, one in Sweden and one in the United States, exemplify the potential ramifications of these approaches. The Swedish plant continues to operate with excellent performance indicators, while undertaking a comprehensive and long-term modernization program. The American facility is likely to be decommissioned due to unsustainable economic performance. (author)

  1. Operating Experience at NPP Krsko

    Kavsek, D.; Bach, B.

    1998-01-01

    Systematic analysis of operational experience by assessment of internal and industry events and the feedback of lessons learned is one of the essential activities in the improvement of the operational safety and reliability of the nuclear power plant. At NPP Krsko we have developed a document called ''Operating Experience Assessment Program''. Its purpose is to establish administrative guidance for the processing of operating events including on-site and industry events. Assessment of internal events is based on the following methods: Event and Causal Factor Charting, Change Analysis, Barrier Analysis, MORT (Management Oversight and Risk Tree Analysis) and Human Performance Evaluation. The operating experience group has developed a sophisticated program entitled ''Operating experience tracking system'' (OETS) in response to the need for a more efficient way of processing internal and industry operating experience information. The Operating Experience Tracking System is used to initiate and track operational events including recommended actions follow up. Six screens of the system contain diverse essential information which allows tracking of operational events and enables different kinds of browsing. OETS is a part of the NPP Krsko nuclear network system and can be easily accessed by all plant personnel. (author)

  2. Reliability analysis of protection systems in NPP applying fault-tree analysis method

    Bokor, J.; Gaspar, P.; Hetthessy, J.; Szabo, G.

    1998-01-01

    This paper demonstrates the applicability and limits of dependability analysis in nuclear power plants (NPPS) based on the reactor protection refurbishment project (RRP) in NPP Paks. This paper illustrates case studies from the reliability analysis for NPP Paks. It also investigates the solutions for the connection between the data acquisition and subsystem control units (TSs) and the voter units (VTs), it analyzes the influence of the voting in the VT computer level, it studies the effects of the testing procedures to the dependability parameters. (author)

  3. Design features and operation experience of the main circulating pumps for the ''Loviisa'' NPP with the WWER-440 reactor

    Iofs, D.; Kujyala, I.; Timperi, I.; Shlejfer, G.; Vistbakka, V.; Prudovskij, A.M.; Turetskij, L.I.; Vorona, P.N.

    1980-01-01

    Technical characteristics and the operation of main circulating pumps (MCP) designed and mounted at the ''Loviisa'' NPP by Finnish firms ''Alstrem'' and ''Stremberg'' are described. The above MCP have specific advantages over similar pumps mounted at other NPP with pressurized water cooled reactors. This is a possibility of substitution of potentially most damaged units (bearing and pump shaft sealing) for several hours, without MCP disassembly as a whole as well as using rolling bearings together with the original electromagnetic unloading system from the axial force instead of usually employed in similar MCP radial thrust slip bearings. The two year operation experience has confirmed the efficiency and reliability of ''Loviisa'' NPP main circulating pumps

  4. The Service Life Evaluation for Concrete Structure of NPP

    Lee, Choon Min; Kim, Seong Soo; Bae, Sung Hwan; Sik, Yoon Eui

    2014-01-01

    Prolonged exposure to the marine environment degrades the durability of concrete and shortens the service life of concrete due to degradation factors such as chloride, carbonation, freezing and thawing, sulfate. Therefore, many country's organizations like the Korea Concrete Institute (KCI), the American Concrete Institute (ACI), the International Federation for Structural Concrete (FIB), the American Society for Testing and Material (ASTM) which recognized the seriousness of this deterioration proposed equation models to evaluate the service life for the concrete structures. As a result, this paper is to especially consider the service life evaluation using these equation models for concrete structure of NPP in Korea compared with 60 years as a design service life. The concrete durability evaluation for Shin-Hanul NPP units 1 and 2 is carried out by using typically proposed assessment models in domestic and foreign standard. It is confirmed that the service life of concrete durability for each of deterioration factors is significantly higher than 60 years as a design service life. As a result, the study of combined deterioration for the concrete structures of NPP in future is positively necessary and maintenance control through regular monitoring should be conducted to secure safety margin basis

  5. Methodical recommendations for power unit comprehensive engineering and radiation survey

    Nosovskij, A.V.

    2000-01-01

    The article describes power unit radiation survey methods developed and applied during conduction of Ch NPP unit I Comprehensive Engineering Radiation Survey. Special requirements for units under decommissioning, main survey principals, criteria for definition of volume and the order of survey for various systems of a NPP Unit are included

  6. Does climate directly influence NPP globally?

    Chu, Chengjin; Bartlett, Megan; Wang, Youshi; He, Fangliang; Weiner, Jacob; Chave, Jérôme; Sack, Lawren

    2016-01-01

    The need for rigorous analyses of climate impacts has never been more crucial. Current textbooks state that climate directly influences ecosystem annual net primary productivity (NPP), emphasizing the urgent need to monitor the impacts of climate change. A recent paper challenged this consensus, arguing, based on an analysis of NPP for 1247 woody plant communities across global climate gradients, that temperature and precipitation have negligible direct effects on NPP and only perhaps have indirect effects by constraining total stand biomass (Mtot ) and stand age (a). The authors of that study concluded that the length of the growing season (lgs ) might have a minor influence on NPP, an effect they considered not to be directly related to climate. In this article, we describe flaws that affected that study's conclusions and present novel analyses to disentangle the effects of stand variables and climate in determining NPP. We re-analyzed the same database to partition the direct and indirect effects of climate on NPP, using three approaches: maximum-likelihood model selection, independent-effects analysis, and structural equation modeling. These new analyses showed that about half of the global variation in NPP could be explained by Mtot combined with climate variables and supported strong and direct influences of climate independently of Mtot , both for NPP and for net biomass change averaged across the known lifetime of the stands (ABC = average biomass change). We show that lgs is an important climate variable, intrinsically correlated with, and contributing to mean annual temperature and precipitation (Tann and Pann ), all important climatic drivers of NPP. Our analyses provide guidance for statistical and mechanistic analyses of climate drivers of ecosystem processes for predictive modeling and provide novel evidence supporting the strong, direct role of climate in determining vegetation productivity at the global scale. © 2015 John Wiley & Sons Ltd.

  7. Seismic qualification tests of fans of the NPP of Laguna Verde U-1 and U-2

    Jarvio C, G.; Garcia H, E. E.; Arguelles F, R.; Vela H, A.; Naranjo U, J. L.

    2013-10-01

    This work presents the results of the seismic qualification tests applied to the fans that will be installed in the control panels of the three divisions of the diesel generators of the nuclear power plant (NPP) of Laguna Verde, Unit-1 and Unit-2. This seismic qualification process of the fans was carried out using two specimens that were tested in the seismic table (vibrating) of the Engineering Institute of Universidad Nacional Autonoma de Mexico (UNAM), in accordance with the requirements of the standard IEEE 344-1975, to satisfy the established requirements of seismic qualification in the technical specifications and normative documents required by the nuclear standards, in order to demonstrate its application in the diesel generators Divisions I, II and III of the NPP. The seismic qualification tests were developed on specimens that were retired of the NPP of Laguna Verde recently with a service life of 7.75 years. (Author)

  8. Electrical Grid Conditioning For First NPP Integration, a Systems Engineering Approach Incorporating Quality Function Deployment

    Pwani, Henry; James, J. [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    Nuclear power plant has a high potential to cause serious harm to environment as evidenced by effects of Fukushima and Chernobyl accidents. A reliable electrical power is required for a NPP to facilitate cooling after a shutdown. Failure of electrical power supply during shutdown increases core damage probability. Research shows that a total of 39% of LOOP related events in US are electrical grid centered. In Korea, 38% and 29% of all events that led to NPP shutdown at Hanul units 3-6 and at Hanbit units 3-6 respectively were electrical related. Electric grids for both operating and new NPPs must therefore be examined and upgraded for reliability improvement in order to enhance NPP safety.

  9. Conceptual design of covering method for the proposed LILW near-surface repository at Cernavoda

    Diaconu, Daniela

    2003-01-01

    The disposal concept of the low and intermediate level (LIL) wastes resulting during NPP operation combines both the natural and engineered barriers in order to ensure the safety of the environment and population. Saligny site has been proposed for LIL waste disposal. Preliminary performance assessments indicate that the loess and clay layers are efficient natural barriers against water flow and radionuclide migration through the vadose zone to the local aquifers. At present, the studies on site characterization are concentrated on investigation of the potential factors affecting the long-term integrity of the disposal facility. This analysis showed that surface erosion by wind and water and bio-intrusion by plant roots and burrowing animals could affect the long-term disposal safety. Based on the preliminary erosion results, as well as on the high probability of bio-intrusion by the plant roots and burrowing animals (i.e. moles, mice), different covering systems able to ensure the long-term safety of the repository has been proposed and analyzed. FEHM and HYDRUS 2D water flow simulations have been performed in order to compare their efficiency in the diminution of the infiltration rate in the repository. From this point of view, the covering system combining the capillary barrier and the resistive layer proved to have the best behavior

  10. ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

    Caeny, P.; Chyly, M.; Suchon, D.; Smejkalova, E.; Fabova, V.; Mancikova, M.; Muller, P.

    2009-01-01

    Programs ESTE EMO and ESTE EBO are emergency response systems that help the crisis staff of the NPP in assessing the source term (predicted possible release of radionuclides to the atmosphere ), in assessing the urgent protective measures and sectors under threat, in assessing real release (symptoms of release really detected and observed), in calculating radiological impacts of real release, averted or avertable doses, potential doses and doses during transport or evacuation on specified routes. Both systems serve as instruments in case of severe accident (DBA or BDBA) at NPP Mochovce or NPP Bohunice, accidents with threat of release of radioactivity to the atmosphere. Systems are implemented at emergency centre of Mochovce NPP and Bohunice NPP and connected online to the sources of technological and radiological data from the reactor, primary circuit, confinement, secondary circuit, ventilation stack, from the area of NPP (TDS 1) and from the emergency planning zone (TDS 11). Systems are connected online to the sources of meteorological data, too. (authors)

  11. ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

    Caeny, P.; Chyly, M.; Suchon, D.; Smejkalova, E.; Fabova, V.; Mancikova, M.; Muller, P.

    2008-01-01

    Programs ESTE EMO and ESTE EBO are emergency response systems that help the crisis staff of the NPP in assessing the source term (predicted possible release of radionuclides to the atmosphere ), in assessing the urgent protective measures and sectors under threat, in assessing real release (symptoms of release really detected and observed), in calculating radiological impacts of real release, averted or avertable doses, potential doses and doses during transport or evacuation on specified routes. Both systems serve as instruments in case of severe accident (DBA or BDBA) at NPP Mochovce or NPP Bohunice, accidents with threat of release of radioactivity to the atmosphere. Systems are implemented at emergency centre of Mochovce NPP and Bohunice NPP and connected online to the sources of technological and radiological data from the reactor, primary circuit, confinement, secondary circuit, ventilation stack, from the area of NPP (TDS 1) and from the emergency planning zone (TDS 11). Systems are connected online to the sources of meteorological data, too. (authors)

  12. Study on human factor at NPP

    Nopp, I.

    1984-01-01

    Factors affecting the reliabilty of the reactor control by an NPP operator are considered on the base of the Czechoslovakia NPP operating experience. The reliability level of NPP operators depends on objective factors (conditions and regime of labour) determining the labour productivity and on subjective ones (psychological morale, physical and mental abilities and occupational level of personnel). Problems of the effect of physical and mental abilities and professional level on the reliability of personnel are considered to be the most important ones. The effect of individual abilities and specific features of the human body on changes in his occupational abilities can be estimated only to a certain degree

  13. Inspection Qualification Centre in NPP 'Kozloduy'

    Mikhovski, M.

    2000-01-01

    In May 1999 according to the working plan of the IAEA project RER 4/020 and the decision of the NPP the Inspection Qualification Centre (IQC) has been established in order to provide examination services in the NPP. During year 1999 IVC (AEA Technology) in the framework of the DTI project provides consulting and technical assistance to the NPP, IQC, Bulgarian Academy of Sciences and Regulatory Authorities in setting up the IQC infrastructure. Now IQC work as an independent inspection body B type. The IQC activities for the period 1999-2000 are presented and further tasks are outlined

  14. A brief overview of Ignalina NPP safety issues

    Almenas, K.; Ushpuras, E.

    1998-01-01

    A description of the safety of Ignalina NPP in a very popular form is presented. Answers to the most frequently recurring questions concerning the Ignalina NPP are provided based on recently completed international studies. Questions are like these: can a similar accident to the one that occurred in Chernobyl take place at Ignalina NPP, does the Ignalina NPP have a containment, what are the probabilities and potential consequences of accidents, etc. The brochure contains a short description of Ignalina NPP safety improvement programs

  15. Krsko NPP radioactive waste characteristics

    Skanata, D.; Kroselj, V.; Jankovic, M.

    2007-01-01

    In May 2005 Krsko NPP initiated the Radioactive Waste Characterization Project and commissioned its realization to the consulting company Enconet International, Zagreb. The Agency for Radwaste Management was invited to participate on the Project. The Project was successfully closed out in August 2006. The main Project goal consisted of systematization the existing and gathering the missing radiological, chemical, physical, mechanical, thermal and biological information and data on radioactive waste. In a general perspective, the Project may also be considered as a part of broader scope of activities to support state efforts to find a disposal solution for radioactive waste in Slovenia. The operational low and intermediate level radioactive waste has been structured into 6 waste streams that contain evaporator concentrates and tank sludges, spent ion resins, spent filters, compressible and non-compressible waste as well as specific waste. For each of mentioned waste streams, process schemes have been developed including raw waste, treatment and conditioning technologies, waste forms, containers and waste packages. In the paper the main results of the Characterization Project will be briefly described. The results will indicate that there are 17 different types of raw waste that have been processed by applying 9 treatment/conditioning technologies. By this way 18 different waste forms have been produced and stored into 3 types of containers. Within each type of container several combinations should be distinguished. Considering all of this, there are 34 different types of waste packages altogether that are currently stored in the Solid Radwaste Storage Facility at the Krsko NPP site. Because of these findings a new identification system has been recommended and consequently the improvement of the existing database on radioactive waste has been proposed. The potential areas of further in depth characterization are indicated. In the paper a brief description on the

  16. Trial operation of TVS-2 at Balakovo NPP. Analysis of results and further modernization

    Vasilchenko, I.; Molchanov, V.; Pavlovichev, A.; Novikov, A.; Enin, A.

    2006-01-01

    In this report the more detailed specifications of TVS-2 considering modifications of separate units, and also the conditions and results of its operation at Balakovo NPP on the basis of three fuel loads are presented. Implementation of TVS-2 at power units of Balakovo NPP in the fuel cycle 3x350 eff. days has been started in 2003 and the reactor core full loading at Balakovo NPP, Unit 1 has been achieved in 2005. Considering positive operational experience of TVS-2 at Unit 1 implementation of TVS-2 by full make-ups has been started at other units of Balakovo NPP. The operational results confirm the predicted essential increasement in reliability of reactor scram, possibility of implementation of new design restrictions, which enable to form the fuel loading with small neutron leakage. Besides, the favorable results on performance of transport - technological procedures enabling to reduce time of PM has been obtained. On the basis of this structure the detailed project report of a new FA modification with lengthened fuel stack has been developed, the necessary calculational and experimental justifications have been performed, materials for obtaining a license to trial operation of the first lot of such fuel assemblies beginning from 2006 are being prepared

  17. Intranet portal at the Krsko NPP, Slovenia

    2016-01-01

    The intranet portal (named IntraNEK) at Krsko NPP serves as a single entry point to access the internet and various plant applications and links. The front page consists of the standard internet search bar and links to various applications that can either reside within the technological computer network (TRM) or within the plant business computer network. Access to the TRM applications is read only. Some applications on the business computer network are open to all personnel who log on to the network while some applications are restricted and secured, and require additional login entries. A selected link will open in a new window. Documents will open with the appropriate software tool depending on the document file format. Some categories of documents are available in image form only (e.g. procedures, drawings etc.), while some are available in fully searchable PDF format (e.g. technical specifications, updated safety analysis reports (USARs) etc.). Plant departments (organizational units) have their own pages accessible from the front page. Their pages contain links to their own information resources or links to other resources and applications, tailored to the department needs. During recent years a number of web based applications have been developed that are connected also with a common Oracle database. Some are designed to serve for data entry and browsing while others serve for browsing only

  18. Treatment of NPP wastes using vitrification

    Sobolev, I.A.; Lifanov, F.A.; Stefanovsky, S.V.; Kobelev, A.P.; Savkin, A.E.; Kornev, V.I.

    1998-01-01

    Glass-based materials to immobilize various liquid and solid radioactive wastes generated at nuclear power plants (NPP) were designed. Glassy waste forms can be produced using electric melting including a cold crucible melting. Leach rate of cesium was found to be 10 -5 -10 -6 g/(cm 2 day) (IAEA technique). Volume reduction factor after vitrification reached 4-5. Various technologies for NPP waste vitrification were developed. Direct vitrification means feeding of source waste into the melter with formation of glassy waste form to be disposed. Joule heated ceramic melter, and cold crucible were tested. Process variables at treatment of Kursk, Chernobyl (RBMK), Kalinin, Novovoronezh (VVER) NPP wastes were determined. The most promising melter was found to be the cold crucible. Pilot plant based on the cold crucibles has been designed and constructed. Solid burnable NPP wastes are incinerated and slags are incorporated in glass. (author)

  19. Environmental impact assessment of NPP decommissioning

    Hinca, R.

    2009-01-01

    In this presentation the following potential impacts of decommissioning of NPP are discussed: - Impacts on population; Impacts on natural environment; Land impacts; Impacts on urban complex and land utilisation; Possible impacts on area as a result of failure.

  20. Radiation ecological monitoring in NPP region

    Egorov, Yu.A.; Kazakov, S.V.

    1985-01-01

    The known principle of sanitary-hygienic regulation of NPP radiation effect on man and environment is analyzed. An ecological approach is required to optimize NPP relations with the environment and to regulate radioactivity of the NPP - environment system. The ecological approach envisages the development of standards of permissible concentrations of radioactive and chemical substances (as well as heat) in natural environment, taking into account their synergism, corresponding to ecologically permissible response reactions of biota to their effect. The ecological approach also comprises the sanitary-hygienic principle of radiation protection of man. Attention is paid to ecological monitoring in NPP region, comprising consideration of factors, affecting the environment, evaluation of the actual state of the environment, prediction of the environmental state, evaluation of the expected environmental state