Low level radioactive waste disposal in Kozloduy NPP in Bulgaria

International Nuclear Information System (INIS)

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)

Document status for 1 and 2 Kozloduy NPP decommissioning activities -Phase 'Final Shutdown'

International Nuclear Information System (INIS)

Vangev, A.; Boyadjiev, Z.

1997-01-01

Decommissioning process (D and D) is the final phase of each nuclear reactor life cycle. The first nuclear reactor generation has reached his expiration life date. Decommissioning working documentation had not been taken into account at the project and construction stage. The decommissioning activities, planning and legislation has to develop along their operation. Most of developed nuclear energetic countries have gathered good experience and have create their own decommissioning strategy. This report represents in brief an overview of different country's approaches and the Kozloduy NPP decommissioning activity intention in near future and reviews the D and D working document status for 1 and 2 Kozloduy NPP Units decommissioning. Kozloduy NPP D and D task to the moment is to plan the first stage of the decommissioning process - 'The Final Shutdown' and to prepare the working documents for the phase execution. The Final Shutdown of Kozloduy NPP - 1 is the termination of operation of the Units 1 and 2 and the electricity production cessation after their useful life exhaust. In accordance with the legal legislation in Bulgaria only the normal planned termination of operation on units 1 and 2 should be prescribed. The project results concern the initial condition of the equipment and systems, their preparation and sequence for defueling, decontamination and dismantling. A plan for activities' organization for D and D and Complex Characterization of the Site under consideration will contain the following documents: 1. Time-schedule for the sequence of activities during the stages of the Final Shutdown and Safe Enclosure preparation. Technical project for organization of work related to Final Shutdown; 2. Complex Characterization Programme for a condition investigation of the Units 1 and 2 equipment and systems. 3. Technical project for design modifications and dismantling of equipment and systems which violate the radiation and nuclear safety during the Final Shutdown

Seismic hazard analysis of the NPP Kozloduy site

International Nuclear Information System (INIS)

Petrovski, D.; Stamatovska, S.; Arsovski, M.; Hadzievski, D.; Sokerova, D.; Solakov, D.; Vaptzarov, I.; Satchanski, S.

1993-01-01

The principal objective of this study is to define the seismic hazard for the NPP Kozloduy site. Seismic hazard is by rule defined by the probability distribution function of the peak value of the chosen ground motion parameter in a defined time interval. The overall study methodology consists of reviewing the existing geological, seismological and tectonic information to formulate this information into a mathematical model of seismic activity of the region and using this assess earthquake ground motion in terms of probability. Detailed regional and local seismological investigations have been performed. Regional investigations encompass the area within a radius of 320 km from the NPP Kozloduy site. The results of these investigations include all seismological parameters that are necessary for determination of the mathematical model of the seismicity of the region needed for the seismic hazard analysis. Regional geological and neotectonic investigations were also performed for the wider area including almost the whole territory of Bulgaria, a large part of Serbia, part of Macedonia and almost the whole south part of Romania

A comparison of the Kozloduy NPP and Temelin NPP I and C projects

International Nuclear Information System (INIS)

Cook, B.M.

2004-01-01

Because Kozloduy NPP and Temelin NPP are both VVER 1000 plants of roughly the same vintage, they are very similar in design. However, from the viewpoint of their I and C modernization projects, there are significant differences between these plants. Some of these differences stem from the evolution of I and C technology over the relatively short period between the two projects. Other differences arise from the fact that the Kozloduy project is a phased upgrade of the I and C systems in an operating plant while the Temelin project was a 'one time' installation of the entire plant I and C system. This paper discusses these differences as well as trends in the nuclear I and C field that will shape the industry in the future. In addition to technology evolution, the comparative advantages or problems in phased upgrade versus 'one time' installations are discussed. Conclusions drawn provide insight for the planning of future I and C upgrades in VVERs and other types of nuclear power plants. (author)

Kozloduy NPP units 3 and 4 rest life time program execution

International Nuclear Information System (INIS)

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

Implementation of the KASKAD computer code system for WWER-440 at Kozloduy NPP

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Full scale dynamic testing of Kozloduy NPP unit 5 structures

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

Medical consequences of NPP and TPP operation

International Nuclear Information System (INIS)

Bliznakov, V.

1996-01-01

Results from a comparative analysis of health conditions of the staff in the Kozloduy NPP and the Maritsa Iztok TPP are reported. It is found that the general disease incidence with temporary incapacity for work of Kozloduy workers is lower than those data for the workers at thermal power stations. The incidence of some social diseases like neoplasms, TBC, hypertension, ischemia etc. is also lower for the staff of NPP. No cases of radiation injuries have been registered for a period of 21 years

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

International Nuclear Information System (INIS)

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

Women in nuclear energy – motivation and prospects at Kozloduy NPP report

International Nuclear Information System (INIS)

Radneva, R.

2015-01-01

The report presents part of the study of the staff motivation at Kozloduy NPP plc, which is performed annually. A total of 25 factors have been considered, and for 8 of them the internal motivation characteristics have been discussed, while the remaining 17 factors determine the satisfaction from external motivation stimuli: positive ones (remuneration, bonuses, awards, etc.), as well as negative (little lead time, sanctions, punishments, excessive control in the performance of tasks, etc.). Women in the nuclear industry contribute to the unique image of nuclear organisations and are an especially valued asset. In the selection of staff for vacancies there is no sex discrimination, and it is increasingly becoming evident from the number of women employed in jobs considered until recently as typically male. The satisfaction from the measured Internal motivation factors concerning the women working at Kozloduy NPP is presented in this work.

Environmental monitoring of the Kozloduy NPP: 20 year experience

Energy Technology Data Exchange (ETDEWEB)

Aleksiev, A; Tsochev, S; Dimitrov, M; Avramov, V [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

The radiation monitoring system of the Kozloduy NPP is described and the assessment of the environmental impact of the power plant is presented. Measurements are carried out in 36 control points distributed in 3 areas: radiation protected area (3 km diameter), radiation controlled area (12 km) and surveillance area (100 km). Comparison of radiation monitoring data for 1993 with data recorded in the pre-operational period (1972-74) show that no significant changes can be detected in the activity of {sup 90} Sr and gross beta activity. An increase in Cs-137 activity (38 Bq/kg d.w. versus 7 Bq/kg d.w.) is found in the soil and bottom sediments in the Danube river, which is attributed to Chernobyl accident. The Kozloduy NPP operation is continuously monitored for release of artificial radionuclides by gaseous and liquid effluents. It is reported that the average population exposure in the 30 km area due to liquid effluents is 3-4.10{sup -4} man Sv/a. A system for automated continuous radiation monitoring in 10 control stations is available in case of radiation accidents. It is supplemented by a mobile laboratory. Meteorological measurements are carried out by automatic station MC-10 and a second station is under construction. 21 refs., 2 figs., 6 tabs.

Environmental monitoring of the Kozloduy NPP: 20 year experience

International Nuclear Information System (INIS)

Aleksiev, A.; Tsochev, S.; Dimitrov, M.; Avramov, V.

1995-01-01

The radiation monitoring system of the Kozloduy NPP is described and the assessment of the environmental impact of the power plant is presented. Measurements are carried out in 36 control points distributed in 3 areas: radiation protected area (3 km diameter), radiation controlled area (12 km) and surveillance area (100 km). Comparison of radiation monitoring data for 1993 with data recorded in the pre-operational period (1972-74) show that no significant changes can be detected in the activity of 90 Sr and gross beta activity. An increase in Cs-137 activity (38 Bq/kg d.w. versus 7 Bq/kg d.w.) is found in the soil and bottom sediments in the Danube river, which is attributed to Chernobyl accident. The Kozloduy NPP operation is continuously monitored for release of artificial radionuclides by gaseous and liquid effluents. It is reported that the average population exposure in the 30 km area due to liquid effluents is 3-4.10 -4 man Sv/a. A system for automated continuous radiation monitoring in 10 control stations is available in case of radiation accidents. It is supplemented by a mobile laboratory. Meteorological measurements are carried out by automatic station MC-10 and a second station is under construction. 21 refs., 2 figs., 6 tabs

Testing of components on the shaking table facilities of AEP and contribution to full scale dynamic testing of Kozloduy NPP. Final report

International Nuclear Information System (INIS)

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

New excitation equipment for 220 MW generators in Kozloduy NPP

International Nuclear Information System (INIS)

Tomerlin, D.

2001-01-01

Rehabilitation on the excitation equipment for Generator 5, Reactor Unit 3, in Kozloduy NPP was completed in November 2000. ABB's Static Excitation System based on UNITROL 5000 technology has been chosen by the Bulgarian National Utility and Kozloduy NPP to substitute the original Russian excitation system equipment with electro-magnetic voltage regulators. The substitution is in a rehabilitation package of four excitation system equipment for Generator 5 and 6 of Reactor Unit 3 and Generator 7 and 8 of Reactor Unit 4 after a short overview of the original excitation system this paper describes the new Static Excitation System UNITROL 5000 including configuration with block diagram, its main features and merits such as modes of operation, limiter, special control functions and diagnostic facilities. Furthermore, new facilities, which are implemented in UNITROL 5000, such as dynamic current distribution among the thyristors working in parallel as well as the start-up from the residual magnetism are mentioned. Special functions including a so-called free-running mode of operation and automatic change over sequence from new excitation system to the stand-by excitation system, which is DC exciter machine, are described. Some records of the transient responses performed during the commissioning and a photograph of a manufactured system are provided. (author)

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

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

Information on current status of equipment and activities for extension of NPP Kozloduy life time

International Nuclear Information System (INIS)

Pekov, B.

1995-01-01

The NPP Kozloduy personnel activities are described directed to undertake measures to overcome the difficulties entailed by equipment failures and human errors in order to avoid recurrent emergency events and to reduce their total numbers. 12 figs, 2 tabs

Water chemistry of secondary circuit and SG currently status NPP 'Kozloduy' 3

Energy Technology Data Exchange (ETDEWEB)

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)

Trends and results in In-Core management for the Kozloduy NPP WWER-440 reactors

International Nuclear Information System (INIS)

Haralampieva, Tz.; Antov, A.; Georgieva, N.; Spasova, V.

2001-01-01

The paper presents the experience gained during the design and operation of the last fuel cycles of the four WWER-440/V-230 units at Kozloduy NPP. High efficiency and economy of the fuel utilization requires very precise procedures for fuel in-core management, including calculations and analyses for reloading scheme design, compared with results from operational measurements and fuel cycle efficiency. The paper describes the main stages of implementation of advanced fuel assemblies in the Kozloduy NPP WWER-440 reactors. New advanced fuel has been implemented after the completion of comprehensive neutron-physical, thermal-hydraulic and thermal-mechanical analyses by using advanced computer codes. As a general task of the fuel cycle improvements it is pointed the increasing of the final fuel burnup and decreasing of the number of spent fuel assemblies. Series of calculations and analyses, related to the introducing of the advanced fuel assemblies and improvement of the fuel cycle characteristics have been carried out to guarantee the safe operation and fuel reliability

Floor response spectra for seismic qualification of Kozloduy VVER 440-230 NPP

International Nuclear Information System (INIS)

Kostov, M.K.; Prato, C.A.; Stevenson, J.D.

1993-01-01

In this paper the floor response spectra generation methodology for Kozloduy NPP, Unit 1-2 of VVER 440-230 is presented. The 2D coupled soil-structure interaction models are used combined with a simplified correction of the final results for accounting of torsional effects. Both time history and direct approach for in-structure spectra generation are used and discussion of results is made

Floor response spectra for seismic qualification of Kozloduy VVER 440-230 NPP

Energy Technology Data Exchange (ETDEWEB)

Kostov, M.K. [Bulgarian Academy of Sciences, Sofia (BG). Central Lab. for Seismic Mechanics and Earthquake Engineering; Ma, D.C. [Argonne National Lab., IL (United States); Prato, C.A. [Univ. of Cordoba (AR); Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (US)

1993-08-01

In this paper the floor response spectra generation methodology for Kozloduy NPP, Unit 1-2 of VVER 440-230 is presented. The 2D coupled soil-structure interaction models are used combined with a simplified correction of the final results for accounting of torsional effects. Both time history and direct approach for in-structure spectra generation are used and discussion of results is made.

Non-destructive control at the Kozloduy NPP; Nerazrushayushchij kontrol` v AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Mikhovsky, M [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Skordev, A [SIME-CONTROL, Sofia (Bulgaria); Nichev, V; Tsokov, P; Popova, N [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

A program for technical diagnostics using non-destructive methods is being carried out at the Kozloduy NPP. The main target is to test mechanical equipment integrity (metal control, mechanical stress control, etc.) as well as electrical equipment. Computer methods and simulation are widely used in program implementation. Non-destructive testing is based on methods involving optical, radiation, ultrasonic and magnetic processes. Control procedures are standardised in special technological documents and one of them is described as an example. It refers to ultrasonic control of the austenitic steel welds of the WWER-440 piping system (DU-500). Graphic representing the microstructure of the welds, the distribution of surface ultrasonic wave and the longitudinal and vertically polarised perpendicular waves are presented. 6 refs. 8 figs.

Development of safety culture at Kozloduy NPP: The role of the regulatory body

International Nuclear Information System (INIS)

Miliovsky, Ventzislav

2002-01-01

An evolution is made upon external factor that accompany the development of safety culture at Kozloduy NPP (KNPP). The two basic stages and the major results achieved independently and with external assistance were considered in the process of development of safety culture. The areas in which the regulatory body insists on having active participation were defined. (author)

A cytogenetic study of personnel of the Kozloduy NPP with a view to the hazards of late effects

Energy Technology Data Exchange (ETDEWEB)

Bulanova, M; Benova, D; Georgieva, I; Georgieva, V; Yagova, A; Rupova, I; Kusheva, R; Khadzhidekova, V; Topalova, S; Nikolova, T [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

Chromosomal analysis of 40 Kozloduy NPP workers has been carried out. Three cytogenetic end-points have been considered: chromosomal aberrations (CA), sister-chromatid exchanges and micro nuclear assays in peripheral blood lymphocytes. A higher incidence of CA has been detected in the investigated group in comparison with a control group. This is attributed to the radiation factor taking into consideration that the highest occurrence is that of dicentric chromosomes induced by radiation exposure. 95% of the workers have been employed for more than 5 years and 60% have received a dose of more than 30 cSv. However no direct relation of CA incidence to the accumulated dose has been observed. Tobacco smoking potentiates additionally the damage of the chromosome structures caused by ionizing radiation. 15 refs., 3 tabs.

Kozloduy NPP - its 20 years operational experience; AEhS `Kozloduy`: 20-letni opyt ehksploatatsii

Energy Technology Data Exchange (ETDEWEB)

Yankov, M; Grizanov, I; Sabinov, S [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

The main technical and economic results of 20 year operation of the Kozloduy NPP are summarised. The total electricity produced amounts to more than 200 billions KWh. The energy produced by the plant accounts for more than 40% of the national electricity output since 1993. Details of electricity production in different years by all 6 units are given. The efficiency of units 1-4 (WWER-440) is 29-30% and of units 5-6 (WWER-1000) is 29-33%. The Unit 6 has best characteristics. Since 1989 a safety test is being carried out in cooperation with the IAEA. Units 1 and 2 have been reconstructed in order to enhance safety and reliability. 1 tab.

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

International Nuclear Information System (INIS)

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

Environmental radioactivity of the Danube basin in the vicinity of the Kozloduy NPP (July 1994)

Energy Technology Data Exchange (ETDEWEB)

Badulin, V; Zlatanova, R; Botsova, L; Mireva, Z [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

Analytical results from radiation monitoring carried out at the Kozloduy NPP area are reported. Sampling of water, sediment, soil and grass for beta and gamma activity has been done in 13 points at distances ranging from 6 to 90 km from the plant. The comparison of data with the values for the previous year does not show any significant variations in radioactivity. The values of {sup 90}Sr activity in river water are less than 10 mBq/l, in river bottom sediment - less than 2 Bq/kg, in soil - less than 4 Bq/kg and in grass -below 8 Bq/kg. Activity of Cs-137 is highest in river bottom sediment - 6-43 Bq/kg which is attributed to the Chernobyl accident. It is concluded that the radioactive effluents and atmospheric releases from the Kozloduy NPP do not produce any noticeable changes in environmental radioactivity caused by the global fallout and the Chernobyl accident. 9 figs., 1 tab.

Experience with Periodic Safety Review (PSR) at Kozloduy NPP after 20 years of operation

International Nuclear Information System (INIS)

Popov, V.

2011-01-01

Conclusion: Measures in the long-term Programs for improving safety and radiation protection of unit 5&6, based on PSR outcome and addressed on the units’ operation licence renewal are under way. • NPP Kozloduy intends to fulfils requirements on modern nuclear power plants which occasionally exceeds limits of the effective national nuclear legislation

Drawings: Kozloduy NPP

International Nuclear Information System (INIS)

Boyadjiev, Z.

1995-01-01

This paper includes drawings of Kozloduy nuclear power plant needed for study for the seismic analysis and testing. It covers the list and schemes of safety and safety related systems for normal operation as well as protection and control systems

PSB-VVER simulation of Kozloduy NPP 'loss of feed water transient'

Energy Technology Data Exchange (ETDEWEB)

Groudev, P.P. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: pavlinpg@inrne.bas.bg; Stefanova, A.E. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: antoanet@inrne.bas.bg; Gencheva, R.V. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: roseh@inrne.bas.bg; Pavlova, M.P. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: pavlova@inrne.bas.bg

2005-04-01

This paper provides a comparison between the PSB test facility experimental results obtained during the simulation of loss of feed water transient (LOFW) and the calculation results received by INRNE computer model of the same test facility. Integral thermal-hydraulic PSB-VVER test facility located at Electrogorsk Research and Engineering Center on NPPs Safety (EREC) was put in operation in 1998. The structure of the test facility allows experimental studies under steady state, transient and accident conditions. RELAP5/MOD3.2 computer code has been used to simulate the loss of feed water transient in a PSB-VVER model. This model was developed at the Institute for Nuclear Research and Nuclear Energy for simulation of loss of feed water transient. The objective of the experiment 'loss of feed water', which has been performed at PSB-VVER test facility is simulation of Kozloduy NPP LOFW transient. One of the main requirements to the experiment scenario has been to reproduce all main events and phenomena that occurred in Kozloduy NPP during the LOFW transient. Analyzing the PSB-VVER test with a RELAP5/MOD3.2 computer code as a standard problem allows investigating the phenomena included in the VVER code validation matrix as 'integral system effects' and 'natural circulation'. For assessment of the RELAP5 capability to predict the 'Integral system effect' phenomenon the following RELAP5 quantities are compared with external trends: the primary pressure and the hot and cold leg temperatures. In order to assess the RELAP5 capability to predict the 'Natural circulation' phenomenon the hot and cold leg temperatures behavior have been investigated. This report was possible through the participation of leading specialists from Kozloduy NPP and with the support of Argonne National Laboratory (ANL), under the International Nuclear Safety Program (INSP) of the United States Department of Energy.

Behaviour of NPP Kozloduy (Bulgaria) during the three strong Vranchea earthquakes

International Nuclear Information System (INIS)

Sachanski, S.; Krutzik, N.; Sachanski, G.

1991-01-01

Following the new tendency a coordinated program with IAEA-Vienna for increasing of NPP Kozloduy seismic safety is in realisation. To check the real characteristics of 440 MW blocks, to establish more realistic mathematical model and response of structure is purpose of this study. The revaluated and increased the design peak ground acceleration with 40 % needs additional analysis of the structures and equipment. Space mathematical model and three component seismic excitation, represented with power spectra density function, are under consideration for revaluation of seismic safety. (author)

Modeling of behaviour of main type personnel in Kozloduy NPP during different operational conditions

International Nuclear Information System (INIS)

Hristova, R.; Kalchev, B.

2000-01-01

The subject of this article is the personnel behavior and initiating events modeling, based on the operational experience in the NPP 'Kozloduy' initiating events reports. The development of models on qualitative information is much more difficult comparing the quantitative modeling. The modelling process is based on the artificial intelligence theory and methods including knowledge base and inference machine in the frame of logical models and semantic networks. (author)

Nuclear fuel utilization in Kozloduy NPP

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

Cs 137 and Sr 90 content in the Kozloduy NPP environment; Soderzhanie 137Cs i 90Sr v obektakh okruzhayushchej sredy v rajone AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Karaivanova, R; Totseva, R; Badulin, V; Zlatanova, R; Fajtondzhieva, K [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

The radioactivity status of soil and plant samples collected in the 12 km controlled zone surrounding Kozloduy has been investigated in the period 1990-1993. The average annual concentrations of Sr-90 and Cs-137 are compared to the values taken at 40 km distance. Cs-137 has in general higher concentrations in soil samples from the NPP close surroundings - e.g. 50-55 Bq/kg in 1992 versus 2-2.5 Bq/kg for Sr-90. Radionuclide concentrations in grass do not differ significantly from the data at 40 km distance. It is concluded that the average annual doses follow the radionuclide dynamics in the global fallout and the effect of Kozloduy operation can not be separated from the background radioactivity status. 4 refs., 21 figs.

Development of a methodology for maintenance optimization at Kozloduy NPP

International Nuclear Information System (INIS)

Kitchev, E.

1997-01-01

The paper presents the overview of a project for development of an applicable strategy and methods for Kozloduy NPP (KNPP) to optimize its maintenance program in order to meet the current risk based maintenance requirements. The strategy in a format of Integrated Maintenance Program (IMP) manual will define the targets of the optimization process, the major stages and elements of this process and their relationships. IMP embodies the aspects of the US NRC Maintenance Rule compliance and facilitates the integration of KNPP programs and processes which impact the plant maintenance and safety. The methods in a format of IMP Instructions (IM-PI) will define how the different IMP stages can be implemented and the IMP targets can be achieved at KNPP environment. (author). 8 refs

Seismic re-evaluation of Kozloduy NPP criteria, methodology, implementation

International Nuclear Information System (INIS)

Kostov, M.

2003-01-01

The paper describes some features of the methodology applied for seismic upgrading of civil structures at the site of the Kozloduy NPP. The essence of the methodology is the use of as-build data, realistic damping and inelastic reduction factors. As an example of seismic upgrading the analyses of units 3 and 4 are presented. The analyses are showing that for effective seismic upgrading detailed investigations are needed in order to understand the significant response modes of the structures. In the presented case this is the rotation of the attached flexible structures to the stiff reactor building. Based on this an upgrading approach is applied to increase the seismic resistance for the predominant motion. The second significant approach applied is the strengthening of the prefabricated element joints. Although it is very simple it allows use of the available element capacity. (author)

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

International Nuclear Information System (INIS)

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

Floor response spectra of WWER-1000, NPP Kozloduy generated from local seismic excitation

International Nuclear Information System (INIS)

Bojadziev, Z.; Kostov, M.

1996-01-01

The seismic review level characteristics for the Kozloduy NPP site were set to 0.2 g and a respective free field acceleration response spectra were derived after a profound site conformation project. Accordingly a separate investigation is recommended for local seismic excitation. The goals of the analyses are: to define the seismic motion characteristics from local seismic sources; to perform structural analyses and in-structure spectra generation for local seismic excitation; and to compare the forces (spectra) from local events with those generated as seismic design review basis

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

International Nuclear Information System (INIS)

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

Nuclear fuel utilization at the Kozloduy NPP

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

Cytochalasin-b micronucleus test of peripheral blood lymphocytes of Kozloduy NPP workers

International Nuclear Information System (INIS)

Hadjidekova, V.; Hristova, R.; Atanassova, P.; Stainova, A.; Popova, L.

2006-01-01

Full text: The cytokinesis-block micronucleus assay in peripheral blood lymphocytes was applied to evaluate occupational radiation exposure of 65 nuclear power plant workers. Blood samples were collected from 43 workers aged between 32-54 years, mean age 41,7 years. The accumulated radiation doses for each subject varied between 7,9 - 766,4 mSv, mean level of the whole group is 237,78 mSv. Controls were 22 healthy individuals, (13 male and 9 female), aged between 27-52 years, mean age 38,8 years, selected from the administrative staff. All subjects participating in this study were interviewed concerning health status, professional history, smoking habit and other aspects relevant to the study. At least 1000 binucleated cells were analysed per person. The detected frequencies of micronuclei in the control group were ranged between 4.0 and 23.5 per 1000 binucleated cells, with the average incidence yield of 12.16 ±5.59 %. The mean group value of the frequency of micronuclei in peripheral lymphocytes of exposed workers was found to be 18.46±6.72 % in 1000 cells. The difference between the mean frequency of micronuclei in the group of exposed subjects and the control group was statistically significant (P<0,001). The correlation coefficient for duration of employment and accumulated doses is 0,30 (P<0,05). After 1,5 Gy in vitro irradiation of peripheral blood from investigated workers and controls a decreased radiosensitivity of NPP workers is detected using micronucleus assay. Decreased radiosensitivity of the professionally exposed workers could be due to the phenomenon of adaptive response. Micronucleus assay in peripheral blood lymphocytes is useful approach in cytogenetic monitoring of occupationally exposed nuclear industry workers

Information technologies in radioactive waste management, applied in NPP-Kozloduy, Bulgaria

International Nuclear Information System (INIS)

Jeliazkov, J.; Jeliazkova, L.; Atanasov, Sv.

1994-01-01

Radioactive waste (RAW) management in NPP is a complex problem, that can be considered as a combination of sub problems, for example scientific, administrative, social, economical, etc. The separate examination of these sub problems does not lead to creation of overall system for optimal RAW management. There's no doubt that such an administrative system, supported by information technologies, should present in every one existing and planned nuclear power plant to optimize its operation as a whole, not only separate elements. The aim is to avoid the fallacy of the single and the complex. This paper presents a basic part of the whole information management system as defined above that concerns RAW management. The information management system is prepared for NPP-Kozloduy, Bulgaria by means of modern concepts and technological schemes and is aimed to help the administrative personnel in this very important activity - RAW management. On the base of objective data about the available waste and prognoses about arisings in the future, on the base of chosen technologies and equipment the system gives multi-variant plan for treatment, processing and disposal of waste, after the choice of a variant it monitors its application in the practice

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

International Nuclear Information System (INIS)

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

Content of Strontium-90 in soils and sediments from the vicinity of the Kozloduy NPP for the period 2011-2012

Energy Technology Data Exchange (ETDEWEB)

Kamenova-Totzeva, R.; Kotova, R.; Tenev, J.; Ivanova, G.; Badulin, V. [Public Exposure Monitoring Laboratory, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

2013-07-01

The National centre of radiobiology and radiation protection (NCRRP) – Sofia has carried out periodic radiation environmental monitoring and control of the region since the pre-operational period of the Nuclear power plant Kozloduy. The latest analytical results of the radiation monitoring for the period 2011- 2012 are described in this article. The object of study is the content of Strontium-90 in soils and bottom sediment samples at 17 points located from 6 to 90 km from the Kozloduy NPP. Obtained results of the investigation and analyses for the period 2011-2012 are shown in tables and figures. Annual results are compared with data from previous years as well as with data from the pre-operational period. (author)

Seismic safety review mission to assist in the evaluation of the design of seismic upgrading for Kozloduy NPP. Sofia, Bulgaria, 19-23 October 1992

International Nuclear Information System (INIS)

Ma, D.; Prato, C.; Godoy, A.

1992-10-01

A seismic Safety Review Mission to assist in the evaluation of the design of seismic upgrading for Kozloduy NPP was performed in Sofia from 19-23 October 1992. The objectives of the mission were to assist the Bulgarian authorities in: the evaluation of the floor response spectra of the main buildings of units 1-4 at Kozloduy NPP, calculated for the new defined seismic parameters at site (Review Level Earthquake - RLE); the evaluation of the remedial and strengthening measures proposed for the seismic upgrading of the pump house and diesel generator buildings to the new defined RLE. This mission completed the scope of previous IAEA mission - BUL/9/012-18b - (see Report 3262) performed from 3-7 August 1992, with regard to tasks which were not evaluated at that time because they had not been finished. 2 tabs

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

International Nuclear Information System (INIS)

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

Radio ecological monitoring of soils within the region of Kozloduy NPP

International Nuclear Information System (INIS)

Naidenov, Ilko; Tsibranski, Rusiyan; Avramov, Valentin; Popov, Lubomir

2005-01-01

The main approach of assessing the radio ecological impact of nuclear power plants is systematic monitoring of major environmental components, status indicators and indicators on the dynamics of radiation status and those appearing as an inseparable part of the food chain for radioactivity intake by humans. Such ecological components are air, water, soil, plants, agricultural products - grain-fodder crops, meat, milk etc.- within NPP areas. All of these components participate directly or indirectly into the internal irradiation of human body, as different forms of intake from land and water ecosystem. The accumulation of natural and artificial radionuclides in main ecological components and its analysis are subject of a continuous scientific interest and research, and are mandatory part of the scope of control in the ecological monitoring programs. Modern high-sensitive methods, such as gamma spectrometry, radiochemical separation, radiometry of radiostrontium, alpha spectrometry of trans-uranium elements, etc., are being used for laboratory radiation analyses. Along with the monitoring of radiation gamma background of air and water, that is reasonably the largest in its volume and frequency in the ecological programs, research and radioactivity of soils is of high significance. The interest to the radiation status of soils is justified by the fact that they are the 'ecological stamp of time' and they give valuable information on the history and origin of radioactive contaminations. Radioactivity of soils within the region of Kozloduy NPP has been a subject of detailed and systematic research since the commissioning of the plant in 1974. The monitoring conducted by EML covers the region that is divided into three areas in order to be able to localize possible radiation impact by KNPP - 3 km, 12 km, and 100 km. Samples are taken and analysis of soils are made at 36 control points within the 100 km area of observation. An issue of great interest is the content of

Radio ecological monitoring of soil within the region of Kozloduy NPP

International Nuclear Information System (INIS)

Naidenov, I.; Tsibranski, R.; Avramov, V.; Popov, L.; Naidenov, Ilko; Tsibranski, Rusiyan; Avramov, Valentin; Popov, Lubomir

2005-01-01

Full text: The main approach of assessing the radio ecological impact of nuclear power plants is systematic monitoring of major environmental components, status indicators and indicators on the dynamics of radiation status and those appearing as an inseparable part of the food chain for radioactivity intake by humans. Such ecological components are air, water, soil, plants, agricultural products - grain-fodder crops, meat, milk etc.- within NPP areas. All of these components participate directly or indirectly into the internal irradiation of human body, as different forms of intake from land and water ecosystem. The accumulation of natural and artificial radionuclides in main ecological components and its analysis are subject of a continuous scientific interest and research, and are mandatory part of the scope of control in the ecological monitoring programs. Modern high-sensitive methods, such as gamma spectrometry, radiochemical separation, radiometry of radiostrontium, alpha spectrometry of trans-uranium elements, etc., are being used for laboratory radiation analyses. Along with the monitoring of radiation gamma background of air and water, that is reasonably the largest in its volume and frequency in the ecological programs, research and radioactivity of soils is of high significance. The interest to the radiation status of soils is justified by the fact that they are the 'ecological stamp of time' and they give valuable information on the history and origin of radioactive contaminations. Radioactivity of soils within the region of Kozloduy NPP has been a subject of detailed and systematic research since the commissioning of the plant in 1974. The monitoring conducted by EML covers the region that is divided into three areas in order to be able to localize possible radiation impact by KNPP - 3 km, 12 km, and 100 km. Samples are taken and analysis of soils are made at 36 control points within the 100 km area of observation. An issue of great interest is the

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

International Nuclear Information System (INIS)

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

Experience from the transportation of irradiated WWER-440 fuel assemblies at the Kozloduy NPP site after a short cooling time

International Nuclear Information System (INIS)

Stoyanova, I.; Kamenov, A.; Byrzev, L.; Christoskov, I.

2003-01-01

Results from the analysis and experimental verification of the radiation and shielding characteristics of non-standard loading patterns of the VSPOT transport cask used for transportation of irradiated fuel assemblies after a short cooling time (120 180 days) on the site of the Kozloduy NPP are presented. An additional safety criterion related to the introduced modifications to the standard procedure of using the transport cask is formulated and discussed (Authors)

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

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

Analysis of buried pipelines at Kozloduy

International Nuclear Information System (INIS)

Asfura, A.

1999-01-01

This paper describes the analysis of the buried pipelines at Kozloduy NPP. It involves the description of the studied pipelines, their properties, a detailed description of the methodology applied, and the evaluation of the soil strain field as well as the graphical representation of the results obtained

Determination and elimination of the reasons for increased control rod insertion time of the Kozloduy NPP WWER-1000

International Nuclear Information System (INIS)

Nikolov, K.

1996-01-01

The emergency insertion speed of the control rod upon reactor shutdown is of crucial importance for reactor safety. The designed insertion time for WWER-1000 reactors should be in the limits 1,5 to 4 s. Having in mind some data about increased insertion times of WWER-1000 type reactors in Russia and Ukraine, a practice of measuring this parameters during each planned outage of the Kozloduy NPP Unit 6 is introduced. Some technical improvements of the fuel assembly are made in order to reach the nominal parameters of the unit

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

A brief account of Kozloduy 6 full-scope replica control room simulator upgrade experience: An engineering point of view

International Nuclear Information System (INIS)

Dinkov, Y.D.

2006-01-01

A short excursion throughout Kozloduy NPP history, and Kozloduy 6 Full-Scope Replica Control Room Simulator procurement, is proposed for a reader, which is not familiar with the Kozloduy circumstances. A brief account of five year operation and upgrade experience is presented as seen by the Kozloduy simulator engineering team. During the last five years Kozloduy 6 is going through a complex and expensive modernization programme so Simulator is a subject of a series of changes twice per year. Simulator is used for training six months of the year during spring and autumn most of this time in two shifts daily. Remaining six months during winter and summer are allocated to other simulator uses including five months downtime for hardware reconstruction, software integration, troubleshooting and testing. Quantitative information concerning scope of software and hardware changes is given. Kozloduy NPP simulator engineering team approach toward various upgrade projects is given in an attempt to facilitate a discussion about how a simulator upgrade should be performed. Projects mentioned vary from small to big, in-house or contracted, already completed or planned for future realization

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

International Nuclear Information System (INIS)

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

The Kozloduy absurdity: Legal and political dimensions of the Bulgarian Nuclear Power Plant issue

International Nuclear Information System (INIS)

Semov, A.

2006-01-01

The issue of Kozloduy NPP is long-standing and sensitive. Complicated technical, legal, economical, political and purely ethical issues are involved in it. Their entire review in this brief presentation is impossible. The paper therefore only dwells on some of the major issues, the way they have been presented by the Civil Committee for Kozloduy NPP Defence. Following an outline of the way the situation developed, the paper discusses legally binding acts and then considers other legally relevant factors. The possible existence of a friendly political climate in Europe allowing reconsideration of the matter is also dealt with. (author)

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

International Nuclear Information System (INIS)

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)

Seismic upgrading of the spent fuel storage building at Kozloduy NPP

International Nuclear Information System (INIS)

Alexandrov, A.; Borov, V.; Jordanov, M.; Karamanski, T.; Mihaylov, K.

2001-01-01

The Spent Fuel Storage Building at Kozloduy NPP site has been analysed for new review level earthquake with 0.2 g peak ground acceleration (compared to the initial design basis earthquake with 0.1 g PGA). The preliminary seismic analysis of the existing building structure using the 5% site specific response spectrum showed the need of seismic structural upgrading. Two upgrading concepts were evaluated on the basis of several factors. The main factor considered was preventing the collapse of the hall structure and the travelling cranes on the fuel storage area during and after a SSE. A three dimensional finite element model was created for the investigation of the seismic response of the existing structure and for the design of the building upgrading. The modelling of the heavy travelling crane and its sub-crane structure was one of the key points. Different configurations of the new upgrading and strengthening structures were investigated. Some interesting conclusions have been drawn from the experience in analysing and upgrading of such a complex industrial structure, comprised of elements with substantial differences in material, rigidity, construction and general behaviour. (author)

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

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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)

An opportunity for capacity up-rating of 1000 MW steam turbine plant in Kozloduy NPP

International Nuclear Information System (INIS)

Popov, D.

2005-01-01

In connection with earlier and forced decommissioning of the Kozloduy NPP units 1 - 4, an alternative has to be found in order to substitute these capacities. As a reasonable options, capacity up-rating of 1000 MW steam turbine plants without nuclear reactor thermal capacity increase, is investigated in the present study. The cooling water for these units is delivered by Danube river. The cooling water temperatures substantially decrease during the winter months. These changes create an opportunity for steam back end pressure reduction. It was found that when the cooling water temperature decreases from 15 0 C to 3 0 C, the steam back end pressure is on the decrease of from 3.92 kPa to 2.3 kPa. As a result capacity of the plant could be raised up to 50 MW without any substantial equipment and systems change

Regulatory approach to NPP ageing in Bulgaria

International Nuclear Information System (INIS)

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

Design and implementation experience of seismic upgrades at Kozloduy and Paks NPPs

Energy Technology Data Exchange (ETDEWEB)

Borov, V; Trichkov, V; Alexandrov, A; Jordanov, M [EQE-Bulgaria, Sofia (Bulgaria)

1995-07-01

Series of upgrades have been designed and implemented by EQE-Bulgaria at Kozloduy NPP and as a subcontractor of EQE-International - at Paks NPP. Wide variety of facilities have been upgraded, including Electrical Equipment, Control and Instrumentation Equipment, Technological Equipment, Brick Walls and Building Structures. Different design approaches and concepts have been applied in compliance with the specific technological and structural conditions. The effect of the excitation intensity as well as the presence of specific floor response spectra over the upgrading concept and cost is discussed. Specific problems of supporting heavy technological equipment are noted. A practical approach for seismic upgrading of Brick Walls, as well as a tendency for unification of the engineering design is shown. The first completely upgraded Building Structure at Kozloduy NPP is the structure of the Electrical Control Building to the Diesel Generator of the River-bank Pump Station. Specific problems of the implementation of the final upgrading design of the Diesel Generator Building are outlined. (author)

Design and implementation experience of seismic upgrades at Kozloduy and Paks NPPs

International Nuclear Information System (INIS)

Borov, V.; Trichkov, V.; Alexandrov, A.; Jordanov, M.

1995-01-01

Series of upgrades have been designed and implemented by EQE-Bulgaria at Kozloduy NPP and as a subcontractor of EQE-International - at Paks NPP. Wide variety of facilities have been upgraded, including Electrical Equipment, Control and Instrumentation Equipment, Technological Equipment, Brick Walls and Building Structures. Different design approaches and concepts have been applied in compliance with the specific technological and structural conditions. The effect of the excitation intensity as well as the presence of specific floor response spectra over the upgrading concept and cost is discussed. Specific problems of supporting heavy technological equipment are noted. A practical approach for seismic upgrading of Brick Walls, as well as a tendency for unification of the engineering design is shown. The first completely upgraded Building Structure at Kozloduy NPP is the structure of the Electrical Control Building to the Diesel Generator of the River-bank Pump Station. Specific problems of the implementation of the final upgrading design of the Diesel Generator Building are outlined. (author)

An application of low leakage loading pattern to reduce fast neutrons. Fluence on WWER-440 reactor pressure vessel in Kozloduy NPP

International Nuclear Information System (INIS)

Haralampieva, Tz.; Antonov, A.; Monev, M.

2001-01-01

The neutron exposure of a reactor pressure vessel (RPV) is one of the key factors that have to be quantified and assess reliably to provide plant life assurance and for an extension to operational life. This paper summarizes the principal methods that are used in core design optimisation for WWER-440 reactors in NPP-Kozloduy in order to reduce flux of fast neutrons at the RPV. Results of fast neutron fluence changes during the all last cycles of units 1-4 with WWER-440 reactors are considered (Authors)

Knowledge management at Kozloduy NPP - challenges and solutions

International Nuclear Information System (INIS)

Tzotchev, S.; Pironkov, L.

2004-01-01

Like any highly technical endeavor, the use of nuclear technology relies heavily on a vast accumulation of knowledge - volume upon volume of scientific research, engineering analysis, design documentation, operational data, maintenance records, regulatory reviews and countless other pieces of technical information, combined with complex reservoir of scientists, engineers, technicians and managers with relevant background and expertise. The effective management of nuclear knowledge includes systematic and organized application of accumulated specific knowledge as well as ensuring the sustainable availability of qualified personnel. This means that: 1) The know-how should be properly identified, captured and classified; 2) Adequate tools for support, access and transfer of data should be available; 3) Renewing of workforce without loss of institutional memory should be guaranteed. During the centuries this process has been applied spontaneously and there are a lot of examples that the world use to be workable earlier too. However nowadays this type of spontaneous knowledge management is ineffective. Information volume and the communication efficiency have increased so much that new tools have to be created to handle the knowledge being communicated trough numerous sources. Besides information space is strongly polluted. The information channels provide unnecessary redundant information. Target oriented searching and delivering of useful information is difficult and requires significant resources. What value this know-how represent, how can it be maintained for and passed to the next generation, what are the problems of aging and renewing of workforce, what measures have been taken by Kozloduy NPP and what are the challenges to be faced yet - these are the issues to be addressed in this paper. (authors)

Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime

Energy Technology Data Exchange (ETDEWEB)

Vodenicharov, S [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite; Kamenova, Tz [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite; Tzokov, P; Videnov, A [Kombinat Atomna Energetika, Kozloduj (Bulgaria); Pekov, B [Committee on the Use of Atomic Energy for Peaceful Purposes, Sofia (Bulgaria)

1996-12-31

The processes of metal embrittlement induced by neutron irradiation embrittlement (NIE) and neutron re-irradiation embrittlement (NRE) of the rector pressure vessel (RPV) are investigated. Radiation lifetime is calculated using two approaches for re-embrittlement: a conservative law and a lateral shift of the critical transition temperature curve after neutron irradiation. In order to prevent NIE the following measures have been taken at the Kozloduy NPP: loading of dummy elements into core periphery; heating the water for emergency core cooling to 55{sup o} C; fast acting valves in the main steam piping, etc. The critical embrittlement temperature, the residual part of temperature shift and the radiation lifetime have been calculated for units 1 - 4 using the two approaches and updated information on P and Cu impurities content. It is concluded that if the lateral re-embrittlement law is adopted and the P content does not exceed 0.05%, all RPV should reach their design lifetime. The NIE in WWER-440/230 is related to C and P content in the weld 4 and is negligible for the Unit 4 in particular, which has low impurities content. In order to reach the design lifetime of the Units 1 - 3 it is necessary to install MSIV. A verification of chemical composition of the Unit 1 RPV weld 4 metal is recommended. 7 refs., 3 figs., 6 tabs.

Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime

International Nuclear Information System (INIS)

Vodenicharov, S.; Pekov, B.

1995-01-01

The processes of metal embrittlement induced by neutron irradiation embrittlement (NIE) and neutron re-irradiation embrittlement (NRE) of the rector pressure vessel (RPV) are investigated. Radiation lifetime is calculated using two approaches for re-embrittlement: a conservative law and a lateral shift of the critical transition temperature curve after neutron irradiation. In order to prevent NIE the following measures have been taken at the Kozloduy NPP: loading of dummy elements into core periphery; heating the water for emergency core cooling to 55 o C; fast acting valves in the main steam piping, etc. The critical embrittlement temperature, the residual part of temperature shift and the radiation lifetime have been calculated for units 1 - 4 using the two approaches and updated information on P and Cu impurities content. It is concluded that if the lateral re-embrittlement law is adopted and the P content does not exceed 0.05%, all RPV should reach their design lifetime. The NIE in WWER-440/230 is related to C and P content in the weld 4 and is negligible for the Unit 4 in particular, which has low impurities content. In order to reach the design lifetime of the Units 1 - 3 it is necessary to install MSIV. A verification of chemical composition of the Unit 1 RPV weld 4 metal is recommended. 7 refs., 3 figs., 6 tabs

Modernization program of NPP Kozloduy, units 5 and 6

International Nuclear Information System (INIS)

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.)

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

International Nuclear Information System (INIS)

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)

The development of the Kozloduy NPP in the conditions of liberalized energy market

International Nuclear Information System (INIS)

Ivanov, A.

2003-01-01

production show that the following processes are significant: social pressure for limitation og the nuclear power and programs for waste storage; extension of the term for the building of new nuclear facilities; increase of the funds for new facilities and maintenance of the existing ones. The conception, developed for the Kozloduy NPP in the competitive environment includes: limitation of the government role in the management and commercial activities; organization of a electricity producers pool (from different type of electricity production) with share in the electricity distribution. In the same pool with the Kozloduy NPP other capacities supplying up to 30% reserve should be present. For granting of a long-term development of the formation and providing of a minimal reliable market, consumers should be integrated

Inspection Qualification Centre in NPP 'Kozloduy'

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

Spent fuel generated by the Kozloduy nuclear power plant within the period 1974 - 1994

International Nuclear Information System (INIS)

Peev, P.

1994-01-01

The spent fuel management during the 20-year operation of Kozloduy NPP is described. Formally this period is divided into two stages. The first one covers 1977 - 1988 when the spent fuel after short-term (3 years) storage in the reactor building was dispatched to the former Soviet Union. Within this period 21 shipments of spent fuel (about 3086 fuel assemblies) with various level of enrichment and burnup were performed. The second stage covers the period 1988 - 1994. In that period the authorities responsible for the safe operation of Kozloduy NPP faced a number of problems related to necessity of on-site spent-fuel storage commissioning. A reassessment of the seismic risk after Vrancha earthquake and the Russia's attitude towards the former Soviet Union policy of spent fuel storage was discussed

Spent fuel generated by the Kozloduy nuclear power plant within the period 1974 - 1994

Energy Technology Data Exchange (ETDEWEB)

Peev, P [National Electricity Company, Sofia (Bulgaria)

1994-12-31

The spent fuel management during the 20-year operation of Kozloduy NPP is described. Formally this period is divided into two stages. The first one covers 1977 - 1988 when the spent fuel after short-term (3 years) storage in the reactor building was dispatched to the former Soviet Union. Within this period 21 shipments of spent fuel (about 3086 fuel assemblies) with various level of enrichment and burnup were performed. The second stage covers the period 1988 - 1994. In that period the authorities responsible for the safe operation of Kozloduy NPP faced a number of problems related to necessity of on-site spent-fuel storage commissioning. A reassessment of the seismic risk after Vrancha earthquake and the Russia`s attitude towards the former Soviet Union policy of spent fuel storage was discussed.

Qualitative and quantitative methods for human factor analysis and assessment in NPP. Investigations and results

International Nuclear Information System (INIS)

Hristova, R.; Kalchev, B.; Atanasov, D.

2005-01-01

A description of the most frequently used approaches for human reliability assesment is given. The relation between different human factor causes for human induced events in Kozloduy NPP during the period 2000 - 2003 is discussed. A comparison between the contribution of the casual factors for events occurrences in Kozloduy NPP and an Japanese NPP is presented. It can be concluded that for both NPPs the most important casual factors are: 1) written procedures and documents; 2) man-machine interface; 3) environmental working conditions; 4) working practice; 5) training and qualification; 6) supervising methods

Experience from transportation of irradiated WWER-440 fuel assemblies at Kozloduy NPP site after a short cooling time

International Nuclear Information System (INIS)

Stoyanova, I.; Kamenov, A.; Byrzev, L.; Christoskov, I.

2003-01-01

The presented results from the computation and analysis of the radiation characteristics of the irradiated fuel assemblies by the date of their transportation according to the selected loading patterns of the VSPOT cask and following the modified technology of transportation, i.e. without replacement of the pool solution by pure condensate, as well as the corresponding experimental results, confirm the applicability of the newly introduced safety criterion for the selection of a loading pattern of the cask with irradiated fuel assemblies after a short cooling time. The comparison between measured and computed surface dose rates shows that during the procedure of transfer of irradiated fuel assemblies from the pools of Units 1 and 2 to the pools of Kozloduy NPP Units 3 and 4 all safety limits, incl. the radiation protection requirements, were met

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

International Nuclear Information System (INIS)

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)

Status and operational experience report of spent fuel storage facility in Kozloduy NPP for the period 1990 - 1994

Energy Technology Data Exchange (ETDEWEB)

Kalimanov, M [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1994-12-31

Spent Fuel Storage Facility (SFSF) of Kozloduy NPP is designed for a long-term storage of 4920 spent fuel assemblies which are generated by all units for ten year operational period. The assemblies are stored in SFSF after 3 year storage in the reactor cooling pool. The SFSF operational safety is ensured by a number of strictly followed regulations related to: arrangement of the assemblies and conditions at which they are stored; transportation of the assemblies to the facility; residual heat removal; quality of the water used in the storage pool; water temperature and level control. Two independent groups of experts have carried out investigations to study the building safety. Their reports have been considered and accepted by the council of the Ministry of Environment which was the final step in licensing the SFSF.

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

International Nuclear Information System (INIS)

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.)

Neutron embrittlement of the Kozloduy NPP unit 1 reactor

International Nuclear Information System (INIS)

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

Preparation for decommissioning of the Kozloduy Nuclear Power Plant units 1 and 2

International Nuclear Information System (INIS)

Delcheva, T.; Ribarski, V.; Demireva, E.

2006-01-01

The first decommissioning strategy of units 1 and 2 of Kozloduy NPP (KNPP) stipulated 3 phases: a 5 year phase including the post operation activities and preparation of the safe enclosure (SE); a 35 years SE period, followed by deferred dismantling. 'Updated Decommissioning Strategy for Units 1-4 of Kozloduy NPP' was issued in June 2006. The Updated Strategy is based on the so called 'Continuous Dismantling' Concept. The updated Strategy starts preparatory work earlier and then moves into dismantling work without a significant gap. The aim is to achieve a more optimal distribution of the dismantling activities along the time, saving jobs and the existing knowledge of the plant personnel during the decommissioning, and ensuring smooth and more effective use of financial and human resources and of the available infrastructure for waste treatment. This paper gives general information about the updated strategy and activities required for its implementation. (author)

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

International Nuclear Information System (INIS)

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)

A model for severe accidents management of WWER 440 at Kozloduy NPP

International Nuclear Information System (INIS)

Genovski, I.; Bonev, B.; Velev, V.; Grigorov, A.; Filipov, L.

2006-01-01

In order to reduce the residual risk associated with hypothetical severe nuclear accidents, systems and components for filtered containment venting and H2 reduction were implemented in the Kozloduy NPP units 3 and 4. The system technologies developed have to fulfill the following main tasks: 1) Creating a new pressure barrier system to confine the activity inventory by maintaining a slight containment sub-atmospheric pressure thereby preventing any relevant unfiltered activity releases. 2) Retaining a great extend of the airborne activity in the liquid phase of the venturi scrubber unit and return these activity back into the containment. 3) Controlling the containment atmosphere H2 gas mixture to prevent fast deflagration that may jeopardize the containment integrity. To meet above mentioned requirement a system was developed, consisting of a venturi scrubber unit which comprises a high speed long venturi section, a metal fibre filter section and molecular sieve. The system is operated by a turbo blower unit supplied with electrical power from the unaffected unit. The system keeps a slight sub-atmospheric pressure (approx. 5 - 10 mbar) in the containment with the purpose to minimize the uncontrolled radioactive release from the containment to the environment. The final analysis showed that the containment performance in combination with above mentioned countermeasures could be increased significantly and the impact to the environment is minimized

Modeling of coherent heat and mass-exchange phenomena for a specter of primary circuit leaks in a NPP with WWER-1000 type reactor

International Nuclear Information System (INIS)

Stanev, I.; Mladenova, S.; Hadjiev, V.

2004-01-01

Subject of study are the inter-relations between the primary leak parameters, the containment pressure and the functioning of the WWER-1000/V320 plant systems. The model includes systems for normal operation and safety systems, which are actuated in the initial stage of the accident. The studied specter of primary leaks includes diameters from 10 to 60 mm. The model is based on the design features of unit 5 in NPP Kozloduy. This paper presents a fragment of the work, performed jointly by Atoma Consult Ltd and NPP Kozloduy Plc on the validation of the symptom oriented emergency operation procedures for units 5 and 6 in NPP Kozloduy. (authors)

Full-scale and in-situ tests on the structures and sites of Kozloduy and Belene NPPs

International Nuclear Information System (INIS)

Simeonov, S.

1995-01-01

This paper includes a detailed list of full scale and in-situ tests that were carried out on the structures and the sites of Kozloduy and Belene nuclear power plants. This involves reactor buildings and turbine halls of the five Kozloduy units, foundations of deaerator and turbine of unit 1, boreholes near channels for additional technical water supply, boreholes near units 2, 3 and 5, boreholes near the concrete center. Special measurement profile and gravel embankment of Belene NPP are included as well

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

Application of modified version of SPPS-1 - HEXAB-2DB computer code package for operational analyses of fuel behaviour in WWER-440 reactors at Kozloduy NPP

Energy Technology Data Exchange (ETDEWEB)

Kharalampieva, Ts; Stoyanova, I; Antonov, A; Simeonov, T [Kombinat Atomna Energetika, Kozloduj (Bulgaria); Petkov, P [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. za Yadrena Izsledvaniya i Yadrena Energetika

1994-12-31

The modified version of SPPS-1 code called SPPS-1-HEXAB-2DB was applied for the purposes of the operational analysis and power peaking factors and reactor core critical parameters predictions of WWER-440s. The results of the calculations performed by the use of SPPS-1-HEXAB-2DB code and the corresponding parameters obtained from experiments at Kozloduy NPP WWER-440s as well as the results of fuel rod power distribution are presented. The method of operation simulation of reactor core with 349 assemblies (Unit 4) and with 313 fuel assemblies and 36 dummy fuel assemblies (Unit 1) is outlined. The modified code calculates not only fuel burnup and Pm-149 and Sm-149 concentrations distributions but also the space distribution of I-135 and Xe-135 concentrations. In this way it makes possible to perform the reactor operation simulation during the immediate periods after the reactor start-up or shut-down and to predict the critical reactor core parameters during transients. The results obtained show that SPPS-1-HEXAB-2DB code describes adequately the reactor core status. The new SPPS-1 code algorithm for estimation of assembly-wise power peaking factors distribution in reactor core is also described. The new code provides an option for checking the correctness of reactor core symmetry. The experience from the use of the modified SPPS-1-HEXAB-2DB code system confirms the provision of improved availability of operational analysis, prediction of Kozloduy NPP WWER-440s safe operations and fuel behaviour estimation. 14 tabs., 4 figs., 5 refs.

Probability safety assessment of the Kozloduy-5 and Kozloduy-6 reactors

Energy Technology Data Exchange (ETDEWEB)

Boyadzhiev, A; Manchev, B [Risk Engineering Ltd., Sofia (Bulgaria)

1996-12-31

A probability safety assessment (PSA) of Level 1 (assessment of plant failures leading to the determination of core damage frequency) has been carried out for the NPP Kozloduy Units 5 and 6 (reactors WWER-1000). The scope of the study includes all significant accident initiators including seismic (earthquake) and fire initiators. Event trees for all initiators and fault trees for front line systems, support systems and major safety systems have been built. A distribution of the different initiators has been established as follows: internal initiators - 85%, seismic initiators - 5%, fire initiators- 10%. The loss of offsite power was identified as main contributor from the internal initiators with frequency 1,1.10{sup -4}/y. It is concluded that the safety functions of WWER-1000 are adequately covered by the safety systems. 4 refs., 2 tabs.

Auto-radiographical study of activity distribution of high-dispersity hot particles from NPP

International Nuclear Information System (INIS)

Bonchev, Ts.; Andreev, Ts.; Todorov, N.; Andreev, P.; Kasabov, I.

1995-01-01

Autoradiograms of hot particles (HP) detected at Kozloduy NPP have been obtained with ordinary photographic film using direct contact. HP diameter and activity have been calculated by computer processing of the image.The distribution of HP weight and the precipitation time on surfaces has been estimated. Results on 37 HP found at the Kozloduy NPP units 1-4 and 9 HP found in special rooms containing waste are reported. The emitters are identified as 60 Co, 54 Mn and α emitters with specific activities 2.10 8 Bq/g, 2.10 7 Bq/g and 3.10 4 Bq/g respectively. 5 refs., 6 figs., 3 tabs

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

International Nuclear Information System (INIS)

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)

Determination of neutron fluence and radiation brittleness temperature of WWER-440 and WWER-1000 pressure vessels in Kozloduy NPP

International Nuclear Information System (INIS)

Ilieva, K.; Apostolov, T.; Belousov, S.; Petrova, T.; Antonov, S.; Ivanov, K.; Prodanova, R.

1993-01-01

In Units 1-4 of Kozloduy NPP (WWER-440/230), the weld 4 of RPV undergoes the most severe irradiation embrittlement. Neither witness-samples, nor detectors are designed for these reactors. Transport calculations of fast neutron fluence on WWER-440 RPV and ex-vessel measurements by threshold activation detectors are the primary means for adequate assessment of metal state and for prognosis concerning the reactor life span. In WWER-1000 reactors (Units 5-6) the maximum neutron fluence occurs on the weld 3. The systematical observation of metal state is performed through witness-samples and threshold activation detectors ( 54 Fe (n,p), 63 Cu (n,α), 93 Nb (n,n')) placed above the reactor top edge and at the first vessel ring level. There are big differences in energy spectrum and integral neutron flux falling onto the weld 3, the RPV base metal and the staff detectors. This requires additional neutron measurements in the air gap between the RPV and the thermal insulation. (author)

Initial data of seismic input and soil conditions of Kozloduy NPP site. Extension to Part 2 soil conditions, issued October '93

International Nuclear Information System (INIS)

Boyadjiev, Z.

1995-01-01

On the basis of the results of the carried out experimental (laboratory and in situ) investigations of the dynamic characteristics, the following conclusions for the Kozloduy NPP site are presented. (1) The established through experimental studies relationships for the shear module and the damping factor as strain dependent of representative samples of soils of the site profile, can be used for all similar soils in the profile in the different parts of the site, taking into account the possible differences by means of the initial shear module in the normalized relationship for the respective generalized soil type. (2) When solving the problems of the site response and the 'soil - structure analysis', the geotechnical seismic model of the 'free field' profile can be assumed for all parts of the NPP site. (3) The changes of the lithological profile in different parts of the site, in respect to type and thickness, as well as in view of the different way and depth of the NPP structures foundation, make it necessary the elaboration of a geotechnical seismic model of the profile below the foundation plates of the reactor buildings of the NPP units in each particular case. These models can be made out on the basis of the summarized data about the shear velocities of the soil types, the lithological data of the studied boreholes in these places and the data having natural bulk density from 30 - 40 m depth determined by the laboratory studies of samples of these soils, assuming with approximation that the geotechnical seismic model below this depth is the same as the one of the 'free field'. (4) Studies have been carried out through in situ and laboratory studies of all the fundamental structures on the NPP site and the results of them are sufficient as an addition to the present initial data for solving the problems of the site response and the 'soil-structure inter-action' analyses of each structure

Auto-radiographical study of activity distribution of high-dispersity hot particles from NPP

Energy Technology Data Exchange (ETDEWEB)

Bonchev, Ts [Sofia Univ. (Bulgaria). Fizicheski Fakultet; Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Andreev, Ts; Todorov, N [Kombinat Atomna Energetika, Kozloduj (Bulgaria); Andreev, P; Kasabov, I [Sofia Univ. (Bulgaria). Fizicheski Fakultet

1996-12-31

Autoradiograms of hot particles (HP) detected at Kozloduy NPP have been obtained with ordinary photographic film using direct contact. HP diameter and activity have been calculated by computer processing of the image.The distribution of HP weight and the precipitation time on surfaces has been estimated. Results on 37 HP found at the Kozloduy NPP units 1-4 and 9 HP found in special rooms containing waste are reported. The emitters are identified as {sup 60} Co, {sup 54} Mn and {alpha} emitters with specific activities 2.10{sup 8} Bq/g, 2.10{sup 7} Bq/g and 3.10{sup 4} Bq/g respectively. 5 refs., 6 figs., 3 tabs.

Neutron fluence determination for operation effectiveness assessment and prediction of WWER pressure vessel lifetime at the Kozloduy NPP

Energy Technology Data Exchange (ETDEWEB)

Apostolov, T; Ilieva, K; Belousov, S; Petrova, T; Antonov, S; Ivanov, K; Prodanova, R; Penev, I; Taskaev, E [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. za Yadrena Izsledvaniya i Yadrena Energetika; Ivanov, I; Tsokov, P; Nelov, N; Lilkov, B; Tsocheva, V; Monev, M; Velichkov, V; Kharalampieva, Ts [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

Embrittlement processes in reactor pressure vessel (RPV) metal have been investigated by neutron dosimetry. A software package for fluence calculations has been developed and used for evaluation of the accumulated neutron fluence, the critical temperature of radiation embrittlement and the RPV lifetime. A digital reactivity meter DR-8 has been introduced for continuous neutron fluence monitoring. Estimates of the neutron fluence and the radiation state of all 6 units of the Kozloduy NPP are presented. The Unit 4 RPV is in the best state regarding metal embrittlement, while the Units 2 and 3 can be safely operated up to the end of their design lifetime only using dummy cassettes. The neutron fluence accumulation in the Unit 1 RPV is quite big and can not be reduced with annealing. Activity measurements of the Unit 1 internal wall shavings are made after the 14-th cycle which show a good agreement with calculated values (1.10{sup 5} Bq/g). The critical embrittlement temperature of the Units 1 - 4 is estimated as a function of the working cycles. 11 figs., 1 tab.

Calculational results for radiation embrittlement of WWER pressure vessel at the Kozloduy NPP

Energy Technology Data Exchange (ETDEWEB)

Apostolov, T; Ilieva, K; Petrova, T [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. za Yadrena Izsledvaniya i Yadrena Energetika

1996-12-31

Determination of radiation impact on metal state in the case of WWER-440/230 is made only by calculation methods since a special sample-witness (SW) incorporation had not been implemented. In WWER-1000 reactors such SW are foreseen but their spots are high above the active core. This is why in both reactors the appliance of a calculational procedure for radiation embrittlement determination is compulsory. The authors propose such a procedure accounting for the change in critical temperature of neutron brittleness by the neutron fluence. The neutron fluence and the shift of critical embrittlement temperature have been calculated for the maximum overloaded location and for the weld metal of the Kozloduy-5 and Kozloduy-6 reactors (WWER-1000). The shift of critical temperature in weld 4 of the Units 1-4 (WWER-440) is plotted versus work cycles and compared to experimental values. 4 figs., 5 tabs.

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

International Nuclear Information System (INIS)

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

Safety systems I/C reliability analysis of the Kozloduy NPP units 5 and 6; Analiz nadezhnosti KIP i sistem bezopasnosti pyatogo i shestogo bloka AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Marinova, B [Risk Engineering Ltd., Sofia (Bulgaria)

1996-12-31

The purpose of the analysis is to assess the safety systems I/C equipment reliability of the Kozloduy-5 and the Kozloduy-6 reactors. The assessment of quantitative and qualitative effect of control systems unavailability on the safety systems unavailability is performed. The analysis is limited to the following systems: sprinkler management, low pressure emergency spray, emergency injection of boric acid, hydro accumulators, pressure compensator and compressed air. The code for probabilistic safety assessment PSAPACK has been used in analysis. Fault trees for all analysed safety systems have been constructed. Results indicates a high reliability of the safety systems management.

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

International Nuclear Information System (INIS)

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)

Safety systems I/C equipment reliability analyses of the Kozloduy NPP units 3 and 4

Energy Technology Data Exchange (ETDEWEB)

Halev, G; Christov, N [Risk Engineering Ltd., Sofia (Bulgaria)

1996-12-31

The purpose of the analysis is to assess the safety systems I/C equipment reliability. The assessment includes: quantification of the safety systems unavailability due to component failures; definition of the minimal cut sets leading to the analysed safety systems failure; quantification of the I/C equipment importance measures of the dominant contribution components. The safety systems I/C equipment reliability has been analysed using PSAPACK (a code for probabilistic safety assessment). Fault trees for the following safety systems of the Kozloduy-3 and Kozloduy-4 reactors have been constructed: neutron flow control equipment, reactor protection system, main coolant pumps, pressurizer safety valves `Sempell`, steam dump systems, spray system, low pressure injection system, emergency feeding water system, essential service water system. THree separate reports have been issued containing the performed analyses and results. 1 ref.

Seismic response and resistance capacity of 'as built' WWER 440-230 NPP Kozloduy: Verification of the results by experiments and real earthquake

International Nuclear Information System (INIS)

Sachanski, S.

1993-01-01

Although Kozloduy NPP units 1 and 2 were not designed for earthquakes they have withstood successfully the Vrancea Earthquake in 1977 with sire peak ground acceleration of 83 sm/s 2 . Both units as well as units 3 and 4 were later recalculated for maximum peak acceleration of 0.1 g. According to values calculated by two-dimensional model, in 1980 reactor buildings had sufficient earthquake resistance capacity for the accepted design seismic excitation. The non symmetric design of WWER-440 structures in plan and elevation, the large eccentricity between the center of rigidities and masses as well as technological connections between the separate substructures and units led to complicated space response and rotational effects which cannot be calculated by two-dimensional models. Three dimensional detailed 'as built' mathematical models were established and verified by series of experiments and real earthquake for: detailed analysis of 'as built' structural response, comparing the results of two and three dimensional models, detailed analyses of seismic safety margins

Regulatory aspects of NPP safety

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Design safety improvements of Kozloduy NPP to meet the modern safety requirements towards the old generation PWR

International Nuclear Information System (INIS)

Hinovski, M.P.; Sabinov, S.

2001-01-01

Activities related to safety improvement of Kozloduy NPP units, started at the end of 1970s included seismic resistance upgrading, fire safety improvement, reliable heat final absorber etc. During the last 10 years the approach was systematized and improved. Units 1 to 4 are of great interest; therefore here we will discuss these units only. As a result of studies and analyses performed at the end of the 1980s and the beginning of the 1990s, problems related to the safety were identified and complex of technical measures was developed and planned. A considerable part of these measures has already been implemented, and the rest will be performed during the next years. Activities were performed by stages, and at the moment the last stage is under way. It shall be finished by the year 2003. The number of the measures is quite large to describe them here in full scope -- during the first stage of the safety program (1991-1993) were developed and analyzed more than 4200 documents and more than 160 measures were executed. During the second and third stages more than 300 important improvements were realized. In the frame of the program, financed by EBRD, 10 new systems with great importance were implemented and 8 systems were significantly modified. The main measures are described below. (author)

Cytogenetic analysis in peripheral blood lymphocytes of the Kozloduy NPP workers

International Nuclear Information System (INIS)

Hristova, R.; Hadjidekova, V.; Atanasova, P.; Popova, L.; Grigorova, M.; Nikolova, T.; Staynova, A.; Boulanova, M.; Georgieva, I.; Benova, D.

2006-01-01

The frequencies of chromosome aberrations of 32 workers from nuclear power plant were compared with those of 26 controls from administrative staff. The aim of study is to investigate the relationship between cumulative doses and the frequency of dicentrics, as well as the influence of smoking habit and alcohol intake. The frequency of all type of chromosome aberrations in exposed subjects was significantly higher then those in control group. It was found low correlation between age and cell with aberrations, but not for dicentrics. Duration of work also correlates with frequencies of dicentrics and cells with aberrations. It was not proved positive influence of cigarette smoking and alcohol intake. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

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.

The Kozloduy project management unit

International Nuclear Information System (INIS)

Carnes, W.S.; Gros-Gean, P.; Demireva, E.

2004-01-01

The Project Management Unit (PMU) has been established in support to the Kozloduy NPP decommissioning department. It is comprised of a Consortium of the British Nuclear Group, EDF and subcontractor ENPRO Consult. It is responsible for the management of seven projects (a facility for dry storage of spent fuel; equipment to treat low activity liquid radioactive waste; provision of physical separation of the plant systems and areas to be decommissioned from the ones in operation; equipment to decontaminate and clean pools and large tanks; a facility to provide high volume reduction of solid radioactive wastes and retrieval and conditioning of ion exchange resins and other sorbents; equipment to provide measurement for the free-release of materials and components; a facility for personnel monitoring, decontamination and clothes changing for work outside of the normal radiological control areas) that will be used in support of the KNPP decommissioning process. The projects will be tendered in compliance with the European Bank for Reconstruction and Development requirements

Experiences in seismic upgrading of equipment and structures in Kozloduy nuclear power plant (440 WWER-PWR)

International Nuclear Information System (INIS)

Ordonez Villalobos, A.

1993-01-01

Within the framework of the 'Emergency programme for Nuclear Safety of Kozloduy NPP' it has been concluded that the increase in seismic safety of a NPP can be achieved by upgrading the key equipment in a cost effective way. Essential and vulnerable equipment has to be identified. Seismic capacity should be evaluated base don realistic state of the art criteria. Seismic review teams ef experienced engineers should conduct planned walk-downs in order to propose effective upgrading solutions. Team work of plan engineers and construction engineers would enhance the effectiveness of the solutions. It is recommended that all the participants be motivated and have a clear understanding of the objectives of the upgrading

Malignant neoplasm rate in inhabitants of the Kozloduy NPP area; Zabolevaemost` zlokachestvennymi novoobrazovaniyami sredi naselenya v rajone AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Dimitrov, P [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

Illness incidence of malignant formations in lungs, mammary gland, thyroid gland, lymph and blood producing tissues is investigated in the 30 km area around Kozloduy and compared to data from two other locations in Bulgaria. The number of malignant growth in the lungs, mammary or thyroid gland on 100 000 persons is lower than the average number for the country as a whole. The number of malignant formations in lymph and blood producing tissues is higher than the average number for the country but the difference is statistically insignificant. Thyroid gland diseases occur with very small frequency for the investigated period (1985-1990). 8 refs., 4 figs.

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

International Nuclear Information System (INIS)

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

Future needs in radiation protection training for NPP workers of Slovenia

International Nuclear Information System (INIS)

Kozelj, M.; Bogovic, T.

1999-01-01

Short review of history of radiation protection training for NPP workers in Slovenia and legal requirements regarding this field are presented. Courses developed in co-operation between Milan Copic Nuclear Training Centre and Krsko Nuclear Power Plant are briefly described and their implementation presented. Using available data we have predicted probable number of courses and participants in forthcoming years. Some results from inquiry on courses for regularly exposed workers are presented, enabling us to modify courses according to participants' needs.(author)

Safety of NPP with WWER-440 and WWER-1000 reactors

Energy Technology Data Exchange (ETDEWEB)

Balabanov, E [Energoproekt, Sofia (Bulgaria); Gledachev, J; Angelov, D [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

The WWER-440 and WWER-1000 reactors used at the Kozloduy NPP have been analyzed in terms of safety. There are currently 4 reactors WWER-440/230 and 2 reactors WWER-1000/320. The former do not comply completely with the modern safety requirements due to the regulations acted in the sixties when they have been designed. The main features of these reactors are: low power density in the core; three levels of reactor control and protection; six primary loops; horizontal steam generators; two turbines; large number of cross-unit connections. The low thermal density in the core, the low specific thermal loading in the rods and the large coolant inventory enhance the safety, while the major deficiencies are identified as follows: insufficient capabilities for emergency core cooling; low diversification and physical separation of the safety systems; old fashioned control systems; inadequate fire protection; lack of full containment. It is pointed out that several design and operation actions have been completed in the Kozloduy NPP in order to enhance their safety. The WWER-1000 units are 320 model and feature a high safety level, complying completely with OPB-82 regulations and with all current international safety standards. 3 refs., 7 figs., 1 tab.

Safety of NPP with WWER-440 and WWER-1000 reactors

International Nuclear Information System (INIS)

Balabanov, E.; Gledachev, J.; Angelov, D.

1995-01-01

The WWER-440 and WWER-1000 reactors used at the Kozloduy NPP have been analyzed in terms of safety. There are currently 4 reactors WWER-440/230 and 2 reactors WWER-1000/320. The former do not comply completely with the modern safety requirements due to the regulations acted in the sixties when they have been designed. The main features of these reactors are: low power density in the core; three levels of reactor control and protection; six primary loops; horizontal steam generators; two turbines; large number of cross-unit connections. The low thermal density in the core, the low specific thermal loading in the rods and the large coolant inventory enhance the safety, while the major deficiencies are identified as follows: insufficient capabilities for emergency core cooling; low diversification and physical separation of the safety systems; old fashioned control systems; inadequate fire protection; lack of full containment. It is pointed out that several design and operation actions have been completed in the Kozloduy NPP in order to enhance their safety. The WWER-1000 units are 320 model and feature a high safety level, complying completely with OPB-82 regulations and with all current international safety standards. 3 refs., 7 figs., 1 tab

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

Dose limit for emergency workers. Application of Fukushima-Daiichi NPP accident and problems for the future

International Nuclear Information System (INIS)

Sugai, Kenji

2012-01-01

Described are details of management for workers' personal exposure dose, of problems raised and of their solutions taken under various complicated conditions of Fukushima Daiichi Nuclear Power Plant (NPP) Accident (Mar. 2011). As the entrance/exit (en/ex) for the NPP site with regular control were impossible due to the hydrogen explosion which expanded the control area to 20 km distance from the site, Japan Football Village (J-Village) localizing at the border and Important Anti-seismic Building in the site were defined to be the bases of en/ex and of their control, respectively. Flooded 5,000 alarm pocket dosimeters (APD) by tsunami were not usable and only 320 APD remained available. At the quite early stage of working at the site, one representative worker in a group had only one APD. Management of internal exposure was also difficult essentially because the power source of the whole body counter was unavailable. At an early emergent stage alone, workers with higher dose than the limit (100 mSv for emergency) were observed, but >90% of workers were exposed to <50 mSv (the limit for the radiation worker). Six male Tokyo Electric Power Company (TEPCO) personnel were exposed to 250 mSv (specially defined dose limit) or more with the maximum 678.80 mSv, in whom the internal exposure due to radioiodine largely attributed. They were examined for their health by the expert doctors in National Institute of Radiological Sciences, were found free of abnormality and were to be followed up thereafter. Out of 19 female TEPCO personnel, two had exceeded the dose limit 5 mSv/3 mo and other 2, the annual limit 1 mSv. They received the examination by the industrial doctor, were found free of abnormality, but were decided not to work at the site. Recently, about 5,000 APD have been purchased for personal usage and dose management is conducted by bar-coding of individual workers, and internal exposure is managed with 11 whole body counters by once a month measurement in J

Plant life extension and ageing mechanisms: an ANSALDO proposal for the application to Kozloduy NPPs

International Nuclear Information System (INIS)

Orlandi, S.; Macco, A.; Zanaboni, P.

1999-01-01

In the frame of extension of NPP's installations lifetime, ageing management has become a topical subject to obtain the items: - Evaluation of residual life of the plant through the investigation of the residual life of well identified Safety Related Equipment in the as built configuration; - Organization of identified representative equipment per typological Classes (as Piping Systems, Tanks, Valves, Pumps, Electrical Equipment, Pressurized Components) in order to define for each High Level Class a set of elementary families capable to have, within each family, a common ageing mechanism and methodological investigation and potential common on-line monitoring; Application of a consistent methodology for residual life evaluation at each High Level Class (and subsequent elementary family and group if any) in order to assess an integral approach to backfitting and ageing management, taking also into account the economical investment effort required to the utility. In this report, a technical proposal for the application of the ANSALDO standard methodology approach, applied to the re-evaluation of the Kozloduy NPP's (Unit 1 - to 4) is presented. (authors)

Final report on research project: Soil liquefaction testing and evaluation for Kozloduy nuclear power plant units 5 and 6

Energy Technology Data Exchange (ETDEWEB)

Simeonov, S [Energoproekt plc., Power Consulting Engineers, Hydropower Division, Sofia (Bulgaria)

1995-07-01

The object of this study is the region of the channels of additional technical water supply of Kozloduy NPP, Units 5 and 6. This region is chosen because there are enough data for water saturated sands, necessary for the analysis, including data from cyclic triaxial tests and standard penetration tests. Three kinds ofprocedures for estimation of liquefaction potential of water saturated sands are used in the study. The results obtained by different procedures were compared, analyzed and conclusions drawn about the liquefaction potential of water saturated sands in the area of the channels of additional technical water supply.

The World Bank mission in Bulgaria with the objective of estimating the possibility to increase the safety of the Kozloduy NPP

International Nuclear Information System (INIS)

Laaksonen, J.

1992-01-01

This is a report of the World Bank mission in Bulgaria held from 22 March to 31 April 1992. The author considers the present state of the safety level of all Kozloduy NPP reactors with emphasis of the units 1-4 which are of the WWER-440/230 type. Three main factors are discussed in detail: 1) design inherent safety; 2) equipment protection from accidental events connected with the equipment quality; 3) quality and culture of operation and quantitative evaluation of the safety. The areas requiring special attention in view of the safety enhancing are: safety goal policy; creation of national safety culture; planning and implementation of the improvement programme; assuring the equipment reliability; updating and protection the existing systems; furnishing the plant with new systems. A review of all on-going and proposed projects of the national authorities, IAEA, EC, WANO and BEQE is made. Some remarks are given also about the WWER-1000 type units 5 and 6. The estimated cost of all necessary measures for equipment improvement is $100-200 million and of the annual investment after the main reconstruction and innovation of the reactors - about $10 million which should be included in the normal operational expenses of the plant. A new approach to the responsibility role of the Bulgarian specialists should be created. A new and well grounded proposal for modifications in the equipment should be made from the National Electrical Company including economical evaluations. Another expert assessment will be requested from the foreign banks before financing

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4E. Paks NPP: Analysis and testing. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

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

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4E. Paks NPP: Analysis and testing. Working material

International Nuclear Information System (INIS)

1995-01-01

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

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4F. Paks NPP: Analysis and testing. Working material

International Nuclear Information System (INIS)

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

Detection of primary coolant leaks in NPP

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Analysis of heavy radiological accidents in NPP and gamma-irradiators

Energy Technology Data Exchange (ETDEWEB)

Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Semova, T; Bonchev, Ts [Sofia Univ. (Bulgaria). Fizicheski Fakultet

1996-12-31

A review of several heavy radiological accidents, their cause, character, radioactivity emission, victims and economical impact is presented in the form of uniform tables. Eleven cases of incidents in power plants and 4 cases of accidents involving powerful gamma irradiators are considered. Radiological accidents in Bulgaria, not connected with the Kozloduy NPP, are listed. The human factor has been identified as the main cause for most of the accidents. It is stressed that the probability of heavy accident increases at the time of reactor refuelling, repair or testing. Technical failures could be eliminated by improved check and diagnostics procedures. 2 tabs., 12 refs.

Analysis of heavy radiological accidents in NPP and gamma-irradiators

International Nuclear Information System (INIS)

Angelov, V.; Semova, T.; Bonchev, Ts.

1995-01-01

A review of several heavy radiological accidents, their cause, character, radioactivity emission, victims and economical impact is presented in the form of uniform tables. Eleven cases of incidents in power plants and 4 cases of accidents involving powerful gamma irradiators are considered. Radiological accidents in Bulgaria, not connected with the Kozloduy NPP, are listed. The human factor has been identified as the main cause for most of the accidents. It is stressed that the probability of heavy accident increases at the time of reactor refuelling, repair or testing. Technical failures could be eliminated by improved check and diagnostics procedures. 2 tabs., 12 refs

Knowledge Management and Organizational Proficiency with NPP

International Nuclear Information System (INIS)

Marler, M.

2016-01-01

Full text: The pace of new NPP construction, startup, and operation is straining the supply of proficient operators, technicians, and engineers. This technical brief explains an approach implemented by a US nuclear utility to capture and transfer knowledge possessed by proficient workers to new workers using the VISION learning content management system. This approach could also be used to accelerate worker proficiency in new NPP organizations. (author

Health risk indicators in NPP - a continuous discussion

International Nuclear Information System (INIS)

Bliznakov, V.

1999-01-01

An evaluation of the costs connected with the health consequences due to occupational exposure for the personnel in the NPP 'Kozloduy' is made. The methods used are WTP (willingness to pay) and COI (cost of illness). The estimations in USD are as follows: for chronic bronchitis in adults 126 000 - 3336 000 (WTP); visit to medical unit - 265 - 795 (COI); asthma attacks per day - 12 - 55 (WTP); acute respiratory syndrome - 5 - 15 (WTP). Health - demographic data are used for the risk assesment. The weighted mean value for personnel irradiation is 2.5 - 8.7 mSv/year. Determination of individual dose limit, individual radiation risk, and individual annual dose limit is discussed

Project for qualification of the Kozloduy confinement system; Proyecto de cualificacion del sistema de confinamiento de Kozloduy

Energy Technology Data Exchange (ETDEWEB)

Montes Rodriguez, J L [Empresarios Agrupados, A.I.E., Madrid (Spain)

1993-12-15

One of the projects awarded to Empresarios Agrupados within the Six-Month WANO Programme for Kozloduy NPP, financed through the European Community's PHARE Programme, relates to the first tasks of plant confinement system qualification. Development of this project - the results of which will serve as a reference for other power plants with VVER-440/230 models - aroused considerable interest in the Bulgarian nuclear community as well as in international entities which render assistance to Eastern power plants. In fact, this is one of the few projects in the programme which takes into account hardware-oriented activities to be carried out urgently in the plant. The VVER-440/230 confinement system performs functions parallel to the containment system of Western PWR reactors. However, it differs significantly in its criteria and operation details. These important differences form the basis for a rational and prudent application of the essence of Western codes and standards relating to the qualification of these systems. The criteria which are developed to make this application viable constitute the most challenging and, at the same time, most risky part of this job. The project will be in its final stages when the 18th Annual Meeting of the Spanish Nuclear Society is held; it is therefore likely that this paper will advance the results and conclusions expected. (author)

Calculational experimental examination and ensuring of equipment and pipelines seismic resistance at starting and operating water-cooled and moderated reactor WWER-type NPPs. Final report

International Nuclear Information System (INIS)

1999-01-01

The results of testing of equipment at Bohunice NPP and pipeline systems at Unit 3 of Kozloduy NPP (WWER-440 type reactors) are presented in this Final Report. These results side by side with experimental values of natural frequencies and decrements also include experimental data about vibration modes of tested equipment and pipelines. For the first time the results of new calculational-experimental examination of equipment seismic resistance at Unit 2 of Armenian NPP are presented. At Kozloduy NPP direction's request the planed additional tests of some selected items were put off on 1997. Instead of postponed tests we carried out detailed analysis of our past inspections of numerous equipment seismic resistance at the Unit 5 of Kozloduy NPP. Experimental data with results of additional analysis are presented

Report of an experts' mission to review the modernization programme of the Kozloduy NPP units 5 and 6 Kozloduy, Bulgaria 26 June - 1 July 1995

International Nuclear Information System (INIS)

1995-01-01

The purpose of the IAEA Safety Review Mission was to review the safety aspects of the Kozloduy 5/6 modernization programme, and to advise on the completeness and adequacy of the safety improvements proposed. The IAEA draft report ''Ranking of Safety Issues for WWER-1000 Model 320 NPPs'', WWER-SC-104, 1995-05-29 (referred to as the Issue Book in the subsequent text) was the basis for the experts' review. The IAEA NUSS standards and guides, and internationally accepted safety concepts and practices and national standards, complemented by the Russian safety rules in force, were used in the preparation of the issue book. The scope of the review covered the plant design and operational safety aspects as proposed in the modernization programme. The upgrading measures, which are only related to the improvement of plant availability, were not included in the review

Equipment maintenance as a tool for raising of safety and efficiency of the NPP'Kozloduy' operation

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 1. Data related to sites and plants: Paks NPP, Kozloduy NPP. Working material

International Nuclear Information System (INIS)

1995-01-01

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 sites and NPPs Paks and Kozloduy

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 1. Data related to sites and plants: Paks NPP, Kozloduy NPP. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

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 sites and NPPs Paks and Kozloduy.

Resins characterization strategy at Kozloduy Nuclear Power Plant

International Nuclear Information System (INIS)

Fenoy, A.; González, R.; Molleda, P.; Sánchez, L.; Herrera, J.

2013-01-01

The Consortium ENSA- Gas Natural Fenosa Engineering has a contract with Kozloduy Nuclear Power Plant (KNPP) for the retrieval and conditioning of the resins. Before that, the project deals with resins characterization to verify the fulfillment the Bulgarian authorities’ requirements. The project includes all the resins generated during the operation of the BACKGROUND Resins characterization strategy at Kozloduy Nuclear Power Plant units 1, 2, 3 and 4, which were stored into six big dimensions tanks: four low tanks and two intermediate tanks. They only have a manhole above for tanks access. The methodology and the progress of the work are presented

Determination of P, Cu, Cr, Va and Ti in samples of welded joint No.4 of Kozloduy-1 reactor pressure vessel; Opredelenie soderzhanya fosfora, medi, nikelya, khroma, vanadya i titana v struzhkakh 4 shva 1 bloka AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Taskaev, E [Kombinat Atomna Energetika, Kozloduj (Bulgaria); Penev, I; Taskaeva, M [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. za Yadrena Izsledvaniya i Yadrena Energetika; Aleksieva, L [Sofia Univ. (Bulgaria); Tsokov, P [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

An analysis of reactor steel composition has been carried out in 1989 in order to determine metal embrittlement. The samples consist of shavings taken at 3-4 mm depth from the 4-th welded joint of Unit 1 of the Kozloduy NPP. The shavings have been gradually dissolved in a mixture of acids and the solution evaporated. Quantitative analysis has been carried out by spectrophotometry and by ICP emission spectroscopy. The following element concentrations have been found: P - from 0.0462 to 0.052% by weight; Ni - 0.25 - 0.26% (passport data 0.29%); Cr - 1.47 - 1.54 (passport 1.58%); V - 0.1% (passport 0.15%); Cu - 0.11-0.13% (passport 0.12); Ti - 0.002. The data have been used to calculate metal embrittlement. 4 refs., 8 tabs.

Qualitative and quantitative methods for human factor analysis and assessment in NPP. Investigations and results

International Nuclear Information System (INIS)

Hristova, R.; Kalchev, B.; Atanasov, D.

2005-01-01

We consider here two basic groups of methods for analysis and assessment of the human factor in the NPP area and give some results from performed analyses as well. The human factor is the human interaction with the design equipment, with the working environment and takes into account the human capabilities and limits. In the frame of the qualitative methods for analysis of the human factor are considered concepts and structural methods for classifying of the information, connected with the human factor. Emphasize is given to the HPES method for human factor analysis in NPP. Methods for quantitative assessment of the human reliability are considered. These methods allow assigning of probabilities to the elements of the already structured information about human performance. This part includes overview of classical methods for human reliability assessment (HRA, THERP), and methods taking into account specific information about human capabilities and limits and about the man-machine interface (CHR, HEART, ATHEANA). Quantitative and qualitative results concerning human factor influence in the initiating events occurrences in the Kozloduy NPP are presented. (authors)

Increase nuclear safety of WWER-440

International Nuclear Information System (INIS)

Nochev, T.; Sabinov, S.

2000-01-01

A complete program for increasing nuclear safety has been made at NPP Kozloduy with the participation of German, French, Russian and American specialists. This effort cost greater than 100 mil $. This report includes the methods of increasing nuclear safety. The style of management in NPP Kozloduy has been changed for the last seven years. (authors)

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

International Nuclear Information System (INIS)

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)

Project for qualification of the Kozloduy confinement system

International Nuclear Information System (INIS)

Montes Rodriguez, J.L.

1993-01-01

One of the projects awarded to Empresarios Agrupados within the Six-Month WANO Programme for Kozloduy NPP, financed through the European Community's PHARE Programme, relates to the first tasks of plant confinement system qualification. Development of this project - the results of which will serve as a reference for other power plants with VVER-440/230 models - aroused considerable interest in the Bulgarian nuclear community as well as in international entities which render assistance to Eastern power plants. In fact, this is one of the few projects in the programme which takes into account hardware-oriented activities to be carried out urgently in the plant. The VVER-440/230 confinement system performs functions parallel to the containment system of Western PWR reactors. However, it differs significantly in its criteria and operation details. These important differences form the basis for a rational and prudent application of the essence of Western codes and standards relating to the qualification of these systems. The criteria which are developed to make this application viable constitute the most challenging and, at the same time, most risky part of this job. The project will be in its final stages when the 18th Annual Meeting of the Spanish Nuclear Society is held; it is therefore likely that this paper will advance the results and conclusions expected. (author)

Demographic and health characteristics of the population residing within the 30-km area around the Kozloduy NPP

International Nuclear Information System (INIS)

Dimitrov, P.; Bliznakov, V.

1993-01-01

Based on detailed analysis of data on demographic and health state of the population residing within the 30-km zone around the Kozloduj NPP, an attempt was made to detect any impact of the power plant on population health under normal NPP operational conditions. The health characteristics of the population revealed no unfavorable trends. Particular attention was given to diseases of the blood and blood-forming organs, malignant new growths, complications of pregnancy, and congenital anomalies. (author)

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

International Nuclear Information System (INIS)

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

The Information System for Operational Activity Organization as a Tool for Configuration Management in NPP

International Nuclear Information System (INIS)

Manchev, B. L.; Yordanova, V. S.; Nenkova, B. G.

2008-01-01

The Configuration Management (CM) is an integrated management process by means of which conformity between design requirements, physical configuration and the plant documentation is ascertained. This conformity is maintained during the entire life cycle of the facility. CM ensures that during the entire operational life of the plant the following requirements are met: The basic design requirements of the plant are established, documented and maintained; The physical structures, systems and components (SSC) of the plant are in conformity with the design requirements; The physical and functional characteristics of the plant are correctly incorporated in the operational documentation and the documentation for repair, as well as in the documents for tests and training; The changes in the design documentation are incorporated in the physical configuration and the operative documentation; The changes in the design are minimized by management process for review according to approved criteria; The changes proposed in the equipment and documentation of the plant are estimated entirely with the purpose of determining their effect and are reviewed and approved by appropriate managing staff before their introduction. The information system for organization of the operational activity (IS OOA) consists of several modules used for storage and retrieval of data for different aspects of the operation of the equipment at the site of Kozloduy NPP, as defects and failures, design requirements and bases, design data and characteristics, tests, life time, maintenance and repair, as well as changes in the design or the design documentation. IS OOA consists of single relational database and provides built-in connections to the database of the SmartDoc system for control of the documentation, as well as to the database for human resources. Central place in IS OOA is taken by the 'Equipment' module while all other modules are connected with the identification data of the structures

Opening address; Allocution d`ouverture

Energy Technology Data Exchange (ETDEWEB)

Carle, R

1996-12-31

In this opening address the president of WANO underlines the relative isolation of the Kozloduy NPP from the international nuclear community due to the lack of information and contacts. The need for eliminating the isolation is stressed and the following measures are proposed: to make the Kozloduy NPP an active member of the international community; to improve and maintain the safety level; to contribute to the electricity exchange system of Southeastern Europe.

The monetary value of the man-mSv for Korean NPP radiation workers assessed by the radiation aversion factor

International Nuclear Information System (INIS)

Lee, B. I.; Suh, D. H.; Kim, S. I.; Jeong, M. S.; Lim, Y. K.

2008-01-01

The monetary value of the man-mSv for operators of Korean nuclear power plants (NPPs) was calculated using a radiation aversion factor based on a survey of NPP workers. Initially, the life expectancy in the population is 79.4 y, the average age of cancer occurrence is 60 y, the average annual wage for an electric worker is 56 000 $ y -1 and the nominal risk coefficient induced by radiation is 4.2 E-5 mSv were used to evaluate the basic monetary value (α base) resulting in 45.6 $ mSv -1 . To investigate the degree of radiation aversion, the subject of the investigation was selected as the working radiation workers in 10 NPPs in Korea (Kori 1-2, Yeonggwang 1-3, Ulchin 1-3 and Wolseong 1-2). In August 2010, with the cooperation of KHNP and partner companies, a total of 2500 survey questionnaires to 10 NPPs (or 250 surveys to each NPP) were distributed to currently employed radiation workers. From these, 2157 responses were obtained between August and October 2010. The assessed radiation aversion factor and the monetary value of the man-mSv from the calculated radiation aversion factor were 1.26 and ∼50 $ in the 0-1 mSv range, 1.38 and ∼200 $ in the 1-5 mSv range, 1.52 and ∼1000 $ in the 5-10 mSv range, 1.65 and ∼4000 $ in the 10-20 mSv range and 1.74 and ∼8500 $ >20 mSv. (authors)

Vibration system identification of Paks and Kozloduy reactor buildings on the basis of the blast test results

International Nuclear Information System (INIS)

Varpasuo, P.

1999-01-01

System identification allows to build mathematical models of a dynamic system based on measured data. System identification is carried out by adjusting parameters within a given model until its output coincides as well as possible with the measured output. The aim of this study is to investigate and model the behavior of complex vibratory systems on the basis of measured excitation and response. The first part of the study describes the theory used in the analysis and the software tools used in the analysis. The second part of the study describes the investigation and modeling of the response of single degree of freedom oscillator excited by sinusoidal and blast excitation. In the third part of the study the system identification of the Kozloduy NPP unit 5 reactor building and Paks NPP unit 1 reactor building is studied and the models are estimated using the method of segmentation of excitation and response. System identification is carried out using MATLAB software by adjusting parameters within a given model until its output coincides as well as possible with the measured output. The types of models used for the were: l) ARX models; 2) ARMAX model; 3) Output-Error (OE) models; 4) Box-Jenkins (BJ) models; 5) State-space models. The model coefficients for different models were calculated using the least-squares and maximum likelihood estimation methods available in MATLAB system identification toolbox. Excitation was in both Paks and Kozloduy case the measured free-field excitation and responses were the vibration responses of the building on the foundation slab level and top of the building. By examining the established models the frequency characteristics of vibration systems were determined with 95 % accuracy and the amplitude response with 80 % accuracy. In case of the steady state response of sinusoidally excited single dof oscillator the modelling gave almost exact results. But in the case of the blast response of the reactor building the obtaining of the

Behavior of antimony isotopes in the primary coolant of WWER-1000-type nuclear reactors in NPP Kozloduy during operation and shutdown

International Nuclear Information System (INIS)

Dobrevski, Ivan D.; Zaharieva, Neli N.; Minkova, Katia F.; Gerchev, Nikolay B.

2009-01-01

This paper focuses on the behavior of the antimony isotopes 122 Sb and 124 Sb in the coolant of the WWER reactors in the nuclear power plant Kozloduy (Bulgaria) during operation and shutdown. It is concluded that the chemical properties of their actual precursor, the isotope 121 Sb, determine the behavior of 122 Sb and 124 Sb during operation, load fluctuations, and shutdown as well as during the reactor coolant purification process. It is supposed that differences between the reactor bulk and the core fuel cladding surface chemistry as well as the presence of sub-cooled nucleate boiling at the fuel cladding may create conditions under which a local oxidizing environment may come into existence. (orig.)

Planning and management support for NPP personnel SAT-based training programmes

International Nuclear Information System (INIS)

Ziakova, M.

1998-01-01

Planning and management support for NPP personnel SAT-based training programmes is described for the following job positions: reactor operator; turbine operator; reactor maintenance worker; pump maintenance worker; chemistry foreman; health physics foreman; electric maintenance worker

Dry spent fuel storage facility at Kozloduy Nuclear Power Plant

International Nuclear Information System (INIS)

Goehring, R.; Stoev, M.; Davis, N.; Thomas, E.

2004-01-01

The Dry Spent Fuel Storage Facility (DSF) is financed by the Kozloduy International Decommissioning Support Fund (KIDSF) which is managed by European Bank for Reconstruction and Development (EBRD). On behalf of the Employer, the Kozloduy Nuclear Power Plant, a Project Management Unit (KPMU) under lead of British Nuclear Group is managing the contract with a Joint Venture Consortium under lead of RWE NUKEM mbH. The scope of the contract includes design, manufacturing and construction, testing and commissioning of the new storage facility for 2800 VVER-440 spent fuel assemblies at the KNPP site (turn-key contract). The storage technology will be cask storage of CONSTOR type, a steel-concrete-steel container. The licensing process complies with the national Bulgarian regulations and international rules. (authors)

Testing of components on the shaking table facilities of AEP and contribution to full scale dynamic testing of Kozloduy NPP. Final report

International Nuclear Information System (INIS)

Ambriashvili, Y.

1996-01-01

This final report summarizes the results of components testing on the shaking table facilities of 'Atomenergoproject' which are considered as a contribution to the full scale dynamic testing of the Kozloduy nuclear power plant Units 5 and 6. It was designed on 1.0 g according to the calculations that were based on accelerograms which included artificial and already known recordings of real earthquakes. Maximum acceleration of the designed spectrum and new spectrum which are recommended are now within the range of frequencies 2.5-20 Hz. Active reactor and the primary loop are seismic stable as well as the tested equipment tested by 'Atomenergoproject'

Bulgaria: INIS Center - 45 years experience

International Nuclear Information System (INIS)

Georgieva, Albena

2015-01-01

Bulgaria is one of 35 countries in the world operating nuclear power plants. Bulgaria's nuclear program was launched in 1956 with the construction of an IRT-2000 research reactor at the Institute for Nuclear Research and Nuclear Energy (INRNE), which was commissioned in 1961. The reactor is now under reconstruction. In 1960, construction of the first Bulgarian nuclear power plant started. At the moment, there are 6 power units at the Kozloduy NPP site; 4 of them (VVER-440/B-230) under decommissioning and 2 (VVER-1000/B-320) in operation. Several storage facilities for radioactive waste, mainly from the Kozloduy NPP and from various sources of ionizing radiation in medicine and industry are also in operation. The Kozloduy NPP, INRNE, Sofia University, the Technical University, and the State Enterprise Radioactive Waste are the main generators of nuclear information in Bulgaria and the main consumers of INIS products. The Bulgarian INIS Center, therefore, maintains continuous and effective cooperation with these Institutions

On the problem of radioprotective foods

Energy Technology Data Exchange (ETDEWEB)

Kiradzhiev, G; Paskalev, Z [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

The authors claim that purposely created food with anti-radiation effect (radioprotective food) is of no use for the Kozloduy NPP workers. Their reason is that internal radiation doses represent only 14-24% of the total dose while in cases with the highest content of radionuclides the activity is less than 10% of the annual intake limits. Measures to protect the respiratory tract are recommended instead. Radioprotective food can be used not only for protection of the population in case of accidents but also for disease treatment, rehabilitation and prophylactics. 11 refs.

On the problem of radioprotective foods

International Nuclear Information System (INIS)

Kiradzhiev, G.; Paskalev, Z.

1995-01-01

The authors claim that purposely created food with anti-radiation effect (radioprotective food) is of no use for the Kozloduy NPP workers. Their reason is that internal radiation doses represent only 14-24% of the total dose while in cases with the highest content of radionuclides the activity is less than 10% of the annual intake limits. Measures to protect the respiratory tract are recommended instead. Radioprotective food can be used not only for protection of the population in case of accidents but also for disease treatment, rehabilitation and prophylactics. 11 refs

Qualification of ISI for Bulgarian NPP: UK support

International Nuclear Information System (INIS)

Booler, R.

2000-01-01

UK Regulator (NII) Phare project provides an assistance to the Bulgarian Regulator in setting up the technical infrastructure for inspection qualification consistent with IAEA Guidelines and western European practice. The Strategy Document defines the methodology for inspection qualification and general roles and responsibilities of the involved organizations. The Qualification Inputs Document describes the information required for the Technical Specifications (component details, inspection aims and limitations). It applies the idea of qualification level - level 1(lowest) to level 3 (highest). The Qualification Procedure Document provides a guidance to the utility ('Kozloduy' NPP) on the preparation of Qualification Procedures (QP). The appendix provides a specific guidance on the performance of the all aspects of qualification at different levels and recommendations for technical justification. QB Method Working Document provides guidance for the Qualification Body. Facilities and Resources Document defines the facilities and resources required for the Qualification Body to perform the tasks described in the Method Working Document. High level QA Document defines the principles of quality control. Other issues and progress report are also presented

Development of the temperature field at the WWER-440 core outlet monitoring system and application of the data analyses methods

International Nuclear Information System (INIS)

Spasova, V.; Georgieva, N.; Haralampieva, Tz.

2001-01-01

On-line internal reactor monitoring by 216 thermal couples, located at the reactor core outlet, is carried out during power operation of WWER-440 Units 1 and 2 at Kozloduy NPP. Automatic monitoring of technology process is performed by IB-500MA, which collects and performs initial data processing (discrediting and conversion of analogue signals into digital mode). The paper also presents the results and analyses of power distribution monitoring during the past 21-th and current 22-th fuel cycle at Kozloduy NPP, Unit 1 by using archiving system capacity and related software. The possibility to perform operational assessment and analysis of power distribution in the reactor core in each point of the fuel cycle is checked by comparison of the neutron-physical calculation results with reactor coolant system parameters. Paper shows that the processing and analysis of accumulated significant amount of data in the archive files increases accuracy and reliability of power distribution monitoring in the reactor core in each moment of the fuel cycle of WWER-440 reactors at Kozloduy NPP

RELAP5/MOD3.2 investigation of loss of in-house supply power for WWER 1000/320V

International Nuclear Information System (INIS)

Gencheva, R.; Pavlova, M.; Groudev, P.

2001-01-01

This paper discusses the results of the thermal-hydraulic investigations of the 'Loss of in-house supply power' accident at the Kozloduy NPP Unit 6. The RELAP5/MOD3.2 computer code has been used to stimulate the loss of in-house supply power accident in a WWER 1000 Nuclear Power Plant model. This model was developed at the Institute for Nuclear Research and Nuclear Energy for analyses of operational occurrences, abnormal events and design basis scenarios. It will provide a significant analytical capability for the Bulgarian technical specialists located at the Kozloduy NPP. The criteria used in selecting transient are: importance to safety, availability and suitability of data followed by suitability for RELAP5 code validation. The investigation of 'Loss of normal and reverse AC power' is a process that compares the analytical results obtained by RELAP5/MOD3.2 model of the WWER 1000 against experimental transient data obtained from Kozloduy NPP Unit 6. The comparisons between the RELAP5 results and the test data indicate good agreement

Decommissioning and radioactive waste management. The European Commission overview

International Nuclear Information System (INIS)

Rehak, M

2010-01-01

In this lecture author deals with the European Commission overview on the decommissioning and radioactive waste management. Financial support of European Commission of decommissioning of the Ignalina NPP, Bohunice V1 NPP and Kozloduy Units 1 and 2 is presented.

Analysis of design floor response spectra and testing of the electrical systems

International Nuclear Information System (INIS)

Ambriashvili, Y.

1996-01-01

This report covers the following activities as foreseen according to the working plan of 'Atmoenergoproject': analysis of calculated floor response spectra used during the design of Kozloduy NPP and comparison with other spectra recommended for this NPP; analysis of floor response spectrum for the most important systems (reactor, main coolant loop, electrical systems); tests of main electrical systems and analysis of the results on seismic stability of those systems. Results of the response spectra analysis are given, some of the electrical systems are identified by the Kozloduy authorities to be analyzed in future according to the results of the test on seismicity

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

International Nuclear Information System (INIS)

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.

A recommended epidemiological study design for examining the adverse health effects among emergency workers who experienced the TEPCO fukushima daiichi NPP accident in 2011.

Science.gov (United States)

Yasui, Shojiro

2016-01-01

Results from medical examinations conducted in 2012 of workers who were engaged in radiation work in 2012 as a result of the 2011 Fukushima Daiichi Nuclear Power Plant (NPP) accident showed that the prevalence of abnormal findings was 4.21%, 3.23 points higher than the 0.98% that was found prior to the accident in the jurisdiction area of the labor inspection office which holds jurisdiction over the NPP. The Ministry of Health, Labour and Welfare (MHLW) concluded that the 2010 and 2012 data cannot be easily compared because 70% of the enterprises within the jurisdiction of the office that reported the 2012 results were different from those that did so in 2010. In addition, although the radiation workers' estimated average dose weighted by number of workers was 3.66 times higher than decontamination workers' dose, the prevalence among radiation workers was only 1.14 times higher than that among decontamination workers. Based on the results of the medical examinations, however, the MHLW decided to implement an epidemiological study on the health effects of radiation exposure on all emergency workers. This article explains key issues of the basic design of the study recommended by the expert meeting established in the MHLW and also identifies challenges that could not be resolved and thus required further consideration by the study researchers. The major issues included: (a) study methods and target group; (b) evaluation of cumulative doses; (c) health effects (end points); (d) control of confounding factors; and (e) study implementation framework. Identified key challenges that required further deliberation were: (a) preventing arbitrary partisan analysis; (b) ensuring a high participation rate; (c) inquiry about the medical radiation doses; and (d) the preparedness of new analytical technology. The study team formulated and implemented the pilot study in 2014 and started the full-scale study in April 2015 with funding from a research grant from the MHLW.

A study of the pressure vessel steel of the WWER-440 unit 1 of the Kozloduy nuclear power plant

Science.gov (United States)

Kostadinova, E.; Velinov, N.; Avdjieva, T.; Mitov, I.; Rusanov, V.

2017-11-01

A comparison between highly neutron irradiated samples from the region of weld № 4 and low irradiated samples from weld № 1 taken from the pressure vessel of the WWER-440 Unit № 1 of the Kozloduy NPP has been performed. Measurements of the residual activity of samples from the outer surface of the reactor pressure vessel bottom corpus reveal very low activity of 60Co. Insofar as there the base and weld metal appear to be exposed to a very low neutron fluence, the samples from these locations can be considered as practically not affected and may serve as a reference basis for comparison with highly irradiated pressure vessel regions. The Mössbauer parameters isomer shift (IS) and quadrupole splitting (QS) were found to be absolutely irradiation insensitive. A stepwise reduction of the internal hyperfine magnetic field Bhf, each by about 2.6 T, was observed. This can be attributed to the replacement of one or two surrounding iron atoms as first nearest neighbors by non-iron alloying atoms. The Mössbauer experimental line widths for irradiated and non-irradiated samples are practically the same, which is a quite unexpected result. The area fraction ratio for the three main Zeeman sextet subspectra S1:S2:S3 shows very high irradiation sensitivity. For the bottom low irradiated region of the reactor vessel the values are S1:S2:S3 = 50.1:40.0:9.4. After seven years of operation between the pressure vessel annealing in 1989 and the autumn of 1996 when the samples from weld № 4 were taken the ratio changes strongly to S1:S2:S3 = 56.4:34.7:8.5. A possible explanation of this result is that neutron irradiation gives rise to a precipitation process involving predominantly alloying atoms as Ni, Mn, Cr, Mo and V which become mobile and precipitate in the form of carbides and/or P-rich phases and alloying atom aggregates. This "refinement" process lowers the partial area of subspectra S2 and S3 where alloying atoms are involved and leads to a higher area fraction of

Kozloduy Nuclear Power Plant (Unit 1 and 2). Proposed modifications to increase the seismic capability of equipment and main structures; Central Nuclear de Kozloduy (Unidades 1 y 2). Modificaciones propuestas a los equipos y estructuras principales para incrementar su capacidad sismica

Energy Technology Data Exchange (ETDEWEB)

Ordonez Villalobos, A [Empresarios Agrupados, A.I.E., Madrid (Spain); Monette, P R [Westinghouse Energy Systems International (WESI), Bussels (Belgium)

1993-12-15

Within the framework of the European Community's PHARE Programme of improvement to facilities, their operating systems, equipment and buildings of the Kozloduy NPP in Bulgaria, plant safety during seismic events is considered to be an issue of overriding importance, especially in view of the earthquakes the region suffered during the last decade. Westinghouse Energy Systems International (WESI) and Empresarios Agrupados (EA) have initiated an intensive programme for physical upgrading of equipment with a view to augmenting its seismic capability and, at the same time, to studying design modifications in the diesel-generator buildings, pump house and main building structures (turbines, electrical building). The implementation of these modifications requires an in situ inspection of the real conditions of the various elements, analyses, conceptual design and detail engineering, all of which has to be done in short periods of time using resources available at the plant. This activity is performed by the companies mentioned above, with the collaboration of two engineering companies, Energoproekt of Bulgaria and INITEC of Spain. This paper describes the activities developed and the treatment given to the various aspects of improvement of the seismic capability of equipment and structures. (author)

Project management. A discipline which contributes to project success

International Nuclear Information System (INIS)

Hoch, G.

2008-01-01

The presentation covers the following topics: description of the Project - a contract was signed between KNPP and European Consortium Kozloduy (ECK) consisting of Framatome ANP GmbH as Leader (63%), Framatome ANP S.A.S. (17%), Atomenergoexport (20%) ; Project management in the modernization of NPP Kozloduy units 5 and 6; Project management process within AREVA NP GmbH; current status

Quality and Safety Assurance - Priority Task at Nuclear Power Projects Implementation

International Nuclear Information System (INIS)

Nenkova, B.; Manchev, B.; Tomov, E.

2010-01-01

Quality and safety assurance at implementation of nuclear power engineering projects is important and difficult task for realization. Many problems arise during this process, when many companies from different countries participate, with various kinds of activities and services provided. The scope of activities necessary for quality and safety assurance is therefore quite expanded and diverse. In order to increase the safety and reliability of Kozloduy NPP Plc (KNPP) Units 5 and 6, as well as to bring the units in conformity with the newest international requirements for quality and safety in the field of nuclear energy, a program for their modernization on the basis of different technical studies and assessments was implemented. The Units 5 and 6 Modernization Program of Kozloduy Nuclear Power Plant was composed of 212 modifications aimed to improve the safety, operability, and reliability of the Units. The Program was realized by stages during yearly planned outages since year 2002 to 2007, without additional outages. A major Program Objective was to extend the Units Life Time in at least 15 Years, under a continuous, safe, and reliable operation. The Modernization Program of Units 5 and 6 of the Bulgarian Nuclear Power Plant in Kozloduy was the first and for the time being the only one in the world, program in the field of nuclear power engineering, by which the full scope of recommendations for improvement of the Kozloduy NPP units was applied. The main goal of the National Electric Company, which is the Employer for the construction of new nuclear facility in Bulgaria, is after completion of all activities regarding construction of Belene NPP the plant to meet or exceed the requirements of the respective national and international quality and safety codes and standards, as well as the IAEA guidelines, as they are established. The objective of this report is to describe different aspects of the quality assurance according to the requirements of quality and

Rest-lifetime evaluation of equipment and facilities of NPP Kozloduy 3 and 4 and development of an ageing management program

International Nuclear Information System (INIS)

Erve, M.; Schmidt, J.; Kastner, B.; Gledatchev, I.; Sabinov, S.; Stoev, M.; Korneev, V.; Strombach, Y.

2001-01-01

The task indicated in the title is part of a comprehensive upgrading program for Units 3 and 4 of the Kozloduy plant executed in a Consortium between Framatome ANP (a Framatome and Siemens company) and the Russian company Atomstroyexport. It comprises an evaluation of the residual service life of components/systems/plants subject to acceptance by international experts, identifying the need for further investigations/calculations in certain cases, and finding solutions for improvements that achieve a consensus of safety and economy. The initial results are: Walkdowns revealed no clear knock-out point for the plants, however there are preliminary hints for necessary further improvements. Investigations of templates taken from the RPV of Unit 1 were started: the results are still preliminary, but can be considered very positive; their transfer to the RPV of Unit 3 would mean that the latest safety analyses of the Unit 3 RPV are conservative. The general work program was successfully applied on the batteries as a pattern for the electrical equipment: parameters for the computer database and proposals for an effective aging management program were addressed. (author)

Report of the experts' mission to review thermal hydraulic and structural analyses for PTS assessment of Kozloduy NPP units 1-4 reactor pressure vessels, Sofia, Bulgaria 3-7 April 1995

International Nuclear Information System (INIS)

1995-01-01

Based upon a request of the Government of Bulgaria and in order to assist its Regulatory Body, an experts' mission was carried out to Sofia and Kozloduy, 21-25 November 1994 within the framework of the IAEA TC Project BUL/9/013-05 and of the IAEA Extrabudgetary Programme on the Safety of the WWER NPPs. The mission also specified the technical content of further assistance by the IAEA. With respect to the findings and recommendations made in November 1994, WWER-SC-109, a follow-up expert's mission was carried out to Sofia, Bulgaria, April 3-7, 1995. The objective of the mission was to review the selection of transients, thermal hydraulic, stress and fracture mechanics analyses for reactor pressure vessel integrity assessment of Kozloduy unit 1-4. In addition, an update on the activities completed, underway and planned related to unit 1 reactor pressure vessel embrittlement was presented and discussed. The review was carried out by 4 international experts from Finland, France, Russia and IAEA in co-operation with the Bulgarian regulatory body, plant, Energoproject Sofia and Institute of Metals staff. The mission was conducted out within the frame of the IAEA TC Project BUL/9/013-05 and of the IAEA Extrabudgetary Programme on the Safety of the WWER NPPs. 18 refs

Utilization of the residual water resource from the Kozloduy NPP's hot channel for building a small hydropower plant (TK1)

International Nuclear Information System (INIS)

Tolev, T.

2004-01-01

A hydropower plant built on the hot channel of the NPP should be capable to utilise the whole changing water flow from the NPP cooling system. Tree factors - level of the hot channel, level of the Danube river and the water flow - determine the power potential of the HPP. The water level in the hot channel varies between 31.20 and 32.50 m with an optimum at 31.50 m. The Danube river level varies in a wide range. The head at 85% of the river level and at a level of the channel 31.50 m is 7.2 m. The water flow depends on the NPP operation and it is between 45 m 3 /s and 140 m 3 /s. Thus the nominal power of the HPP is 5 740 kW. The construction of the HPP is justified in case of at least 30 years of operation. The calculations are made for the operation of units 5 and 6 which are expected to work during this period. A significant role for the maximal utilisation of the resource of the hot channel plays the choice of the hydro-turbines. The horizontal PIT-Kaplan turbines are considered as the most appropriate. The integrating of the plant into the electric network and possible impact on the environment are also considered

Low-dose effects hypothesis and observations on NPP personal

Energy Technology Data Exchange (ETDEWEB)

Georgieva, R.; Acheva, A.; Boteva, R.; Chobanova, N.; Djounova, J.; Gyuleva, I.; Ivanova, K.; Kurchatova, G.; Milchev, A.; Negoicheva, K.; Nikolov, V.; Panova, D.; Pejankov, I.; Rupova, I.; Stankova, K.; Zacharieva, E. [Radiobiology Department, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

2013-07-01

In the modern world the use of various sources of ionizing radiation is nearly ubiquitous. They have numerous applications in industry, medicine, science, agriculture, etc. Radiation doses to workers nevertheless are commensurable to the natural background exposure. Published data on the health effects of occupational radiation exposure are often contradictory. Addressing the issue of „negative” (bystander effects, genomic instability) and „positive” (adaptive response, radiation hormesis) effects of low doses is important and has a significant social and economic impact. In this paper we summarize the results of our extensive monitoring of nuclear power plant (NPP) staff. We believe it is a cohort suitable for analysis of health effects at low doses, because of their good medical and dosimetric control. Our results rather support the idea of absence of adverse health effects in NPP workers. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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)

Monitoring program of surrounding of the NPP SE-EBO

International Nuclear Information System (INIS)

Dobis, L.; Kostial, J.

1997-01-01

The paper dealt with monitoring program of radiation control of surrounding of the NPP Bohunice, which has the aim: (1) to ensure the control of influence of work of the NPP Bohunice on the environment in their surrounding; (2) to ensure the back-ground for regular brief of control and supervisory organs about condition of the environment in surrounding of the NPP Bohunice; (3) to maintain the expected technical level of control of the NPP Bohunice and to exploit optimally the technical means; (4) to solicit permanently the data about the radioactivity of environment in surrounding of the NPP Bohunice for forming of files of the data; (5) to exploit purposefully the technical equipment, technical workers and to maintain their in permanent emergency and technical eligibility for the case of the breakdown; (6) to obtain permanently the files of the values for qualification of the reference levels. This program of monitoring includes the radiation control of surrounding of the NPP Bohunice, in the time of normal work of power-station's blocks, inclusively of all types of trouble-shooting and repairer works in surrounding of the NPP Bohunice, up to distance 20 km from power-station. The monitoring includes: outlets from the NPP Bohunice, monitoring of radiation characteristics in surrounding of the NPP Bohunice, (aerosols, fall-outs, soil), the links of food chains: (grass and fodder, milk, agriculture products), hydrosphere in surrounding (surface waters, drink water, bores of radiation control in complex of the NPP Bohunice, components of the hydrosphere), measurement of radiation from external sources (measurement of the dose rates, measurement of the doses [sk

Kozloduy Nuclear Power Plant (Unit 1 and 2). Proposed modifications to increase the seismic capability of equipment and main structures

International Nuclear Information System (INIS)

Ordonez Villalobos, A.; Monette, P.R.

1993-01-01

Within the framework of the European Community's PHARE Programme of improvement to facilities, their operating systems, equipment and buildings of the Kozloduy NPP in Bulgaria, plant safety during seismic events is considered to be an issue of overriding importance, especially in view of the earthquakes the region suffered during the last decade. Westinghouse Energy Systems International (WESI) and Empresarios Agrupados (EA) have initiated an intensive programme for physical upgrading of equipment with a view to augmenting its seismic capability and, at the same time, to studying design modifications in the diesel-generator buildings, pump house and main building structures (turbines, electrical building). The implementation of these modifications requires an in situ inspection of the real conditions of the various elements, analyses, conceptual design and detail engineering, all of which has to be done in short periods of time using resources available at the plant. This activity is performed by the companies mentioned above, with the collaboration of two engineering companies, Energoproekt of Bulgaria and INITEC of Spain. This paper describes the activities developed and the treatment given to the various aspects of improvement of the seismic capability of equipment and structures. (author)

Revision report about the in-situ tests of 1000 MW unit 5 Kozloduy (Bulgaria)

International Nuclear Information System (INIS)

Muzzi, F.

1995-01-01

This report refers to the technical revision performed on the technical report about the in-situ tests performed on 1000 Unit 5 nuclear power station of Kozloduy (Bulgaria), within the frame of the IAEA benchmark study for the seismic analysis and testing of an existing Nuclear Power Plant. After a foreword to define the aims of the job and the identification of the scope of the work, a brief description of the plant is made. A brief description of the theory about the modal parameter determination and the soil-structure interaction analysis by experimental tests is made. The following chapters collect some comments about the tests carried out in Kozloduy, with special reference to the general correctness of testing procedure and to data special requirements for the seismic safety margin assessment procedures to be applied on the existing power station

Soil-structural interaction analysis of RBMK type NPP for seismic event. Progress report. From 1 July 1998 - 30 June 1999

International Nuclear Information System (INIS)

1999-01-01

The objective of the project is to assess the structural behavior and safety capacity of a RBMK-1000 MW Main Building Complex under critical combination of loads including seismic events. This project is part of the Coordinated Research Program carried out by International Atomic Energy Agency on safety of RBMK Type Nuclear Power Plants (NPP) in Relation to External Events. The nuclear power plant considered for this study is the Sosnovy Bor NPP, located near St.Petersburg, Russia. The Soviet standard design RBMK-1000 MW type units installed in Sosnovy Bor NPP were originally designed for a Safe Shutdown Earthquake (SSE) with a peak ground acceleration (PGA) of 0.1 g. The relevant response spectra are not available for reference and assessment. The new international requirements for nuclear power plants in operation require site specific seismic hazard studies as a basis for the definition of a Review Level Earthquake (RLE) for reassessment of the structures and safety related equipment Ell - As the RLE site specific seismic data is still not available, the RLE earthquake spectra for Kozloduy NPP scaled to PGA=0.1 g were used in this study. This value is intentionally chosen for comparison purposes. The Russian design requirements (if design floor response spectra are available) will be compared with the international regulations. The scope of the study is to perform a Soil-Structure Interaction (SSI) seismic response analysis of the referenced RBMK-11000 MW. Main Building Complex to evaluate the effect on the structural response of a greater than design earthquake. The analysis is focused on a realistic assessment of the structural response to a potentially higher earthquake level instead of a conservative design type analysis. Special attention is paid on the seismic response of the sub-structures in the safe shutdown path, as well as on the locations of the heavy equipment

Using bentonite for NPP liquid waste treatment

International Nuclear Information System (INIS)

Bui Dang Hanh

2015-01-01

During operation, nuclear power plants (NPPs) release a large quantity of water waste containing radionuclides required treatment for protection of the radiation workers and the environment. This paper introduces processes used to treat water waste from Paks NPP in Hungary and it also presents the results of a study on the use of Vietnamese bentonite to remove radioactive Caesium from a simulated water waste containing Cs. (author)

Comparison of p53 levels in lymphocytes and in blood plasma of nuclear power plant workers

International Nuclear Information System (INIS)

Roessner, Pavel; Chvatalova, Irena; Schmuczerova, Jana; Milcova, Alena; Roessner, Pavel; Sram, Radim J.

2004-01-01

p53 levels were assessed in lymphocytes and in blood plasma of workers from two Czech nuclear power plants (NPP): 114 subjects working in Temelin and 108 subjects working in Dukovany. Ionizing radiation (IR) exposure data were available for 64 and 59 subjects working in the monitored zones from the NPP in Temelin and Dukovany, respectively. The short-term doses of IR for these subjects were 0.01 and 0.12 mSv, and the long-term doses were 0.46 and 5.68 mSv, in the Temelin and Dukovany NPP, respectively. As a control group, 46 subjects living in Ceske Budejovice, a city nearby the Temelin NPP, were analyzed. The concentration of p53 in lymphocytes was significantly higher in workers from the monitored zone in the Dukovany NPP (median value 6.4 pg/μg protein, P < 0.001) than in workers from the Temelin NPP (3.2 pg/μg) as well as in the control group (3.5 pg/μg). In contrast, plasma levels of p53 were comparable in the control group (median value 116 pg/ml plasma) and workers from the monitored zone of Dukovany NPP (102 pg/ml), but lower in workers from Temelin NPP (5 pg/ml). Other factors affecting p53 levels were studied. Smoking resulted in increased p53 lymphocyte levels. The effect of polymorphisms in metabolic and DNA repair genes on p53 levels was analyzed. The correlation was found between p53 levels in lymphocytes and p53 codon 72 polymorphism in subjects working in NPPs, but not in the control group. The results of measurement p53 levels in lymphocytes suggest that this biomarker could reflect the short-term as well as long-term effects of low doses IR. Its impact on human health should be further explored

Cytogenetic techniques as biological indicator and dosimeter of radiation damage

International Nuclear Information System (INIS)

Hadjidekova, V.; Hristova, R.

2006-01-01

Full text: The cytogenetic methods are established techniques for bio monitoring and bio dosimetry of professionally and accidentally exposed to ionizing radiation subjects. They are applied to continue the evaluation of the physical dosimetry and to consider the individual radiosensitivity. The results of cytogenetic monitoring and dosimetry of radiation exposed subjects carried out during the last 5 years in laboratory of Radiation Genetics, NCRRP is reported. Laboratory of Radiation genetics performs cytogenetic monitoring of low dose radiation professionally or medically exposed subjects: workers in Kozloduy NPP, radioactive waste repository workers, X-rays diagnostically exposed patients, and radiotherapy exposed as well. Three cytogenetic indicators are applied as the most sensitive indicators for human radiation exposure: analysis of micronuclei (MN), chromosomal aberrations (CA) and stable translocations (FISH). The optimized methodology for application of different cytogenetic techniques for radiation estimation is discussed

Some results from a sociological study at Kozloduy NPP concerning atomic energy perspectives in the country

International Nuclear Information System (INIS)

Nanov, D.

1994-01-01

The results from an empirical sociological investigation among the personnel of the Kozloduj NPP are reported. The purpose of the study was to explore the opinions and assessment of the people working in the plant about their plant during the past years and at present. The necessary information was gathered from a representative excerpt of 231 persons. The questionnaire contained topics as: assessment of the operation and development of the plant as a whole and in comparison with other European NPPs; opinion about the security and safety of the plant; satisfaction by the work; necessity of additional qualification; assessment of payment and social policy of the plant. The results showed a variety of positive and negative assessment. The criticism expressed by this study point out the main significant problems of the station and will give rise to future efforts for eliminating the reasons of the deficiencies at work. (orig.)

Atomic Questions Group peer review mission to Bulgaria

International Nuclear Information System (INIS)

Vapirev, E.; Georgiev, J.; Sabinov, S.

2004-01-01

The objective of the Atomic Questions Group (AQG) peer review mission (17-19 Nov 2003) was to monitor the status of the recommendations contained in the 2001 Report on Nuclear Safety in the Context of Enlargement focusing specifically those recommendations identified in the 2002 Peer Review Status Report as requiring further attention or monitoring. Most AQG/WPNS 2001 recommendations were found as adequately addressed with the exception of the following to which Bulgaria was expected to devote further attention: 2nd General Recommendation NPP type I regarding Safety Analysis Reports (SARs); 1st Specific Recommendation NPP type I regarding the new nuclear legislation; 1st General Recommendation Other Nuclear Installations type II regarding the storage of radioactive waste. In addition WPNS recommended further monitoring of the following commitments: 1st General Recommendation NPP type I regarding the plant specific safety improvement programmes - to ensure that the programmes are completed in accordance with the plans; 2nd General Recommendation NPP type I regarding Safety Analysis Reports (SARs) - to ensure that the SARs are completed in accordance with the plans; 2nd General Recommendation NPP type I regarding Emergency Operating Procedures (EOPs) - to ensure the completion of work on EOPs in accordance with the plans and so that these provide for the development of appropriate guidance on the management of beyond design basis accidents; 2nd Specific Recommendation NPP type I regarding the resources of the regulator - to ensure that adequate human and financial resources will be provided according to the developed plan; 5th Specific Recommendation NPP type I regarding the implementation of specific upgrading improvements at Kozloduy units 3 and 4- to specifically follow these items during the monitoring associated with 1st General recommendation NPP type I, Upgrading programme; 6th Specific Recommendation NPP type I regarding high-energy pipe breaks at Kozloduy

Nuclear safety improvement activities related to WWER-440 units in Bulgaria

International Nuclear Information System (INIS)

Gantchev, T.

1998-01-01

The systematic evaluation of the deficiencies of the original design of the WWER reactors brought to the development of a Short Term Programme for Safety Upgrading and Modernisation of Kozloduy WWER-440 units. The implementation of this Programme was completed in 1997. The strive for continuos improvement of Kozloduy Nuclear Power Plant (NPP) safety level, the new requirements of the Bulgarian Nuclear Safety Authority and the public concern initiated the development of new Complex Programme for Safety Improvement (PRG'97), now in a process of implementation. (author)

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4B. Paks NPP: Analysis/testing. Working material

International Nuclear Information System (INIS)

1995-01-01

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 dynamic study of the main building of the Paks NPP; shake table investigation at Paks NPP and the Final report of the Co-ordinated Research Programme

Enemona's Company experience in management of complex construction and modernization projects in sectors of industry and energetics

International Nuclear Information System (INIS)

Kalionski, V.

2005-01-01

The purpose of this paper is to present the Enemona's Company experience, gained during the management of complex projects related to Kozloduy NPP Modernization Program, enriched during the long-term collaboration with the international companies which are the executors of modernization projects. For the successful implementation of tasks on Framatom, Westinghouse, Atomenergo export projects, an exchange of process transfer, managerial practices were established between the Employers companies and Enemona Company, which along with the use of material resources, organization and personnel gave Enemona opportunity to implement and optimize goals that were set to the company. Some principles, approaches and methods of works have been established, based on strict scientific methods and practices that support Enemona to be competitive in order to assume fulfillment of similar projects not only at Kozloduy NPP site, but also at new projects and sites including the challenge for the erection of Belene NPP. In order to meet requirements of foreign companies, Enemona is able to apply new technologies and achievements in assurance of high quality of repair and installation activities on construction of new objects or their modernization

Fukushima – Impact on the Industry

International Nuclear Information System (INIS)

2012-01-01

The response to the accident is presented. European Stress Tests Peer Review Report is presented. The Worley Parsons Stress Test Experience includes performing “Stress tests” for Kozloduy NPP and Performing “design stress tests” : in Bulgaria – A92; Russia – AES 2006; Turkey – AES 2006. Nuclear energy outlook includes the Germany case and an overview of main activities in Europe: Finland - Two active projects (one greenfield site); Both approved by government Sweden - On-going project for replacement power Poland - Site characterization for first NPP on its way Lithuania -Final negotiations with GE-Hitachi Czech Republic - Tender for 2 new Temelin units due July 2; Bulgaria - Switch from Belene to Kozloduy UK – Government passing of new legislation to give investment security France -Committed to Flammanville and Penly; Policy change of new government questionable

Indicators for monitoring of safety operation and condition of nuclear power stations

International Nuclear Information System (INIS)

Manova, D.

2001-01-01

A common goal of all employees in the nuclear power field is safety operation of nuclear power stations. The evaluation and control of NPP safety operation are a part of the elements of safety management. The present report is related only to a part of the total assessment and control of the plant safety operation, namely - the indicator system for monitoring of Kozloduy NPP operation and condition. (author)

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 2B. General material: codes, standards, criteria. Working material

International Nuclear Information System (INIS)

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

Reliability analysis of the reconstructed safety systems of the Kozloduy-2 WWER-440/V-230 reactor

Energy Technology Data Exchange (ETDEWEB)

Kalchev, B [Energoproekt, Sofia (Bulgaria)

1996-12-31

The Unit 2 of the Kozloduy NPP started operations in 1975. As it is designed according to safety standards of the middle sixties, it needs reconstruction in order to prolong its operational life up to the design age of 30 years, in agreement with the increased safety requirements in Bulgaria. The reliability analyses of front line systems of the unit are performed to this end. The approach taken in the study is the fault tree methodology to determine the unavailability of each system. Common mode failures are considered for the pumps and valves using the beta factor method. The mission time for each system is 24 hours and the test period is 720 hours. Support systems and human errors are also included. All the systems control and instrumentation signals are modelled explicitly in the fault trees. The generic IDEA reliability data base is used for all quantifications. The initiating events that would require the system operation are presented and on this basis the thermohydraulic analysis success criteria for each system are determined. The code for probabilistic safety assessment PSAPACK is used. Fault trees for the following front line safety systems are constructed: the high pressure injection system, the spray system and the auxiliary feed water system. The analysis consider some proposed decisions for reconstruction. The results show that the reliability of these systems has increased after reconstruction and the safety has been upgraded. This decrease the core damage frequency from 3.53E{sup -3}, 1/RY to 1.07E{sup -3}, 1/RY. 5 refs., 2 tabs., 5 figs.

Reliability analysis of the reconstructed safety systems of the Kozloduy-2 WWER-440/V-230 reactor

International Nuclear Information System (INIS)

Kalchev, B.

1995-01-01

The Unit 2 of the Kozloduy NPP started operations in 1975. As it is designed according to safety standards of the middle sixties, it needs reconstruction in order to prolong its operational life up to the design age of 30 years, in agreement with the increased safety requirements in Bulgaria. The reliability analyses of front line systems of the unit are performed to this end. The approach taken in the study is the fault tree methodology to determine the unavailability of each system. Common mode failures are considered for the pumps and valves using the beta factor method. The mission time for each system is 24 hours and the test period is 720 hours. Support systems and human errors are also included. All the systems control and instrumentation signals are modelled explicitly in the fault trees. The generic IDEA reliability data base is used for all quantifications. The initiating events that would require the system operation are presented and on this basis the thermohydraulic analysis success criteria for each system are determined. The code for probabilistic safety assessment PSAPACK is used. Fault trees for the following front line safety systems are constructed: the high pressure injection system, the spray system and the auxiliary feed water system. The analysis consider some proposed decisions for reconstruction. The results show that the reliability of these systems has increased after reconstruction and the safety has been upgraded. This decrease the core damage frequency from 3.53E -3 , 1/RY to 1.07E -3 , 1/RY. 5 refs., 2 tabs., 5 figs

Nuclear power: the political challenge

International Nuclear Information System (INIS)

Adam, G.

2009-01-01

A brief overview of the political and economical situation and nuclear energy problems in Europe is given. The author presented his opinion on topic such as need of nuclear power, Kozloduy NPP units 1-4 shutdown, climate change , energy security, environmental problems

Operational behaviour of WWER nuclear power units after Chernobyl accident

International Nuclear Information System (INIS)

Milivojevic, S.; Spasojevic, D.

2000-01-01

The indicators of effectiveness of WWER operation, in 1987-1998 were analyzed. For three groups of nuclear units (WWER, NPP Kozloduy, NPP Paks), the trends of Indicators flow were established. The comparative analysis of forced outage rate, and load factor of WWERs and nuclear units all in the world was carried out; it gives the general picture of accident influence on the states and the relations of these indicators in considered period (author)

Status and prospects of WWER in-core fuel management activities

International Nuclear Information System (INIS)

Novikov, A.N.; Pavlov, V.I.; Pavlovichev, A.M.; Proselkov, V.N.; Saprykin, V.V.

1994-01-01

A short review is given of recent extensive calculational and experimental studies carried out in Russia and Bulgaria for WWER fuel cycle modernization. The main activities performed at Kola NPP, Novovoronezh NPP, Kozloduy NPP and Balakovo NPP are outlined. Based on experience gained, the following improvements in the fuel cycle have been introduced: 1) increased fuel burnup; 2) reduced natural uranium consumption and decreased amount of separation work per energy output unit; 3) increased efficiency of the reactor emergency protection; 4) reduced fast neutron flux onto the reactor vessel. The main characteristics of modernized fuel cycles of WWER-440 and WWER-1000 are presented. 4 tabs., 3 figs., 14 refs

Status and prospects of WWER in-core fuel management activities

Energy Technology Data Exchange (ETDEWEB)

Novikov, A N; Pavlov, V I; Pavlovichev, A M; Proselkov, V N; Saprykin, V V [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

1994-12-31

A short review is given of recent extensive calculational and experimental studies carried out in Russia and Bulgaria for WWER fuel cycle modernization. The main activities performed at Kola NPP, Novovoronezh NPP, Kozloduy NPP and Balakovo NPP are outlined. Based on experience gained, the following improvements in the fuel cycle have been introduced: (1) increased fuel burnup; (2) reduced natural uranium consumption and decreased amount of separation work per energy output unit; (3) increased efficiency of the reactor emergency protection; (4) reduced fast neutron flux onto the reactor vessel. The main characteristics of modernized fuel cycles of WWER-440 and WWER-1000 are presented. 4 tabs., 3 figs., 14 refs.

First approval procedure of the TL dosimetric service of the NPP in Slovenia

International Nuclear Information System (INIS)

Janzekovic, H.; Krizman, M.; Pucelj, B.; Stuhec, M.; Zdesar, U.

2001-01-01

The individual dosimetry of exposed workers in a NPP is one of the essential parts which demonstrates the radiation protection standards achieved in a facility. According to the current legislation the Ministry of Health of the Republic of Slovenia has the authority to grant approvals to personal dosimetric services which perform the dosimetric monitoring of workers in Slovenia. Due to the fact that the detailed approval procedure is not given in national regulations, the Ministry of Health in 2000 established a group of experts with the task to prepare technical and organising requirements for such approval. Based on international documents [1,2,3] the Approval procedure for the thermoluminescence dosimetric (TL) services was created. Following this procedure the assessment of the TL dosimetric service in the NPP was performed. The problems related to the technical and organising requirements with the emphasise on the QA/QC criteria of the TL dosimetric service will be discussed.(author)

Bituminization of liquid radioactive wastes. Part 2

International Nuclear Information System (INIS)

Gradev, G.D.; Ivanov, V.I.; Stefanova, I.G.; Milusheva, A.G.; Guteva, E.S.; Stefanov, G.I.; G'oshev, G.S.

1991-01-01

The leaching of alcaline cations, as well as of chloride, sulphate and borate anions and radionuclides was studied. The leach rates and the diffusion coefficients of some of the incorporated ions for the salt-bitumen products obtained from Bulgarian bitumens (road bitumen PB 66/90 and hydroinsulating bitumen HB 80/25) and salts (chlorides, sulphates, borates, salt mixtures modelling the concentrate from the evaporators at the Kozloduy NPP and radionuclides) were determined. Most suitable for technological research under the conditions of the Kozloduy NPP proved to be the road bitumen PB 66/90 with softening temperature at 48 o C. The optimum bitumen/salt ratio is found to be about 1.2. Admixtures of natural inorganic sorbents (clinoptiolite, vermiculite and bentonite) in quantities of 5-10% are found to decrease the leaching of radionuclides from the bitumen products. The action of the hydromica vermiculite is particularly pronounced. 6 tabs., 5 refs

Radiation monitoring in the NPP environment, control of radioactivity in NPP-environment system

International Nuclear Information System (INIS)

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

Technology for NPP decantate treatment realized at Kola NPP

International Nuclear Information System (INIS)

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)

Immune cells in Chernobyl radiation workers exposed to low-dose irradiation

International Nuclear Information System (INIS)

Bazyka, D.; Chumak, A.; Byelyaeva, N.; Gulaya, N.; Margytich, V.; Thevenon, C.; Guichardant, M.; Lagarde, M.

2002-01-01

the aim of this work was to study immune response parameters in Chernobyl emergency and recovery operation radiation workers and nuclear industry workers exposed under professional limits. The monohydroxylated fatty acid content in peripheral blood mononuclear cell of radiation workers compared to unexposed control at the 12-th year after Chernobyl NPP accident was studied too

The future of Bulgarian nuclear sector

International Nuclear Information System (INIS)

Iordanov, I.; Yankov, I.

2012-01-01

The problems of the Bulgarian nuclear energy sector in Bulgaria and possible solutions are presented. The priorities are summarized as: extension of life for units 5 and 6 in NPP Kozloduy establishing of contacts with producers of SMR long‐term strategy for Bulgarian energy sector

Approach to training the operators of WWER-440 reactors

International Nuclear Information System (INIS)

Pironkov, L.; Minakova, R.

2002-01-01

The paper has three parts. (1) Personnel Training and Qualifications (2) Description of Kozloduy NPP Training and Qualification System (TQS) built in the last 7 years and its interfaces with the Certification System and (3) Application of the TQS for the Senior Reactor Operator (SRO). (author)

Bituminization of liquid radioactive wastes. Part 1

International Nuclear Information System (INIS)

Gradev, G.D.; Ivanov, V.I.; Stefanova, I.G.; Milusheva, A.G.; Guteva, E.S.; Zhelyazkov, V.T.; Stefanov, G.I.; G'oshev, G.S.

1991-01-01

Salt-bitumen products are produced by the method of 'hot mixing' of some Bulgarian bitumens (road bitumen PB 66/99 and the hydroinsulating bitumen HB 80/25) and salts (chlorides, sulphates, borates, salt mixtures modelling the liquid waste from nuclear power plants) in different ratios to determine the optimum conditions for bituminization of liquid radioactive waste. The penetration, ductility and softening temperature were determined. The sedimentation properties and the thermal resistance of the various bitumen-salt mixtures were studied. The most suitable bitumen for technological research at the Kozloduy NPP was found to be the road bitumen PB 66/90 with softening temperature at 48 o C. The optimum amount of salts incorporated in the bitumen - about 45% - was found. No exothermal effects were observed in the bituminization process in the temperature range of up to 200 o C. The results obtained may be useful in the elaboration of a technology for bituminization of liquid radioactive wastes in the Kozloduy NPP. 4 tabs., 5 figs., 4 refs

Decommissioning of Brennilis NPP

International Nuclear Information System (INIS)

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

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 5C. Experience data. Working material

International Nuclear Information System (INIS)

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

Decommissioning of NPP A-1

International Nuclear Information System (INIS)

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.

Preliminary results from uranium/americium affinity studies under experimental conditions for cesium removal from NPP ''Kozloduy'' simulated wastes solutions

International Nuclear Information System (INIS)

Nikiforova, A.; Kinova, L.; Peneva, C.; Taskaeva, I.; Petrova, P.

2005-01-01

We use the approach described by Westinghouse Savannah River Company using ammonium molybdophosphate (AMP) to remove elevated concentrations of radioactive cesium to facilitate handling waste samples from NPP K ozloduy . Preliminary series of tests were carried out to determine the exact conditions for sufficient cesium removal from five simulated waste solutions with concentrations of compounds, whose complexing power complicates any subsequent processing. Simulated wastes solutions contain high concentrations of nitrates, borates, H 2 C 2 O 4 , ethylenediaminetetraacetate (EDTA) and Citric acid, according to the composition of the real waste from the NPP. On this basis a laboratory treatment protocol was created. This experiment is a preparation for the analysis of real waste samples. In this sense the results are preliminary. Unwanted removal of non-cesium radioactive species from simulated waste solutions was studied with gamma spectrometry with the aim to find a compromise between on the one hand the AMP effectiveness and on the other hand unwanted affinity to AMP of Uranium and Americium. Success for the treatment protocol is defined by proving minimal uptake of U and Am, while at the same time demonstrating good removal effectiveness through the use of AMP. Uptake of U and Am were determined as influenced by oxidizing agents at nitric acid concentrations, proposed by Savannah River National laboratory. It was found that AMP does not significantly remove U and Am when concentration of oxidizing agents is more than 0.1M for simulated waste solutions and for contact times inherent in laboratory treatment protocol. Uranium and Americium affinity under experimental conditions for cesium removal were evaluated from gamma spectrometric data. Results are given for the model experiment and an approach for the real waste analysis is chosen. Under our experimental conditions simulated wastes solutions showed minimal affinity to AMP when U and Am are most probably in

Optimization of radiation protection at Bohunice NPP

International Nuclear Information System (INIS)

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)

International technical assistance example. Consortium action in Bulgaria

International Nuclear Information System (INIS)

Mattei, J.M.; Milhem, J.L.

1993-03-01

The safety status achieved last year at the Kozloduy Nuclear Power Plant (NPP) and the capability of the Bulgarian Nuclear Safety Authority (BNSA) to assess the safety of the plant and the adequacy of proposed improvements have been matters of international concern. However, the Kozloduy NPP contributes 35-40 per cent of the electrical generating capacity in Bulgaria. For further operation of the plants, it is therefore, essential that safety is improved. In july 1991, the Commission of the European Communities (CEC) instituted a Six Months Emergency Action Programme for Bulgaria under the PHARE regional nuclear safety programme. The programme consisted of three parts: - an industrial emergency programme supporting the utility of the Kozloduy NPP, - a study to evaluate Bulgaria's electricity needs, - technical assistance for reinforcement of the Bulgarian Nuclear Safety Authority. For the third part, complementary to the industrial emergency programme carried out by the WANO (World Association of Nuclear Operators), a Consortium of expert institutions and regulatory from EC member states was established by CEC for assistance to BNSA. The Consortium consisted of: - Institut de Protection et de Surete Nucleaire (IPSN), France, technical support of the French regulatory body, - Gesellschaft fur Anlagen und Reaktorsicherheit (GRS) mbH, Germany, an organization in safety engineering, technical support of governmental regulatory body, - AIB-Vincotte Nuclear (AVN), Belgium, the organization authorized by the Belgian Government for licensing and inspection of nuclear power plants, - UK Atomic Energy Authority (AEA Technology), an independent UK Government owned nuclear R and D and consultancy organization, - Nuclear Installations Inspectorate (NII) of the Health and Safety Executive, United Kingdom, the nuclear regulatory body for the United Kingdom

International technical assistance example. Consortium action in Bulgaria; Exemple d`assistance internationale. Cas de la Bulgarie, action du consortium

Energy Technology Data Exchange (ETDEWEB)

Mattei, J M; Milhem, J L [CEA Centre d` Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Heuser, F W; Kelm, P [Gesellschaft fuer Reaktorsicherheit mbH (GRS), Koeln (Germany)

1993-03-01

The safety status achieved last year at the Kozloduy Nuclear Power Plant (NPP) and the capability of the Bulgarian Nuclear Safety Authority (BNSA) to assess the safety of the plant and the adequacy of proposed improvements have been matters of international concern. However, the Kozloduy NPP contributes 35-40 per cent of the electrical generating capacity in Bulgaria. For further operation of the plants, it is therefore, essential that safety is improved. In july 1991, the Commission of the European Communities (CEC) instituted a Six Months Emergency Action Programme for Bulgaria under the PHARE regional nuclear safety programme. The programme consisted of three parts: - an industrial emergency programme supporting the utility of the Kozloduy NPP, - a study to evaluate Bulgaria`s electricity needs, - technical assistance for reinforcement of the Bulgarian Nuclear Safety Authority. For the third part, complementary to the industrial emergency programme carried out by the WANO (World Association of Nuclear Operators), a Consortium of expert institutions and regulatory from EC member states was established by CEC for assistance to BNSA. The Consortium consisted of: - Institut de Protection et de Surete Nucleaire (IPSN), France, technical support of the French regulatory body, - Gesellschaft fur Anlagen und Reaktorsicherheit (GRS) mbH, Germany, an organization in safety engineering, technical support of governmental regulatory body, - AIB-Vincotte Nuclear (AVN), Belgium, the organization authorized by the Belgian Government for licensing and inspection of nuclear power plants, - UK Atomic Energy Authority (AEA Technology), an independent UK Government owned nuclear R and D and consultancy organization, - Nuclear Installations Inspectorate (NII) of the Health and Safety Executive, United Kingdom, the nuclear regulatory body for the United Kingdom.

Mochovce NPP simulator

International Nuclear Information System (INIS)

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

Two managerial grids in NPP

International Nuclear Information System (INIS)

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)

The politics of nuclear safety regulation

International Nuclear Information System (INIS)

Adam, G.

2002-01-01

The paper discusses political aspects of decision making about the safety of nuclear power plants especially in Eastern Europe and in connection with the enlargement of the European Union. The problem of the Kozloduy NPP safety is also discussed. Recommendations on the policy and tasks for nuclear regulators are given

Health risk in nuclear power plants

International Nuclear Information System (INIS)

Bliznakov, V.

1997-01-01

Worked out are the health risk indices for NPP personnel that could be used in normal operation and in case of accident. These indices concern temporary incapacity for work, invalidity, lethality, cancer, etc. Risk estimation is based on produced energy in NPP or on the collective dose of personnel exposure. Assessed are the specific risk values for NPP ''Kozloduy'', which show that the risk in normal operation is significantly low (of the order of 2.3 ./. 7.2 x 10 -4 for invalidity, lethality and cancer). Health risk indices can be used when comparing various alternative energy sources, as well as for determination of the power strategy of a country. (author)

Second report of the Republic of Bulgaria on the fulfilment of the obligations on the Convention on nuclear safety

International Nuclear Information System (INIS)

Committee on the use of atomic energy for peaceful purposes

2003-01-01

The document presents article 17 'NPP siting', article 18 'NPP design and construction' , and article 19 'NPP operation' from the Second National Report. For the siting the issues concerning the new circumstances in the studies of the sites 'Kozloduy' and 'Belene' are presented. A brief review of the corresponding article in the First National report is made. No changes are made in the legislation concerning design and construction for this period. Under article 19 the following topics are presented: Permission for commissioning; Limits and conditions for the operation; Operational documentation; Emergency procedures; Maintenance; Reporting of the events and analysis of the operational experience; Generation and treatment of radioactive waste

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

Science.gov (United States)

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.

Contamination control by laundry monitor at NPP

International Nuclear Information System (INIS)

Singh, Vishwanath P.; Rana, P.K.; Lokeshwar Rao, S.; Managanvi, S.S.

2010-01-01

The operation of nuclear power reactor produces electricity as well as small quantity of radioactive waste as gaseous, liquid and solid. The waste contains radionuclides produced by fission and activation in reactor systems with wide spectrum of energy and half life. The long-lived nuclides Sr, Cs, Ba, Iodine and Co etc compared to short-lived are important in view of radiation protection. The radioactive contamination on the materials, human body or other places where it is undesirable is enormously harmful to workers at Nuclear Power Plant (NPP). The spread of radioactive from controlled areas is very complex problem for power reactor plant management

NPOESS Preparatory Project (NPP) Science Overview

Science.gov (United States)

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.

Risk assessment of the Krsko NPP normal operation on the public in the Zagreb area

International Nuclear Information System (INIS)

Skanata, D.; Pevec, D.

1994-01-01

In the paper, a very short review of the ICRP recommendations related to effective dose limitation for the workers as well as for the public, is given. Particular attention is paid to the risk coefficients values. In the short manner, description of the applied methodology and achieved result related to the risk assessment of the Krsko NPP normal operation on the public in the Zagreb Area, are given too. The mentioned assessment was performed as an activity within the Case Study Zagreb Project developed under the Inter-Agency Programme on the Assessment and Management of Health and Environmental Risks from Energy and Other Complex Industrial Systems (UNEP, WHO, IAEA and UNIDO). Making comparison between assessment risk of the Krsko NPP normal operation and risks to which inhabitants of the City of Zagreb are normally exposed, it is concluded that living in the vicinity of such nuclear power plant as it is Krsko NPP (PWR, 664 MWe), is not so risky as risky are some everyday activities

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

International Nuclear Information System (INIS)

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

Improving nuclear safety of VVER-440 units

International Nuclear Information System (INIS)

Nochev, T.; Sabinov, S.

2001-01-01

In this paper authors deals with improvement of nuclear safety of WWER-440 units in Kozloduy NPP. Main directions for improving nuclear safety of WWER-440 units were: - to expand number of the design accident; - to increase reliability of equipment important for the safety; - to decrease the probability of initiating events; - improvements the integrity of the primary circuit (application LBB concept, qualification of the pressure safety valves to avoid pressurized thermal shock); - improvement of the fire protection; - improvement of the operation including upgrading and improvement of operational documents, implementation of new system for training the operators and etc.; - reassessment of the seismic response of the plant. Main actions were made at NPP Kozloduy to increase nuclear safety of VVER-440 units. 1. Modernization of Emergency High Pressure Safety Injection System. The modernization includes dividing of independent channels with reservation of active elements. Pumps were exchanged with more effective and reliable ones. HPSIS was increased reliability in general through decrease number of active elements and exchanged with passive. 2. For the purpose of avoiding fast cooling at the primary circuit and obtaining thermal shock of reactor vessel, Main Safety Insulation Valves are installed at NPP Kozloduy. 3. Modernization of Emergency power supplies AC. Oil breakers VMP-10 are exchanged with gas FS-4. 4. Generator breakers are installed to decrease probability of loss power supply and blackout. They provide reliable power supply to the system important for the safety in case of failure on generator. 5. I and C system has been qualified and optimized. 6. Reassessments of Limiting Conditions of Operation and new scram signals have been introduced. 7. An operators-oriented Informational System has been developed. It includes ensuring and updating of equipment data, new informational support of operator and etc. 8. A new auxiliary independent system for

Structural capacity assessment of WWER-1000 MW reactor containment. Progress report

International Nuclear Information System (INIS)

Jordanov, M.

1999-01-01

The objective of the project is to provide assessment of the structural behaviour and safety capacity of the WWER-1000 MW Reactor Building Containment at Kozloduy NPP under critical combination of loads according to the current international requirements. The analysis is focused on a realistic assessment of the Containment taking into account the non-linear shell behaviour of the pre-stressed reinforced concrete structure. Previous assessments of the status of pre stressing cables pointed out that the efficiency of the Containment as a final defence barrier for internal and external events depends on their reliability. Due to this, the experimental data obtained from embedded sensors (gauges) at pre-stressed shell structure is to be compared with the results from analytical investigations. The reliability of the WWER-1000 MW accident prevention system is under evaluation in the project. The Soviet standard design WWER-1000 MW type units installed in Kozloduy NPP were originally designed for a Safe Shutdown Earthquake (SSE) with a peak ground acceleration (PGA) of 0.1g. The new site seismicity studies revealed that the seismic hazard for the site significantly exceeds the originally estimated and a Review Level Earthquake (RLE) anchored to PGA=0.20g was proposed for re-assessment of the structures and equipment at Kozloduy NPP. The scope of the study is a re-assessment of the Containment structure under critical combination of loads according to the current safety and reliability requirements, including comparison between the Russian design requirements and the international regulations. Additionally, an investigation of the pre-stressing technology and the annual control of the cables' pre-stressing of the Containment is to be made. The crane influence on the dynamic behaviour of the Containment will be done as well as a study of the integrity of the Containment as a final defence barrier

Seismic functional qualification of active mechanical and electrical components based on shaking table testing

International Nuclear Information System (INIS)

Jurukovski, D.

1999-01-01

The seismic testing for qualification of one sample of the NPP Kozloduy Control Panel type YKTC was carried out under Research Contract no: 8008/Rl, entitled: 'Seismic Functional Qualification of Active Mechanical and Electrical Components Based on Shaking Table Testing'. The tested specimen was selected by the Kozloduy NPP staff, Section 'TIA-2' (Technical Instrumentation and Automatics), however the seismic input parameters were selected by the NPP Kozloduy staff, Section HTS and SC (Hydro-Technical Systems and Engineering Structures). The applied methodology was developed by the Institute of Earthquake Engineering and Engineering Seismology staff. This report presents all relevant items related to the selected specimen seismic testing for seismic qualification such as: description of the tested specimen, mounting conditions on the shaking table, selection of seismic input parameters and creation of seismic excitations, description of the testing equipment, explanation of the applied methodology, 'on line' and 'off line' monitoring of the tested specimen, functioning capabilities, discussion of the results and their presentation and finally conclusions and recommendations. In this partial project report, two items are presented. The first item presents a review of the existing and used regulations for performing of the seismic and vibratory withstand testing of electro-mechanical equipment. The selection is made based on MEA, IEEE, IEC and former Soviet Union regulations. The second item presents the abstracts of all the tests performed at the Institute of Earthquake Engineering and Engineering Seismology in Skopje. The selected regulations, the experience of the Institute that has been gathered for the last seventeen years and some theoretical and experimental research will be the basis for further investigations for development of a synthesised methodology for seismic qualification of differently categorized equipment for nuclear power plants

Enhancement of equipment services for Kozloduy NPP

International Nuclear Information System (INIS)

Schultz, Christophe

2013-01-01

Conclusion After 5 years of maintenance services, KNPP and AREVA have continuously intensified their partnership Close cooperation between KNPP, AREVA Local Office Engineers and OEM experts Involvement of sophisticated tools for diagnostics and condition monitoring Performance of engineering services and obsolescence evaluation Possibilities to perform equipment modernization of Electrical and IC equipment in future

Study of the excretion of catecholamines in the Kozloduj NPP personnel

International Nuclear Information System (INIS)

Bliznakov, V.; Topalova, M.

1990-01-01

The changes in catecholamine excretion are determined in dynamics in 9 persons from the reactor hall, having received cumulative individual doses 0.022 - 0.50 Gy and exposed to thermal, sound and psycho-emotional impact. As controls 10 workers from a thermal power plant have been studied having a similar working conditions but without ionizing radiation. The noradrenaline (NA) and adrenaline (A) excretion have been determined in urine, collected in the beginning of the shift (8-11 a.m.) and in the end of the working day (1-4 p.m.). Statistically significant increase in the values of A and NA are established in NPP personnel in the beginning of the working day; they retain increased also later. The changes are interpreted as activation of sympathico-adrenaline system - a part of developing of common adaptation syndrome, connected with the labour activity in NPP. 2 tabs

NPP life management (abstracts)

International Nuclear Information System (INIS)

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

Fuel assembly leak tightness control on WWER-1000 reactor

International Nuclear Information System (INIS)

Ivanova, R.; Gerchev, N.; Mateev, A.

2001-01-01

The main index for integrity of the fuel rods cladding is the specific activity value of the primary coolant. This value determines the safe operation of the reactor. The limit for safe operation of WWER-1000 reactor is the value of the total activity of Iodine isotopes in the primary coolant 5.0x10 -3 Ci/l. The paper briefly describes the methodology for performing a fuel tightness test (sipping test) and shows the results from these tests performed during the period 1987 -1999 in units 5 and 6 at the Kozloduy NPP. An additional index related to the safe operation is defined to characterize the fuel cladding integrity Fuel Reliability Index (FRI). The FRI is defined as value of the average activity of 131 I in the primary coolant, corrected with a part of precipitated 235 U migration and fixed to the general permanent purification frequency. Two criteria (quantitative and statistic) are determined to qualify the fuel cladding integrity. The results from sipping tests show good reliability of the fuel irradiated in unit 5 and 6 at the Kozloduy NPP

Managing RTP Console Upgrading Project: Best Practice for Nuclear Malaysia as TSO in Supporting NPP Development

International Nuclear Information System (INIS)

Nurfarhana Ayuni Joha; Syahirah Abdul Rahman; Izhar Abu Hussin

2011-01-01

Human Resource Development (HRD) is required for Nuclear Power Programme (NPP). To be a Technical Support Organisation (TSO) for NPP, Nuclear Malaysia should be ready to take the responsibility in supporting Nuclear Regulatory Agency (NRA) and NPP Operators. In nurturing Nuclear Malaysia as TSO, the prime important and focus of HRD for the NPP is the reactor engineering technology. Nuclear Malaysia gives various phases of supports needed to build NPP such as during siting, design, planning, licensing, construction, commissioning, operation and maintenance in its own way and capability. The current Nuclear Malaysia unique approach is the TRIGA PUSPATI reactor (RTP) upgrading project. Research reactor plays an important role in Research and Developpement organization as a nuclear facility to assist the development of NPP. Therefore, upgrading the research reactor is needed to build the skills and gain knowledge of workers to work safely. After 29 years of operation, the RTP system is facing aging problems due to many components in the reactor are outdated. Therefore, immediate action should be carried out to mitigate the aging factor of the reactor to prevent the worsening of the aging problem, and to prevent untoward incident from happening. Action should also cover short and long term planning to prevent current situation from recurring. Currently, RTP is upgrading its console from analog to digital system. One of the achievements in this console upgrading project is the development and implementation of project management. This paper comprises the overview on the RTP console upgrading project, the project management and how this project can lead Nuclear Malaysia to be a good TSO for the development of NPP. (author)

The radiation factor 'hot particles': origin, methods of investigation, characterization and risk factors

International Nuclear Information System (INIS)

Bonchev, Ts.; Vapirev, E.; Yanev, Y.

1993-01-01

The problem of hot particles (HP) is reviewed chronologically following published data. The term appeared in the 50-s when HP have been found in fallout as a result of nuclear explosions in the atmosphere. After the Chernobyl accident there is a growing interest in HP. In 1986 HP have been discovered in American nuclear power plants (NPP) and in 1992 some have been found at Kozloduy NPP in Bulgaria as well. Detection and collection methods and different approaches for HP investigation are discussed. The direct and indirect risks from HP are described. It is concluded that the problem deserves further investigation and the discovery of HP inside NPP is of special interest

The radiation factor `hot particles`: origin, methods of investigation, characterization and risk factors

Energy Technology Data Exchange (ETDEWEB)

Bonchev, Ts; Vapirev, E; Yanev, Y

1994-12-31

The problem of hot particles (HP) is reviewed chronologically following published data. The term appeared in the 50-s when HP have been found in fallout as a result of nuclear explosions in the atmosphere. After the Chernobyl accident there is a growing interest in HP. In 1986 HP have been discovered in American nuclear power plants (NPP) and in 1992 some have been found at Kozloduy NPP in Bulgaria as well. Detection and collection methods and different approaches for HP investigation are discussed. The direct and indirect risks from HP are described. It is concluded that the problem deserves further investigation and the discovery of HP inside NPP is of special interest.

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

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. This volume of Working material contains reports related analyses and testing of Kozloduy nuclear power plant, units 5 and 6.

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

International Nuclear Information System (INIS)

1995-01-01

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. This volume of Working material contains reports related analyses and testing of Kozloduy nuclear power plant, units 5 and 6

The V-1 NPP and V-2 NPP upgrading

International Nuclear Information System (INIS)

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

Experience of Bohunice V-1 NPP

International Nuclear Information System (INIS)

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

NPP Decommissioning: the concept; state of activities

International Nuclear Information System (INIS)

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

ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

International Nuclear Information System (INIS)

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)

ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

International Nuclear Information System (INIS)

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)

On some problems concerning the national emergency planning

Energy Technology Data Exchange (ETDEWEB)

Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Bonchev, Ts [Sofia Univ. (Bulgaria). Fizicheski Fakultet; Andonov, S [Civil Defence Administration, Sofia (Bulgaria); Semova, T [Sofia Univ. (Bulgaria). Fizicheski Fakultet; Ganchev, N [Committee on the Use of Atomic Energy for Peaceful Purposes, Sofia (Bulgaria); Georgiev, V [Energoproekt, Sofia (Bulgaria)

1996-12-31

The basic principles of national emergency planning and preparedness in case of severe nuclear accident are discussed. Recommendations concerning the participating authorities in Bulgaria and their cooperation are given. The need to synchronize the plan with the NPP Kozloduy emergency plan is pointed out. The introduction of new legislation outlining the necessity of national emergency planning is stressed. 13 refs.

On some problems concerning the national emergency planning

International Nuclear Information System (INIS)

Angelov, V.; Bonchev, Ts.; Semova, T.; Georgiev, V.

1995-01-01

The basic principles of national emergency planning and preparedness in case of severe nuclear accident are discussed. Recommendations concerning the participating authorities in Bulgaria and their cooperation are given. The need to synchronize the plan with the NPP Kozloduy emergency plan is pointed out. The introduction of new legislation outlining the necessity of national emergency planning is stressed. 13 refs

Status and objectives of the Bulgarian nuclear energy sector

International Nuclear Information System (INIS)

Kouzmanov, K.

1996-01-01

A brief overview of the current situation and problems to be solved in the Bulgarian nuclear energy is presented. The main task is to increase the availability of the Kozloduy NPP in terms of time and power. The following technical solutions for reconstruction of units 1-4 (WWER-440) are discussed: defence against external events; emergency cooling of the primary and secondary circuits; reliability analysis used in probabilistic safety assessment; management of beyond design basis accident conditions. The necessity of retrofitting of units 5-6 (WWER-1000) and completion of the Belyane NPP project is also stressed

NPP service life management

International Nuclear Information System (INIS)

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

ALARA radiation protection applications at NPP A1 decommissioning using VISPLAN planning tool

International Nuclear Information System (INIS)

Slavik, O.; Kucharova, D.; Listjak, M.

2005-01-01

The SCK.CEN developed during the BR3 reactor decommissioning a graphical interfaced 3D dose assessment tool aimed at the above mentioned dose optimization problems. The tool was improved further and commercialized under the name VISIPLAN 3D ALARA planning tool. The use of VISIPLAN tool at NPP A1 decommissioning was advised by EDF within the IAEA TCP SLR/4008 project missions as a component of a 3D technological chain ensuring acquisition and evaluation of digitized information leading to ALARA optimisation of the developed decommissioning working procedures (see Fig. 1). VISIPLAN license was purchased by IAEA and granted to VUJE and NPP A1 within the IAEA TCP project SLR/4008, covering also the necessary basic and advanced training (at NPP A1 real decommissioning environment), and is currently used by VUJE analysts at NPP A1 decommissioning as an ALARA tool for intervention planning and optimisation. The VISIPLAN allows a fast dose assessment for work planned in a radioactive environment. The calculations are based on a 3D model of the work place. This PC-based tool is user friendly and calculates a detailed dose account for different work scenarios defined by the ALARA analyst, taking into account worker position, work duration and subsequent geometry and source distribution changes. The VISIPLAN methodology is described. The VISIPLAN tool was applied to several ALARA studies carried out by the VUJE within development and analysis of various Work Programs for NPP Al decommissioning tasks. The applications ranged from simpler to complex ALARA planning tasks covering simple shielding applications to selection of the most suitable order of complex working procedures. Removal of inner liners from underground reservoirs 6/1 and 6/2 as well as Dismantling of pipes and components from a (hostile) 60 m corridor are described. (authors)

Modernization programme at Dukovany NPP

International Nuclear Information System (INIS)

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)

Emergency preparedness at Ignalina NPP

International Nuclear Information System (INIS)

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

Optimization of chronic obstructive pulmonary disease treatment in clean-up workers of the Chornobyl NPP accident in the remote period after irradiation

International Nuclear Information System (INIS)

Sushko, V.O.; Shvajko, L.Yi.; Bazika, K.D.; Ryazhs'ka, A.S.

2015-01-01

Studied 60 chronic obstructive pulmonary disease (COPD) patients before treatment and 1 year after from the beginning, who were randomly assigned to two groups: the first group of patients (32 persons) additionally was appointed long reception (6 months) combination Ambroxol (30 mg x 3 times per day) and Essenciale (600 mg x 3 times per day), in the second group (28 people) patients received only basic therapy. The doses of radiation exposure were 25-500 mSv. Were studied clinical, functional characteristics, the number of exacerbations. Low response to the basic COPD therapy were shown by clean-up workers of the Chornobyl NPP accident, which is defined by the absence of significant changes in lung function tests. Additional appointments to the basic treatment of COPD combination of Ambroxol (30 mg x 3 times per day) and Essenciale (600 mg x 3 times per day) within 6 months of the liquidators of the Chernobyl made it possible to reduce the frequency of exacerbations in 46.9% patients without significant improvement in lung function tests

Does climate directly influence NPP globally?

Science.gov (United States)

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.

Estimation of embrittlement damage risk at neutron embrittled vessel constructions

International Nuclear Information System (INIS)

Staevski, K.; Madzharov, D.; Detistov, P.; Petrova, T.

1998-01-01

In this work a methodology based on Damage mechanics criteria is proposed. This methodology serves for probability assessment of the brittle damage risk for the neutron embrittled vessel elements. The developed methodology is realised in RISK code and has been verified on the base of tough reliability of the pressure vessel, 'Kozloduy' NPP Unit 2. This investigation has been carried out at the given parameters of the possible defects on the vessel's weld 4 taking into account requirements of the western and Russian standards. The obtained values for ductile to brittle transition temperatures, defining the equipment life-time in the presence of maximal defect, are in good consistence with the experimentally determined ones. The analyses of results show that the pressure vessel of 'Kozloduy' NPP Unit 2 has got a high level of reliability from brittle damage risk point of view and that the western standards give more conservative evaluation. On the bases of the results a conclusion is made that the developed methodology enables analysing the influence of possible defects in the neutron embrittled elements on their to reliability and their remained life-time

Adaption, validation and application of advanced codes with 3-dimensional neutron kinetics for accident analysis calculations - STC with Bulgaria

International Nuclear Information System (INIS)

Grundmann, U.; Kliem, S.; Mittag, S.; Rohde, U.; Seidel, A.; Panayotov, D.; Ilieva, B.

2001-08-01

In the frame of a project on scientific-technical co-operation funded by BMBF/BMWi, the program code DYN3D and the coupled code ATHLET-DYN3D have been transferred to the Institute for Nuclear Research and Nuclear Energy (INRNE) Sofia. The coupled code represents an implementation of the 3D core model DYN3D developed by FZR into the GRS thermal-hydraulics code system ATHLET. For the purpose of validation of these codes, a measurement data base about a start-up experiment obtained at the unit 6 of Kozloduy NPP (VVER-1000/V-320) has been generated. The results of performed validation calculations were compared with measurement values from the data base. A simplified model for estimation of cross flow mixing between fuel assemblies has been implemented into the program code DYN3D by Bulgarian experts. Using this cross flow model, transient processes with asymmetrical boundary conditions can be analysed more realistic. The validation of the implemented model were performed with help of comparison calculations between modified DYD3D code and thermal-hydraulics code COBRA-4I, and also on the base of the collected measurement data from Kozloduy NPP. (orig.) [de

New approach of second Romanian NPP siting

International Nuclear Information System (INIS)

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)

The seismic reassessment Mochovce NPP

International Nuclear Information System (INIS)

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)

Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant

International Nuclear Information System (INIS)

Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Kunugita, Naoki; Okuda, Kengo; Svendsen, E.R.

2015-01-01

The Fukushima Daiichi Nuclear Power Plant (NPP) 1 was severely damaged from the chain reaction of the Great East Japan Earthquake and Tsunami on 11 March 2011, and the consequent meltdown and hydrogen gas explosions. This resulted in the worst nuclear accident since the Chernobyl accident of 1986. Just as in the case of Chernobyl, emergency workers were recruited to conduct a wide range of tasks, including disaster response, rescuing activities, NPP containment, and radiation decontamination. This paper describes the types and efficacy of the various occupational health interventions introduced to the Fukushima NPP radiation workers. Such interventions were implemented in order to prevent unnecessary radiation overexposure and associated adverse health effects and work injuries. Less than 1% of all emergency workers were exposed to external radiation of >100 mSv, and to date no death or health adversities from radiation have been reported for those workers. Several occupational health interventions were conducted, including setting of new regulatory exposure limits, improving workers' radiation dosimetry, administration of stable iodine, running an occupational health tracking system, and improving occupational medicine and preventative care. Those interventions were not only vital for preventing unnecessary radiation, but also for managing other general health issues such as mental health, heat illness and infectious disease. Long-term administration of the aforementioned occupational health interventions is essential to ensure the ongoing support and care for these workers, who were put under one of the most severe occupational health risk conditions ever encountered. (author)

Ignalina NPP: living and working conditions

International Nuclear Information System (INIS)

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

Spain in South Ukraine NPP

International Nuclear Information System (INIS)

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)

Training in fundamentals of radiological coverage in Laguna Verde NPP

International Nuclear Information System (INIS)

Lara H, M. A.

2014-10-01

In 2010, the Institute of Nuclear Power Operations (INPO) celebrates the Knowledge Transfer and Retention Workshop, an event where nuclear regulators and operators presented the strategies that various NPP to worldwide were implemented to mitigate the consequences of this generational change and take advantage of it, the trend in the presented works was the same: the generational change occurs in a faster way that the transfer of knowledge, the future was already here and many NPP had not been adequately prepared to train its nuclear technicians and engineers in the tasks demanded by the industry of them, so in addition to preparing these workers to forced marches was necessary to establish strategies to retain at more experienced staff in the industry. The Laguna Verde NPP has not been exempt to this process; the preparation of personnel squares to replace those that reaching retirement age in the Comision Federal de Electricidad (CFE) has become extensive in the last five years, sometimes leading to have personnel covering functions without an alternate to the next lower position, the cause? Not enough staff. In the specific case of radiation protection (Rp) the time required for obtaining the status of Rp technician according to the ANSI/ANS 3.1 standard is 2 years, one of the tasks that most occupies part of these two years is training in radiological coverage, this training requires a mix of knowledge and experience, recently one of the concepts used for training in Rp is the evaluation and management of the radiological risk, topic that is considered in this technical work. (Author)

Analytical validation of operator actions in case of primary to secondary leakage for VVER-1000/V320

Energy Technology Data Exchange (ETDEWEB)

Andreeva, M., E-mail: m_andreeva@inrne.bas.bg; Groudev, P., E-mail: pavlinpg@inrne.bas.bg; Pavlova, M., E-mail: pavlova@inrne.bas.bg

2015-12-15

Highlights: • We validate operator actions in case of primary to secondary leakage. • We perform four scenarios related to SGTR accident for VVER-1000/V320. • The reference power plant for the analyses is Unit 6 at Kozloduy NPP. • The RELAP5/MOD 3.2 computer code is used in performing the analyses. • The analyses confirm the effectiveness of operator actions during PRISE. - Abstract: This paper presents the results of analytical validation of operator actions in case of “Steam Generator Tube Rupture” (SGTR) for VVER-1000/V320 units at Kozloduy Nuclear Power Plant (KNPP), done during the development of Symptom Based Emergency Operating Procedures (SB EOPs) for this plant. The purpose of the analyses is to demonstrate the ability to terminate primary to secondary leakage and to indicate an effective strategy for preventing secondary leakage to the environment and in this way to prevent radiological release to the environment. Following depressurization and cooldown of reactor coolant system (RCS) with isolation of the affected steam generator (SG), in these analyses are validated options for post-SGTR cooldown by: • back up filling the ruptured SG; • using letdown system in the affected SG and • by opening Fast Acting Isolation Valve (FAIV) and using Steam Dump Facility to the Condenser (BRU-K). The results of the thermal-hydraulic analyses have been used to assist KNPP specialists in analytical validation of EOPs. The RELAP5/MOD3.2 computer code has been used for the analyses in a VVER-1000 Nuclear Power Plant (NPP) model. A model of VVER-1000 based on Unit 6 of Kozloduy NPP has been developed for the thermal-hydraulics code RELAP5/MOD3.2 at the Institute for Nuclear Research and Nuclear Energy – Bulgarian Academy of Sciences (INRNE-BAS). This paper is possible through the participation of leading specialists from KNPP.

Selection of NPP for Kazakhstan

International Nuclear Information System (INIS)

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

A brief overview of Ignalina NPP safety issues

International Nuclear Information System (INIS)

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

Kozloduy NPP units 1-4 significance for Bulgaria

International Nuclear Information System (INIS)

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

External hazards at Kozloduy and Belene NPP sites

International Nuclear Information System (INIS)

Kostov, Marin; Varbanov, Georgy; Andonov, Anton

2011-01-01

Conclusions 1. KNPP and BNPP have adequate seismic design base that corresponds to the current standards 2. There is available seismic margin and cliff-edge effects are not probable 3. The external flooding hazard is properly assessed and there is available design margin 4. Anthropogenic hazards are properly assessed and there is available margin. The BNPP is designed also for the largest available aircraft impact (malevolent) 5. The tornado hazard in Bulgaria is negligible. The extreme combination of EQ, flooding, extreme wind, extreme cold and hot weather have to be studied 7. The risk of failure of all surrounding infrastructure due to earthquake, flooding or anthropogenic actions have to be studied 8. The preparedness for extreme hazards have to be improved and trained 9. The extreme hazard mitigation measures have to be constant and continuous effort

A study on the applicability for primary system decontamination through analysis on NPP decommission technology and international experience

Energy Technology Data Exchange (ETDEWEB)

Song, Jong Soon; Jung, Min Young; Lee, Sang Heon [Chosun University, Gwangju (Korea, Republic of)

2016-03-15

Decontamination is one of the most important technologies for the decommissioning of NPP. The purpose of decontamination is to reduce the Risk of exposure of the decommissioning workers, and to recycle parts of the plant components. Currently, there is a lack of data on the efficiency of the decontamination technologies for decommissioning. In most cases, the local radiation level can be lowered below a regulatory limitation by decontamination. Therefore, more efficient decontamination technology must be continuously developed. This work describes the practical experiences in the United States and the European countries for NPP decommissioning using these decontamination technologies. When the decommissioning of domestic nuclear power plant is planned and implemented, this work will be helpful as a reference of previous cases.

Safety investigation of team performance in accidents

International Nuclear Information System (INIS)

Petkov, G.; Todorov, V.; Takov, T.; Petrov, V.; Stoychev, K.; Vladimirov, V.; Chukov, I.

2004-01-01

The paper presents the capacities of the performance evaluation of teamwork (PET) method. Its practicability and efficiency are illustrated by retrospective human reliability analyse of the famous nuclear and maritime accidents. A quantitative assessment of operators' performance on the base of thermo-hydraulic (T/H) calculations and full-scope simulator data for set of NPP design basic accidents with WWER is demonstrated. The last data are obtained on the 'WWER-1000' full-scope simulator of Kozloduy NPP during the regular practical training of the operators' teams. An outlook on the 'evaluation system of main control room (MCR) operators' reliability' project, based on simulator data of operators' training is given

NPP Krsko decommissioning concept

International Nuclear Information System (INIS)

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)

NPP Krsko decommissioning concept

International Nuclear Information System (INIS)

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)

Guidance for Deployment of Mobile Technologies for Nuclear Power Plant Field Workers

Energy Technology Data Exchange (ETDEWEB)

Heather D. Medema; Ronald K. Farris

2012-09-01

This report is a guidance document prepared for the benefit of commercial nuclear power plants’ (NPPs) supporting organizations and personnel who are considering or undertaking deployment of mobile technology for the purpose of improving human performance and plant status control (PSC) for field workers in an NPP setting. This document especially is directed at NPP business managers, Electric Power Research Institute, Institute of Nuclear Power Operations, and other non-Information Technology personnel. This information is not intended to replace basic project management practices or reiterate these processes, but is to support decision-making, planning, and preparation of a business case.

Operation Aspect of the Main Control Room of NPP

International Nuclear Information System (INIS)

Sahala M Lumbanraja

2009-01-01

The main control room of Nuclear Power Plant (NPP) is operational centre to control all of the operation activity of NPP. NPP must be operated carefully and safely. Many aspect that contributed to operation of NPP, such as man power whose operated, technology type used, ergonomic of main control room, operational management, etc. The disturbances of communication in control room must be anticipated so the high availability of NPP can be achieved. The ergonomic of the NPP control room that will be used in Indonesia must be designed suitable to anthropometric of Indonesia society. (author)

Radiation ecological monitoring in NPP region

International Nuclear Information System (INIS)

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

Environmental impact of the NPP Krsko

International Nuclear Information System (INIS)

Novosel, N.

1996-01-01

The Ministry of Economic Affairs has for six years now been monitoring the operation of the Krsko NPP (NEK) and its impact on the environment. A bulletin titled 'NEK - Energy and Environment' is being issued every three months. It contains information on operation of the Krsko NPP for the previous three months, a graph of duration of temperature increase of water in the Sava river (delta T) in that period, an assessment of the radiological impact of Krsko NPP on the environment through an equivalent dose cumulatively throughout the calendar year, and a short current text related to Krsko NPP. The Ministry of Economic Affairs organizes a press conference on every issue of the bulletin, as an attempt of introducing this subject to the media and to the public. This paper contains a review of information given in the NEK bulletin from 1990 to 1995 with a special emphasis on the contribution of the Krsko NPP to the artificially caused radiation on the border between the Republic of croatia and the Republic of Slovenia. (author)

NPP Prevlaka - Preparation of construction

International Nuclear Information System (INIS)

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)

Seismic strengthening of overhead roads between reactor buildings of WWER-1000 MW type NPP

International Nuclear Information System (INIS)

Stoyanov, G.; Jordanov, M.

2005-01-01

This paper presents results obtained during the upgrading design of overhead roads (OHR) between WWER-1000 MW Reactor Units at Kozloduy NPP. In order to avoid the deficiencies of OHR seismic capacity different approaches were developed based on the site and structure specifics. Overhead roads are precasted RC structures. They consist of pedestrian gallery and pipeline RC box, connecting reactor buildings with auxiliary building. They are mounted at approximately 10 m above ground level. The overhead roads are evaluated at their as-is status and a seismic upgrading of the structure is designed. The analysis of the upgraded structure is performed for Review Level Earthquake (RLE). Soil-Structure Interaction (SSI) effects are taken into account through equivalent soil springs with frequency adjusted stiffnesses. The upgraded structure is checked for conformance with the specially developed technical design specification based on International, US and Bulgarian standards and codes, taking into account site specific conditions. The general approach is consistent with up-to-date practice for evaluation and upgrade of nuclear power plant facilities. The existing site conditions and Owner's requirements are taken into account during development of the upgrading. The proposed upgrading measures can be divided in two major categories global and local. Special attention is paid to improvement of the ductile behavior of the structure through new detailing and upgrading of existing connection. These measures are grouped in two final design concepts and after a comparative study one of them is chosen for implementation. For the upgraded structure response spectra are derived at locations where equipment is attached. (authors)

Seismic characterization of the NPP Krsko site

International Nuclear Information System (INIS)

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

Some problems of NPP personnel training

International Nuclear Information System (INIS)

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

Fuel leak testing performance at NPP Jaslovske Bohunice

International Nuclear Information System (INIS)

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

Fuel leak testing performance at NPP Jaslovske Bohunice

Energy Technology Data Exchange (ETDEWEB)

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.

Preparation for Ignalina NPP decommissioning

International Nuclear Information System (INIS)

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

Krsko NPP Periodic Safety Review program

International Nuclear Information System (INIS)

Basic, I.; Spiler, J.; Novsak, M.

2001-01-01

The need for conducting a Periodic Safety Review for the Krsko NPP has been clearly recognized both by the NEK and the regulator (SNSA). The PSR would be highly desirable both in the light of current trends in safety oversight practices and because of many benefits it is capable to provide. On January 11, 2001 the SNSA issued a decision requesting the Krsko NPP to prepare a program and determine a schedule for the implementation of the program for 'Periodic Safety Review of NPP Krsko'. The program, which is required to be in accordance with the IAEA safety philosophy and with the EU practice, was submitted for the approval to the SNSA by the end of March 2001. The paper summarizes Krsko NPP Periodic Safety Review Program [1] including implemented SNSA and IAEA Expert Mission comments.(author)

Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant.

Science.gov (United States)

Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Okuda, Kengo; Svendsen, Erik Robert; Kunugita, Naoki

2015-05-01

The Fukushima Daiichi Nuclear Power Plant (NPP) 1 was severely damaged from the chain reaction of the Great East Japan Earthquake and Tsunami on 11 March 2011, and the consequent meltdown and hydrogen gas explosions. This resulted in the worst nuclear accident since the Chernobyl accident of 1986. Just as in the case of Chernobyl, emergency workers were recruited to conduct a wide range of tasks, including disaster response, rescuing activities, NPP containment, and radiation decontamination. This paper describes the types and efficacy of the various occupational health interventions introduced to the Fukushima NPP radiation workers. Such interventions were implemented in order to prevent unnecessary radiation overexposure and associated adverse health effects and work injuries. Less than 1% of all emergency workers were exposed to external radiation of >100 mSv, and to date no deaths or health adversities from radiation have been reported for those workers. Several occupational health interventions were conducted, including setting of new regulatory exposure limits, improving workers' radiation dosimetry, administration of stable iodine, running an occupational health tracking system, and improving occupational medicine and preventative care. Those interventions were not only vital for preventing unnecessary radiation, but also for managing other general health issues such as mental health, heat illness and infectious diseases. Long-term administration of the aforementioned occupational health interventions is essential to ensure the ongoing support and care for these workers, who were put under one of the most severe occupational health risk conditions ever encountered. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Financial and organizational models of NPP construction projects

International Nuclear Information System (INIS)

Ivanov, Timur

2010-01-01

The recent evolution of financial and organizational models of NPP projects can be truly reputed to open a new page of the world market of NPP construction. The definition of the concrete model is based mostly on specific cooperation backgrounds and current terms and conditions under which the particular NPP project is being evolved. In this article the most commonly known strategies and schemes of financing structuring for export NPP construction projects are scrutinized. Special attention is paid to the analysis of BOO/BOT models which are based on the public-private partnership. Most BOO/BOT projects in the power sector has Power Purchase Agreements (PPA) as an integral part of them. The PPA key principles are studied here as well. The flexibility and adaptability of the public-private partnership models for financing and organization of the NPP projects contributes substantially to the competitiveness of the NPP projects especially under current economic conditions. (orig.)

External flood probabilistic safety analysis of a coastal NPP

International Nuclear Information System (INIS)

Pisharady, Ajai S.; Chakraborty, M.K.; Acharya, Sourav; Roshan, A.D.; Bishnoi, L.R.

2015-01-01

External events pose a definitive challenge to safety of NPP, solely due to their ability to induce common cause failures. Flooding incidents at Le Blayais NPP, France, Fort Calhoun NPP, USA and Fukushima Daiichi have pointed to the importance of external flooding as an important contributor to NPP risk. A methodology developed for external flood PSA of a coastal NPP vulnerable to flooding due to tsunami, cyclonic storm and intense local precipitation is presented in this paper. Different tasks for EFPSA has been identified along with general approach for completing each task

Predisposal of Radioactive Waste from NPP 1000 MWe

International Nuclear Information System (INIS)

Suryantoro

2007-01-01

Predisposal of radioactive waste from NPP 1000 MW which was planned to be operated in 2016 has been conducted. In this study NPP applying PWR type was assumed. This assessment comprises all aspects of radioactive waste coming from NPP. One through cycle was chosen consequently no reprocessing step will be conducted. The assessment shows that technologically all radioactive waste treatment process rising from NPP operation has similarities to the existing radioactive waste process conducted by RWI which has lower scale of waste amount. (author)

Operation safety at Ignalina NPP

International Nuclear Information System (INIS)

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

Treatment of NPP wastes using vitrification

International Nuclear Information System (INIS)

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)

NPP electrical price and tariff in the world

International Nuclear Information System (INIS)

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)

Individual protection of NPP personnel

International Nuclear Information System (INIS)

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

Safety culture at Mochovce NPP

International Nuclear Information System (INIS)

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)

Dissemination of Knowledge about NPP Instrumentation and Control Systems

International Nuclear Information System (INIS)

Yastrebenetsky, M.

2016-01-01

Full text: Instrumentation and control (I&C) systems are the most variable part in the nuclear power plants (NPP) comparatively with any other NPP systems. This statement is connected with the wide use of computers, rapid changes in information technologies, with the appearance of new computer complex electronic components, e.g., field programmable gate arrays (FPGA) and with appropriate point of their insertion into NPP I&C life cycle. The changes in NPP I&C systems require the dissemination of the knowledge about these systems. Lessons after Fukushima accident increase necessity of these actions. The elaboration and following dissemination of this knowledge took place in different directions: • Writing and issue of three new books about NPP I&C systems for specialists and for students which were issued in Ukrainian and USA public houses (the last book was issued in 2014); • Organization of five international scientific technical conferences, devoted to NPP I&C safety problems; • Elaboration of national (Ukrainian) standards and regulations pertaining to safety important NPP I&C systems (the last standard was issued in 2015) and participation in elaboration of international standards; • Lecturing for university students, NPP specialists and I&C designers. These actions in all directions are added to IAEA activity in the area NPP I&C systems (e.g., IAEA NP-T-3.12 “Core Knowledge on I&C systems in NPP”). (author

Mathematical models in nuclear safety and radiation protection of nuclear energy

International Nuclear Information System (INIS)

1993-01-01

This collection of papers contains the full texts of 33 reports presented at the Seminar, all of which are indexed and abstracted separately for the INIS database. The topics of the reports cover the mathematical models and computer codes for risk analysis, reactor reliability simulating, safety-related benchmarks, thermohydraulic studies, reactor kinetics, hypothetical accidents and their radiological consequences, etc. The investigations refer mainly to WWER-440 and WWER-1000 type reactors of the Kozloduy NPP

Experience in scientific guidance during start-up and normal operation of NPPs with WWER reactors; Opyt nauchnogo rukovodstva puskom i soprovozhdeniya pri ehkspluatatsii ehnergoblokov AEhS s WWER

Energy Technology Data Exchange (ETDEWEB)

Abagyan, A; Kazakov, V; Kryakvin, L [All-Russian Inst. for NPP Operation, Moscow (Russian Federation)

1996-12-31

The experience gained in the All-Russian Research Institute of NPP Operation (RU) in improvement of reactor start-up and normal operation of NPPs has been reported. The work was carried out on NPPs in Russia, Ukraine, Bulgaria, Hungary and Czechoslovakia. All scientific programmes applied use the system approach, modern methods of safety assessment and the principle of loss effect optimization. For the Kozloduy NPP the following projects have been implemented: design of accelerated unloading system for WWER-1000; refinement of water feeding unit for the WWER-1000 steam generator; response analysis of the safety anti-breakdown system of the second loop. The importance of technical substantiation in the process of decision making is stressed. 6 refs.

Resent studies in nuclear energy at INRNE - BAS

International Nuclear Information System (INIS)

Tonev, D.

2013-01-01

Institute for Nuclear Research and Nuclear Energy performs research of its own and actively participates in European projects for the development and validation of the new generation software for reactor simulation and safety analysis. Current results and planned activities aim to improve the performance and safety of the Kozloduy NPP. The scientific and technical support of the nuclear industry and the education of young specialists contribute to the sustainable development of nuclear power in Bulgaria. In this paper the main research activities of the Institute for Nuclear Research and Nuclear Energy in nuclear energy like: Core physics; Reactor dynamics and safety; NPP safety analysis; Spent fuel analysis; Nuclear fuel performance; Reactor dosimetry are presented

Probabilistic assessment of NPP safety under aircraft impact

International Nuclear Information System (INIS)

Birbraer, A.N.; Roleder, A.J.; Arhipov, S.B.

1999-01-01

Methodology of probabilistic assessment of NPP safety under aircraft impact is described below. The assessment is made taking into account not only the fact of aircraft fall onto the NPP building, but another casual parameters too, namely an aircraft class, velocity and mass, as well as point and angle of its impact with the building structure. This analysis can permit to justify the decrease of the required structure strength and dynamic loads on the NPP equipment. It can also be especially useful when assessing the safety of existing NPP. (author)

NPP Bohunice experience with ASSET services

Energy Technology Data Exchange (ETDEWEB)

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).

NPP Bohunice experience with ASSET services

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4C. Paks NPP: Analysis and testing. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

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 involves comparative analysis of the seismic analysis results of the reactor building for soft soil conditions, derivation of design response spectra for components and systems; and upper range design response spectra for soft soil site conditions at Paks NPP.

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4C. Paks NPP: Analysis and testing. Working material

International Nuclear Information System (INIS)

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 involves comparative analysis of the seismic analysis results of the reactor building for soft soil conditions, derivation of design response spectra for components and systems; and upper range design response spectra for soft soil site conditions at Paks NPP

Metamorphosis of NPP A1, V1, V2

International Nuclear Information System (INIS)

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

NPP A-1 decommissioning - Phase I

International Nuclear Information System (INIS)

Krstenik, A.; Blazek, J.

2000-01-01

Nuclear power plant A-1 with output 150 MW e , with metallic natural uranium fuelled, CO 2 cooled and heavy water moderated reactor had been prematurely finally shut down in 1977. It is necessary to mention that neither operator nor regulatory and other authorities have been prepared for the solution of such situation. During next two consecutive years after shutdown main effort of operator focused on technical and administrative activities which are described in the previous paper together with approach, condition and constraints for NPP A-1 decommissioning as well as the work and research carried out up to the development and approval of the Project for NPP A-1 decommissioning - I. phase. Subject of this paper is description of: (1) An approach to NPP A -1 decommissioning; (2) An approach to development of the project for NPP A-1 decommissioning; (3) Project - tasks, scope, objectives; (4) Mode of the Project realisation; (5) Progress achieved up to the 1999 year. (authors)

Sociological investigations on Ignalina NPP and within its surroundings

International Nuclear Information System (INIS)

Chiuzhas, A.

1998-01-01

The purpose of this study was to determine the impact of Ignalina NPP and Visaginas town on the social territorial processes in the region and to reveal the impact of Ignalina NPP on the regional economic, social, demographic, political and cultural processes in the context of ecological and psychological affect. According to the results of this research three quarters of the inhabitants and the functionaries of local administration hold an opinion that operation of Ignalina NPP posses threat for the population and environment. Meanwhile they are sure that danger of Ignalina NPP is not critical. 21 - 35 % of the local administrators speak for the closure of Ignalina NPP , whereas half of Visaginas residents and three quarters of the local administrators indicate that operation of reactors is expedient. Over 90% of the population do not have sufficient information on the operation of Ignalina NPP. In the opinion of the rest Lithuanian people Ignalina NPP zone is related with the physical danger and the image of Visaginas residents as the 'others', 'strangers'. More than 90% of Ignalina NPP employees are Russian speaking, not native Lithuanians. The social relations of Visaginas with the environment are poor as a result of the situation of the town, lack of communications and cultural self isolation. (author)

Ageing management database development for PWR NPP steam generator

International Nuclear Information System (INIS)

Liu Hongyun; Xu Liangjun; Xiong Changhuai; Wang Xianyuan

2005-01-01

Steam generator (SG) is one of the key safe important equipment of NPP, which is covered by NPP aging management program. Steam Generator Aging Management Dabatase (SGAMDB) is developed to provide necessary information for SG aging management. RINPO is developing SGAMDB for domestic NPP. This system contains information and data about SG design, manufacture, operation and maintenance. The information include NPP fundamental data, SG design data, SG aging mechanism, SG operation data, SG ISI data, SG maintenance data and SG evaluation interface. The system runs at the intranet of Qinshan-1 NPP with B/S mode. It can provide information inquire and fundamental analysis for NPP SG aging team and SG aging researcher's. In addition, it provides necessary information and data for SG aging analysis and evaluation, such as all pressure test process and flaws of tubes, and collects the analysis results. (authors)

Accounting and analysis of the real labour input for objects and types of works during NPP construction

International Nuclear Information System (INIS)

Shuvaev, P.P.

1983-01-01

A technique for determining the actual labour input for PP construction according to types of works, construction units and objects is considered. The data are presented on specific expenditures on civil engineering, heat and electric installation, insulation and anticorrosion works for construction of the Chernobylsk and Kursk NPPs. A conclusion is drawn about the necessity of computer utilization in calculating the labour input for different types of works, number of workers and planning works during the NPP construction

Principles of tariff determination for NPP electric power generation

International Nuclear Information System (INIS)

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

Manufacturer's part in NPP personnel training in the FRG

International Nuclear Information System (INIS)

Martin, H.D.

1987-01-01

This paper describes the regulatory guidelines and the training and retraining procedures and programs for NPP personnel in the Federal Republic of Germany. Reference is also made to the three years dual workshop/factory and classroom education of skilled workers in Germany. KWU as a turnkey manufacturer of Nuclear Power Plants holds the nuclear operating license towards the authority after first fuel loading of a new plant. In this respect it has extensive overall training obligations not only towards its customers but also with regards to its own shift personnel during nuclear power operation up to commercial operation and hand over of the plant. KWU's philosophy of training, its infrastructure, its various obligations and services are described for new plants as well as with regards to retraining for older plants

Leningrad NPP and energetics of north-western Russia

International Nuclear Information System (INIS)

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

Investigation of the templets cut out of the Kozloduy Unit 2 reactor pressure vessel

Energy Technology Data Exchange (ETDEWEB)

Klausnitzer, E; Leitz, C; Rieg, C Y [Electricite de France (EDF), 75 - Paris (France); Kryukov, A [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

1994-12-31

Instrumented impact tests were carried out on sub-size specimens of base and weld metal. Using correlation dependencies, values of ductile-to-brittle transition temperature were determined before and after annealing for base and weld metal corresponding to standard specimen tests. The experimental results were compared to a prediction of the extent of radiation-induced embrittlement of Kozloduy Unit 2 pressure vessel materials. It was confirmed that radiation-induced embrittlement of the base metal does not impose any limitation on the radiation-limited lifetime of the pressure vessel. The predicted increase of the ductile-to-brittle transition temperature of weld metal as a result of irradiation (about 165 C) is practically equal to the experimental result (162 C). The ductile-to-brittle transition temperature of the weld metal was recovered by no less than 85 %.

Overview of Cernavoda NPP training programme

International Nuclear Information System (INIS)

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)

Organization of monitoring of agricultural products in NPP region

International Nuclear Information System (INIS)

Panteleev, L.I.; Spirin, E.V.; Sanzharova, N.I.

1990-01-01

Problem of organizing chemical and radiation monitoring of agricultural products in NPP region is considered. Attention is paid to monitoring during NPP siting and designing, to monitoring of radioactive contamination of agricultural products under normal NPP operation, emergency situations and decommissioning

Belene NPP

International Nuclear Information System (INIS)

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.)

Study on human factor at NPP

International Nuclear Information System (INIS)

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

Perspectives of NPP personnel training in the future?

International Nuclear Information System (INIS)

Khess, R.E.

1996-01-01

Problems of the NPP personnel education are discussed during radical reorganization of the state regulation of energy production and distribution when nuclear energetics will appears in the market conditions. Effective methods of the NPP personnel training developed by the corporation GPU Nuclear are given. Potentials of the application of simulators and computerized programs for increasing the NPP personnel education efficiency are considered

Seismic assessment of Kozloduy WWER-440, model 230 nuclear power plant

International Nuclear Information System (INIS)

Monette, P.; Baltus, R.; Yanev, P.; Campbell, R.

1993-01-01

A preliminary report is given of the findings of an IAEA sponsored walkdown of the WWER-440, model 230 at Kozloduy, in May 1991. The scope of the IAEA mission was to determine the lower bound seismic capacity of the plant and to make recommendations for improvements to increase the earthquake resistance. The methodology utilized in the assessment is that used for evaluation of the seismic margin in U.S. nuclear power plants subjected to earthquakes beyond their design basis. Included in the assessment is the establishment of a safe shutdown path which would include the capacity to mitigate a small break in the primary system, performance of a walkdown of the safe shutdown path and calculation of the high-confidence-of-low-probability-of-failure (HCLPF) of the safe shutdown path. Excluding system design deficiency relative to U.S. and Western Europe standards, it was found that the plant has many seismic vulnerabilities similar to those that existed in many of the U.S. plants prior to about 1979 when the Systematic Evaluation Program was initiated. (Z.S.) 1 tab., 1 fig

Integrated ageing management of Atucha NPP

International Nuclear Information System (INIS)

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)

Integrated Ageing Management of Atucha NPP

International Nuclear Information System (INIS)

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)

Integrated ageing management of Atucha NPP

Energy Technology Data Exchange (ETDEWEB)

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)

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

International Nuclear Information System (INIS)

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

Project No. 10 - Partial restoration of Ignalina NPP territory

International Nuclear Information System (INIS)

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

Possible use of dual purpose dry storage casks for transportation and future storage of spent nuclear fuel from IRT-Sofia

International Nuclear Information System (INIS)

Manev, L.; Baltiyski, M.

2003-01-01

Objectives: The main objective of the present paper is related to one of the priority goals stipulated in Bulgarian Governmental Decision No.332 from May 17, 1999 - removal of SNF from IRT-Sofia site and its exporting for reprocessing and/or for temporary storage at Kozloduy NPP site. The variant of using dual purpose dry storage casks for transportation and future temporary storage of SNF from IRT-Sofia aims to find out a reasonable alternative of the existing till now variant for temporary SNF storage under water in the existing Kozloduy NPP Spent Fuel Storage Facility until its export for reprocessing. Results: Based on the given data for the condition of 73 Spent Nuclear Fuel Assemblies (SNFA) stored in the storage pool and technical data as well as data for available equipment and IRT-Sofia layout the following framework are specified: draft technical features of dual purpose dry storage casks and their overall dimensions; the suitability of the available equipment for safety and reliable performance of transportation and handling operations of assemblies from storage pool to dual purpose dry storage casks; the necessity of new equipment for performance of the above mentioned operations; Assemblies' transportation and handling operations are described; requirements to and conditions for future safety and reliable storage of SNFA loaded casks are determined. When selecting the technical solutions for safety assurance during performance of site handling operations of IRT-Sofia and for description of the exemplary casks the Effective Bulgarian Regulations are considered. The experience of other countries in performance of transfer and transportation of SNFA from such types of research reactors is taken into account. Also, Kozloduy NPP experience in SNF handling operations is taken into account. Conclusions: The Decision of Council of Minister for refurbishment of research reactor into a low power one and its future utilization for experimental and training

Recommended reactor coolant water chemistry requirements for WWER-1000 units with 235U higher enriched fuel

International Nuclear Information System (INIS)

Dobrevski, I.; Zaharieva, N.

2011-01-01

The last decade worldwide experience of PWRs and WWERs confirms the trends for the improvement of the nuclear power industry electricity production through the implementation of high burn-up or high fuel duty, which are usually accompanied with the usage of UO 2 fuel with higher content of 235 U - 4.0% - 4.5% (5.0%). It was concluded that the onset of sub-cooled nucleate boiling (SNB) on the fuel cladding surfaces and the initial excess reactivity of the core are the primary and basic factors accompanying the implementation of uranium fuel with higher 235 U content, aiming extended fuel cycles and higher burn-up of the fuel in Pressurized Water Reactors. As main consequences of the presence of these factors the modifications of chemical / electrochemical environments of nuclear fuel cladding- and reactor coolant system- surfaces are evaluated. These conclusions are the reason for: 1) The determination of the choices of the type of fuel cladding materials in respect with their enough corrosion resistance to the specific fuel cladding environment, created by the presence of SNB; 2) The development and implementation of primary circuit water chemistry guidelines ensuring the necessary low corrosion rates of primary circuit materials and limitation of cladding deposition and out-of-core radioactivity buildup; 3) Implementation of additional neutron absorbers which allow enough decrease of the initial concentration of H 3 BO 3 in coolant, so that its neutralization will be possible with the permitted alkalising agent concentrations. In this paper the specific features of WWER-1000 units in Bulgarian Nuclear Power Plant; use of 235 U higher enriched fuel in the WWER-1000 reactors in the Kozloduy NPP; coolant water chemistry and radiochemistry plant data during the power operation period of the Kozloduy NPP Unit 5, 15 th fuel cycle; evaluation of the approaches and results by the conversion of the WWER-1000 Units at the Kozloduy NPP to the uranium fuel with 4.3% 235 U as

Main principles of NPP project ecological expert investigation

International Nuclear Information System (INIS)

Dibobes, I.K.; Revina, S.K.; Glushkov, V.P.

1983-01-01

NPP project ecological expert investigation among the other objectives is to provide implementation of standards, rules and requirements as well as government decrees and international obligations of the USSR concerning the environment protection. The expert investigation takes into consideration both environment protection, regional, resources, ecological, demographic and economic aspects. The NPP siting and the local environment and resources state are estimated as well as the structure of utilization of the latter, the expected damage to the environment due to NPP construction and the measures directed towards the optimal using of natural resources. On the basis of the presented issues suggestions about NPP projects coordination with Goskomgidromet's institutions are given [ru

Epidemiology of non-tumor diseases in Chernobyl clean-up workers

International Nuclear Information System (INIS)

Buzunov, V.A.; Pirogova, E.A.; Tereshchenko, V.M.; Krasnikova, L.I.; Vojchulene, Yu.S.

2004-01-01

Epidemiological study of non-tumor diseases in Chernobyl clean-up workers was effectuated on the materials of State Registry of Ukraine for Victims of Chernobyl NPP Accident. Percent of healthy people among the clean-up workers of 1986 - 1987 decreased from 67.6% in 1988 to 9.6% in 1998, patients with chronic diseases increased from 12,8% in 1988 to 79,1% in 1998. Quantitative risk-analysis proves to possible relationship with absorbed doses prevalences of diseases of blood and hemopoietic organs, coronary hearth disease, cerebrovascular diseases, thyroid pathology. The age at the time of investigation, tobacco smoking and stress were statistically significant non-radiation factors of relative risk

Automatic control system at the ''Loviisa'' NPP

International Nuclear Information System (INIS)

Kukhtevich, I.V.; Mal'tsev, B.K.; Sergievskaya, E.N.

1980-01-01

Automatic control system of the Loviisa-1 NPP (Finland) is described. According to operation conditions of Finland power system the Loviisa-1 NPP must operate in the mode of week and day control of loading schedule and participate in current control of power system frequency and capacity. With provision for these requirements NPP is equipped with the all-regime system for automatic control functioning during reactor start-up, shut-down, in normal and transient regimes and in emergency situations. The automatic control system includes: a data subsystem, an automatic control subsystem, a discrete control subsystem including remote, a subsystem for reactor control and protection and overall station system of protections: control and dosimetry inside the reactor. Structures of a data-computer complex, discrete control subsystems, reactor control and protection systems, neutron flux control system, inside-reactor control system, station protection system and system for control of fuel element tightness are presented in short. Two-year experience of the NPP operation confirmed advisability of the chosen volume of automatization. The Loviisa-1 NPP operates successfully in the mode of the week and day control of supervisor schedule and current control of frequency (short-term control)

EMAS at Doel NPP

International Nuclear Information System (INIS)

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)

On psichological problem of NPP operation and control

International Nuclear Information System (INIS)

Mashin, V.A.

1994-01-01

The role of psichological factor as a reserve for increasing NPP safety connected with human factor is discussed. It is emphasized that the process of NPP personnel professional training should not be restricted by formation of a certain set of knowledge, skills and experience. It is necessary to initiate ability for constant self-developing. Control for assurance of effective interaction of the whole NPP personnel is an important problem

Bohunice V1 NPP upgrading programme

International Nuclear Information System (INIS)

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)

Psychology of NPP operation safety

International Nuclear Information System (INIS)

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

From the chronicle of training of Dukovany NPP staff

International Nuclear Information System (INIS)

2005-01-01

The long way the Dukovany NPP had to go before the plant staff was fully qualified and skilled is described. First the training concept was prepared, then the necessary training facilities were set up, lecturers and instructors were hired and trained, training programmes and training materials were developed, and ultimately the first training course was launched in 1979. A training NPP was constructed and a full-scope simulator of the Dukovany NPP was set up. The current status of organization of NPP staff training by the CEZ utility is highlighted. (author)

Training center of Rovenskaya NPP. The experience of creation

International Nuclear Information System (INIS)

Fedorov, O.M.; Aristov, B.N.

1991-01-01

Experience in creation of a teaching-training centre at the Rovno NPP, which uses means available at unified NPPs, at most is discussed. The centre hardware complex functions include the event filing and providing for user-friendly interface with NPP technical personnel under training. The system of personnel training at the Rovno NPP teaching-training centre gives an opportunity to analyze accidents and emergency conditions more completely and carefully. The taching analysis of failures and accidents by a NPP operators using the complex of the teaching-training centre hardware sufficiently improves knowledge of particular accidents

Observation and modeling of NPP for Pinus elliottii plantation in subtropical China

Institute of Scientific and Technical Information of China (English)

MA ZeQing; LIU QiJing; WANG HuiMin; LI XuanRan; ZENG HuiQing; XU WenJia

2008-01-01

Based on the stem analysis of 59 individuals of Pinus elliottii in combination with tree biomass models,we calculated annual biomass increment of forest plots at Qianyanzhou Ecological Station,Chinese Academy of Sciences in subtropical China. In addition,canopy layer and community NPP were calculated based on 12 years' litter fall data. NPP of the 21-year-old forest was estimated by using the BIOME BGC model; and both measured NPP and estimated NPP were compared with flux data. Community lation between annual litter fall and annual biomass increment; and the litter fall was 1.19 times the biomass increment of living trees. From 1985 to 2005,average NPP and GPP values based on BGC simulated tree layer NPP values. NPP accounted for 30.2% (25.6%-32.9%) of GPP,while NEP accounted for 57.5% (48.1%-66.5%) of tree-layer NPP and 41.74% (37%-52%) of stand NPP. Soil respiration accounted for 77.0% of measured tree NPP and 55.9% of the measured stand NPP. NEE based on eddy covariance method was 12.97% higher than the observed NEP.

Radiobiological significance of radioactive contamination - summary assessment based on great number of measurements

International Nuclear Information System (INIS)

Angelov, V.; Bonchev, Ts.; Mavrodiev, V.; Kyrdzhilov, N.

1995-01-01

In order to facilitate quantitative and qualitative characterisation of radioactive contamination the authors introduce a relative estimate of radionuclide activity by setting as a reference the most abundant element -Co-60 in the case of the Kozloduy NPP. The ratio η i of the mean annual permissible concentration in air for each radionuclide (RPC-92) to that of Co-60 is calculated. It is found that η i has the same or close values for groups of radionuclides, e.g. η i = 2.10 -4 for 238 Pu, 239 Pu, 240 Pu, 241 Am, 244 Cm; η i = 5 for 89 Sr, 91 Y; 93 Nb, 134 Cs, 137 Cs; η i = 50 for 55 Fe, 63 Ni, 95 Zr, 95 Nb, 140 Ba, 140 La. Then it is compared to the experimentally measured values of the same quantity η iexp , derived from surface contamination data. The ratio η iexp /η i is plotted against log η i . The resulting nomograms give graphic representation of the radiobiological significance of various radionuclide groups. Data from different locations at the Kozloduy NPP are presented. It is found that the alpha emitter contamination has highest values in the Unit 1 (WWER-440) control rooms after repair. The Unit 5 (WWER-1000) has lower alpha contamination compared to WWER-440 units. 1 ref., 5 figs., 1 tab

Investigation of interfacing NPP simulators with PSCAD software

International Nuclear Information System (INIS)

Zahedi, P.

2006-01-01

This paper demonstrates a new method of interfacing a NPP simulator with the PSCAD software so that the interaction between the plant dynamics and the grid dynamics can be studied. Through this method, data extracted from NPP simulator, as an object, will be communicated to a server running PSCAD software. This paper will illustrate the use of Remote Procedure Calls (RPC) as a distributed, client-server based application used to establish a connection between NPP simulator running on UNIX server and PSCAD running on a PC. Using this method, the called procedure need not exist in the same address space as the calling procedure. Communication protocols available in the NPP simulator are used to export data from the simulator. (author)

Licensing of the Ignalina NPP

International Nuclear Information System (INIS)

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

Ignalina Nuclear Power Plant

CERN Document Server

2002-01-01

Description of RPC inspections conducted at Ignalina NPP and enterprises sending their workers to work at Ignalina NPP is provided. Data on distribution of doses of Ignalina NPP workers and outside workers during 2002 are analysed. Statistical data on evolution of collective doses of Ignalina NPP and outside workers during 1995-2002 are provided.

Safety Analysis Report for Ignalina NPP

International Nuclear Information System (INIS)

Negrivoda, G.

1997-01-01

In December 1994 an agreement was signed between the European Bank for Reconstruction and Development and the Republic of Lithuania for the grant of 32.86 MECU for the safety Improvement at Ignalina NPP. One of the conditions for the provision of the grant, was a requirement for an in-depth analysis of the safety level at Ignalina NPP in the scope and according to the standards acceptable for a western nuclear power plant, and to publish a Safety Analysis Report (SAR). The report should investigate and analyze any factor that could limit a safe operation of the plant, and provide recommendations for actual safety improvements. According to the agreement, Lithuania had to finalize the SAR until 31 December, 1995. The bank has also organized and financed investigation of safety at Ignalina NPP and preparation of the SAR. EBRD made an agreement with Sweden's Vattenfall, which subcontracted well-known companies from Canada, USA, Germany, etc., and also the Russian Research and Development Institute of Power Engineering (NIKIET), reactor designer of Ignalina NPP. The SAR is a very comprehensive document and contains about 8000 pages of text, diagrams and tables. The main findings of the SAR are provided in the article. A large number of discrepancies with modern rules and western practices was detected, but they were not proved to be serious enough to require reactors shutdown. Based on the recommendations of the SAR Ignalina NPP has worked out Safety Improvement Program No. 2 (SIP-2), which is planned for three years and will cost 486 MLT. (author)

Research on the NPP human factors engineering operating experience review

International Nuclear Information System (INIS)

Ren Xiangchen; Miao Hongxing; Ning Zhonghe

2006-01-01

This paper addresses the importance of the human factors engineering (HFE) for the design of nuclear power plant (NPP), especially for the design of human-machine interface in the NPP. It also summarizes the scope and content of the NPP HFE. The function, scope, content and process of the NPP human factors engineering operating experience review (OER) are mainly focused on, and significantly discussed. Finally, it briefly introduces the situation of the studies on the OER in China. (authors)

Reserves of labour content reduction in NPP construction

International Nuclear Information System (INIS)

Bekerman, R.E.

1986-01-01

Specific labour contents when constructing NPP with RBMK-1000 and WWER-1000 type reactors are presented. Factors affecting labour content of NPP construction are shown. Measures aimed at labour content decrease are suggested

Reactor plant for Belene NPP completion

International Nuclear Information System (INIS)

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

NPP Krsko secondary side analysis

International Nuclear Information System (INIS)

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)

Present status and progress of safeguards activities and physical protection on the eve of year 2000 in Bulgaria

International Nuclear Information System (INIS)

Simov, R.; Gotzev, A.

1999-01-01

From the very beginning of the IAEA safeguards implementation in Bulgaria, up to now the IAEA inspections verified no deviations or uncertainties in accounting of the nuclear materials. According to the official IAEA reports Bulgaria has fulfilled completely its duties under the safeguards and the Non-proliferation Treaty and has fully assisted the IAEA inspection activity. As for the physical protection, the complicated up-to-date system was established contributing to the safety of Kozloduy NPP and the plant operation

Hydrodynamics and sediment transport at Muria Peninsula NPP Site

International Nuclear Information System (INIS)

Heni Susiati; Berni A Subki; Harman A

2011-01-01

Coastal along the coast of the Muria Peninsula, particularly the location of the Muria NPP site candidate is a dynamic region, the interaction between physical oceanographic factors such as currents, waves and tides in the coastal sediments cause abrasion or accretion. Interactions have resulted in coastal dynamics needs to be considered in siting NPP is essential in order to plan. Capacity of hydro-oceanographic data is essential in order to plan the development of the Muria NPP. The process of selecting a safe site for hydro-oceanographic aspects carried out according to IAEA safety standards on site selection. For the evaluation stage of hydro oceanographic potential site (site survey stage), the analysis is more focused on the tidal along the northern coast, bathymetry, potential water resources and hydrologic systems in the Muria NPP siting locations, Jepara. The method used is a secondary, confirmation of field data collection and interpretation of modeling results. The results showed that the preparation for the construction of NPP need to be evaluated further to coastal conditions with respect to the increase coastal erosion in the area of prospective NPP siting. (author)

Human Resources Training Requirement on NPP Operation and Maintenance

International Nuclear Information System (INIS)

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)

Safety culture in Ignalina NPP, regulatory view

Energy Technology Data Exchange (ETDEWEB)

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.

Safety culture in Ignalina NPP, regulatory view

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Replacement of the computerized control system at NPP under operation

International Nuclear Information System (INIS)

Ermolaev, A.D.; Rakitin, I.D.

1985-01-01

Reasons and preconditions for replacement of the computerized control systems (CCS) at NPP under operation are consi-- dered. Problems dealing with management of CCS replacement, maintenance of a new CCS as well as NPP personnel training for the new system maintenance are discussed. A necessity of NPP personnel participation in these works in order to adapt CCS to requirements of NPP operation personnel and to initiate the training process is underlined. Replacement of CCS at NPP under operation is associated, as a rule, with obsolescence of old systems not ensuring growing requirements to NPP workability and safety. Principles observed at CCS replacement are reduced, mainly, to the following; maximum utilizatian of existing equipment, metal strUctures, cables, instruments, power supplies, ventilation system minimum of construction works and new communications; the least change of acting panels and boxes; changes in control desks should be introduced on the basis of the analysis of operator actions '

Application of Robotic System for Emergency Response in NPP

International Nuclear Information System (INIS)

Jeong, Kyung Min; Seo, Yong Chil; Shin, Ho Chul; Lee, Sung Uk; Cho, Jae Wan; Choi, Young Soo; Kim, Chang Hoi; Kim, Seung Ho

2010-01-01

Increasing energy demand and concerns over climate change make increasing use of nuclear power plant in worldwide. Even though the probability of accident is greatly reduced, safety is the highest priority issue in the nuclear energy industry. Applying highly reliable and conservative 'defense in depth' concepts with the design and construction of NPP, there are very little possibilities with which accidents are occur and radioactive materials are released to environments in NPP. But NPP have prepared with the emergency response procedures and conduct exercises for post-accident circumstance according to the procedures. The application of robots for emergency response task for post-accident in nuclear facilities is not a new concept. Robots have been sent to recover the damaged reactor at Chernobyl where human workers could receive a lifetime dose of radiation in minutes. Based on NRC's TMI-2 Cleanup Program, several robots were built in the 1980s to help gather information and remove debris from a reactor at the Three Mile Island nuclear power plant that partially melted down in 1979. The first robot was lowered into the basement through a hatch and human operators monitoring in a control room drove it through mud, water and debris, capturing the initial post-accident images of the reactor's basement. It was used for several years equipped with various tools allowing it to scour surfaces, scoop samples and vacuum sludge. A second version carried a core sampler to determine the intensity and depth of the radiation that had permeated into the walls. To perform cleanup tasks, they built Workhorse that featured system redundancy and had a boom extendable to reach high places, but it was never used because it had too many complexities and to clean and fix. While remote robotics technology has proven to remove the human from the radioactive environment, it is also difficult to make it useful because it may requires skill about remote control and obtaining remote

Application of Robotic System for Emergency Response in NPP

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kyung Min; Seo, Yong Chil; Shin, Ho Chul; Lee, Sung Uk; Cho, Jae Wan; Choi, Young Soo; Kim, Chang Hoi; Kim, Seung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

Increasing energy demand and concerns over climate change make increasing use of nuclear power plant in worldwide. Even though the probability of accident is greatly reduced, safety is the highest priority issue in the nuclear energy industry. Applying highly reliable and conservative 'defense in depth' concepts with the design and construction of NPP, there are very little possibilities with which accidents are occur and radioactive materials are released to environments in NPP. But NPP have prepared with the emergency response procedures and conduct exercises for post-accident circumstance according to the procedures. The application of robots for emergency response task for post-accident in nuclear facilities is not a new concept. Robots have been sent to recover the damaged reactor at Chernobyl where human workers could receive a lifetime dose of radiation in minutes. Based on NRC's TMI-2 Cleanup Program, several robots were built in the 1980s to help gather information and remove debris from a reactor at the Three Mile Island nuclear power plant that partially melted down in 1979. The first robot was lowered into the basement through a hatch and human operators monitoring in a control room drove it through mud, water and debris, capturing the initial post-accident images of the reactor's basement. It was used for several years equipped with various tools allowing it to scour surfaces, scoop samples and vacuum sludge. A second version carried a core sampler to determine the intensity and depth of the radiation that had permeated into the walls. To perform cleanup tasks, they built Workhorse that featured system redundancy and had a boom extendable to reach high places, but it was never used because it had too many complexities and to clean and fix. While remote robotics technology has proven to remove the human from the radioactive environment, it is also difficult to make it useful because it may requires skill about remote control and

Validation of MCNP NPP Activation Simulations for Decommissioning Studies by Analysis of NPP Neutron Activation Foil Measurement Campaigns

Directory of Open Access Journals (Sweden)

Volmert Ben

2016-01-01

Full Text Available In this paper, an overview of the Swiss Nuclear Power Plant (NPP activation methodology is presented and the work towards its validation by in-situ NPP foil irradiation campaigns is outlined. Nuclear Research and consultancy Group (NRG in The Netherlands has been given the task of performing the corresponding neutron metrology. For this purpose, small Aluminium boxes containing a set of circular-shaped neutron activation foils have been prepared. After being irradiated for one complete reactor cycle, the sets have been successfully retrieved, followed by gamma-spectrometric measurements of the individual foils at NRG. Along with the individual activities of the foils, the reaction rates and thermal, intermediate and fast neutron fluence rates at the foil locations have been determined. These determinations include appropriate corrections for gamma self-absorption and neutron self-shielding as well as corresponding measurement uncertainties. The comparison of the NPP Monte Carlo calculations with the results of the foil measurements is done by using an individual generic MCNP model functioning as an interface and allowing the simulation of individual foil activation by predetermined neutron spectra. To summarize, the comparison between calculation and measurement serve as a sound validation of the Swiss NPP activation methodology by demonstrating a satisfying agreement between measurement and calculation. Finally, the validation offers a chance for further improvements of the existing NPP models by ensuing calibration and/or modelling optimizations for key components and structures.

Principles of Defense-in-depth philosophy applied in NPP engineering management

International Nuclear Information System (INIS)

Wu Guangwei

2011-01-01

Based on the Defense-in-depth Concept in nuclear and radiation safety, Defense-in-depth Concept for design management of Nuclear Power Plant (NPP) is developed in this paper to analyze the feasibility and importance of the application of the basic principle: Defense-in-depth concept in NPP systems performed during the design control of NPP. This paper focuses on the NPP engineering management process, and according to the analysis of such process, 5 principles of Defense-in-depth Concept applied in NPP design management are raised: (1) preventing the non-conformities of design via effective design quality management system; (2) discovering and correcting non-conformities of design quality in time via design checkup and design review meeting; (3) carrying out timely analysis and treatment against design non-conformities which have been transferred to construction phase; (4) Assessing and judging the severe non-conformities in construction phase, putting forward treatment opinions and remedies accordingly so as to avoid the existence of such non-conformities in physical construction of NPP; (5) Paying 'return-visit' and performing 'post-assessment' for NPP design to assess the designed functions and safety of NPP comprehensively. (author)

Planning and management support for NPP personnel SAT-based training programmes

International Nuclear Information System (INIS)

Ziakova, M.

1998-01-01

This paper deals with planning and management support for NPP personnel SAT based training programmes based on IAEA TC Project SLR/0/003 on upgrading NPP personnel training, with the aim of upgrading NPP safety and reliability of NPP operation and maintenance. The costs needed include both Slovak and IAEA sources. Five stages of the Project are defined: planning; organizing; motivating; implementation; control, review and accountability

Current technological trends in development of NPP systems

International Nuclear Information System (INIS)

Florescu, Gheorghe; Panaitescu, Valeriu

2010-01-01

The recent nuclear research issues look for new technologies and continuous progress in finding different and efficient solutions for sustained and upraising energy demand. The trend of increasing energy consumption and occurring of new and large consumers, especially from Asian countries, imposes finding of new means for clean, large scale and sustained energy production. NPPs availability was continuously monitored and improved; at the same time the safety of the nuclear energy production was under surveillance. The present development of the new technologies, the discoveries of new materials and development of efficient technological processes offer the opportunities for their appropriate implementation and use in the NPP system configurations and functioning/operation. The new technologies and scientific discoveries, and also the international cooperation, offer the opportunities to mitigate the actual barriers in order to cumulate and use advanced energy production, to find new energy sources and to build improved, reliable and safe power plants. The monitoring systems, intelligent sensors and SSCs, nanotechnologies and new/intelligent materials constitute the main ways for improvement of the NPP systems configuration and processes. The paper presents: - The state of the art in the level of the currently applied technologies for nuclear power systems development; - The actual technological limits that need to be over passed for improving the NPP systems ; - The main systems that need improvement and reconfiguration for development of currently operating NPPs as well as raising the operation efficiency, availability and total safety; - The actual energy production issues; - The key arguments in sustaining the R and D new NPP systems development; - Future trends in NPP development; - The limitations in industrial processes knowledge and use. Appropriate R and D in the field of NPP systems have specific characteristics that were considered in paper completion

Summary of NPP personnel training in Czech Republic

International Nuclear Information System (INIS)

1996-01-01

The preparation of NPP personnel is one of the most important phases of the process of construction, commissioning, operation and maintenance of nuclear power facilities. The objective is to improve personnel abilities so that they would be able to assure reliable, safe and economic operation of these facilities with high investment costs. It is the purpose of Nuclear Training Centre Brno (NTC Brno) to provide training and services which are responsive to the technological demands and emerging educational standards and criteria of the NPP and the nuclear industry. Fulfilling this purpose is a challenging task. The staff of NTC Brno, in a joint effort with NPP Dukovany and NPP Temelin, has responded to the challenge with comprehensive programs aimed at meeting customers needs. The programs are broadly based, yet flexible so that they can incorporate specific customer requirements

Morbidity pattern of non-cancer endocrine disease in ChNPP accident emergency workers (1992-2013 Clinical/ Epidemiological Registry data)

International Nuclear Information System (INIS)

Kamyins'kij, O.V.; Pronyin, O.V.; Afanas'jev, D.Je.

2014-01-01

Effects of ionizing radiation and other hazardous factors on endocrine system in the ChNPP AEW appeared upon 15-25 years. There was a significant (2-10-fold) and reliable (p < 0.01) increase of the incidence of the nodular goiter, autoimmune thyroiditis, obesity, type 2 diabetes mellitus. And there is a trend to further increase

SAT for NPP personnel training in Spain

International Nuclear Information System (INIS)

Gonzalez, M.

1995-01-01

The SAT process objectives as applied to Spanish NPPs are: Perform JTA for selected job positions at the NPPs; develop the associated training plans; develop training support media; prepare training instructors as teachers and as task analysts; develop a SAT database. A lesson-learned from the task assessments conducted at Spanish NPPs is that the final task list should be obtained with full participation of workers so that they feel the final training plan has been developed taking into account their own opinion and experience. The breakdown of the tasks into its elements and the concordant job performance measure was presented. The process of determining knowledge and skills associated with the task elements and the structure and use of the taxonomy codes (for component, system, and academic skills and knowledge) was shown and explained. Based on the Spanish experience, the average time devoted to analyze a complete task is 5.33 person-hours per task. This data has permitted training and plant management to allocate the NPP human resources to support the analysis phase of SAT (which can be very time-consuming)

Emergency preparedness at Barsebaeck NPP in Sweden

International Nuclear Information System (INIS)

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

Jose Cabrera NPP severe accident management activities

International Nuclear Information System (INIS)

Blanco, J.; Almeida, P.; Saiz, J.; Sastre, J.L.; Delgado, R.

1998-01-01

To prepare a common acting plan with respect to Severe Accident Management, in 1994 was founded the severe accident management ''ad-hoc'' working group from the Spanish Westinghouse PWR Nuclear Power Plant Owners Group. In this group actively collaborated the Jose Cabrera NPP Training Centre and the Department of Nuclear Engineering of UNION FENOSA. From this moment, Jose Cabrera NPP began the planning of its specific Severe Accident Management Program, which main point are Severe Accident Management Guidelines (SAMG). To elaborate this guidelines, the Spanish translation of Westinghouse Owners Group (WOG) Severe Accident Management Guidelines were considered the reference documents. The implementation of this Guidelines to Jose Cabrera NPP started on January 1997. Once the specific guidelines have been implemented to the plant, training activities for the personnel involved in severe accident issues will be developed. To prepare the training exercises MAAP4 code will be used, and with this intention, a specific Jose Cabrera NPP MAAP-GRAAPH screen has been developed. Furthermore, a wide selection of MAAP input files for the simulation of different scenarios and accidental events is available. (Author)

Transition cycle fuel management problems of NPP Krsko

International Nuclear Information System (INIS)

Petrovic, B.; Pevec, D.; Smuc, T.; Urli, N.

1989-01-01

Transition cycle fuel management problems are described and illustrated using results and experience attained during core reload design of NPP Krsko. Improved version of computer code package PSU-LEOPARD/Mcrac is successfully applied to NPP Krsko loading pattern design. (author)

On the NPP structural reliability

International Nuclear Information System (INIS)

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

Technical and economical problems of decommissioning nuclear power plants (NPP) in Russia

International Nuclear Information System (INIS)

Vaneev, M.

2001-01-01

The introduction per new century has brought to atomic Engineering many new problems. One of them, which has got a serious urgency, we now shall consider. It is a problem of decommissioning NPP in Russia. By 2014 all maintained nowadays NPP in Russian Federation will develop the regular service life. And all of them on idea should be removed from operation. But, as we understand, in today's difficult economic conditions, to it NPP the procedure of prolongation of service life will be applied, and where it is impossible by virtue of the various reasons, the procedure of translation NPP in nuclear - safe condition and in a mode of a long storage under supervision, before acceptance of the decision about a method and way of financing of a decommissioning will be applied. Possible the following variants will be: use platforms of the old NPP for construction new NPP, or using as burial place NPP. The variant of a decommissioning up to a condition 'green grass' is represented unprofitable because of its dearness. The similar decommissioning was carried out in Japan. Was removed from operation research reactor of a type WWR. The expenses for this method of a decommissioning considerably surpass expenses for a method of a burial place NPP basically because of high cost of dismantle and transportation in long-term storehouses of the 1 contour equipment. The most urgent problem of decommissioning NPP, which developed their regular service life - is financing this final stage of a exploitation cycle of the block. I shall remind, that the financing is carried out from uniform fund of decommissioning. The formation of this fund occurs by deduction 1.3 % of cost of the put electric power to the consumers by all maintained NPP of Russia. The expenditure of this fund is carried on time on some tens years. They are spent for 3 basic stages: preparation to decommissioning NPP, long endurance under supervision, dismantle and burial the NPP equipment. Nowadays on faculty NPP MPEI

Unit Commissioning of “Belene” NPP (Bulgaria)

International Nuclear Information System (INIS)

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

Constructive approaches to the space NPP designing

International Nuclear Information System (INIS)

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

Chernobyl NPP accident. Overcoming experience. Acquired lessons

International Nuclear Information System (INIS)

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

Sitting Safety Aspects of Second Romanian NPP

International Nuclear Information System (INIS)

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

Considerations related to Cernavoda NPP lifetime management

International Nuclear Information System (INIS)

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

Radiation protection in Bohunice NPP. Description of present status

International Nuclear Information System (INIS)

Dobis, L.

2001-01-01

Radiation protection (RP) at Bohunice NPP has reached the high international standard. The fact was approved by several independent international missions (OSART , WANO, WENRA, ...). A lot of modifications have been done in order to improve the standard of radiation protection. All the BSS requirements have been implemented into the plant regulations before the State Law No 290/1996 and 470/2000 came into the force. Internal audits are regularly performed at NPP in order to reveal potential deficiencies. In 2001 there were 4 such audits focused on quality assurance, software operation, LBB concept and limits and condition of safe operation. State Health Institute, the regulatory body in the radiation protection, performs the inspection at least ones a month. Good relationship with the inspectors of State Health Institute also contributes to the safe operation of the NPP. There were not any radiation accident. All anomalies or radiation events are investigated at a plant level. The results of root cause analysis and proposal of corrective actions are provided to IAEA and WANO databases for the distribution. The Radiation protection department of Bohunice NPP cooperates with the other Czech and Slovak NPPs. Regular meetings on radiation protection and lately also on emergency preparedness are organized. The cooperation is excellent. Occupational exposure is reviewed also with respect of ISOE data. Bohunice NPP (even with high dose burden caused by reconstruction of V1 NPP) can be found in the first half of world PWR speaking about the collective exposure per reactor. V2 NPP itself reaches the lowest collective exposure in the world. All doses are below the limits and kept ALARA. ALARA system has been established already in 1997 at Bohunice NPP and its results are obvious for example looking at dose results during the reconstruction works at V1 NPP. The operation of Bohunice NPP has negligible influence to its surroundings. The values of gas and liquid effluents move

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

Using the digital reactor control systems at NPP

International Nuclear Information System (INIS)

Schirl, G.; Hertel, J.

2006-01-01

A conception of application of the digital reactor control systems (RCS) at NPP is presented. The digital RCS architecture and safety ensuring are considered. The strategy and algorithm of the operating NPP equipping with the new digital RCS are given too [ru

A review of cancer mortality data of radiation workers of Nuclear Power Plant, Paks, Hungary, in the light the international radiation epidemiology study

International Nuclear Information System (INIS)

Turai, I.; Kerekes, A.; Otos, M.; Veress, K.

2007-01-01

Complete text of publication follows. Objective: To give a review of cancer mortality data among Hungarian radiation workers in nuclear industry in comparison with the results of the international nuclear workers' study prevailing the size of the study group of all former studies. Methods: Retrospective cohort study including 598,068 workers of 154 nuclear establishments in 15 countries (AUS, BEL, CAN, FIN, FRA, GER, HUN, JAP, LIT, ROK, SLK, SPA, SWE, UK, USA) coordinated by the International Agency for Research on Cancer (IARC, Lyon, France). The national study was extended for an additional 4-year period. Results: In the international study 407,391 persons in 13 years of average employment received 19.4 mSv mean cumulative dose, while in the national study 3322 radiation workers of Nuclear Power Plant (NPP) Paks, Hungary, in 14 years of follow-up period accumulated in average 5.13 mSv, only. There were 5233 cancer deaths registered in the international study, associated with an estimated ERR of 0.97 per Sv. Thus, 19.4 mSv recorded cumulative dose can explain 1 to 2% of cancer death cases. In radiation workers of NPP, Paks, during the period of 1985-1998 there were 40 cancer deaths observed against the expected 58.8 cases. In a further four year period (1999-2002) 29 cancer death cases were identified vs. the expected 65.5 cases. The SMR for the cancer death cases registered in recent and former radiation workers of NPP, Paks in the 18-year follow-up period is 56%. The SMR from all causes was even lower, 40% only. Conclusions: In the international study the mean accumulated radiation dose received by nuclear workers in 13 years is below of the recent annual dose limit (20 mSv/yr of the effective dose). The average value for the whole of radiation workers in 15 countries is almost 4-times higher of that registered in Hungary. The 'healthy worker effect' in the nuclear industry, and particularly in Hungary has been proven, once again. Nevertheless, the results

Radioactive wastes management of NPP

International Nuclear Information System (INIS)

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

NPP construction cost in Canada

International Nuclear Information System (INIS)

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%

Heat delivery from Bohunice NPP, Slovakia

International Nuclear Information System (INIS)

Paley, I.

1998-01-01

Experience with nuclear district heating in the Slovak Republic is reported. The heating system of the town of Trnava is supplied by the Bohunice NPP and conventional sources. Construction of the hot water heating system from the Bohunice NPP began in 1983. Commercial operation began on 10 December 1987. Heat delivery has gradually increased from 478 TJ in 1988, to 1,104 TJ in 1995. The heat cost is low, resulting in an increasing number of consumers. (author)

Ukrainian Nuclear Society International Conference 'Modernization of the NPP with VVER reactor' (abstracts)

International Nuclear Information System (INIS)

Bar'yakhtar, V.G.

1999-01-01

Abstracts of the papers presented at International conference of the Ukrainian Nuclear Society 'Modernization of the NPP with VVER reactor'. The following problems are considered: improving the NPP's safety and reliability; reactor modernization, the lifetime prolongation; increasing of the reactor operating characteristics; methods of capacity factor increasing: refueling control, maintenance control; technical and economical aspects of NPP modernization; modernization of the automated control system of the fuel process at the NPP's; technical features and methods for the continued radiation and technology control at the NPP's; training, increasing the staff qualification and NPP modernization

IAEA activities on NPP personnel training and qualification

International Nuclear Information System (INIS)

Kossilov, A.

1998-01-01

Activities of IAEA concerning training and qualification of NPP personnel consider the availability of sufficient number of competent personnel which is one of the most critical requirements for safe and reliable NPP operation and maintenance. Competence of personnel is essential for reducing the frequency of events connected to human errors and equipment failures. The IAEA Guidebook on Nuclear Power Plant Personnel Training and its Evaluation incorporates the experience gained worldwide and provides recommendations on the use of SAT being the best practice for attaining and maintaining the qualification and competence of NPP personnel and for quality assurance of training

NPP Krsko on-line low pressure containment tightness monitoring implementation

International Nuclear Information System (INIS)

Dudas, M.; Basic, I.

2004-01-01

Containment Integrated Leak Rate Test (CILRT) 1999 in NPP Krsko was completely performed following regulation of 10CFR50 Appendix J Option A and ANSI/ANS 56.8-1987 at a design pressure (3.15 kp/cm2). In 2001 NPP Krsko proposed to Slovenian Nuclear Safety Administration (SNSA) the Technical Specification (TS) and Updated Safety Analysis Report (USAR) changes that describe implementation of new test intervals for Type A, B and C tests according to 10CFR50, Appendix J, Option B. After the positive final independent review of proposed changes by Authorized Institution, NPP Krsko received the License Amendment requiring from NPP Krsko to define technical solution for surveillance of containment tightness between two 10-years CILRT. This paper intends to discuss proposed methods by NPP Krsko, test equipment, performed measurements in 2004, associated analyses and evaluation.(author)

Studies for improvement of WWER-440 neutron fluence determination

International Nuclear Information System (INIS)

Ilieva, Kr.; Belousov, S.; Apostolov, T.

2001-01-01

For assessment of radiation embrittlement and prediction of reactor vessel lifetime with reasonable conservatism a 'best estimated' neutron fluence is necessary. New studies purposed to improve the fluence determination are presented: 1) study on the reliability of multigroup presentation of the neutron cross sections, and 2) impact of negative gradient of reactor power in the periphery assemblies on the neutron fluence evaluation. The results of these studies are base for improvement of neutron fluence determination methodology applied by the INRNE, BAS at Kozloduy NPP. (author)

Spent fuel pool risk analysis for the Dukovany NPP

Energy Technology Data Exchange (ETDEWEB)

Hust' ak, S.; Jaros, M.; Kubicek, J. [UJV Rez, a.s., Husinec-Rez (Czech Republic)

2013-07-01

UJV Rez, a.s. maintains a Living Probabilistic Safety Assessment (Living PSA) program for Dukovany Nuclear Power Plant (NPP) in the Czech Republic. This project has been established as a framework for activities related to risk assessment and to support for risk-informed decision making at this plant. The most extensively used PSA application at Dukovany NPP is risk monitoring of instantaneous (point-in-time) risk during plant operation, especially for the purpose of configuration risk management during plant scheduled outages to avoid risk significant configurations. The scope of PSA for Dukovany NPP includes also determination of a risk contribution from spent fuel pool (SFP) operation to provide recommendations for the prevention and mitigation of SFP accidents and to be applicable for configuration risk management. This paper describes the analysis of internal initiating events (IEs) in PSA for Dukovany NPP, which can contribute to the risk from SFP operation. The analysis of those IEs was done more thoroughly in the PSA for Dukovany NPP in order to be used in instantaneous risk monitoring. (orig.)

Current status of Chernobyl NPP decommissioning

International Nuclear Information System (INIS)

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

Meeting up-to-date safety requirements in the Russian NPP projects

International Nuclear Information System (INIS)

Tepkyan, G. O.; Yashkin, A. V.

2014-01-01

Safety features in Russian NPP designs are implemented by the combination of active and passive safety systems • Russian NPP designs are in compliance with up-to-date international and European safety requirements and refer to Generation III+ • Russian state-of-the-art designs have already implemented some design solutions, which take into account “post-Fukushima” requirements. Russian NPP design principles have been approved during the European discussions in spring 2012, including the IAEA extraordinary session addressed to Fukushima NPP accident

Results and development prospects for the Cernavoda NPP

International Nuclear Information System (INIS)

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

The analysis of financial risk management application for NPP project in Indonesia

International Nuclear Information System (INIS)

Imam Bastori; Moch Djoko Birmano

2012-01-01

NPP Project is one of full dynamic, risky and challenging business. Application of financial risk management t in Nuclear Power Plant (NPP) project becomes one alternative to be considered carefully. This paper explains an analysis to make a decision in the risk management application so that it can be applied in the NPP's construction in Indonesia. As case study, is NPP of conventional PWR type of class 1150 MWe. To calculate the economics and financing of NPP is used Spreadsheet INOVASI, further the decision of financial risk management were analyzed using a Model of Cash Flow Adjustment, which developed by Richard Fairchild. The analysis showed that the Method of Cash Flow Adjustment developed by Richard Fairchild is better than the method of NPV Adjustment on a NPP project, because it have included the aspects of financial risk management. NPP project can only be executed if the NPV 2 0 and decision to execute the financial risk management should be based on NPVrm > NPV. The application of financial risk management in NPP project is not needed if an insurance premium more expensive than all costs of financial distress, unless the insurance company can give discount of at least 20%. (author)

Near Regional and Site Investigations of the Temelin NPP Site

International Nuclear Information System (INIS)

Prachar, Ivan; Vacek, Jiri; Heralecky, Pavel

2011-01-01

The Temelin NPP is worldwide through heated discussion with nuclear energetic opposition. In addition this discussion goes beyond a border of the Czech Republic. On the other side, results of several international supervisions shown that Temelin NPP is fully comparable with the safest nuclear power plants in the world regarding its technical design and safety functions. This presentation deals with the near regional and site investigations of the Temelin NPP Site. It must be noted that although the Temelin site is situated in the area with low seismicity, item of seismicity is a basic argument against Temelin NPP and therefore a detail seismic hazard assessment was performed

Risk management solutions for Cernavoda Unit #2 NPP completion

International Nuclear Information System (INIS)

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)

The Effect of NPP's Stack Height to Radiation Dose

International Nuclear Information System (INIS)

Pandi, Liliana Yetta; Rohman, Budi

2003-01-01

The purpose of dose calculation for accidents is to analyze the capability of NPP to maintain the safety of public and workers in case an accident occurs on the Plant in a site. This paper calculates the Loss of Coolant Accident in PWR plant. The calculation results shows that no risks of serious radiation exposure are given to the neighboring public even if such a large accident occurred, and the effect of stack height can be predicted by analysis of the calculation results. The whole dose is calculated for some location (100 m, 300 m, 500 m, 700 m, 900 m, 1500 m, and 2000 m) with three difference stack height i.e. 0 m, 40 m and 100 m. The result of the whole dose calculation is under permitted criteria for whole dose : 0.25 Sv and thyroid dose : 3.0 Sv. The calculation of radiation dose in this paper use EEDCDQ code

Attitude of the population and students to further construction of NPP

International Nuclear Information System (INIS)

Machacek, Ladislav

1993-01-01

This presentation shows the public opinion poll young people on NPP in the Slovakia i.e. comparative research results on Attitude of the Slovak population (1991 - a sample 1104 respondents, and Slovak students 1992 - a sample 291 respondents) to the nuclear energy and NPP; Source of information about NE and NPP, motivation of apprehensions of young people concerning NE; what meaning for young people have the arguments FOR and AGAINST construction of NPP in Slovakia; whom students from Bratislava believe during discussions about NE

New trends in designing NPP control boards

International Nuclear Information System (INIS)

Kondrat'ev, V.V.

1981-01-01

A short analytical summary of the latest developments and future trends in designing NPP control boards is given. The designs of the Westinghause and the Hynkley-Point NPP control boards are described in detail. The essence of the advanced control board concept consists , firstly, in expanded use of computer-controlled displays for the sake of reducing the content of unimportant information presented to an operator, and, secondary, in better account of human possibilities to convert the NPP operation information into a more suitable form. An enlarged use of the direct digital reactor control utilizing microprocessors is expected. Besides, the employment of full-scale control board mock-ups and information desks as well as testing newly-developed control boards at computer reactor simulators are concluded to be used at all-growing rate [ru

Some problems of NPP construction base improvement

International Nuclear Information System (INIS)

Movchan, S.V.

1984-01-01

NPP construction bases are characterized by high cost of construction and large area. Duration of base construction makes up 3-4 years, labour contents for their erection constitute 600-900 thousand man-days. Delays in organizing functional base services essentially decelerate construction rates of the main NPP buildings. Maximum joining of separate buildings by their functional assignment and structural peculiarities, wide application of container buildings, partial utilization of permanent buildings of production centre for construction needs; transition to new organizational form of construction based on industrial production of buildings; production of volumetric structural-technological cells with mounted equipment manufactured at specialized plants, mounting NPP components with stock produced cells, consideration of the problem of large power centre creation are necessary for reduction of construction centres, area reduction of cost and duration of their construction

Qinshan NPP large break LOCA safety analysis

International Nuclear Information System (INIS)

Shi Guobao; Tang Jiahuan; Zhou Quanfu; Wang Yangding

1997-01-01

Qinshan NPP is the first nuclear power plant in the mainland of China, a 300 MW(e) two-loop PWR. Large break LOCA is the design-basis accident of Qinshan NPP. Based on available computer codes, the own analysis method which complies with Appendix k of 10 CFR 50 has been established. The RELAP4/MOD7 code is employed for the calculations of blowdown, refill and reflood phase of the RCS respectively. The CONTEMPT-LT/028 code is used for the containment pressure and temperature analysis. The temperature transient in the hot rod is calculated using the FRAP-6T code. Conservative initial and functional assumptions were adopted during Qinshan NPP large break LOCA analysis. The results of the analysis show the applicable acceptance criteria for the loss-of-coolant accident are met

Construction of large-thickness sand cushions for NPP foundations

International Nuclear Information System (INIS)

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

Decommissioning of units 1 - 4 at Kozloduy nuclear power plant in Bulgaria

International Nuclear Information System (INIS)

Dishkova, Denitsa

2014-01-01

Nuclear safety and security are absolute priorities for the European Union countries and this applies not only to nuclear power plants in operation but also to decommissioning. In terms of my technical background and my working experience in the field of licensing and environmental impact assessment during the decommissioning of Units 1 to 4 at Kozloduy Nuclear Power Plant (KNPP) in Bulgaria, I decided to present the strategy for decommissioning of Units 1 to 4 at KNPP which was selected and followed to achieve safe and effective decommissioning process. The selected strategy in each case must meet the legislative framework, to ensure safe management of spent fuel and radioactive waste, to provide adequate funding and to lead to positive socio-economic impact. The activities during the decommissioning generate large volume of waste. In order to minimize their costs and environmental impact it should be given a serious consideration to the choice, the development and the implementation of the most adequate process for treatment and the most appropriate measurement techniques. The licensing process of the decommissioning activities is extremely important and need to cope with all safety concerns and ensure optimal waste management. (authors)

Irradiation Embrittlement Monitoring Programs of RPV's in the Slovak Republic NPP's

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Procedure for Application of Software Reliability Growth Models to NPP PSA

International Nuclear Information System (INIS)

Son, Han Seong; Kang, Hyun Gook; Chang, Seung Cheol

2009-01-01

As the use of software increases at nuclear power plants (NPPs), the necessity for including software reliability and/or safety into the NPP Probabilistic Safety Assessment (PSA) rises. This work proposes an application procedure of software reliability growth models (RGMs), which are most widely used to quantify software reliability, to NPP PSA. Through the proposed procedure, it can be determined if a software reliability growth model can be applied to the NPP PSA before its real application. The procedure proposed in this work is expected to be very helpful for incorporating software into NPP PSA

National Report of Bulgaria [National practice at WWER sites

International Nuclear Information System (INIS)

2017-01-01

Kozloduy NPP Plc. is located in north-western Bulgaria at about 3 km from the Danube River, which serves as a source of cooling water and a receiver of liquid released from the plant (Fig. I.3). Six nuclear units were constructed on Kozloduy NPP site. Units 1 to 4 are WWER-440/230 reactors and Units 5 and 6 are WWER-1000/320 reactors. Units 1 to 4 were commissioned from 1974 to 1982. Units 5 and 6 were commissioned in 1987 and 1991, respectively. On December 31, 2002 Units 1 and 2 were shut down and on December 31, 2006 Units 3 and 4 were shut down as well. Spent Nuclear Fuel was removed from the pre-reactor pools and the reactors have been prepared for decommissioning. Units 1 and 2 (in 2008) and Units 3 and 4 (in 2012) were declared as Decommissioning Facilities by Ministerial Decree and outsourced from the plant. A separate complex consisting of facilities for treatment and conditioning of wet and dry solid radioactive waste (RAW) and a facility for storage of conditioned RAW was commissioned in 2001 on site. The complex is situated next to the Auxiliary Building of Units 5 and 6. In 2005 this complex was outsourced as a separate enterprise called the Specialized Enterprise for Radioactive Waste (SE RAW). There are two Spent Fuel Storage Facilities (SFSF) for wet and dry storage located on the plant site as well.

Ignalina NPP Safety Analysis: Models and Results

International Nuclear Information System (INIS)

Uspuras, E.

1999-01-01

Research directions, linked to safety assessment of the Ignalina NPP, of the scientific safety analysis group are presented: Thermal-hydraulic analysis of accidents and operational transients; Thermal-hydraulic assessment of Ignalina NPP Accident Localization System and other compartments; Structural analysis of plant components, piping and other parts of Main Circulation Circuit; Assessment of RBMK-1500 reactor core and other. Models and main works carried out last year are described. (author)

Radionuclide localization at the Chernobyl' NPP territory

International Nuclear Information System (INIS)

Mamaev, L.A.; Galkin, G.A.; Khrabrov, S.L.; Polyakov, A.S.; Mikhejkin, S.V.

1989-01-01

Experience is generalized of using different dust suppression (DS) compounds during Chernobyl' accident consequence elimination. Polymer DS compounds were used at the NPP operating site; the compounds kept dust-like radioactive contaminations during 1-2 months. DS at the country was realized by means of the compound on base of latex. The conclusion is made that the DS measures improved radiation situation in the NPP zone. 7 refs

Preparation of Long Term Operation in Dukovany NPP, Czech Republic

International Nuclear Information System (INIS)

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)

Low-water considerations for NPP sites

International Nuclear Information System (INIS)

Jensen, J.; Frank, T.; Wahl, T.

2009-01-01

In the frame of reactor safety considerations flood protection and the evaluation of low-water events are safety relevant issues. Therefore low-water statistics were performed for the coastal region Cuxhaven and the Elbe river estuary. The consideration of the longitudinal profile of water levels during low-tide in connection with surface water effects, morphodynamic changes of the river and anthropogenic modifications is of importance for conclusions concerning the NPP sites in some distance of the reference tide gauge. The authors performed a statistical low-tide analysis for the NPP sites Brunsbuettel and Brokdorf.

NPP Krsko natural circulation performance evaluation

International Nuclear Information System (INIS)

Segon, Velimir; Bajs, Tomislav; Frogheri, Monica

1999-01-01

The present document deals with an evaluation of the natural circulation performance of the Krsko nuclear power plant. Two calculation have been performed using the NPP Krsko nodalization (both similar to the LOBI A2-77 natural circulation experiment) - the first with the present steam generators at NPP Krsko (Westinghouse, 18% plugged), the second with the future steam generators (Siemens, 0% plugged). The results were evaluated using the natural circulation flow map derived in /1/, and were compared to evaluate the influence of the new steam generators on the natural circulation performance. (author)

Model of nanodegradation processes in electronic equipment of NPP Kozloduy

International Nuclear Information System (INIS)

J. Boucher Blvd, 1164 Sofia, BG (Bulgaria))" data-affiliation=" (Sofia University, Faculty of Physics, 5 J. Boucher Blvd, 1164 Sofia, BG (Bulgaria))" >Popov, A

2014-01-01

From the complex studies it was proof that the main degradation processes in the three groups of elements for the extended period of time are slow; do not lead to a hopping change in basic parameters and to catastrophic failures. This gives grounds to suggest a common diffusion model, which is limited to the following: -in electronic components containing a p-n junction, is performed diffusion of residual cooper atoms, that are accumulated in the area of a spatial charge under the influence of the electric field and the local temperature, creating micro-shunt regions; -in the contactor systems whose contact surfaces are made of metal alloys under the influence of increased temperature starts decomposition of a homogeneous alloy. Conditions are created for diffusion of individual atoms to the surface, micro-phases of homogeneous atoms are formed and modify the contact resistances; -in the course of time in the insulating materials are changed the mechanisms of polarization, double bonds and dipoles are disrupting, leading to the release of carbon atoms. The latter diffuse at elevated temperatures and form conductive cords, which amend the dielectric losses and the specific resistance of the materials

Nuclear safety, international cooperation and perspectives of Bulgaria; Yadernaya bezopasnost`, mezhdunarodnoe sotrudnichestvo i perspektivy dlya Bolgarii

Energy Technology Data Exchange (ETDEWEB)

Yanev, Y

1996-12-31

The use of atomic energy in Bulgaria is under regulation since 1985 by the Atomic Energy Law. The main points of the Law are discussed and some deficiencies are pointed out. The ratification of the Vienna and Paris conventions has contributed to updating the legislation. The participation in international projects related to the use of atomic energy and nuclear safety in particular is revised. Future development of nuclear energy in Bulgaria depends mainly on successful reconstruction, modernization and safety enhancement of the Kozloduy NPP and development of a national grid of technical and consultant firms.

Training human resource for NPP in Vietnam

International Nuclear Information System (INIS)

Nguyen, Trung Tinh; Dam, Xuan Hiep

2008-01-01

Vietnam will establish the first NPP in the near future. With us the first important thing is the human resource, but now there is no university in Vietnam training nuclear engineers. In EPU (Electric Power University), now we are preparing for training nuclear engineers. In this paper, we review the nuclear man power and the way to train the high quality human resource for NPP and for other nuclear application in Vietnam. (author)

Russian normative approach to the question of management of NPP life time

International Nuclear Information System (INIS)

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)

Observation and modeling of NPP for Pinus elliottii plantation in subtropical China

Institute of Scientific and Technical Information of China (English)

2008-01-01

Based on the stem analysis of 59 individuals of Pinus elliottii in combination with tree biomass models, we calculated annual biomass increment of forest plots at Qianyanzhou Ecological Station, Chinese Academy of Sciences in subtropical China. In addition, canopy layer and community NPP were calcu- lated based on 12 years’ litter fall data. NPP of the 21-year-old forest was estimated by using the BIOME BGC model; and both measured NPP and estimated NPP were compared with flux data. Community biomass was 10574 g·m-2; its distribution patterns in tree layer, shrub layer, herbaceous layer, tree root, herbaceous and shrub roots and fine roots were 7542, 480, 239, 1810, 230, 274 and 239 g·m-2, respectively. From 1999 to 2004, the average annual growth rate and litter fall were 741 g·m-2·a-1 (381.31 gC·m-2·a-1) and 849 g·m?2·a?1 (463 gC·m-2·a-1), respectively. There was a significant corre- lation between annual litter fall and annual biomass increment; and the litter fall was 1.19 times the biomass increment of living trees. From 1985 to 2005, average NPP and GPP values based on BGC modeling were 630.88 (343.31 - 906.42 gC·m-2·a-1) and 1 800 gC·m-2·a-1 (1351.62 - 2318.26 gC·m-2·a-1). Regression analysis showed a linear relationship (R2=0.48) between the measured and simulated tree layer NPP values. NPP accounted for 30.2% (25.6%-32.9%) of GPP, while NEP ac- counted for 57.5% (48.1%-66.5%) of tree-layer NPP and 41.74% (37%-52%) of stand NPP. Soil respi- ration accounted for 77.0% of measured tree NPP and 55.9% of the measured stand NPP. NEE based on eddy covariance method was 12.97% higher than the observed NEP.

Actual status of project Mochovce NPP units 3 and 4 completion

International Nuclear Information System (INIS)

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.

Review of accident analyses performed at Mochovce NPP

International Nuclear Information System (INIS)

Siko, D.

2000-01-01

In this paper the review of accident analysis performed in NPP Mochovce V-1 is presented. The scope of these safety measures was defined and development in the T SSM for NPP Mochovce Nuclear Safety Improvements Report' issued in July 1995. The main objectives of these safety measures were the followings: (a) to establish the criteria for selection and classification of accidental events, as well as defining the list of initiating events to be analysed. Accident classification to the individual groups must be performed in accordance with RG 1.70 and IAEA recommendations 'Guidelines for Accidental Analysis of WWER NPP' (IAEA-EBR-WWER-01) to select boundary cases to be calculated from the scope of initiating events; (b ) to elaborate the accident analysis methodology that also includes acceptance criteria for their result evaluation, initial and boundary conditions, assumption related with the application of the single failure criteria, requirements on the analysis quality, used computer codes, as well as NPP models and input data for the accident analysis; (c) to perform the accident analysis for the Pre-operational Safety Report (POSAR); (d) to provide a synthetic report addressing the validity range of codes models and correlations, the assessment against relevant tests results, the evidence of the user qualification, the modernisation and nodding scheme for the plant and the justification of used computer codes. Analyses results showed that all acceptance criteria were met with satisfactory margin and design of the NPP Mochovce is accurate. (author)

The Bohunice NPP V-1 units nuclear safety upgrading

International Nuclear Information System (INIS)

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)

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

International Nuclear Information System (INIS)

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

New appraisement of siting for a NPP on Mures river

International Nuclear Information System (INIS)

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)

Revision of Krsko NPP Quality Assurance Plan

International Nuclear Information System (INIS)

Biscan, R.; Fifnja, I.; Kavsek, D.

2012-01-01

International standards from nuclear power plant operation area are being frequently upgraded and revised in accordance with the continuous improvement philosophy. This philosophy applies also to the area of Quality Assurance, which has also undergone significant improvement since the early 1950s. Besides just nuclear industry, there are also other international quality standards that are being continuously developed and revised, bringing needs for upgrades also in the nuclear application. Since the beginning of Krsko NPP construction, the overall Quality Assurance program and its applicable procedures were in place to assure that all planned and systematic actions necessary to provide adequate confidence that an item or service will satisfy given requirements to quality, are in place. The overall requirements for quality as one of the major objectives for Krsko NPP operation are also set forth in the Updated Safety Analyses Report, the document that serves as a base for operating license. During more than 30 years of Krsko NPP operation, the quality requirements and related documents were revised and upgraded in several attempts. The latest revision 6 of QD-1, Quality Assurance Plan was issued during the year 2011. The bases for the revision were: Changes of the Slovenian regulatory requirements (ZVISJV, JV5, JV9?), Changes of Krsko NPP licensing documents (USAR section 13?), SNSA inspection requirements, Changes of international standards (IAEA, ISO?), Conclusions of first PSR, Implementation of ISO standards in Krsko NPP (ISO14001, ISO17025), Changes of plant procedures, etc. One of the most obvious changes was the enlargement of the QA Plan scope to cover interdisciplinary areas defined in the plant management program MD-1, such as Safety culture, Self-assessment, Human performance, Industrial Safety etc. The attachment of the QA Plan defining relationships between certain standards was also updated to provide matrix for better correlation of requirements of

The final report of the state scientific programme 'Ignalina NPP and the Environment'

International Nuclear Information System (INIS)

1998-03-01

The final report of the State Scientific Programme 'Ignalina NPP and the Environment' includes the generalised research material on the after effects of Ignalina NPP operation upon natural environment and social processes. The data on changes of thermal state and water balance of lake Drukshiai; the effect of permanent thermal and chemical pollution on the water chemical composition and hydrochemical regime; the geochemical - contaminated state; the condition, dynamics and changes of hydrobiont communities in lake Drukshiai; the bio indication of ecological effects; the toxic and genotoxic influence of Ignalina NPP waste waters and lake Drukshiai water as well as bottom sediments; the state and dynamic of landscape ecosystem components of Ignalina NPP region; the radionuclides in Ignalina NPP area, the medical and biological studies in the Ignalina NPP influence population zone; the impact of Ignalina NPP on social territorial processes in the region are presented. Radioecological and ecotoxilogical state of Ignalina NPP region and lake Drukshiai is estimated as well as changes in lake Drukshiai and Ignalina NPP surrounding area ecosystems under the combine anthropogenic of the plant influence are elucidated. The final report contains the results of final report by the executors of the tasks and themes of the Programme which have been obtained since the beginning of the implementation of the Programme as well as generalising conclusions and recommendations. (author)

Nuclear fuel operation at Balakovo NPP

International Nuclear Information System (INIS)

Morozov, A.

2015-01-01

The presentation addressed the positive experience of the TVS-2M assemblies implementation at Balakovo NPP in 18 month fuel cycles, at uprated power (104%) and the usage of the axial profiled Gd-rods in order to minimize the power peaking factors and linear heat rate in the upper part in some of the fuel rods. The results of the test operation of fuel rods with different claddings, made by E110M, E125 and E635M alloys at Balakovo NPP were also provided. The recently observed problem with the “white crust” on the cladding surfaces was also discussed

Lifetime evaluation of Bohunice NPP components

International Nuclear Information System (INIS)

Kupca, L.

2001-01-01

The paper discuss some aspects of the main primary components lifetime evaluation program in Bohunice NPP which is performed by Nuclear Power Plant Research Institute (NPPRI) Trnava in cooperation with Bohunice and other organizations involved. Facts presented here are based on the NPPRI research report which is regularly issued after each reactor fuel campaign under conditions of project resulted from the contract between NPPRI and Bohunice NPP. For the calculations, there has been used some computer codes adapted (or made) by NPPRI and the results are just the conclusive and very brief, presented here in Tables (Figures). (authors)

Safety upgrading program in NPP Mochovce

International Nuclear Information System (INIS)

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)

Experience on implementing risk-oriented in-service inspection at NPP in USA

International Nuclear Information System (INIS)

Grebenyuk, Yu.P.; Zaritskij, N.S.; Kovyrshin, V.G.; Kostenko, S.P.

2001-01-01

Experience of implementing risk-oriented in-service inspection (RIISI) of pipelines at the US NPP analyzed. RIISI processes according to the methodologies developed by Westinghouse and EPRI are described and compared. The information is addressed concerning practical matters of RIISI implementing at NPP Beaver Valley and Arkansas Nuclear One. Regulatory activity of the US NRC while implementing NRC at the US NPP. It is shown that using RIISI at NPP is aimed at improvement of examination efficiency, decreasing costs and occupational dose loads while inspecting pipelines

Radiation dose optimization in the decommissioning plan for Loviisa NPP

Energy Technology Data Exchange (ETDEWEB)

Holmberg, R.; Eurajoki, T. [Nuclear Power Engineering (Finland)

1995-03-01

Finnish rules for nuclear power require a detailed decommissioning plan to be made and kept up to date already during plant operation. The main reasons for this {open_quotes}premature{close_quotes} plan, is, firstly, the need to demonstrate the feasibility of decommissioning, and, secondly, to make realistic cost estimates in order to fund money for this future operation. The decomissioning for Lovissa Nuclear Power Plant (NPP) (2{times}445 MW, PWR) was issued in 1987. It must be updated about every five years. One important aspect of the plant is an estimate of radiation doses to the decomissioning workers. The doses were recently re-estimated because of a need to decrease the total collective dose estimate in the original plan, 23 manSv. In the update, the dose was reduced by one-third. Part of the reduction was due to changes in the protection and procedures, in which ALARA considerations were taken into account, and partly because of re-estimation of the doses.

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 4D. Paks NPP: Analysis and testing. Working material

International Nuclear Information System (INIS)

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 seismic margin assessment and earthquake experience based methods for WWER-440/213 type NPPs; structural analysis and site inspection for site requalification; structural response of Paks NPP reactor building; analysis and testing of model worm type tanks on shaking table; vibration test of a worm tank model; evaluation of potential hazard for operating WWER control rods under seismic excitation

Evaluation of the atmospheric transport modeling tools used at the Ignalina NPP

International Nuclear Information System (INIS)

Jasiulionis, R.

2004-01-01

The atmospheric transport modeling system at the Ignalina NPP is part of the radionuclide monitoring system and is designed to help associate radionuclide network signals with possible source regions. The evaluation of the Atmospheric Transport Modeling Tools Used at the Ignalina NPP was based on results published in last years. The model based on semi-empirical formulae of turbulent diffusion in the air and local meteorological data were used for calculation of concentration of radionuclides emitted through the Ignalina NPP stack. Meteorological data (wind velocity and direction as well as temperature at a height of 2 and 30 meters) were obtained from the meteorological station of the Ignalina NPP at Visaginas. Using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, trajectories of air masses transport to the Ignalina NPP region (56.55 N, 26.57 E) during 95 hours at heights of 100, 500 and 1000 m were calculated. The dispersion in the ground-level air of emissions through the Ignalina NPP stack can also be calculated using the HYSPLIT model. The data on the radionuclide activity concentrations in the air at the measurements site and results of calculation can used for the establishment of their field in the Ignalina NPP region. (author)

NPP Krsko Containment Response Following Main Steam Line Break

International Nuclear Information System (INIS)

Spalj, S.; Grgic, D.; Cavlina, N.

2000-01-01

This paper presents the calculation of thermohydraulic environmental parameters (pressure and temperature) inside containment of Krsko NPP after postulated Main Steam Line Break (MSLB) accident. This analysis was done as a part of the ambient parameters specification in the frame of the NPP Krsko Equipment Qualification (EQ) project. The RELAP5/mod2 computer code was used for the determination of MSLB mass and energy release and computer code GOTHIC was used to calculate pressure and temperature profiles inside NPP Krsko containment. The analysis was performed for spectrum of break sizes to account for possible steam superheating during accidents with smaller break sizes. (author)

Risk Assessments for Workers and the Population Following the Chernobyl Accident. Annex XI of Technical Volume 4

International Nuclear Information System (INIS)

2015-01-01

The doses received by emergency workers at the Fukushima Daiichi NPP were much lower than those of the Chernobyl emergency workers (referred to as ‘liquidators’) and there is no evidence of an increased risk for Chernobyl workers below an equivalent dose of 150 mGy, so the inferred risks are expected to be small. Nevertheless, it is useful to adopt a similar modelling approach. The main estimates of radiation risks for the cohort of Chernobyl emergency workers who received moderate doses are in good quantitative agreement with the results for atomic bomb survivors if the linear non-threshold (LNT) model is used. The minimum latency period for radiation related solid cancers in the Russian cohort was estimated as four years. No statistically significant relationship was found between the thyroid cancer incidence and external radiation for the Russian cohort of liquidators

Prospects for the NPP Krsko Radioactive Waste Management

International Nuclear Information System (INIS)

Knapp, A.; Levanat, I.; Saponja-Milutinovic, D.

2016-01-01

Croatia adopted Strategy of radioactive waste, used sources and spent fuel management in 2014, and its Law on radiological and nuclear safety was accordingly modified in 2015. The Strategy foresees (though with some flexibility) and the Law declares decidedly that Croatia will establish a Center for radioactive waste management, in which all necessary facilities for storage and subsequent disposal of the Croatian share of the NPP Krsko radioactive waste and spent fuel will be developed. However, Slovenia and Croatia have recently agreed that a long-term dry storage for spent fuel will be established on the NPP premises by the year 2019. Therefore, only the issues of low and intermediate level waste (LILW) are addressed here. In Slovenia, the LILW repository site Vrbina in Krsko municipality was officially confirmed in 2009. Based on the 2013 investment program for a silo-type disposal facility, preparation of the repository project documentation was contracted with a national engineering company in 2014. Slovenian repository concept has been developed in two variants: one for the Slovenian LILW only, and the other intended to accept the Croatian share of LILW from the NPP as well. In the summer of 2015 Slovenia for the first time made an official offer to Croatia to use Vrbina repository for that purpose. However, the Croatian Strategy also does not preclude the option of management of all LILW from the NPP in Croatia. Therefore, present plan of activities for the third revision of the NPP radioactive waste and spent fuel management program outlines hypothetically symmetrical LILW management options: all in Slovenia, or all in Croatia, or one half in each country. So, what shall it be? This paper discusses the prospects for each of the three above mentioned options. The major problem of the Slovenian disposal plan is its high cost, mostly due to high compensations to the local community, which will be hard to finance without Croatian participation. The simplest

Assessment of NPP VIIRS Ocean Color Data Products: Hope and Risk

Science.gov (United States)

Turpie, Kevin R.; Meister, Gerhard; Eplee, Gene; Barnes, Robert A.; Franz, Bryan; Patt, Frederick S.; Robinson, Wayne d.; McClain, Charles R.

2010-01-01

For several years, the NASA/Goddard Space Flight Center (GSFC) NPP VIIRS Ocean Science Team (VOST) provided substantial scientific input to the NPP project regarding the use of Visible Infrared Imaging Radiometer Suite (VIIRS) to create science quality ocean color data products. This work has culminated into an assessment of the NPP project and the VIIRS instrument's capability to produce science quality Ocean Color data products. The VOST concluded that many characteristics were similar to earlier instruments, including SeaWiFS or MODIS Aqua. Though instrument performance and calibration risks do exist, it was concluded that programmatic and algorithm issues dominate concerns. Keywords: NPP, VIIRS, Ocean Color, satellite remote sensing, climate data record.

The Ignalina NPP and Y2K Problem

International Nuclear Information System (INIS)

Medeliene, D.

2000-01-01

Work on preparing the hardware and software of the Ignalina NPP for the year 2000 was started in December 1998. First of all, a Y2K project team was formed comprising 29 specialists. Some of these are the most experienced computer specialist, others co-ordinate work on the Y2K problem at the divisions of the NPP using computers or microprocessors. The project head was appointed and the schedule of work confirmed. In accordance with the schedule, the work was divided into twelve stages. The results showed that the preparations were adequate. On the New Year night the specialists of the Ignalina NPP Emergency Operation Centre worked together with the managers of the plant. Relation with other Lithuanian and international organisations was established. No any Y2K related event happened

The local impacts of Borssele NPP closing down

International Nuclear Information System (INIS)

Mandos, J.L.

2000-01-01

The municipal council of Borsele considers that the use of nuclear energy is a question of national policy, but considers itself responsible for town and country planning, safety and employment. The two latter aspects are especially significant if plans for shutdown are concerned. Confidence in safety of the NPP in Borsele has increased in recent years due to transparent information policy of the power plant itself as well as the local government and most of the employees living in the area. If considering the circumstances under which the decision about the closure of NPP one could sees this is a purely political decision. The local government will continue the close cooperation with the National government and the Parliament in solving the problem of employment and social impact of NPP shutdown

Technical innovations at NPP Dukovany - for safe and efficient operation

International Nuclear Information System (INIS)

Sabata, M.; Vasa, I.

2000-01-01

Inherent features of the NPP Dukovany design provide a significant confidence in its nuclear safety assurance; among these features should be emphasised the reactor core stability and its control and protection system capability to hold the reactor in safe state following scram or accident conditions. Nevertheless, NPP Dukovany was designed in the early seventies, and current requirements for nuclear safety assurance are more strict and/or specific as a result of the technical development and lessons learned from nuclear accidents. The paper compares the safety design base established at the time of NPP Dukovany project implementation and the current reference design base. The paper also presents procedures applied to implement technical and operational measures which are introduced to fulfil the current basic safety criteria. The scope of such measures applied at NPP Dukovany is compared with that of EU countries introduced for the same reason - to meet the updated safety related requirements. Examples of some innovations already implemented or under implementation give an idea how NPP Dukovany proceeds in reaching the goal of harmonising its safety with the requirements to be met before the Czech Republic becomes a member country of the European Union. (author)

Radiological impact on the surrounding area of Cernavoda NPP operation

International Nuclear Information System (INIS)

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

Current status of NPP generation IV

International Nuclear Information System (INIS)

Yohanes Dwi Anggoro; Dharu Dewi; Nurlaila; Arief Tris Yuliyanto

2013-01-01

Today development of nuclear technology has reached the stage of research and development of Generation IV nuclear power plants (advanced reactor systems) which is an innovative development from the previous generation of nuclear power plants. There are six types of power generation IV reactors, namely: Very High Temperature Reactor (VHTR), Sodium-cooled Fast Reactor (SFR), Gas-cooled Fast Reactor (GFR), Lead-cooled Fast Reactor (LFR), Molten Salt Reactor (MSR), and Super Critical Water-cooled Reactor (SCWR). The purpose of this study is to know the development of Generation IV nuclear power plants that have been done by the thirteen countries that are members of the Gen IV International Forum (GIF). The method used is review study and refers to various studies related to the current status of research and development of generation IV nuclear power. The result of this study showed that the systems and technology on Generation IV nuclear power plants offer significant advances in sustainability, safety and reliability, economics, and proliferation resistance and physical protection. In addition, based on the research and development experience is estimated that: SFR can be used optimally in 2015, VHTR in 2020, while NPP types GFR, LFR, MSR, and SCWR in 2025. Utilization of NPP generation IV said to be optimal if fulfill the goal of NPP generation IV, such as: capable to generate energy sustainability and promote long-term availability of nuclear fuel, minimize nuclear waste and reduce the long term stewardship burden, has an advantage in the field of safety and reliability compared to the previous generation of NPP and VHTR technology have a good prospects in Indonesia. (author)

A reliability evaluation method for NPP safety DCS application software

International Nuclear Information System (INIS)

Li Yunjian; Zhang Lei; Liu Yuan

2014-01-01

In the field of nuclear power plant (NPP) digital i and c application, reliability evaluation for safety DCS application software is a key obstacle to be removed. In order to quantitatively evaluate reliability of NPP safety DCS application software, this paper propose a reliability evaluating method based on software development life cycle every stage's v and v defects density characteristics, by which the operating reliability level of the software can be predicted before its delivery, and helps to improve the reliability of NPP safety important software. (authors)

Knowledge management in the NPP domain

International Nuclear Information System (INIS)

Nilsen, Svein; Bisio, Rossella; Ludvigsen, Jan Tore

2004-03-01

This report gives an outlook on Knowledge Management (KM) activities within NPP related establishments as of today. There may be less activity in the NPP world as compared to many other industrial sectors. Still there is an awakening within the NPP industry demanding that KM should be attended to at a larger scale. The most notable reason for this is maybe an imminent increase in the number of people going into retirement. The types of establishments involved cover the major kinds such as utilities, research institutes and worldwide nuclear organizations. The report sums up a few of those efforts that are presently being implemented. Moreover the report looks at general advancements within the field of knowledge management. Simply stated the endeavours belong to either one of two classes. The first class emphasize the use of technology to solve knowledge management problems. The second class regard knowledge management as a problem pertaining to human factors and organizational issues. This report maintain that knowledge management initiatives should make due considerations to both perspectives. This report also sums up the Halden Reactor Project short term KM initiative. (Author)

International Conference of Ukrainian Nuclear Society ''NPP's safety and protection''(annotations)

International Nuclear Information System (INIS)

Barbashev, S.V.

1997-01-01

The abstracts of reports submitted to the Conference include: - New developments of the safe nuclear installations; - NPP ecological safety; - Methods of personnel and population protection; - Waste management safety (at transportation, processing and storage); - Spent nuclear fuel management; - NPP life extension and decommissioning; - Public opinion as an element of NPP safety; - Training of personnel, scientific support and safety culture; - Forecasting of nuclear power and industry safe development; - Development of international cooperation in nuclear power

NPP Krsko Living PSA Concept

International Nuclear Information System (INIS)

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)

NPP Krsko small break LOCA analysis

International Nuclear Information System (INIS)

Mavko, B.; Petelin, S.; Peterlin, G.

1987-01-01

Parametric analysis of small break loss of coolant accident for the Krsko NPP was calculated by using RELAP5/MOD1 computer code. The model that was used in our calculations has been improved over several years and was previously tested in simulation (s) of start-up tests and known NPP Krsko transients. In our calculations we modelled automatic actions initiated by control, safety and protection systems. We also modelled the required operator actions as specified in emergency operating instructions. In small-break LOCA calculations, we varied break sizes in the cold leg. The influence of steam generator tube plugging on small break LOCA accidents was also analysed. (author)

Quantitative analysis of psychological personality for NPP operators

International Nuclear Information System (INIS)

Gao Jia; Huang Xiangrui

1998-01-01

The author introduces the relevant personality quantitative psychological research work carried out by 'Prognoz' Laboratory and Taiwan, and presents the primary results of the research for Chinese Nuclear Power Plant (NPP) operator's psychological personality assessment, which based on the survey of MMPI, and presents the main contents for the personality quantitative psychological research in NPP of China. And emphasizes the need to carry out psychological selection and training in nuclear industry

Grassland Npp Monitoring Based on Multi-Source Remote Sensing Data Fusion

Science.gov (United States)

Cai, Y. R.; Zheng, J. H.; Du, M. J.; Mu, C.; Peng, J.

2018-04-01

Vegetation is an important part of the terrestrial ecosystem. It plays an important role in the energy and material exchange of the ground-atmosphere system and is a key part of the global carbon cycle process.Climate change has an important influence on the carbon cycle of terrestrial ecosystems. Net Primary Productivity (Net Primary Productivity)is an important parameter for evaluating global terrestrial ecosystems. For the Xinjiang region, the study of grassland NPP has gradually become a hot issue in the ecological environment.Increasing the estimation accuracy of NPP is of great significance to the development of the ecosystem in Xinjiang. Based on the third-generation GIMMS AVHRR NDVI global vegetation dataset and the MODIS NDVI (MOD13A3) collected each month by the United States Atmospheric and Oceanic Administration (NOAA),combining the advantages of different remotely sensed datasets, this paper obtained the maximum synthesis fusion for New normalized vegetation index (NDVI) time series in 2006-2015.Analysis of Net Primary Productivity of Grassland Vegetation in Xinjiang Using Improved CASA Model The method described in this article proves the feasibility of applying data processing, and the accuracy of the NPP calculation using the fusion processed NDVI has been greatly improved. The results show that: (1) The NPP calculated from the new normalized vegetation index (NDVI) obtained from the fusion of GIMMS AVHRR NDVI and MODIS NDVI is significantly higher than the NPP calculated from these two raw data; (2) The grassland NPP in Xinjiang Interannual changes show an overall increase trend; interannual changes in NPP have a certain relationship with precipitation.

Dukovany NPP - Safely 16 TERA

International Nuclear Information System (INIS)

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.

Retrofitting of NPP Computer systems

International Nuclear Information System (INIS)

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

The Chernobyl NPP decommissioning: Current status and alternatives

International Nuclear Information System (INIS)

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

Seismic evaluation of existing nuclear facilities. Proceedings of the SMiRT-14 post conference seminar no. 16

International Nuclear Information System (INIS)

2001-03-01

Since 1992 the IAEA has been assisting Member States to develop NPP specific guidelines used in post-construction seismic safety reevaluation. Technical guidelines were developed with the aim to establish a general framework within which a seismic reevaluation of an operating NPP can be carried out. These guidelines will form the basis of an IAEA Safety Report on seismic evaluation of the existing nuclear facilities. Forty papers from 26 countries were presented. Most of the papers reviewed activities in the field of seismic reevaluation and upgrading of existing plants carried out in recent years. This is essential for the IAEA in the development of a unified approach to the seismic reevaluation of existing facilities applicable to WWERs, CANDU, PWRs, etc. A number of papers deal with the CRP benchmark study for the seismic analysis and testing of WWER type NPPs organized by the IAEA (1993-1997). The focal activities of the CRP were benchmarking exercises, applying similar methodology both for Paks NPP and Kozloduy NPP Unit 5 to test the NPP (mainly reactor building) using blast loading generated by a series of artificially generated underground explosions. This work highlighted the reliability of the available numerical tools, the need for further research, and a general judgement on the best compromise between experimental and numerical tools in the seismic reevaluation process. The final results of the CRP were presented in IAEA-TECDOC-1176

Seismic evaluation of existing nuclear facilities. Proceedings of the SMiRT-14 post conference seminar no. 16

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Since 1992 the IAEA has been assisting Member States to develop NPP specific guidelines used in post-construction seismic safety reevaluation. Technical guidelines were developed with the aim to establish a general framework within which a seismic reevaluation of an operating NPP can be carried out. These guidelines will form the basis of an IAEA Safety Report on seismic evaluation of the existing nuclear facilities. Forty papers from 26 countries were presented. Most of the papers reviewed activities in the field of seismic reevaluation and upgrading of existing plants carried out in recent years. This is essential for the IAEA in the development of a unified approach to the seismic reevaluation of existing facilities applicable to WWERs, CANDU, PWRs, etc. A number of papers deal with the CRP benchmark study for the seismic analysis and testing of WWER type NPPs organized by the IAEA (1993-1997). The focal activities of the CRP were benchmarking exercises, applying similar methodology both for Paks NPP and Kozloduy NPP Unit 5 to test the NPP (mainly reactor building) using blast loading generated by a series of artificially generated underground explosions. This work highlighted the reliability of the available numerical tools, the need for further research, and a general judgement on the best compromise between experimental and numerical tools in the seismic reevaluation process. The final results of the CRP were presented in IAEA-TECDOC-1176.

Programmes design for Bohunice NPP personnel other than control room operators

International Nuclear Information System (INIS)

Kalincik, L.

2002-01-01

This paper deals with project development of training programmes for non-licenced NPP personnel-masters, field operators, maintenance and technical supporting personnel. The programme development focuses on the part stage and on the job training at NPP. Bohunice NPP belongs to plants with higher specific number of personnel per installed power capacity. This factor also influenced the choice of programmes design. Undermentioned procedure is one of various approaches to SAT exploitation for training programmes design. (author)

Knowledge management during decommissioning of Chornobyl NPP

International Nuclear Information System (INIS)

Gora, A.D.; Kuchinskij, V.K.; Stel'makh, D.A.; Tsivun, T.A.

2010-01-01

The article deals with issues on knowledge management during decommissioning by the example of the Chornobyl NPP. This includes how the duration of decommissioning stage, change in organization goal and final state of the site influence on human resources and knowledge management system. The main attention is focused on human assets and intellectual strength of Chornobyl NPP. Mathematical dependencies are proposed to substantiate numerical values. An analysis is given for the current situation, and forecast estimates for values dynamics is performed. The conclusion gives solutions on providing experienced staff in the future.

Shock absorber in Ignalina NPP

International Nuclear Information System (INIS)

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

Framatome Contribution to Chinese NPP Development and Standardization

International Nuclear Information System (INIS)

Charbonneau, S.

1996-01-01

First discussions in 1978 between Framatome and Chinese authorities about the supply of an NPP were successfully concluded in 1986 by the signature of the supply contracts (nuclear islands, conventional islands, nuclear fuel assemblies, and project management assistance) for the Daya Bay NPP. Since then teams of engineers and technicians from Framatome and other French companies, and from relevant Chinese institutes and agencies have gotten to know each other better and have deepened their relationships

Computerized systems of NPP operators support. (Psychological problems)

International Nuclear Information System (INIS)

Mashin, V.A.

1995-01-01

Operator psychological problems arising in the work with NPP operators support computerized systems (OSCS) are considered. The conclusion is made that the OSCS intellectual application will bring the operator into dangerous dependence on his computerized assistant. To avoid this danger it is necessary by creation of the OSCS to divide specially the tasks areas of the operator and OSCS in order to assure the active role of the operator in the NPP control

20 Years of Dukovany NPP Operation and Plans for Future

International Nuclear Information System (INIS)

Vlcek, J.

2006-01-01

NPP Dukovany (4x440MW), the first Czech nuclear power plant and a keystone of Czech Electricity Grid, in 2005 celebrated 20 years of successful operation. In my presentation I am going to speak about next areas. I will start about construction and commissioning history of Dukovany NPP, then I'll put forward what milestones of Dukovany NPP operation were accomplished, I'll say examples about our modernisation and investment activities (including replacement of IandC equipment, modifications for increasing of power and support grid services) and in the end our plans for future. (author)

NPP estimation and seasonal change research of Gansu province in northwest China

Science.gov (United States)

Han, Tao; Wang, Dawei; Hao, Xiaocui; Jiang, Youyan

2018-03-01

Based on GIS and remote sensing technology, this paper estimates the NPP of the 2015 year-round and every season of Gansu province in northwest China by using the CASA(Carnegie Ames Stanford Approach) light energy utilization model. The result shows that the total annual NPP of Gansu province gradually decline from southeast to northwest in the space, which is in accordance with the water and heat condition in Gansu province. The results show that the summer NPP in Gansu Province is the maximum in each season. The maximum value of summer NPP in Gansu Province reached 695 (gCm-2•season-1), and the maximum value was 473 in spring, and 288 in the autumn, and the NPP in the winter in Gansu province were under 60. The fluctuation range of NPP value is large, this is due to the diversity of ecosystem types in Gansu province, including desert, grassland, farmland and forest, among them, the grassland area is the largest, and the grassland type is very diverse, the grassland coverage is obviously different, especially the low coverage grassland growth is affected by precipitation and temperature and other meteorological factors obviously.

Development of NPP Safety Requirements into Kenya's Grid Codes

Energy Technology Data Exchange (ETDEWEB)

Ndirangu, Nguni James; Koo, Chang Choong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2015-10-15

As presently drafted, Kenya's grid codes do not contain any NPP requirements. Through case studies of selected grid codes, this paper will study frequency, voltage and fault ride through requirements for NPP connection and operation, and offer recommendation of how these requirements can be incorporated in the Kenya's grid codes. Voltage and frequency excursions in Kenya's grid are notably frequently outside the generic requirement and the values observed by the German and UK grid codes. Kenya's grid codes require continuous operation for ±10% of nominal voltage and 45.0 to 52Hz on the grid which poses safety issues for an NPP. Considering stringent NPP connection to grid and operational safety requirements, and the importance of the TSO to NPP safety, more elaborate requirements need to be documented in the Kenya's grid codes. UK and Germany have a history of meeting high standards of nuclear safety and it is therefore recommended that format like the one in Table 1 to 3 should be adopted. Kenya's Grid code considering NPP should have: • Strict rules for voltage variation, that is, -5% to +10% of the nominal voltage • Strict rules for frequency variation, that is, 48Hz to 52Hz of the nominal frequencyand.

Development of NPP Safety Requirements into Kenya's Grid Codes

International Nuclear Information System (INIS)

Ndirangu, Nguni James; Koo, Chang Choong

2015-01-01

As presently drafted, Kenya's grid codes do not contain any NPP requirements. Through case studies of selected grid codes, this paper will study frequency, voltage and fault ride through requirements for NPP connection and operation, and offer recommendation of how these requirements can be incorporated in the Kenya's grid codes. Voltage and frequency excursions in Kenya's grid are notably frequently outside the generic requirement and the values observed by the German and UK grid codes. Kenya's grid codes require continuous operation for ±10% of nominal voltage and 45.0 to 52Hz on the grid which poses safety issues for an NPP. Considering stringent NPP connection to grid and operational safety requirements, and the importance of the TSO to NPP safety, more elaborate requirements need to be documented in the Kenya's grid codes. UK and Germany have a history of meeting high standards of nuclear safety and it is therefore recommended that format like the one in Table 1 to 3 should be adopted. Kenya's Grid code considering NPP should have: • Strict rules for voltage variation, that is, -5% to +10% of the nominal voltage • Strict rules for frequency variation, that is, 48Hz to 52Hz of the nominal frequencyand

Upgrading NPP personnel. Competence and training through the systematic approach to training

International Nuclear Information System (INIS)

Mautner Markhof, F.

1998-01-01

This paper presents the reasons for acceptance of SAT (Systematic Approach to Training) as the best international practice in respect to training of NPP personnel and the differences in comparison to traditional approaches to training. The identification and evaluation of the new training needs, resources and other requirements for implementing SAT are discussed as well as new approaches and existing training capabilities and involvement of Regulatory body in training of NPP personnel. The IAEA Guidebook on NPP Personnel Training (TRS-380) was used a a basis for discussion of the mentioned topics with the emphasis on achieving the best possible training programmes for NPP personnel

Validation of S-NPP VIIRS Sea Surface Temperature Retrieved from NAVO

Directory of Open Access Journals (Sweden)

Qianguang Tu

2015-12-01

Full Text Available The validation of sea surface temperature (SST retrieved from the new sensor Visible Infrared Imaging Radiometer Suite (VIIRS onboard the Suomi National Polar-Orbiting Partnership (S-NPP Satellite is essential for the interpretation, use, and improvement of the new generation SST product. In this study, the magnitude and characteristics of uncertainties in S-NPP VIIRS SST produced by the Naval Oceanographic Office (NAVO are investigated. The NAVO S-NPP VIIRS SST and eight types of quality-controlled in situ SST from the National Oceanic and Atmospheric Administration in situ Quality Monitor (iQuam are condensed into a Taylor diagram. Considering these comparisons and their spatial coverage, the NAVO S-NPP VIIRS SST is then validated using collocated drifters measured SST via a three-way error analysis which also includes SST derived from Moderate Resolution Imaging Spectro-radiometer (MODIS onboard AQUA. The analysis shows that the NAVO S-NPP VIIRS SST is of high accuracy, which lies between the drifters measured SST and AQUA MODIS SST. The histogram of NAVO S-NPP VIIRS SST root-mean-square error (RMSE shows normality in the range of 0–0.6 °C with a median of ~0.31 °C. Global distribution of NAVO VIIRS SST shows pronounced warm biases up to 0.5 °C in the Southern Hemisphere at high latitudes with respect to the drifters measured SST, while near-zero biases are observed in AQUA MODIS. It means that these biases may be caused by the NAVO S-NPP VIIRS SST retrieval algorithm rather than the nature of the SST. The reasons and correction for this bias need to be further studied.

Radiobiological significance of radioactive contamination - summary assessment based on great number of measurements

Energy Technology Data Exchange (ETDEWEB)

Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Bonchev, Ts; Mavrodiev, V; Kyrdzhilov, N [Sofia Univ. (Bulgaria). Fizicheski Fakultet

1996-12-31

In order to facilitate quantitative and qualitative characterisation of radioactive contamination the authors introduce a relative estimate of radionuclide activity by setting as a reference the most abundant element -Co-60 in the case of the Kozloduy NPP. The ratio {eta}{sub i} of the mean annual permissible concentration in air for each radionuclide (RPC-92) to that of Co-60 is calculated. It is found that {eta}{sub i} has the same or close values for groups of radionuclides, e.g. {eta}{sub i} = 2.10{sup -4} for {sup 238} Pu, {sup 239} Pu, {sup 240} Pu, {sup 241} Am, {sup 244} Cm; {eta}{sub i} = 5 for {sup 89} Sr, {sup 91} Y; {sup 93} Nb, {sup 134} Cs, {sup 137} Cs; {eta}{sub i} = 50 for {sup 55} Fe, {sup 63} Ni, {sup 95} Zr, {sup 95} Nb, {sup 140} Ba, {sup 140} La. Then it is compared to the experimentally measured values of the same quantity {eta}{sub iexp}, derived from surface contamination data. The ratio {eta}{sub iexp}/{eta}{sub i} is plotted against log {eta}{sub i}. The resulting nomograms give graphic representation of the radiobiological significance of various radionuclide groups. Data from different locations at the Kozloduy NPP are presented. It is found that the alpha emitter contamination has highest values in the Unit 1 (WWER-440) control rooms after repair. The Unit 5 (WWER-1000) has lower alpha contamination compared to WWER-440 units. 1 ref., 5 figs., 1 tab.

Tritium level along Romanian Danube river sector

International Nuclear Information System (INIS)

Varlam, Carmen; Stefanescu, Ioan; Popescu, Irina; Faurescu, Ionut; Dobrinescu, Denisa

2010-01-01

Full text: Danube River lies west from the Black Sea in Central and South-Eastern Europe. Due to its geological and geographical conditions, the Danube River Basin can be divided into 3 main parts: Upper, Middle and Lower Danube Basin. 65% of Lower Danube Basin is the natural border between Romania and Bulgaria. Two important nuclear objectives for both countries are found in this region: Kozloduy NPP located at Kozloduy, Bulgaria and Cernavoda NPP, located at Cernavoda, Romania. Taking into account the future development of this important Romanian nuclear objective, the knowledge of the present status of tritium level becomes a necessity. Therefore, an extensive monitoring program for this radioisotope, along the Romanian sector of the Danube River Basin, starting with Cazane Gorge and ending with the three branches of the Danube Delta has been carried on since 2006 and it was accomplished in 2008. The different tributaries from this sector: Cerna, Jiu, Olt, and Arges were included also in this monitoring program. The highest values were constantly recorded for the sites which are downstream the nuclear power plants. The anthropogenic nuclear activity could be identified by the maximum values acquired, but their effect to the Danube water is far for being critical from radiation protection point of view. Monthly sampling was established for Turnu Severin location (in the beginning of Romanian Danube section) during 2007 in Danube water and precipitation. Tritium level trends of Danube River for this location were compared with seasonal variations of tritium concentration in precipitation during the same period of monthly sampling in Danube water. (authors)

Public acceptance of nuclear energy in Indonesia. A traditional puppet show for NPP in Java

International Nuclear Information System (INIS)

Suyudi Soeliarno

1995-01-01

In Indonesia, activities on public relation have been carried out since the establishment of the agency responsible for research and development of atomic energy in 1958 (which later in the year 1964 became Batan, National Atomic Energy Agency), wile activities on public acceptance started 'at the end of 1985. After the Government indicated that it has to look seriously into the construction of the NPP, as from 1990, the public acceptance (PA) activities have been intensified in anticipation of the construction of the first NPP. An important part of the preparatory activities for the construction of the NPP is preparing the people, particularly those who live near the NPP site, to accept and to support the NPP program. The interdepartmental team has bee established in August 1990 consisting of representatives of several institutions, namely, Ministry of Information, Ministry of Domestic Affairs, Ministry of Defense, Land Utilization Agency, State Electricity Corporation, Office of the Minister for Population and Environment, and Batan. This team, called the 'Team on Public Acceptance of NPP', has the main task providing extensive information to the public concerning the government plan to construct nuclear power plants in Indonesia. From 1990 through the middle of 1994 the activity of the Team on Public Acceptance of NPP was focused on providing information on te NPP program to the local community leaders and the public, particularly in the districts of the NPP site in the Muria Peninsula region. Its main purpose was to precondition the people who live near the NPP site to accept the NPP in their neighbourhood without fear

On-line maintenance at Cofrentes NPP

International Nuclear Information System (INIS)

Roldan Vilches, J.; Moreno Matarranz, M. A.; Hermana Mendioroz, I.

1998-01-01

Cofrentes NPP has begun in 1997 activities related to At Power Preventive Maintenance over trains or systems which lead to a voluntary entry in a Limitative Condition of Operation (LCO) of the Technical Specifications. From others benefits, this program ha improved the risk management and the staff's knowledge over the functions and safety implications of the different systems, the better exploit of the resources, the co-ordination of the different organisations involved (Maintenance an Operation) and the reductions of works during shutdowns. Previous to each work, a feasibility study analyzes qualitative and quantitative (PSA), using the Risk Monitor, the implications on safety of all the tasks, assuring that the global safety of the Plant is always maintained. Tech. Spec. are analyzed in detail and also are analyzed situations of simultaneous unavailabilities of systems which could lead to a high risk situation. Two different risk controls are defined (punctual and accumulated) to assure that high risk situations will not be given. Finally, historical risk profile is analyzed to assure that the accumulated risk increase is not significant. Risk Monitor helps staff in the schedule and follow-up of the activities of On-Line Maintenance. Each one of the tasks are deeply planned and harshly analyzed and are carried out by high qualified workers. By the moment, this program is running with fully satisfaction on the Plant. (Author)

NPP Boreal Forest: Consistent Worldwide Site Estimates, 1965-1995, R1

Data.gov (United States)

National Aeronautics and Space Administration — This data set provides estimates of above- and below-ground biomass, above- and below-ground NPP (ANPP and BNPP), and total NPP(TNPP) for selected North American and...

Use of NESTLE computer code for NPP transition process analysis

International Nuclear Information System (INIS)

Gal'chenko, V.V.

2001-01-01

A newly created WWER-440 reactor model with use NESTLE code is discussed. Results of 'fast' and 'slow' transition processes based on it are presented. This model was developed for Rovno NPP reactor and it can be used also for WWER-1000 reactor in Zaporozhe NPP

About choosing the power unit of NPP

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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)

Temelin NPP commissioning experiences

International Nuclear Information System (INIS)

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

ASSET experience at Paks NPP

International Nuclear Information System (INIS)

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

ASSET experience at Paks NPP

Energy Technology Data Exchange (ETDEWEB)

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.

Analysis of an NPP Structure subjected to Vibrations Induced from Airplane Crashes

International Nuclear Information System (INIS)

Noh, Sang Hoon; Kim, Yong Soo; Kim, Chong Hak

2009-01-01

After the terrorists' attacks with civilian airplanes on September 11, 2001, special attention has been paid to the potential for an airplane crash into a Nuclear Power Plant (NPP) as a man-made hazard. An airplane crash (APC) into an NPP has the potential to damage the roofs and walls of these structures, as well as other systems and components such as pipelines, electric motors, power supplies, power cables of electricity transmission that are important for safety. Therefore, an evaluation of the structural response to an APC is important for the safety of NPPs to be confirmed. A structural integrity analysis was carried out focusing on the vibration effects of an APC on an NPP structure. The NPP structure under consideration has been conceptually redesigned based on APR1400 to have double containments for the purpose of a feasibility study to meet European requirements. The finite element method was used for the structural analysis of the NPP, and the computer code ABAQUS was employed for this analysis

Safety Culture Survey in Krsko NPP

International Nuclear Information System (INIS)

Strucic, M.; Bilic Zadric, T.

2008-01-01

The high level of nuclear safety, stability and competitiveness of electricity production, and public acceptability are the main objectives of Krsko Nuclear Power Plant. This is achievable only in environment where strong Safety Culture is taking dominant place in the way how employees communicate, perform tasks, share their ideas and attitudes, and demonstrate their concern in all aspects of work and coexistence. To achieve these objectives, behaviour of all employees as well as specific ethical values must become more transparent and that must arise from the heart of organization. Continuous ongoing and periodic self assessments of Safety Culture in Krsko NPP present major tools in implementation process of this approach. Benefits from Periodic interdisciplinary focused self assessment approach, which main intention is finding the strengths and potential areas for improvements, was used second time to assess the area of Safety Culture in Krsko NPP. Main objectives of self assessment, performed in 2006, were to increase the awareness of the present culture, to serve as a basis for improvement and to keep track of the effects of change or improvement over a longer period of time. For the purpose of effective self assessment, extensive questionnaire was used to obtain information that is representative for whole organization. Wide range of questions was chosen to cover five major characteristics of safety culture: Accountability for safety is clear, Safety is integrated into all activities, Safety culture is learning-driven, Leadership for safety is clear and Safety is a clearly recognized value. 484 Krsko NPP employees and 96 contractors were participated in survey. 70-question survey provided information that was quantified and results compared between groups. Anonymity of participant, as well as their willingness to contribute in this assessment implicates the high level of their openness in answering the questions. High number of participant made analysis of

Position of radiation protection associations and co-operation with civil society regarding nuclear energy

International Nuclear Information System (INIS)

Milu, C.; Chiosila, I.

1996-01-01

The Romanian Society of Radiation Protection (RSRP), founded in May 1990, is an associate society to the International Radiation Protection Association since June 15, 1992. The main task of RSRP is to supply the Romanian public and the governmental organizations, promptly and competently, with information concerning the following three currently debated issues: 1. Long-term health effects of Chernobyl nuclear accident on population of this country; 2. Potential radioactive pollution impact on the environment and population of Romania from Kozloduy NPP (Bulgaria); 3. Development prospects of the nuclear power program based on CANDU type reactors at Cernavoda NPP. The public opinion is often exposed to panic-generating, unfounded 'information' launched by some sensational segments of the mass media and hence the role of professional and qualified bodies like RSRP to create by scientific arguments a sound opinion from a correctly informed public, a prerequisite of democratic debates and decisions

Ecological radiation monotoring in NPP region, aims and tasks

International Nuclear Information System (INIS)

Egorov, Yu.A.

1986-01-01

Aims and tasks of ecological radiation monitoring in the NPP region are discussed. The aims of monitoring are: to determine possible sequences of NPP radioactive release effects on ecosystems, taking place on the background of chemical and thermal pollution to develop standard of radiation effect on ecosystems; the aims includes also obtaining of information for forecasting and evaluating long-term radiation effects, establishment of factors characterizing the ecosystem state, establishment of a combined effect of radioactive wastes with chemical and thermal ones. Finally, the aim of monitoring consists in providing the natural object conservation in the NPP region under optimal operation conditions. Thus it is necessary to solve the following problems: to observe systematically release, transport and transformation, when transporting radioactive and chemical contaminants in terrestial and aquatic biocenoses, as well as injection and transport in them of waste heat; to observe systematically the natural physico-chemical, chemico-biological processes affecting the injection and transport of contaminants in ecosystem components; to observe systematically the natural and, probably, antropogenic processes; to carry out systematically observations of the ecosystem state in the NPP region and eco-systems-monitors

Calculational-experimental examination and ensuring of equipment and pipelines seismic resistance at starting and operating water-cooled and moderated reactor WWER-type NPPs. Final report from 1 November 1994 to 31 October 1995

International Nuclear Information System (INIS)

Kaznovski, S.

1996-01-01

The method for examination and ensuring of equipment seismic resistance is based on the resonance character of the seismic influence on structures and equipment. Values of natural dynamic characteristics are obtained by using external source for exciting the vibrations of the testing unit. These characteristics with the floor response spectra enabled calculations of the seismic resistance. For tests of Kozloduy NPP equipment a simple shock method was used. The presentation includes the list of inspected equipment. The calculations of the equipment seismic resistance were carried out on the basis of Russian and International standards and demands

BNRA approach to long term operation

International Nuclear Information System (INIS)

Stanimirov, Borislav

2014-01-01

The decision to extend the lifetime of existing plants should be balanced by a significant enhancement of their safety features. It is recognized that more comprehensive and systematic reviews will be performed on the following key issues: Extended ageing management programme; Comprehensive safety reassessment including natural hazards and severe accident management features. Significant modifications are implemented at Kozloduy NPP to minimize the radiological consequences in case of severe accidents. Additional actions are being taken in response to the Fukushima accident. BNRA will take actions to make the process as transparent as possible to stakeholders and public and improve the societal confidence

Determination of radiocesium in environmental water samples using copper ferro(II)cyanide and sodium tetraphenylborate

International Nuclear Information System (INIS)

Popov, L.; Kuleff, I.; Djingova, R.

2006-01-01

A procedure for the radiochemical separation and radiochemical purification of radiocesium ( 134 Cs and 137 Cs) in bulk environmental water samples is proposed. Radiocesium was removed from the water by cation-exchange with copper ferro(II)cyanide and was purified by precipitation with sodium tetraphenylborate. The influence of the concentration of potassium in the water sample on the chemical yield was investigated. The validation of the proposed method was carried out by analyzing reference materials. The application of the method was demonstrated with the determination of the concentration of radiocesium in water samples from rivers around NPP 'Kozloduy', Bulgaria, Danube and Ogosta. (author)

Aspects of the studies for construction of a deep geological repository in Republic of Bulgaria. Concept for development of a specialized database for the purposes of siting and design of a deep geological repository in Republic of Bulgaria

International Nuclear Information System (INIS)

Tomov, E.; Yordanova, V.

2009-01-01

The strategy for the management of spent nuclear fuel and radioactive waste there are considered three options for spent fuel management : Transportation of the all spent fuel for storage and reprocessing; Removal of a part of the spent fuel for storage and reprocessing and store the rest in the repository for long-term dry storage for at least 50 years, i e postponement of the decision making; Transportation of the spent fuel to Russia for storage and processing, return of the high-level activity waste from processing for storage and disposal in Bulgaria, further storage of the spent fuel at NPP Kozloduy

Safety aspects of NPP ageing

International Nuclear Information System (INIS)

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

Qualification of NPP operations personnel

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Assessment of minute volume of lung in NPP workers for Korean reference man

International Nuclear Information System (INIS)

Lee, Y. J.; Song, S. H.; Lee, J.; Jin, Y. W.; Yim, Y. K.; Kim, J. S.

2001-01-01

To formulation of the reference Korean for radiation protection purpose, we measured the forced vital capacity(FVC), forced expiratory volume in second(FEVI), minute ventilation(MV) of Nuclear Power Plant workers using SP-1 Spirometry Unit(Schiller AG. 1998) and eatimated the liters of breathed for working and resting, also compared these data with ICRP 23