Leningrad Nuclear Power Plant Research Articles

Estimate of Tritium Intake in the Air from Coastal Plants of Lake Kyzyltash in 2021

The goal of the research was determination of the level of annual tritium intake in the air from coastal plants of Lake Kyzyltash in 2021 and compliance of tritium content in the air of the coastal area of Lake Kyzyltash in 2021 with radiation safety standards. In the period May-September, 2021, a study of coastal plants near Lake Kyzyltash, a technological reservoir of the Mayak Production Association, was conducted. Within 100 m from the lakeside, humidity level of plants ranged from 41% to 87%, tritium volume activity level in the water of plants and transpiration water varied from 96 Bq/l to ~8.0 kBq/l and from 64 Bq/l to ~9.0 kBq/l, correspondingly. Based on the Cheddock scale, rank correlations between tritium volume activity and: time from the beginning of a vegetation period (weak reverse); distance from the lakeside (marked reverse); humidity of the plants (moderate positive), were revealed. To predict tritium intake in the air in the form HTO during the post-vegetative period, exponential decrease models of humidity and tritium volume activity in the plants with time were developed. The estimates of general periods of semi-decrease in humidity and tritium volume activity in the water of the plants, were 262 and 64 days, correspondingly. Total annual HTO intake in the air in 2021 from coastal plants was 6.92 E+11Bq, with contribution 0.35% of annual tritium intake from Lake Kyzyltash surface. The plants from the zone 0…~5m contribute 81.8% of total annual intake from coastal plants of Kyzyltash Lake (5.66E+11Bq). Annual HTO intake from the plants of Lake Kyzyltash coastline (0…~5m) only, was 5.66E+11Bq and was consistent with tritium release in 2021 from the Kursk Nuclear Power Plant (5.32E+11Bq), and tritium intake from all coastal plants of Lake Kyzyltash – with release from the Leningrad Nuclear Power Plant (6.90E+11Bq). In the course of two expeditions, if there were no precipitations, the mean HTO volume activity in the air of Lake Kyzyltash coastal areas was ~60 Bq/ m3, which is ~30 times less than permissible volume activity in the inhaled air for population 1.9E+3Bq/m3, according to NRB-99/2009. In the case of a hypothetical residence on the lakeside of Lake Kyzyltash in 2021 and a permanent level of tritium volume activity in natural environments, an annual committed effective dose of internal radiation conditioned by inhalation of super-heavy water vapor, will be 31 μSv/year for a critical group of children aged 1-2 years and 8.7 μSv/year for adult residents, according to NRB-99/2009. These estimates are conservative as far as they do not take into account the ice-free period during which there is practically no evaporation of water from Lake Kyzyltash surface and intake from plants.

Forecast of radionuclide migration in groundwater of the zone affected by construction drainage at the Leningrad NPP-2

The distribution of natural (at the level of global background) and technogenic radionuclides in groundwater of the industrial zone in Sosnovy Bor town, where several nuclear power facilities are operating, was analyzed. The main technogenic radionuclides recorded in groundwater samples are cesium (137Cs), strontium (90Sr), and tritium isotopes. The first two aquifers from the surface are subject to contamination: the Quaternary and the upper zone of the Lomonosov aquifer. Based on extensive material on the engineering and geological studies of the work area, a 3D geological model and hydrodynamic and geomigration models of the industrial zone were constructed. By means of modeling, the extent and nature of changes in hydrogeological conditions of area resulting from the construction and operational drainage of the new stage of the Leningrad Nuclear Power Plant (LNPP-2) were determined. The “historical” halo of radioactive contamination of groundwater forming (1970-1990) at the site adjacent to the NPP, where the storage facility of low- and medium-level radioactive waste is located, falls into the zone of influence. Interpretation of monitoring data allowed obtaining the migration parameters for predictive estimates. Modeling has shown that during the time of the LNPP-2 operation there was no intake of contaminated water by the drainage system of the new power plant.

Determination of effective standards for the introduction of fodder additive Aquatan in the diet of rainbow trut with a biological assessment of the influence on fisheries

In connection with the global tendency to prohibit the use of antibiotics in animal husbandry, the prospect of using in ichthyopathological practice preparations from plant materials, which are mostly non-toxic, rarely cause side effects, have an antibacterial effect against a wide range of pathogens of bacterial diseases, opens up. One of these preparations is the feed additive Aquatan (Farmatan Aqua) based on ellagitannins from sweet chestnut wood manufactured by Tanin Sevnica (Slovenia). The aim of this work was to study the effect of different dosages of Aquatan on the survival rate, the rate of mass accumulation and the growth rate of rainbow trout reared in the industrial conditions of the cage farm on the waste warm waters of the nuclear power plant and to assess the production and economic efficiency of the application. The tests were carried out for 34 days in February-March 2021 on the basis of an aquaculture cage farm of LLC “Fish Federation”, located in the water area of the waste canal of warm waste water of the Leningrad nuclear power plant (LNPP) in the area of the LNPP-2 industrial zone in the city of Sosnovy Bor, Leningrad Region. The object of the study is rainbow trout yearlings brought from different fish farms. A total of 247,131 specimens were planted, with an average weight of 156.5–235.7 g and a total weight of 43 950.67 kg. The main hydrochemical indicators of water at the enterprise for the trial period met the water quality requirements for growing salmon fish OST 15.372-87. The feeding was carried out with the production compound feed for salmonids of the firm Alltech® Coppens Supreme-22. In experimental cages, fish were fed with compound feed with the addition of the preparation Aquatan at various concentrations (1, 2, and 3 g/kg of feed); in the control, feed without additive was used. As a result of the experiment, a positive effect of the Aquatan additive in dosages of 2–3 g / 1 kg of feed on growth, mass accumulation, survival and feed costs was established, while when adding 1 g / 1 kg of feed, such an effect was not recorded.

Steam reheater with helical tube bundle for wet steam turbine

Since steam heat exchangers, used at steam cycle of Russian nuclear power stations, were designed while the knowledge about the separation and the heat exchange processes was limited, deviations between its empirical and theoretical characteristics occur. This limitation also determined application of heating pipes with simple straight shape rather than curved. This study explores a steam heat exchanger with helical heating pipes. It was shown that the model may work stably within the range of parameters, simulating work conditions of the moisture separator and steam reheater at Leningrad nuclear power plant. The experiment included processing of pure water steam as well as mixture of steam and nitrogen. It was obtained a relationship between empirical the heat transfer coefficient and the steam mass flow rate. It was noted that presence of incondensable gas does not affect significantly the heat transfer from the coils, processing high pressure steam.

Application of Zoo/plankton Indicators for Assessment of the Nuclear Power Plants Impact upon Cooling Pools

The article discusses the outcomes of the researches of zoo/plankton of various type nuclear power plants cooling pools located in different in terms of hyd ro g r aph ic c h a r ac t e r i s t ic s a nd z o opl a n k t on s t r uc t u re c at c h ment b a s i n s . I n Kop or ye B ay, a part of the Bay of Finland water area, discharge of warmed waters of Leningrad Nuclear Power Plant caused the decrease of plankton invertebrates’ quantitative indicators. In the Beloyarsk Nuclear Power Plant cooling pool warming in the most cases was favorable for the zooplankton abundance and biomass increase. In both researched reser voirs the warm water discharge resulted in the decrease of the total species number in the communities. The Neman River (the Baltic Nuclear Power Plant designed receiver for waste waters) in the period of the research was not affected by the nuclear plant impact. As a whole, for this water course water area ma ximal values of zooplankton abundance and biomass have been registered during spring periods while their decrease has been observed in summer and autumn. The most degree of trophity was noted near towns of Grodno, Kaunas, Yurbarkas and Neman.

RESIDENTS’ ATTITUDE OF THE LENINGRAD REGION AND SOSNOVY BOR TO ENVIRONMENTAL SITUATION AND ISSUES OF RADIATION SAFETY IN THE RESIDENCE PLACES

A sociological survey was conducted in the Leningrad Region in 2016. In total, 1,363 respondents over 18 years of age were interviewed, including 401 respondents residing in the area of the main nuclear industry facility in the region namely the Leningrad nuclear power plant in the urban district Sosnovy Bor. The aim of the study was to investigate the interest of the population of the Leningrad Region and Sosnovy Bor in obtaining information on various aspects of radiation safety, depending on the gender and age of respondents, perception of the environmental situation in the region of their residence, as well as the confidence level in various sources of information. Respondents ‘ interest study of information about radiation and radiation safety issues was revealed that interest to such information is twice higher in Sosnovy Bor than the respondents of the Leningrad region have one. The highest level of confidence among all in the study participating respondents is the information, where Emergency Situations Ministry officers, scientists and specialists are the source one.

УПРАВЛЕНИЕ БЕЗОПАСНОСТЬЮ ПЕРСОНАЛА АЭС ПРИ ПОЖАРЕ

Appropriate protective measures are required to ensure the evacuation of staff to a safe area under the conditions of a potential impact on a nuclear power plant by dangerous fire factors. The article analyzes possible fire scenarios in one of the buildings of the Leningrad nuclear power plant. An approach to assessing the effectiveness of the use of protective equipment for nuclear power plant personnel during a fire is considered.

Simulation of the probable maximum flood in the area of the Leningrad Nuclear Power Plant with account of wind waves

At the designing of nuclear power facilities at the coastal sites the risk of their flooding caused by the combinations of adverse hydrometeorological events should be assessed with the probability of exceedance to 0.01%. According to the IAEA recommendations, the combination of statistical and deterministic methods was used to calculate the flood level of such rare occurrence. The level of flooding caused by the storm surge and reiated wind waves were computed with the probability of 0.01% for the coastal part of the Koporye Bay of the Gulf of Finland in the area of the Leningrad Nuclear Power Plant 2 (LNPP 2) construction; the results are presented. The calculations are based on the CARDINAL and SWAN software and four nested numerical models (for the Baltic Sea, the eastern part of the Gulf of Finland, the Koporye Bay, and a part of the bay in the area of LNPP). The decrease in sea-surface drag coefficient at hurricane winds is taken into account.

Risk-communication issues in radiation safety: еvaluation of public awareness in St. Petersburg and the Leningrad region on the activities of the nuclear industry and public understanding of the hazards

In 2016, St. Petersburg Research Institute of Radiation Hygiene named after Professor P.V. Ramzaev developed a Program for the radiation risk communication management for the adequate perception risks associated with the use of various technologies in the nuclear industry by the public. Carrying out sociological research is one of the stages of this program. The aim of the analysis presented in the article is to study the population’s awareness of radiation safety issues and its attitude to further development of the nuclear industry. The data used in this analysis is a part of a large sociological survey conducted in St. Petersburg and the Leningrad Region The sociological research was conducted by the method of a selective questionnaire survey among the adult population permanently residing in the territory of St. Petersburg and the Leningrad Region. The volume of the sample studied was 2369 respondents: 1006 in St. Petersburg and 1363 in the Leningrad Region, including Sosnovy Bor – 401. The analysis showed that the population of all the studied territories estimates the environmental situation as being mainly favorable. The residents consider the main environmental problems in all areas studied to be a collection, removal, storage, disposal of garbage, as well as air and water pollution. The population of the region is relatively poorly informed about the current projects in the nuclear industry. One-third of the inhabitants of the region perceives the Leningrad nuclear power plant as a source of danger. Respondents see the main danger in the possibility of an accident on it. There is a sharply negative attitude of the population towards the construction of radioactive waste disposal sites anywhere in the region. According to the results of the study, it can be concluded that the population of the studied region is poorly informed about the existing radiation situation and the nuclear industry projects. It requires an optimization of the choice of methods for risk communication.

Влияние Ленинградской АЭС на зоопланктон и зообентос Копорской губы Финского залива

The effects of warm water discharge from Leningrad nuclear power plant (Leningrad NPP) on the physical, chemical and biological properties of a natural water pond (Gulf of Finland Koporskaya Guba) were studied during 2010–2014 period. Quantity and biomass changes in environmental occupied benthic and plankton communities were studied for water pollution assessment. Data collected by IEG RAS were used for assessing of the ecological state of Koporskaya Guba as a cooling pond of Leningrad NPP.

A method for analytical monitoring of surface deposits on jackets of fuel elements of reactors with water heat carrier

A method of postreactor analytical monitoring of elemental composition of deposits on jackets of fuel elements from zirconium alloys based on chemical removal and subsequent quantitative analysis of deposited elements using inductively coupled plasma atomic emission spectroscopy (ICP-AES) is described. The choice of the method of chemical removal of deposits from jackets of fuel elements is substantiated; data on the composition of solution of chemical reagents and temperature-time regime of the procedure are presented. Devices for nondestructively obtaining detailed and precise information on element distribution in deposits along the fuel element height by means of a small length of the analyzed segment and the capability of sequential segment analysis along the whole fuel element length are developed. Advantages of ICP-AES application for analysis of elemental composition of deposits with allowance for the specific features of studies of irradiated reactor materials are considered. A method of quantitative analysis of deposits is developed, its metrological aspects are considered, and results of determination of some elements of deposits on jackets of fuel elements of the RBMK-1000 of the Leningrad Nuclear Power Plant are given.

Analysis of the danger of structural failure with uncertainties present in the initial data

Initial data on the properties of a material, which are often difficult to determine with prescribed accuracy because of large variances in the experimental results, for example, experimental determination of the characteristics of creep in long-time strength of the materials used in the core of a nuclear reactor, are needed for computational simulation of structural deformation and failure. These conditions engender uncertainty in the results of strength calculations, making them improperly posed from the mathematical standpoint. A mathematical method for taking account of the uncertainties in strength calculations is examined. The method is based on the reconstruction of the distributions of random quantities over a sample of empirical data, using nonparametric method of ordered minimization of risk. The method and the computer codes DENSIT, PTUBL, and PCLAD, which are used for performing the calculation, are described. The application of these codes to the analysis of an accident which occurred in the No. 3 unit of the Leningrad nuclear power plant in 1992 is examined.

Validation of lifetime extension of power-generating units with RBMK reactors

A list of measures for extending the lifetime of power-generating units with RBMK reactors is presented. The normative approaches and criteria are indicated, an assessment of the technical possibility of lifetime extension, primarily for the critical components, of at least 15 years is examined. The technical measures for safe operation after the lifetime has been exhausted are examined for the No. 1 unit of the Leningrad nuclear power plant. Finally, validation is given for the possibility of subsequent safe operation of the critical components, equipment, and pipelines of the multiple forced circulation loop up to 2018.

CJSC ECOMET-S facility for reprocessing and utilisation of radioactive metal waste: operating experience

The principal objective of the paper is to present operating experience in management of radioactive metal waste, originating at nuclear power facilities of the Russian Federation. Issues of radioactive metal waste recycling by melting, with the purpose of unrestricted re-use in industry, or restricted re-use within the nuclear industry, have been considered. The necessity for using a method of melting at the final stage of radioactive metal waste recycling has been proved. Priority measures to be taken and results achieved in the implementation of the Governmental purpose-oriented programme 'Radioactive Metal Waste Reprocessing and Utilization' have been considered, the CJSC ECOMET-S being the main contractor on the Programme. Main specifications and results of operating a commercial melting facility, owned by CJSC 'ECOMET-S' and used to recycle low-level radioactive metal waste originated at the Leningrad Nuclear Power Plant, have been presented.

Behavior of Radioactive Iodine Isotopes in the Multiple Forced Circulation Loop in an RBMK Reactor

The flow of iodine, including 131I, into the coolant water in a nuclear power plant with an RBMK-1000 reactor under normal operating conditions and during transient regimes is analyzed. It is shown that under normal operating conditions the specific activity of 131I in the coolant is correlated with the iron concentration. During shutdown, its content increases by factors of 30–200. The emission of 131I into the coolant can be decreased by factors of 10–15 and the degree of unsealing of fuel elements can be decreased if before shutdown the reactor is held for 2–5 days at 50% of the nominal power level. Recommendations are made for decreasing 131I emissions into the atmosphere. The adoption of these recommendations at the Leningrad nuclear power plant has reduced the 131I emissions into the atomsphere by a factor of 17.

Check and Guarantee of Seismic Stability of the Equipment in the Leningrad Nuclear Power Plant

The status of the work on checking and guaranteeing the seismic stability of the equipment in the Leningrad nuclear power plant as part of the development and implementation of comprehensive measures for improving safety is analyzed. New, promising approaches and methods for analyzing earthquake safety of a nuclear power plant are presented.

Acoustic method of leak detection using high-temperature microphones

A leak-detection method based on the use of high-temperature microphones was initially developed for ATR. The next-generation system was developed for RBMK entry and exit piping. Even though there are structural differences between them, RBMK and ATR have the same type of loop cooling. This has made it possible to develop a general approach to coolant leak detection. The microphone system of leak detection has been installed and successfully operating at the Leningrad nuclear power plant. The system detects leaks with sensitivity 0.23 m3/h, and it determines the site of a leak and estimates its size. The experience gained at the Leningrad nuclear power plant has subsequently been used at the Fugen nuclear power plant, where 0.046 m3/h was chosen as the target sensitivity for detecting leaks in the ATR entry piping. The possibility of detecting and determining the site of a small leak by the method proposed has been demonstrated in the present work.

REVISS cobalt-60 production in Russia and beyond

Since Russian English Venture in Isotope Supply and Services (REVISS) Services is one of only two major global suppliers of sealed radiation sources to the industrial sterilization industry, security of supply of raw materials is understandably of primary concern to the users in the market place. This paper outlines the history, facilities and production capability of REVISS isotope suppliers, from MAYAK Production Association and Leningrad Nuclear Power Plant in Russia to Commission Nacional Energia Atomica in Argentina. The paper provides technical details of reactors and handling facilities used for fabrication of 60Co and 137Cs sources for industrial and research gamma irradiators and other applications. Other sources of 60Co in the world today will be reviewed briefly.

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

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

Leak Detection in the Primary Reactor Coolant Piping of Nuclear Power Plant by Applying Beam-Microphone Technology

A microphone leak detection method was applied to the inlet piping of the ATR-prototype reactor, Fugen. Statistical analysis results showed that the cross-correlation method provided the effective results for detection of a small leakage. However, such a technique has limited application due to significant distortion of the signals on the reactor site. As one of the alternative methods, the beam-microphone provides necessary spatial selectivity and its performance is less affected by signal distortion. A prototype of the beam-microphone was developed and then tested at the O-arai Engineering Center of the Japan Nuclear Cycle Development Institute (JNC). On-site testing of the beam-microphone was carried out in the inlet piping room of an RBMK reactor of the Leningrad Nuclear Power Plant (LNPP) in Russia. A leak sound imitator was used to simulate the leakage sound under the leakage flow condition of 1–3 gpm (0.23–0.7 m3/h). Analysis showed that signal distortion does not seriously affect the performance of this method, and that sound reflection may result in the appearance of ghost sound sources. The test results showed that the influences of sound reflection and background noise were smaller at the high frequencies where the leakage location could be estimated with an angular accuracy of 5° which is within the range of localization accuracy required for the leak detection system.