Armenian Nuclear Power Plant Research Articles

Specifics of radioactive waste management at the power unit No.2 of the Armenian nuclear power plant

Specifics of radioactive waste management at the power unit No.2 of the Armenian nuclear power plant

Determining the minimum required cooling time of profiled assemblies at the Armenian Nuclear Power Plant taking into account the load schedule

Determining the minimum required cooling time of profiled assemblies at the Armenian Nuclear Power Plant, taking into account the load schedule, is an analytical process to establish the shortest required period during which profiled assemblies used in the nuclear power plant energy process must remain in active use. This process considers factors related to changes in the electrical load on the station during different periods. Within the scope of this definition, an analysis of the technical characteristics of profiled assemblies is conducted as well as their impact on the overall performance of the nuclear power plant. Key considerations in the cooling time include operational safety, compliance with regulatory requirements, and efficient distribution of energy resources in accordance with the load schedule. The goal of this process is to ensure optimal and safe operation of profiled assemblies, adapted to changes in the electrical grid and aligned with the load schedule, thereby contributing to the more efficient functioning of the nuclear power plant. This study aims to substantiate the minimum required cooling time for profiled nuclear assemblies characterized by an average uranium enrichment of 3.82% and an average burnup of 45.7 Megawatt-days per kilogram of uranium (MWD/kgU). Calculations are performed using the ORIGEN-ARP program, part of the SCALE software package designed for the analysis and modeling of radioactive and nuclear processes. The study considers parameters such as the composition of nuclear assemblies, fuel burnup, modeling using the ORIGEN-ARP program, and safety analysis. The results obtained aim to make a significant contribution to enhancing the efficiency and safety of nuclear energy installations

Development of HELIOS/BIPR/PARCS/MCNP6 Computation Route for WWER RPV Neutron Fluence Analysis and Validation Against Ex-Vessel Detector Measurement Data

A computational route was developed for precise calculation of fast neutron fluence on a WWER-type reactor pressure vessel (RPV). The method is based on the transfer of neutronics data from HELIOS-2 lattice calculations and nodal diffusion neutronics data (power, density, and temperature) from BIPR7.1 and PARCS 3.36/PATHS core calculations into a three-dimensional (pinwise axially distributed) fixed neutron source for modeling of transport of fast neutrons from the reactor core to the outer surface of the RPV using MCNP6.2. Validation of the proposed computational method was carried out based on comparative analysis of MCNP6.2-predicted and neutron dosimetry–measured reaction rates [54Fe(n,p)54Мn, 93Nb(n,nʹ)93mNb, and 58Ni(n,р)58Со] on the outer surface of the Armenian Nuclear Power Plant (ANPP) Unit 2 RPV. Validation revealed that the MCNP6.2-predicted fast neutron fluence results are very sensitive to the ENDF-B neutron data. Particularly, MCNP6.2 with ENDF/B-VIII.0 significantly underpredicts (20% to 30%) fast neutron fluence while using ENDF/B-VII.1 data overpredicts it. Adding revised beta-released evaluations of 54Fe, 56Fe, 57Fe, and 16O from the International Nuclear Data Evaluation Network (INDEN) to ENDF/B-VIII.0 allows one to obtain reasonable agreement with measurement results for all types of measured reaction rates.

The study of gross beta-radioactivity of some medicinal plants in conditions of outdoor hydroponics and soil culture in Ararat Valley

Background: Technogenic and natural radionuclides (RN) along the biogeochemical chains of agrocenoses may enter the human body through irrigation water- soil- plants- agricultural animals, likewise in hydroponic systems through nutrient solution substrate plants, leading to the development of dangerous diseases. Thus, control of herbal raw material’s gross β-radioactivity and obtaining radioactively safe medicinal raw material are priority issues. Since 1996 we have carried out radio monitoring research in the Ararat valley (where the Armenian Nuclear Power Plant (ANPP) is located) in water, soil, and plant systems in zones of the ANPP with a radius of 2-15, 20 (the territory of Ashtarak city), 30 km (Yerevan, territory of Institute of Hydroponics Problems) (IHP), as well as Dilijan Forest Experimental Station (DFES) (the zone of ANPP with 90 km radius). Studies have shown that in natural waters (artesian water, Hrazdan, Qasakh, Metsamor rivers), soils and in various crops (vegetables, fruit of trees, etc.) of Ararat Valley the content of technogenic RN 90Sr (T1/2=28.6 years) and 137Cs (T1/2=30.1 years) did not exceed maximum allowable concentrations (for drinking water MAC 90Sr=5.0 Bq/L, MAC 137Cs=11.0 Bq/L; for vegetables and fruits MAC 90Sr=50 Bq/L, MAC 137Cs=130 Bq/L). Based on these studies, a complex of practical recommendations in this region will give the opportunity of obtaining ecologically pure agricultural products.Objective: Considering that the accumulation of RN in medicinal plants poses a particularly great threat to obtaining radioecologically safe medicinal raw materials, during 2017-2022 we studied the specificities of gross β-radioactivity and accumulation of controlled technogenic RN (90Sr and 137Cs) in medicinal plants under hydroponics and soil conditions in the Ararat valley (the zone of ANPP with 30 km radius). This has a specific practical significance, as it will enable to obtain the most radio-ecologically safe plant material.Methods: Gross β-radioactivity and content of 90Sr and 137Cs of samples (artesian water (irrigation water), nutrient solution, soil layers with depth of 0 - 30 cm and number of medicinal plants) in it were defined with radio-chemical extraction methods through the radiometer UMF-1500 (made in Russia) with low background. 90Sr was determined by the oxalate method with 90Y. RN were determined in dry sediments of waters, nutrient solution, the ash of plants, and soils. The following chemical reagents were used for the analysis: C2H2O4, HNO3, HCl, CH3COOH, CsCl, Y2O3, YCl3, K2SO4, KI, Sr(NO3)2, CeCl3, Ni(NO3)2, SbCl3, K4[Fe(CN)6] 3H2O and others.Results: The radio-chemical studies showed that the gross β-radioactivity of herbs in hydroponics fluctuated between 250 – 740 Bq/kg, and in soil: 140 – 690 Bq/kg. Thus, the medicinal raw material from the medicinal plants cultivated in outdoor hydroponics and soil, is radioecologically safe, since its gross β-radioactivity does not exceed the threshold of 1.0 Bq/g. Medicinal plants grown in hydroponics and soil, with a slight deviation, show the same gross β-radioactivity decreasing pattern as follows: Peucedanum caucasicum (M.Bieb.) K. Koch. > Lycium barbarum > Eleutherococcus senticosus (Rupr. & Maxim.) > Teucrium polium = Humulus lupulus, variety “Crystal” > Echinacea purpurea (L.) Moench > Humulus lupulus, variety “Chinook” > Humulus lupulus, variety “Newport” > Colchicum speciosum Stev. > Moringa oleifera Lam. Our studies have shown that the proportion of 90Sr and 137Cs together in gross β-radioactivity in different medicinal plants fluctuated between 1.0-7.4 % of dry mass in hydroponics and 1.7-10.1 % of dry mass in soil. In the gross β-radioactivity of medicinal plants the share of 90Sr and 137Cs in hydroponics was 1.2-3.0 and 1.3-2.3 times lower than that of soil plants.Conclusion: In artesian waters, gray soils and different medicinal plants grown in hydroponic settings and soil of Ararat Valley the content of controlled technogenic RN (90Sr and 137Cs) did not exceed MAC. Both medicinal raw materials grown in hydroponic settings and soil in Ararat Valley are radioecologically safe.Keywords: technogenic radionuclides, nutrient solution, herbal raw materials, 90Sr, 137Cs

Որոշ գեղազարդ ծառերի տնկիների տերևների բետա-ռադիոակտիվությունն Արարատյան դաշտի և Դիլիջանի անտառային գոտու պայմաններում

The specificities of the accumulation of the gross β-radioactivity and the controlled technogenic radionuclides (RN) 90Sr (T1/2=28.6 years) and 137Cs (T1/2=30.1 years) in leaves of several decorative tree saplings (sophora japonica, biota orientalis, cupressus sempervirens, fagus orientalis and carpinus caucasus) were studied in area of Institute of Hydroponics Problems (IHP) (zone of Armenian Nuclear Power Plant (ANPP) with radius of 30 km) and in Dilijan forest experimental station (DFES). It was revealed that the leaves of the saplings of sophora japonica and biota orientalis prevailed in gross β-radioactivity those of cupressus sempervirens in area of IHP and of fagus orientalis and carpinus caucasus in DFES. Therefore, decorative broad-leaved sophora japonica and conifer biota orientalis that were introduced into Armenia are suggested to be used in green building as natural accumulators of RN to create parks, green zones and forests. It may have important ecological value.

Ways of Energy Supply in the Republic of Armenia

This article discusses the only Armenian nuclear power plant operation in Transcaucasia, the energy demand of the population of the Republic of Armenia, the restoration and secondary launch of nuclear power plants, environmental impact assessment, and prospects for the development of nuclear energy in the country. Data on personnel dose loads, emissions and discharges of nuclear power plants, soil and water pollution in the monitoring area for 2020 are presented.

Mechanical properties and microstructure of VVER 440 RPV steels irradiated to extremely high fluences and the effect of recovery annealing

Mechanical testing and microstructural investigation on VVER-440 15Cr2MoV welds were carried out after irradiation and after recovery annealing treatment at two different temperatures (340 °C and 475 °C) for 100 h. The welds are part of the last surveillance chain of an Armenian nuclear power plant and have been irradiated for ~200,000 h at 270 °C, receiving extreme high fluence values (3.2 × 1025 m−2, E>0.5 MeV). Prolonged irradiation caused severe hardening and embrittlement. The increase of the yield strength and corresponding decrease in the uniform elongation are, 606 MPa and 10.2% respectively, when compared to the as-received state. Annealing at 340 °C did not show noteworthy recovery of the tensile properties. The recovery annealing treatment for 100 h at 475 °C resulted a significant recovery of the yield strength and relative uniform elongation (82% and 97% respectively) in conjunction with the disappearance of the irradiation-induced black-dot damage. The contribution of the observed irradiation-induced microstructural features to the total measured hardening was modelled using the Russel-Brown dispersion hardening model to qualitatively explain the observed hardening and recovery of the tensile properties after irradiation and annealing treatment respectively.

Pinched between the plates: Armenia's voluminous record of volcanic activity

Located in the heart of the Lesser Caucasus mountains, where the Arabian and Eurasian tectonic plates collide, Armenia occupies an exceptional geological position shaped through millions of years of subduction and collision. It is a unique place on the Earth recording extensive intrusive and volcanic activity related to the long‐standing continental convergence. The volcanoes of Armenia provide a rare opportunity to study the sources and processes involved in this unusual type of magmatism. More than 500 Quaternary volcanoes have been mapped in Armenia, most of them formed from single eruptive episodes. Among several large composite volcanoes, the mighty Aragats stands out as the largest volcano in Armenia and the region altogether. Volcanic deposits testify to the range of eruptive styles—from the ignimbrites formed in eruptions as explosive and voluminous as any seen globally in the modern era to the enormous fissure‐fed lava flows that form the Southern Caucasus flood basalt province, the smallest and youngest Large Igneous Province in the world. Several pre‐historical and historical eruptions have been documented, highlighting the potential for future volcanic activity in the region. In recent years, research has focused on the volcanic hazards associated with the Armenian Nuclear Power Plant, located in the foothills of Aragats volcano. This article highlights some of the extraordinary volcanic and intrusive features observed in Armenia and summarizes aspects of recent volcanological and petrological research.

Developing of Technology for Production of Perlite Based Insulation New Material and Elaborating of Methods for Calculation and Design of Damp Thermal Insulation Drying System

During last 20-25 years in Armenia has been established new thermal insulation material’s production. This program in short is named “Developing of perlite insulation technology”. The perlite is a volcanic mineral in form of soft stone, which is extracted from perlite mines of Armenia. First of all, the perlite is a construction material, which traditionally has been used in building construction purposes. At the same time, it is a good row material for making thermal insulation goods. The technology of transformation of perlite stone into perlite insulation material is developed by Professor Zohrab Melikyan jointly with experts of “Yerevan Perlite Company” in the framework of the program “Development of Environmentally Safe, cost Effective and Sustainable Energy Sector of Armenia in the Situation of Shutting Down of the Armenian Nuclear Power Plant”. The project was targeted to compensate the energy deficit that could arise in Armenia, following to shutting down of the Nuclear Power Plant (ANPP).

The Armenian nuclear power plant: problems of electricity export

The prerequisites for the development of Armenia’s nuclear power industry are indicated. The main geopolitical problems of operation of the Armenian NPP are revealed through studying the electric power market of the South Caucasus with the definition of the export opportunities of Armenia. The main problems of nuclear fuel supplies to the Armenian NPP are studied. Recommendations are given on the long-term development of nuclear energy in Armenia.

ILKHAM ALIYEV HEADED TO SUMMIT IN THE U.S.

(By Sokhbet Mamedov. Nezavisimaya gazeta, March 29, 2016, p. 6. Condensed text:) Azerbaijani President Ilkham Aliyev will participate in the fourth Nuclear Security Summit, which will take place in Washington [March 31-April 1]. US President Barack Obama sent an invitation to the head of Azerbaijan back in December 2015.. . . ... Baku attaches special importance to Ilkham Aliyev’s Washington visit. According to Novruz Mamedov, deputy head of the Azerbaijani presidential administration in charge of the foreign relations department, this visit is important for several reasons. the head of state will talk at the summit about Azerbaijan’s progress on nuclear security, as well as outline challenges that lie ahead. Second, various meetings, contacts and discussions will take place during the summit. is during such meetings that important steps are made in developing bilateral relations, Novruz Mamedov said in an interview with the ANS television channel. ... Commenting on Azerbaijan’s participation in the upcoming Washington summit, political analyst Rasim Musabekov told local publications that the US wants very much to ward off any potential attempts to illicitly transfer nuclear materials to Iran via Azerbaijan. nuclear security issue has become even more relevant since sanctions against Iran were lifted [following an agreement reached in July 2015; see Current Digest, Vol. 67, No. 29, pp. 7 - 9 - Trans.]. And I think the US will keep an even closer eye on any Iranian attempts to gain access to nuclear materials and technology in the future. It is important that Azerbaijan meet all of the requirements imposed on countries participating in the Agreement on the International Atomic Energy Agency, Musabekov said. According to the expert, in this light, Azerbaijan must take all measures to ensure strict oversight over the trafficking of nuclear materials and technologies. ... In his comments, the political analyst also touched on Armenia’s participation in the Washington Nuclear Security Summit. In his view, this was expected. First, Armenia, like Azerbaijan, borders Iran. Second, there is the Armenian nuclear power plant, where irradiated fuel is stored, including plutonium, which is widely used in the manufacture of nuclear weapons. The US does not want nuclear materials from Russia to go to Armenia and then on to Iran, the expert said. As for reports of a possible meeting between the heads of Azerbaijan and Armenia during the summit, Musabekov says that this meeting will largely depend on who moderates it. ... If this initiative comes from the cochairs of the Organization for Security and Cooperation in Europe’s Minsk Group, I think the results will be just as fruitless as the last meeting in Bern, Switzerland. It is another matter if a bilateral meeting in a summit format is organized by the US presidential administration, or at least Secretary of State John Kerry, Musabekov told 1news.az.. . .

Nuclear knowledge development in Armenia

Armenia has rather a rich history of nuclear knowledge development. During the last several decades, depending upon circumstances related to the Armenian Nuclear Power Plant main milestones ? construction, putting into operation, shutdown and restarting ? nuclear knowledge has had its ups and downs. Though it has a high level of development, there is still a need to preserve accumulated nuclear knowledge through appropriate processes.

Historical volcanoes of Armenia and adjacent areas: What is revisited?

The validity of some data in Karakhanian et al. [Karakhanian, A., Djrbashian, R., Trifonov V., Philip H., Arakelian S., Avagian, A., 2002. Holocene–historical volcanism and active faults as natural risk factor for Armenia and adjacent countries. Journal of Volcanology and Geothermal Research, 113, 1, 319–344; Karakhanian, A., Jrbashyan, R., Trifonov, V., Philip, H., Arakelian, S., Avagyan, A., Baghdassaryan, H., Davtian, V., Ghoukassyan, Yu., 2003. Volcanic hazards in the region of the Armenian nuclear power plant. Journal of Volcanology and Geothermal Research, 126/1–2, 31–62] that are revisited by R. Haroutiunian is considered. A conclusion is made that the revisions suggested by Haroutiunian concern unessential parts of the content of work by Karakhanian et al. [Karakhanian, A., Djrbashian, R., Trifonov V., Philip H., Arakelian S., Avagian, A., 2002. Holocene–historical volcanism and active faults as natural risk factor for Armenia and adjacent countries. Journal of Volcanology and Geothermal Research, 113, 1, 319–344; Karakhanian, A., Jrbashyan, R., Trifonov, V., Philip, H., Arakelian, S., Avagyan, A., Baghdassaryan, H., Davtian, V., Ghoukassyan, Yu., 2003. Volcanic hazards in the region of the Armenian nuclear power plant. Journal of Volcanology and Geothermal Research, 126/1–2, 31–62]. This article presents new evidence and re-proves the earlier conclusions that are disputed or revised by R. Haroutiunian.

Volcanic hazards in the region of the Armenian Nuclear Power Plant

We address volcanic hazards in the region of the Armenian Nuclear Power Plant and discuss the assessment of these hazards conducted in the framework of the International Atomic Energy Agency (IAEA) programs in 1994–1995. An important problem of volcanic hazard assessment is posed by assumptions that the apparent absence of recent volcanic activity in Armenia means that future eruptions in the vicinity of the site are impossible. We present new historical, archaeological, and field data, as well as records of the volcanic activity based on radiocarbon, fission-track, K/Ar and plateau-age determinations. This new evidence attests to volcanism in Armenia and adjacent areas during Holocene and historical time. Volcanic activity is demonstrated for Tskhouk-Karckar, Porak, Vaiyots-Sar, Smbatassar, Gegham Ridge and Ararat volcanoes. Volcanic eruptions occurred on Ararat at distances of 27 and 52 km from the plant site in 2500–2400 BC and in 1840 AD, respectively. New information permits a re-assessment of the volcanic hazards at a level higher than in the 1994–1995 studies.

Automated Safety System of the Armenian Nuclear Power Plant Based on Skills of Human Behaviour in Extreme Cases

The introduction of digital control systems into electronic utility nuclear power plant raises new and complex issues in relation to human factors. Experience at electric utilities has shown that engineering with human factors in mind generally makes plants safer, improves availability, and extends equipment life.

Emissions of60Co,110mAg, and54Mn at the Armenian nuclear power plant, and their content in the surrounding atmosphere

Six years of operation of the Armenian nuclear power plant (NPP) with a VVER-440 led to an increase in the contribution of radioactive corrosion products, in particular 6~ ~1~ end ~4Mn, to the total activity of the gas--air mixture discharged into the stack (Table I). According to the data for January-September, 1982, these radionnclides contributed 57% of the total activity of the long-lived aerosols discharged into the atmosphere, neglecting I~I. Consequently, the yearly emission of long-lived radioactive aerosols is due largely to radioactive corrosion products.