scholarly journals The Work Results of the Institute for Safety Problems of Nuclear Power Plants of the NAS of Ukraine in 2020

2021 ◽  
Vol 20 ◽  
pp. 96-105
Author(s):  
V. S. Havrylenko ◽  
◽  
I. V. Kutsyna ◽  
D. I. Кhvalin ◽  
◽  
...  

The year 2020 has become a real challenge for almost all aspects of life all over the world. Under these conditions, Ukrainian science, which has been in a state of crisis for more than a year, has been forced to overcome additional difficulties. However, due to the efforts of scientists, scientific work not only did not stop, but also received a large development effort in new directions and formats. In 2020, the Institute for Safety Problems of Nuclear Power Plants was one of the scientific institutions that under the new conditions made every effort to carry out the planned scientific researches and perform works in accordance with its activities. The main results of scientific and scientific-organizational activities of the Institute for Safety Problems of Nuclear Power Plants in 2020 are presented in the article. Despite the difficult economic situation due to the epidemic, the staff of the Institute obtained important results in studies of nuclear and radiation safety of the Shelter object, and in works aimed at improving the reliability and safety of existing Ukrainian and foreign nuclear power plants. The results of works in the field of the Shelter object transformation into an ecologically safe system, safe operation of nuclear facilities, decommissioning of nuclear facilities, spent nuclear fuel and radioactive waste management are presented in the article. The results of the work performed under the International Atomic Energy Agency (IAEA) grant and the Ukrainian-Japanese Science and Technology Research Partnership for Sustainable Development (SATREPS) project are described. The implementation of the results of these studies in practice is indicated. Scientific and expert activities in the interests and at the request of public authorities, cooperation with national and foreign scientific organizations as well as scientific and organizational activities in 2020 are described. Information on internal certification of employees, participation in international and national events, publishing and etc. is presented.

2021 ◽  
Vol 7 (1) ◽  
pp. 9-13
Author(s):  
David A. Hakobyan ◽  
Victor I. Slobodchuk

The problems of reprocessing and long-term storage of spent nuclear fuel (SNF) at nuclear power plants with RBMK reactors have not been fully resolved so far. For this reason, nuclear power plants are forced to search for new options for the disposal of spent fuel, which can provide at least temporary SNF storage. One of the possible solutions to this problem is to switch to compacted SNF storage in reactor spent fuel pools (SFPs). As the number of spent fuel assemblies (SFAs) in SFPs increases, a greater amount of heat is released. In addition, no less important is the fact that a place for emergency FA discharging should be provided in SFPs. The paper presents the results of a numerical simulation of the temperature conditions in SFPs both for compacted SNF storage and for emergency FA discharging. Several types of disturbances in normal SFP cooling mode are considered, including partial loss of cooling water and exposure of SFAs. The simulation was performed using the ANSYS CFX software tool. Estimates were made of the time for heating water to the boiling point, as well as the time for heating the cladding of the fuel elements to a temperature of 650 °С. The most critical conditions are observed in the emergency FA discharging compartment. The results obtained make it possible to estimate the time that the personnel have to restore normal cooling mode of the spent fuel pool until the maximum temperature for water and spent fuel assemblies is reached.


2018 ◽  
Vol 4 (4) ◽  
pp. 251-256 ◽  
Author(s):  
Sergey Shcheklein ◽  
Ismail Hossain ◽  
Mohammad Akbar ◽  
Vladimir Velkin

Bangladesh lies in a tectonically active zone. Earlier geological studies show that Bangladesh and its adjoining areas are exposed to a threat of severe earthquakes. Earthquakes may have disastrous consequences for a densely populated country. This dictates the need for a detailed analysis of the situation prior to the construction of nuclear power plant as required by the IAEA standards. This study reveals the correlation between seismic acceleration and potential damage. Procedures are presented for investigating the seismic hazard within the future NPP construction area. It has been shown that the obtained values of the earthquake’s peak ground acceleration are at the level below the design basis earthquake (DBE) level and will not lead to nuclear power plant malfunctions. For the most severe among the recorded and closely located earthquake centers (Madhupur) the intensity of seismic impacts on the nuclear power plant site does not exceed eight points on the MSK-64 scale. The existing predictions as to the possibility of a super-earthquake with magnitude in excess of nine points on the Richter scale to take place on the territory of the country indicate the necessity to develop an additional efficient seismic diagnostics system and to switch nuclear power plants in good time to passive heat removal mode as stipulated by the WWER 3+ design. A conclusion is made that accounting for the predicted seismic impacts in excess of the historically recorded levels should be achieved by the establishment of an additional efficient seismic diagnostics system and by timely switching the nuclear power plants to passive heat removal mode with reliable isolation of the reactor core and spent nuclear fuel pools.


2019 ◽  
Vol 186 (4) ◽  
pp. 524-529
Author(s):  
Si Young Kim

Abstract The intercomparison test is a quality assurance activity performed for internal dose assessment. In Korea, the intercomparison test on internal dose assessment was carried out for nuclear facilities in May 2018. The test involved four nuclear facilities in Korea, and seven exposure scenarios were applied. These scenarios cover the intake of 131I, a uranium mixture, 60Co and tritium under various conditions. This paper only reviews the participant results of three scenarios pertinent to the operation of nuclear power plants and adopts the statistical evaluation method, used in international intercomparison tests, to determine the significance values of the results. Although no outliers were established in the test, improvements in the internal dose assessment procedure were derived. These included the selection of intake time, selection of lung absorption type according to the chemical form and consideration of the contribution of previous intake.


Author(s):  
Sangmyeon Ahn ◽  
Jungjoon Lee ◽  
Chanwoo Jeong ◽  
Kyungwoo Choi

We are having 23 units of nuclear power plants in operation and 5 units of nuclear power plants under construction in Korea as of September 2012. However, we don’t have any experience on shutdown permanently and decommissioning of nuclear power plants. There are only two research reactors being decommissioned since 1997. It is realized that improvement of the regulatory framework for decommissioning of nuclear facilities has been emphasized constantly from the point of view of IAEA’s safety standards. It is also known that IAEA will prepare the safety requirement on decommissioning of facilities; its title is the Safe Decommissioning of Facilities, General Safety Requirement Part 6. According to the result of IAEA’s Integrated Regulatory Review Service (IRRS) mission to Korea in 2011, it was recommended that the regulatory framework should require decommissioning plans for nuclear installations to be constructed and operated and these plans should be updated periodically. In addition, after the Fukushima nuclear disaster in Japan in March of 2011, preparedness for early decommissioning caused by an unexpected severe accident became important issues and concerns. In this respect, it is acknowledged that the regulatory framework for decommissioning of nuclear facilities in Korea need to be improved. First of all, we focus on identifying the current status and relevant issues of regulatory framework for decommissioning of nuclear power plants compared to the IAEA’s safety standards in order to achieve our goal. And then the plan is established for improvement of regulatory framework for decommissioning of nuclear power plants in Korea. It is expected that if the things will go forward as planned, the revised regulatory framework for decommissioning could enhance the safety regime on the decommissioning of nuclear power plants in Korea in light of international standards.


2020 ◽  
Vol 13 (2) ◽  
pp. 157-168
Author(s):  
Aslan Khuseinovich Abashidze ◽  
Vladimir Mikhailovich Filippov ◽  
Alexander Mikhailovich Solntsev

Abstract States have sovereign rights that allow them to construct nuclear power plants. Moreover, engaging with nuclear power generation makes possible the achievement of the Sustainable Development Goals (2016–30) in combatting climate change, paramount to the Paris Agreement’s initiatives. In the same vein, however, constructing and operating power plants pose strict dangers to both general safety of the public and to national security. Thus, plant operations should strictly abide by the International Atomic Energy Agency (IAEA) standards and international law. As a result, it is important to consider the potential transboundary impacts of nuclear power plants and to conduct an appropriate transboundary environmental impact assessment (EIA). The article examines the construction of the Ostrovets Nuclear Power Plant by Belarus, close to the border of the Republic of Lithuania. The question in focus, however, is as follows: what international procedure can be used to coordinate issues of potentially negative transboundary impacts? Lithuania, in order to avoid the operation of the nuclear power plant, thus sought peaceful settlement of the dispute making use of the dispute resolution mechanisms based on international environmental agreements. The authors of this study show that the treaty bodies, established on the basis of international environmental agreements, provide important assistance in this matter in coordination with the IAEA. The use of these quasi-judicial means of resolving interstate disputes proves effective in pursuing a compromise between economic development and environmental protection. In the absence of such mechanisms at a universal level, one should consider utilizing such mechanisms in other regions of the world.


2014 ◽  
Vol 56 (5) ◽  
pp. 501-514 ◽  
Author(s):  
N. D. Goletskii ◽  
B. Ya. Zilberman ◽  
Yu. S. Fedorov ◽  
A. S. Kudinov ◽  
A. A. Timoshuk ◽  
...  

Author(s):  
Fumio Inada ◽  
Tomomichi Nakamura ◽  
Takashi Nishihara ◽  
Shigehiko Kaneko ◽  
Manwoong Kim ◽  
...  

In nuclear power plants, fluid structure interactions (FSI) occurring in component systems can cause excessive forces or stresses to the structures resulting in mechanical damages that may eventually threaten the structural integrity. FSI in the guidelines includes flow-induced vibration, water hammer, and pipewhip. It can also include movement, deformation, or fracture of equipments by tsunami etc. They can be issues of design and maintenance. Authors cannot find complete guidelines to correspond to the FSI phenomena which can be important in the design and maintenance of nuclear power plants. Based on the background, International Atomic Energy Agency (IAEA) has drafted guidelines on FSI. This paper summarizes general description of FSI as well as design and maintenance against FSI.


2016 ◽  
pp. 44-50
Author(s):  
V. Shestopalov ◽  
Iu. Shybetskyi

The paper considers evidences and mechanisms of potential impact of local depression (microgeodynamic) zones on NPP safety. The depression forms were revealed within the Chornobyl NPP site, including location of the new safe confinement. Nature of zones and character of their influence is determined by fault structures and conjugated deep degassing processes, which cannot be detected and studied by traditional methods of engineering and exploration works during NPP siting. The assumption was made that significant and still unexplored risks for nuclear facilities are related to probable release of deep hydrogen through the bottom of depressions along sub-bottom channels. The approaches were proposed to studying the system of “depression with its sub-bottom channel” within the sites of Chornobyl NPP and other nuclear power plants.


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