Journal articles: 'Nuclear decommissioning and dismantling'

1

Kim, Hyeon-Ki, Sang-Hwa Shin, Chang-Sig Kong, and Chang-Lak Kim. "Evaluation of Worker Radiation Exposure during the Kori Unit 1 Steam Generator Dismantling Process." Science and Technology of Nuclear Installations 2024 (January 30, 2024): 1–7. http://dx.doi.org/10.1155/2024/4230293.

Full text

Abstract:

Kori Unit 1 was permanently shut down on June 18, 2017. Since then, Korea is actively preparing for the decommissioning of the nuclear power plant. Because decommissioning work is performed in a radioactive environment, worker radiation exposure is a significant consideration. In this study, worker radiation exposure is evaluated during the steam generator, one of the heavy components of nuclear power plant, dismantling process. A radiation evaluation for the dismantling process is performed using the code RESRAD-BUILD. A steam generator dismantling scenario and optimal cutting method are designed to evaluate worker radiation exposure, considering pipe dimensions, cutting tool speed, and experience in steam generator replacement. The evaluation results are derived for each work type and year. As a result of the evaluation, worker radiation exposure is 7.5 man-mSv at the year of planned decommissioning.

APA, Harvard, Vancouver, ISO, and other styles

2

Dragusin, Mitica, Octavian Pavelescu, and Ioan Iorga. "Good practices in decommissioning planning and pre-decommissioning activities for the Magurele VVR-S nuclear research reactor." Nuclear Technology and Radiation Protection 26, no. 1 (2011): 84–91. http://dx.doi.org/10.2298/ntrp1101084d.

Full text

Abstract:

The VVR-S Nuclear Research Reactor at the ?Horia Hulubei? National Institute of Physics and Nuclear Engineering in Magurele, Bucharest, will be decommissioned applying the immediate dismantling strategy. The implementation of the decommissioning project started in 2010 and is planned for completion within 11 years. Good practices in decommissioning planning, organization, funding, and logistics are described in this paper.

APA, Harvard, Vancouver, ISO, and other styles

3

Babilas, Egidijus, Eugenijus Ušpuras, Sigitas Rimkevičius, Gintautas Dundulis, and Mindaugas Vaišnoras. "Safety Assessment of Low-Contaminated Equipment Dismantling at Nuclear Power Plants." Science and Technology of Nuclear Installations 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/650810.

Full text

Abstract:

The decommissioning of nuclear facilities requires adequate planning and demonstration that dismantling and decontamination activities can be conducted safely. Existing safety standards require that an appropriate safety assessment be performed to support the decommissioning plan for each facility (International Atomic Energy Agency, 2006). This paper presents safety assessment approach used in Lithuania during the development of the first dismantling and decontamination project for Ignalina NPP. The paper will mainly focus on the identification and assessment of the hazards raised due to dismantling and decontamination activities at Ignalina Nuclear Power Plant and on the assessment of the nonradiological and radiological consequences of the indicated most dangerous initiating event. The drop of heavy item was indicated as one of most dangerous initiating events for the discussed Ignalina Nuclear Power Plant dismantling and decontamination project. For the analysis of the nonradiological impact the finite element model for the load drop force calculation was developed. The radiological impact was evaluated in those accident cases which would lead to the worst radiological consequences. The assessments results show that structural integrity of the building and supporting columns of building structures will be maintained and radiological consequences are lower than the annual regulatory operator dose limit.

APA, Harvard, Vancouver, ISO, and other styles

4

Ilyasov, Damir Fatovich, Artem Yurievich Ivanov, Nikita Petrovich Agafonov, Anastasiya Andreevna Mikhailenko, Ilya Dmitrievich Ovchinnikov, and Polina Olegovna Stepanyan. "Software Development for the Nuclear and Radiation Hazardous Objects Elimination Projects Cost Estimating Using Digital Modeling." Теоретическая и прикладная экономика, no. 4 (April 2022): 67–79. http://dx.doi.org/10.25136/2409-8647.2022.4.38996.

Full text

Abstract:

This article discusses the problems of estimating the projects cost for decommissioning nuclear and radiation hazardous facilities based on BIM data. The software developed at Nuclear Safety Institute of the Russian Academy of Sciences for planning and analyzing decommissioning facilities at the pre-project stage processes is described. In particular, the software main functions are demonstrated: evaluation of the dismantling and decontamination works cost, forecasting the waste generated volume, technological processes planning and the safe waste management cost evaluation, results analysis taking into account the uncertainty of the initial data and sensitivity analysis. The scientific novelty consists in the development by a team of authors of software for financial and economic planning of decommissioning of nuclear and radiation hazardous facilities on the basis of digital information 3D models of objects being created. The need for such development is conditioned by the requirements for systematization and analysis of data on nuclear waste at the preparatory stage for the selection of effective technologies for dismantling and decontamination works and management of radioactive waste, as well as to improve the efficiency of individual decommissioning projects and the Federal Target Program "Providing Nuclear and Radiation Safety for 2016-2020 and for the period up to year 2035" generally.

APA, Harvard, Vancouver, ISO, and other styles

5

Lobach, Yu M., S. Yu Lobach, and V. M. Shevel. "Preliminary safety analysis at the decommissioning of the WWR-M research reactor." Nuclear Physics and Atomic Energy 23, no. 2 (June 25, 2022): 107–15. http://dx.doi.org/10.15407/jnpae2022.02.107.

Full text

Abstract:

Following the demands established by the current Ukrainian legislation, the Decommissioning Concept for the WWR-M research reactor was recently approved. The Concept envisages a strategy of immediate dismantling; it identifies and justifies the main technical and organizational measures for the preparation and implementation of decommissioning, the sequence of planned works and activities, as well as the necessary conditions and infrastructure. Decommissioning requires proper planning and demonstration that all planned dismantling works will be carried out safely. Presented safety assessment is a mandatory component of the Concept and the most important element of the overarching technological scheme. The purpose of the safety analysis is to provide input for detailed planning on how to ensure safety during decommissioning. Based on the results of the safety analysis, the measures to ensure radiation protection are defined while justifying their necessity and sufficiency.

APA, Harvard, Vancouver, ISO, and other styles

6

Lobach, Yu M., S. Yu Lobach, E. D. Luferenko, and V. M. Shevel. "Assessment of the dose load during the dismantling of the WWR-M reactor." Nuclear Physics and Atomic Energy 23, no. 4 (December 25, 2022): 234–44. http://dx.doi.org/10.15407/jnpae2022.04.234.

Full text

Abstract:

The WWR-M is a light-water-cooled and moderated heterogeneous research reactor with a thermal output of 10 MW. The final decommissioning planning is in progress now. The general decommissioning strategy consists of the dismantling and separate removal of the bulky elements as a whole (in one piece) without preliminary segmentation. The dismantling of the primary and secondary cooling loops is considered as one of the key tasks; a separate dismantling design has been developed. The baseline principles for the technical solution and safety are presented in the given paper. Results of the dose assessment showed that the work can be performed at a collective dose of less than 20 man-mSv.

APA, Harvard, Vancouver, ISO, and other styles

7

Mednikov, I. V., V. V. Vasilyev, A. S. Busygin, and A. A. Sobko. "Provision of the radiation safety for the decomissioning of the heavy-water research nuclear reactor NRC «Kurchatov Institute» – ITEP." Radiatsionnaya Gygiena = Radiation Hygiene 13, no. 1 (March 31, 2020): 74–83. http://dx.doi.org/10.21514/1998-426x-2020-13-1-74-83.

Full text

Abstract:

The article provides a brief description of organizational and technical measures aimed at ensuring radiation safety during the decommissioning of the heavy-water research nuclear reactor of Institute for Theoretical and Experimental Physics after A.I. Alikhanov of National Research Centre «Kurchatov Institute». Information is provided on the history and features of the operation of the reactor, including parameters and characteristics that are significant for planning and conducting work. The peculiarities of legal regulation in the field of ensuring radiation safety are given; regulatory acts and rules accompanying other activities during decommissioning and directly related to radiation safety are also considered. The paper describes the work done in preparation for dismantling, the initial and current state of the installation, forthcoming work with examples of dismantled equipment. Methods for handling radioactive waste arising during decommissioning are considered, including methods for fragmentation of large structural elements (examples of mechanical devices are given), methods for sorting according to different specific activity (high activity, low activity), radionuclide composition and physical properties (solid, metallic, non-metallic, liquid). A special method for handling liquid radioactive waste is described, which includes the collection and temporary storage system. To assess the radiation situation at workplaces during the dismantling of the reactor structures, calculations of radiation transfer were carried out on the running and shutdown reactor, during which it was established that the expected dose to the personnel when performing activities on decommissioning of TBR is much lower than the limit values, established by regulatory documents. In accordance with the estimated radiation doses, rules and instructions for personnel were determined, including the procedure for using personal protective equipment, the necessary measures for surface decontamination, etc. Information is given on the procedure for radiation monitoring at all stages of dismantling and at the final stages of decommissioning including control of premises, personnel, equipment, waste of various types, atmospheric air.

APA, Harvard, Vancouver, ISO, and other styles

8

Engovatov, Igor A., and Rinat Kh Adiyatullin. "Providing rationale for the possibility of decommissioning Bilibino nuclear cogeneration plant based on the onsite disposal option." Nuclear Energy and Technology 6, no. 3 (November 6, 2020): 195–201. http://dx.doi.org/10.3897/nucet.6.58969.

Full text

Abstract:

The problem of the NPP decommissioning after the end of the specified or extended life has reached the practical solution stage for countries possessing a nuclear power industry. The major decommissioning options, both in Russia and abroad, include immediate dismantling and deferred dismantling. At the same time, there are NPP units for which, for a number of reasons, none of the two options are acceptable in terms of ensuring the safety of the personnel, the public and the environment. Disposal, the third and a more rare option, shall be used for decommissioning in this case. The purpose of the work is to provide rationale for the possibility of decommissioning Bilibino Nuclear Cogeneration Plant based on the Onsite Disposal option by covering the main building with an inert material with the formation of a mound. The option has been selected considering the results of an integrated analysis taking into account the geographical, operational, radiological, and socioeconomic factors, as well as based on a limited experience of decommissioning commercial uranium-graphite reactors both within and outside Russia. In accordance with Russian law, the decommissioning stage will start after spent nuclear fuel is withdrawn from the unit and removed. Emphasis is placed on the proposed option preparation and implementation issues. Dates and sequences for the performance of operations to dismantle the components and civil works of buildings and structures, as well as the onsite protective mound formation structure and composition are discussed. The geometrical dimensions, as well as the quantities and types of the mound-forming materials have been estimated. The key mound-forming materials will be fragments of the components, the biological shielding, and the civil works, as well as local materials.

APA, Harvard, Vancouver, ISO, and other styles

9

Delgado, Jessica C., Felix Pino, Erica Fanchini, Alessandro Iovane, Daniela Fabris, and Sandra Moretto. "Neutron-gamma survey system for decommissioning and dismantling activities." EPJ Web of Conferences 288 (2023): 07010. http://dx.doi.org/10.1051/epjconf/202328807010.

Full text

Abstract:

The nuclear plant decommissioning and dismantling (D&D) operations will amount to €200 billion in costs over decades around the world, with three-fourths coming from Europe. Decommissioning includes activities such as planning, physical and radiological characterization, facility and site decontamination, dismantling, and materials management. This work is focused on the development of a compact, light and low-power consumption neutron-gamma survey system which could be easily mounted on an remotely operated vehicle. It is made up of a 4”x4”x2” NaIL (NaI:Tl + 1% 6Li [95% enriched]) neutron/gamma scintillation detector coupled to a SiPM array. Digital pulse processing techniques were implemented to acquire and process the signals, by means of a CAEN DT5780 unit. A comprehensive characterization of this system, based on experiments and Monte Carlo simulations, is reported. The system can be used as a secondary inspection tool, useful for identifying radioactive and special nuclear materials in hotspots.

APA, Harvard, Vancouver, ISO, and other styles

10

Craig, David, Lorna Fecitt, Yuri Gorlinsky, Neil Harman, Roger Jackson, Vyacheslav Kolyadin, Yuri Lobach, and Vitaly Pavlenko. "Technical features of the MR reactor decommissioning." Nuclear Technology and Radiation Protection 23, no. 2 (2008): 79–85. http://dx.doi.org/10.2298/ntrp0802079c.

Full text

Abstract:

This paper presents a preliminary technical design for the dismantling of the MR reactor. The goal of the design is the removal of reactor components allowing the re-use of the building for a different nuclear related purpose. The sequence of segmentation procedures is established. Considerations on the size reduction and tooling are presented.

APA, Harvard, Vancouver, ISO, and other styles

11

Daniška, Dušan, Branislav Vrban, and Vladimír Nečas. "DEVELOPMENT OF DATABASE STRUCTURES AND DATA EXCHANGE PRINCIPLES FOR NUCLEAR DECOMMISSIONING PLANNING." Radiation Protection Dosimetry 198, no. 9-11 (August 2022): 740–46. http://dx.doi.org/10.1093/rpd/ncac128.

Full text

Abstract:

Abstract The amount and variety of information used during the nuclear decommissioning project is enormous. If we consider that data and information coming from the whole operational phase of a nuclear power plant (NPP) is important for safe and efficient planning of such projects and waste treatment, packaging, storage and disposal use data coming from the dismantling operations, we can expect that nuclear decommissioning data are live and can be useful for decades. Taking into account a very broad variety of such data (e.g. but not only, their format, storage media, structure, meaning, relevancy, …) it is not a trivial task to develop a complex and reasonably structured database for storing all this information. This paper presents an overview of our research activities in the field of standardization in terms of the data structure and storage technologies and outlines the overall ‘single-source-of-truth’ architecture with centralized server and communication principles for storage and transfer of data used in nuclear decommissioning projects.

APA, Harvard, Vancouver, ISO, and other styles

12

Meyer, Franz. "Decommissioning of the Astra research reactor: Review and status on July 2003." Nuclear Technology and Radiation Protection 18, no. 2 (2003): 61–64. http://dx.doi.org/10.2298/ntrp0302061m.

Full text

Abstract:

The paper describes work on the decommissioning of the ASTRA research reactor at the Austrian Research Centers Seibersdorf. Organizational, planning, and dismantling work done until July 2003 including radiation protection and waste management procedures as well as the current status of the project are presented. Completion of the decommissioning activities is planned for 2006.

APA, Harvard, Vancouver, ISO, and other styles

13

Abramenkovs, Andris. "Decommissioning of the Salaspils Research Reactor." Nuclear Technology and Radiation Protection 26, no. 1 (2011): 78–83. http://dx.doi.org/10.2298/ntrp1101078m.

Full text

Abstract:

In May 1995, the Latvian government decided to shut down the Salaspils Research Reactor and to dispense with nuclear energy in the future. The reactor has been out of operation since July 1998. A conceptual study on the decommissioning of the Salaspils Research Reactor was drawn up by Noell-KRC-Energie- und Umwelttechnik GmbH in 1998-1999. On October 26th, 1999, the Latvian government decided to start the direct dismantling to ?green-field? in 2001. The upgrading of the decommissioning and dismantling plan was carried out from 2003-2004, resulting in a change of the primary goal of decommissioning. Collecting and conditioning of ?historical? radioactive wastes from different storages outside and inside the reactor hall became the primary goal. All radioactive materials (more than 96 tons) were conditioned for disposal in concrete containers at the radioactive wastes depository ?Radons? at the Baldone site. Protective and radiation measurement equipment of the personnel was upgraded significantly. All non-radioactive equipment and materials outside the reactor buildings were released for clearance and dismantled for reuse or conventional disposal. Contaminated materials from the reactor hall were collected and removed for clearance measurements on a weekly basis.

APA, Harvard, Vancouver, ISO, and other styles

14

Lobach, Yuri, Michail Lysenko, Vladimir Makarovsky, and Valery Shevel. "Progress in the decommissioning planning for the Kiev’s research reactor WWR-M." Nuclear Technology and Radiation Protection 25, no. 3 (2010): 239–48. http://dx.doi.org/10.2298/ntrp1003239l.

Full text

Abstract:

The Kiev?s research reactor WWR-M has been in operation for more than 50 years and its further operation is planned for no less than 8-10 years. The acting nuclear legislation of Ukraine demands from the operator to perform the decommissioning planning during the reactor operation stage as early as possible. Recently, the Decommissioning Program has been approved by the regulatory body. The Program is based on the plans for the further use of the reactor site and foresees the strategy of immediate dismantling. The Program covers the whole de- commissioning process and represents the main guiding document during the whole decommissioning period, which determines and substantiates the principal technical and organizational activities on the preparation and implementation of the reactor decommissioning, the consequence of the decommissioning stages, the sequence of planned works and measures as well as the necessary conditions and infrastructure for the provision and safe implementation.

APA, Harvard, Vancouver, ISO, and other styles

15

Onodera, J., H. Yabuta, T. Nishizoro, C. Nakamura, and Y. Ikezawa. "Characterization of aerosols from dismantling work ofexperimental nuclear power reactor decommissioning." Journal of Aerosol Science 22 (1991): S747—S750. http://dx.doi.org/10.1016/s0021-8502(05)80208-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

S, Chitra, S. Anand, Pradeep Bhargava, Jayant Krishan, Kapil Deo S. Singh, M. S. Kulkarni, and D. N. Sharma. "DOSE ASSESSMENT FOR ATMOSPHERIC DISCHARGE OF LONG-LIVED RADIONUCLIDES IN NUCLEAR POWER PLANT DECOMMISSIONING." Radiation Protection Dosimetry 190, no. 2 (June 2020): 139–49. http://dx.doi.org/10.1093/rpd/ncaa088.

Full text

Abstract:

Abstract Decommissioning of nuclear power plants is a multistage process involving complex operations like radiological characterization, decontamination and dismantling of plant equipment, demolition of structures, and processing and disposal of waste. Radioactive effluents released into the environment may result in exposure of population through various exposure pathways. The present study estimates the public dose due to atmospheric discharge of important radionuclides during proposed decommissioning activities of Indian Pressurized Heavy Water Reactors. This study shows that major dose contributing radionuclides are 60Co followed by 94Nb, 134Cs, 154Eu, 152Eu, 133Ba, 99Tc, 93Mo and 41Ca. It is found that infant dose is higher than adult dose and major fraction of total dose (~98%) is through ground shine and ingestion; other pathways such as inhalation and plume shine contribute only a small fraction. This study will be helpful in carrying out radiological impact assessment for decommissioning operations which is an important regulatory requirement.

APA, Harvard, Vancouver, ISO, and other styles

17

Simakov, A., D. Arefeva, Yu Abramov, N. Proskuryakova, I. Kemskiy, and A. Shayahmetova. "Enhancing the Regulatory Support of Occupational Radiation Protection during Decommissioning and Dismantling of Ships with Nuclear Power Installations and Nuclear Service Vessels." Medical Radiology and radiation safety 66, no. 4 (September 13, 2021): 37–41. http://dx.doi.org/10.12737/1024-6177-2021-66-4-37-41.

Full text

Abstract:

Results: Information is provided on the developed regulatory and methodological documents including health physics and organizational requirements for the radiation safety and protection supervision in the course of work on decommissioning and dismantling of nuclear submarines, nuclear service ships and surface vessels with nuclear installations, as well as during storage of reactor compartments of decommissioned nuclear submarines and block packs of nuclear service ships. Conclusion: The developed documents are aimed at further improving the regulatory legal and methodological support of citizens’ rights to safe working conditions, health protection and social protection.

APA, Harvard, Vancouver, ISO, and other styles

18

Jacques, Marie-Bénédicte, Sascha Gentes, Joseph A. Ridao Cabrerizo, and Dušan Daniška. "The use of digital twins for waste estimation in nuclear facilities' dismantling and decommissioning: the PLEIADES project." Safety of Nuclear Waste Disposal 2 (September 6, 2023): 11–12. http://dx.doi.org/10.5194/sand-2-11-2023.

Full text

Abstract:

Abstract. Nowadays, a considerable number of nuclear power plants worldwide have reached or will reach the end of their lifespan and will need to be dismantled within the next few decades. Dismantling and decommissioning (D&D) of nuclear facilities is a challenging, complex, and hazardous task that was never foreseen before the first reactors' shutdowns. As part of D&D activities, the waste minimization and waste management have an essential interest. The EU-funded PLEIADES (PLatform based on Emerging and Interoperable Applications for enhanced Decommissioning processES) project gathers 14 partners (academics and research organizations, small and medium-sized enterprises (SMEs) and industrial companies, and a Technical Safety Organization) representing different stakeholders and providers of the nuclear dismantling domain. Coming from seven European countries, they join forces to demonstrate an innovative digital approach and a new methodology for improving selected key tasks related to D&D. To achieve these goals, the project aims to develop digital twins (DTs) through a BIM (building information modelling) technology-based platform. To structure the data, PLEIADES proposes a decommissioning-oriented ontology that provides a common understanding of the concept, with specific decommissioning terminology. The developed platform provides the integration of the different data and tools. In order to demonstrate the PLEIADES concept, six user stories have been defined based on three real-life use cases from three different European countries, namely France, Norway, and Spain. They allow scenario studies and address application areas such as cost and planning, radiation exposure estimation, and waste assessment. Three of the user stories are directly linked to one use case and focus on comparing alternative scenarios to basic decommissioning activities such as radiological characterization or the decontamination of building surfaces. The other three focus on risk management, uncertainties, regulatory aspects, and waste management strategies. The data feeding the DTs are crucial and require data collection and integration, data security assurance, and data completeness verification. The whole process is iterative until the DTs contain all the necessary information required to perform the user stories simulation. Among others, each simulation using a DT will consider a physical and radiological environment and estimate the waste produced, the waste management process, and the waste management cost. In real applications, the data constituting the DT will depend on each D&D project, but the whole methodology is applicable. This may result in the definition of best practices and the sharing of common processes.

APA, Harvard, Vancouver, ISO, and other styles

19

Jeong, KwanSeong, ByungSeon Choi, Jeikwon Moon, Dongjun Hyun, JongHwan Lee, IkJune Kim, GeunHo Kim, and JaeSeok Seo. "An evaluation of the dismantling technologies for decommissioning of nuclear power plants." Annals of Nuclear Energy 69 (July 2014): 62–64. http://dx.doi.org/10.1016/j.anucene.2014.01.035.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Kindleben, G., R. Baumann, and P. Faber. "Decommissioning and dismantling of the Siemens fuel cycle facilities." Kerntechnik 70, no. 1-2 (February 2005): 74–85. http://dx.doi.org/10.3139/124.100228.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Nam, Chang-Su, and Byung-Sik Lee. "Development of an Integrated Human Error Simulation Model in Nuclear Power Plant Decommissioning Activities." Science and Technology of Nuclear Installations 2023 (January 12, 2023): 1–13. http://dx.doi.org/10.1155/2023/8133223.

Full text

Abstract:

In this study, an integrated human error simulation model in nuclear power plant (NPP) decommissioning activities (HEISM-DA) that can integrate and manage various factors affecting human errors is developed. In the HEISM-DA, an error probability input method suitable for the characteristics of each performance shaping factors (PSFs) was presented. Because each PSF has different importance on human error, the relative importance of decommissioning PSF Levels 1 and 2 and influential factors is considered. A multiplier was selected for each PSF and then used for human error evaluation. To calculate the human error probability (HEP) for the NPP decommissioning activity, the relationship between each PSF is identified and linked to develop a human error evaluation model. Using the HEISM-DA, HEP for reactor pressure vessel internal cutting work is evaluated based on the experience data. HEP is calculated to be approximately 1%. As a result of HEP calculation, it is found that the “operation” factor has a significant influence on the HEP of NPP decommissioning activities. Therefore, if the dismantling work is conducted by supervising the “operation” factors in a detailed and systematic approach, it is believed that the HEP will be reduced as other factors are also affected.

APA, Harvard, Vancouver, ISO, and other styles

22

Kim, Juyoul, and Batbuyan Tseren. "Occupational ALARA Planning for Reactor Pressure Vessel Dismantling at Kori Unit 1." International Journal of Environmental Research and Public Health 17, no. 15 (July 24, 2020): 5346. http://dx.doi.org/10.3390/ijerph17155346.

Full text

Abstract:

Assessing workers’ safety and health during the decommissioning of nuclear power plants (NPPs) is an important procedure in terms of occupational radiation exposure (ORE). Optimizing the radiation exposure through the “As Low As Reasonably Achievable (ALARA)” principle is a very important procedure in the phase of nuclear decommissioning. Using the VISIPLAN 3D ALARA planning tool, this study aimed at assessing the radiological doses to workers during the dismantling of the reactor pressure vessel (RPV) at Kori NPP unit 1. Fragmentation and segmentation cutting processes were applied to cut the primary component. Using a simulation function in VISIPLAN, the external exposure doses were calculated for each work operation. Fragmentation involved 18 operations, whereas segmentation comprised 32 operations for each fragment. Six operations were additionally performed for both hot and cold legs of the RPV. The operations were conducted based on the radioactive waste drum’s dimensions. The results in this study indicated that the collective doses decreased as the components were cut into smaller segments. The fragmentation process showed a relatively higher collective dose compared to the segmentation operation. The active part of the RPV significantly contributed to the exposure dose and thus the shielding of workers and reduced working hours need to be considered. It was found that 60Co contained in the stainless steel of the reactor vessel greatly contributed to the dose as an activation material. The sensitivity analysis, which was conducted for different cutting methods, showed that laser cutting took a much longer time than plasma cutting and contributed higher doses to the workers. This study will be helpful in carrying out the occupational safety and health management of decommissioning workers at Kori NPP unit 1 in the near future.

APA, Harvard, Vancouver, ISO, and other styles

23

Roudil, Danièle, Marielle Crozet, Sébastien Picart, Ben Russell, Margarita Herranz, Sven Boden, Paolo Peerani, and Laura Aldave De Las Heras. "Metrology applications to D&D issues: issues at stake for INSIDER European project." EPJ Nuclear Sciences & Technologies 6 (2020): 17. http://dx.doi.org/10.1051/epjn/2019052.

Full text

Abstract:

Nuclear metrology is an essential aspect to consider for further improvements of the initial characterization of sites under decommissioning. The H2020 Euratom project INSIDER in June 2017 aims at improving the management of contaminated materials arising from decommissioning and dismantling (D&D) operations by proposing an integrated methodology for radiological characterization. This methodology is based on advanced statistical processing and modelling, coupled with adapted or innovative measurement methods. A metrological approach supports the qualification of this integrated methodology with a concrete application to real projects representative of the use cases identified in the project. Assessment of the outcomes will be used for providing recommendations and guidance resulting in pre-standardization texts.

APA, Harvard, Vancouver, ISO, and other styles

24

Simonis, A., P. Poskas, A. Sirvydas, and D. Grigaliuniene. "Modeling of the Radiation Doses during Dismantling of RBMK-1500 Reactor Pressurized Tanks from Emergency Core Cooling System." Science and Technology of Nuclear Installations 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/576432.

Full text

Abstract:

Decommissioning of the Ignalina Nuclear Power Plant involves multiple problems. One of them is personnel radiation safety during the performance of dismantling activities. In this paper, modeling results of radiation doses during the dismantling of the pressurized tank from the emergency core cooling system (ECCS PT) of RBMK-1500 reactor are presented. The radiological surveys indicate that the inner surface of the ECCS PT is contaminated with radioactive products of corrosion and sediments due to the radioactive water. The effective doses to the workers have been modeled for different strategies of ECCS PT dismantling. In order to select the optimal personnel radiation safety, the modeling has been performed by the means of computer code “VISIPLAN 3D ALARA Planning tool” developed by SCK CEN (Belgium). The impacts of dismantling tools, shielding types, and extract ventilation flow rate on effective doses during the dismantling of ECCS PT have been analyzed. The total effective personnel doses have been obtained by summarizing the effective personnel doses from various sources of exposure, that is, direct radiation from radioactive equipment, internal radiation due to inhalation of radioactive aerosols, and direct radiation from radioactive aerosols arising during hot cutting in premises. The uncertainty of the collective doses is also presented in this paper.

APA, Harvard, Vancouver, ISO, and other styles

25

Chen, Ziyuan, Sascha Gentes, Dennis Hartmann, Björn Hein, Siavash Kazemi, and Alena Wernke. "From environmental exploration to clearance measurement – developing mobile robot systems for decommissioning of nuclear power plants." at - Automatisierungstechnik 70, no. 10 (October 1, 2022): 900–911. http://dx.doi.org/10.1515/auto-2022-0058.

Full text

Abstract:

Abstract The number of decommissioning projects related to nuclear power plants is increasing and has been regarded as a challenging task for many nations. For example, Germany has decided to phase out nuclear power plants by the year 2022. To reduce the hazardous potential and the personal radiation exposure of the employees, robotic support in the decommissioning process is needed. In this contribution, a robot-based closed chain is presented as an important component for an automation and digitalization of the dismantling process of a nuclear power plant. The focus of the chain is on the investigation and decontamination of flat wall areas in nuclear facilities. First, geometric and radiation data are collected autonomously with a mobile, agile robot. The collected data is processed by using Building Information Modelling (BIM) methods to support the following steps. A second, industrial platform is modified to enable the positioning of two developed tools, a milling tool, and a contamination array, which will be used for decontamination and clearance measurement of concrete surfaces.

APA, Harvard, Vancouver, ISO, and other styles

26

Park, Jongwon, Chang-Hoi Kim, Kyung-min Jeong, Byung-Seon Choi, and Jeikwon Moon. "Evaluation methodology of a manipulator actuator for the dismantling process during nuclear decommissioning." Annals of Nuclear Energy 91 (May 2016): 22–24. http://dx.doi.org/10.1016/j.anucene.2015.12.038.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Michel, Maugan, Guillaume Amoyal, and Vincent Schoepff. "CLEANDEM, a Cyber physicaL Equipment for unmAnned Nuclear DEcommissioning Measurements." EPJ Web of Conferences 288 (2023): 07004. http://dx.doi.org/10.1051/epjconf/202328807004.

Full text

Abstract:

Human intervention is still required nowadays for most operations conducted during the Dismantling & Decommissioning (D&D) steps, which cover a wide range of radiological conditions: from the harsh initial conditions, nearly identical to when operating, to the final decommissioning steps where radioactivity has been removed. The goal of the three years EU-funded CLEANDEM project, led by CEA List, is to deliver a unique platform which will support the end-users’ operations, from the initial radiological assessment to the final characterization of the facility, while enabling their continuous monitoring during the D&D operations. Ten leading actors from four European countries’ nuclear industry and research, have joined their expertise and efforts in the CLEANDEM consortium to develop a mobile unmanned ground platform (UGV), equipped with upgraded highly-mature detection technologies for 3D-localized radiological measurements. These will complete the facilities’ available data into a 3D and fully detailed Digital Twin of the surveyed area, thus improving the planning and traceability of the D&D operations.

APA, Harvard, Vancouver, ISO, and other styles

28

Engovatov, Igor, and Zhanna Kovalenko. "Algorithm for constructing an organizational and technological model for dismantling NPP buildings." E3S Web of Conferences 263 (2021): 04044. http://dx.doi.org/10.1051/e3sconf/202126304044.

Full text

Abstract:

In coming decade the practical implementation of work on the decommissioning of nuclear power plants will begin. Failure to take into account the decommissioning stage for NPPs of the first generations, the presence of a radiation component in the building structures of NPP buildings and structures, the need to destroy protective barriers are the main problems in the issue of dismantling works. The destruction of barriers and the specifics of dismantling technological processes can lead to the release of radioactivity into the environment, which will lead to an increase in the radiation load on personnel and the population. Radioactive contamination of structures leads to the formation of a large volume of radioactive waste, the amount of which can be significantly reduced due to the competent separation of waste into classes, taking into account the holding time. In this study the design of the reactor building for unit 1 of the Novovoronezh NPP was considered. Based on the analysis of the data of the comprehensive engineering and radiation surveys (CERS), which was completed in 2004, a classification of buildings into three groups was proposed. Based on the results of CERS, the dependences of the total activity of the main radionuclides and the cost of maintaining the block under observation from time are presented. As a result of the performed studies, an algorithm for constructing an organizational and technological model for dismantling buildings and structures of NPP that are being decommissioned is proposed.

APA, Harvard, Vancouver, ISO, and other styles

29

Lucas-Lamouroux, Christine, Olivier Vincent, Brice Roffino, Pauline Suchet, and Mihaela Racape. "Model-based system engineering, an industrialization path for decommissioning projects by ASSYSTEM." EPJ Nuclear Sciences & Technologies 9 (2023): 24. http://dx.doi.org/10.1051/epjn/2023008.

Full text

Abstract:

Dismantling projects (dismantling of the high activity tanks of the UP1 plant, treatment of residual sodium from the Rapsodie facility, recovery of bitumen drums from the STEL Marcoule casemates, …) are complex because of budgets constraints, no return on investment, and characterized by an environment with great uncertainty (NEA OCDE, The decommissioning and dismantling of nuclear facilities, status, approaches, challenges 2020 [1]). This is particularly true for fuel cycle facilities, which are mainly all first-of-a-kind; but it is also valid for commercial NPP (notably on the budget constraints). The main challenges are to (i) conciliate the cost control & risks of uncertainties due to technical subjects, which is the hard skills of the system, and (ii) manage the interfaces between the product owner, engineering, technology provider, operators, & regulators, which is the soft skills of the system. These projects do not progress as much as everyone would like, with a reluctance to move into execution, stuck into several “rounds” of re-engineering studies leading to additional delays and costs. It is necessary to treat the subject as a complex system. The DEMOLOGIST suite is one answer that we implemented to treat these complex projects as systems by deploying a method based on system engineering management of data while developing adapted digital plug-in software to collect, organize and harmonize the data at every stage (archives, regulators requirements, field operations) to feed the method. This is notably the case on a project aiming at studying the best option to deal with sodium management in France.

APA, Harvard, Vancouver, ISO, and other styles

30

Berela, A. I., S. A. Tomilin, and A. G. Fedotov. "Basic principles for the development of competitive projects dismantling decommissioning of nuclear power plants." Izvestiya MGTU MAMI 9, no. 4-5 (October 20, 2015): 191–95. http://dx.doi.org/10.17816/2074-0530-67272.

Full text

Abstract:

In work the basic principles of development of dismantling works technological projects at blocks of nuclear power plants decommission with using of the generalized criterion of their efficiency are presented. The stated rules of application of the generalized criterion of efficiency promote development of the rational projects considering influence of technical and economic factors at an unconditional priority of radiation safety factors of works that promotes their objective choice in the competitive environment of offers of this kind of activity.

APA, Harvard, Vancouver, ISO, and other styles

31

Meyer, Franz, Ferdinand Steger, and Roland Steininger. "Decommissioning of the ASTRA research reactor: Dismantling the auxiliary systems and clearance and reuse of the buildings." Nuclear Technology and Radiation Protection 23, no. 1 (2008): 54–62. http://dx.doi.org/10.2298/ntrp0801054m.

Full text

Abstract:

The paper presents work performed in the last phase of the decommissioning of the ASTRA research reactor at the Austrian Research Centers Seibersdorf. Dismantling the pump room installations and the ventilation system, as well as the clearance of the buildings is described. Some conclusions and summary data regarding the timetable, material management, and the cost of the entire project are also presented.

APA, Harvard, Vancouver, ISO, and other styles

32

Nolden, Markus, Agnes Scaramus, Rahim Nabbi, Frank Charlier, and Klaus Fischer-Appelt. "Radiological characterization of a German pressurized water reactor based on a highly resolved method for activity analysis and dose rate calculation." Safety of Nuclear Waste Disposal 1 (November 10, 2021): 25–26. http://dx.doi.org/10.5194/sand-1-25-2021.

Full text

Abstract:

Abstract. The amendment to the atomic act in 2011 results to phase out nuclear energy in Germany until the end of 2022. Subsequently, the licensee of the nuclear power plant is responsible for decommissioning and dismantling. During operation, activation of structures near the core of the reactor occur which govern the amount of radioactive waste, the dose rate distribution and dismantling strategies. Thus, a detailed radiological characterization of in-core and out-core structures is required to optimize decommissioning processes regarding the quantification and minimization of radioactive waste, radiation protection and reducing radiation exposure. These objectives are achieved using an innovative and efficient method developed and applied at the Chair of Repository Safety (Lehrstuhl für Endlagersicherheit, ELS) RWTH Aachen University. Within the framework of the joint project „Development of a methodology for activity analysis and dose rate estimation“, funded by the Federal ministry of Education and Research, approaches the objective to develop a standardized and highly resolved method to calculate time-dependent activity of components and structures near the reactor core based on operating history of the nuclear power plant and neutron fluence distribution. The approach requires the development of a detailed model for Monte-Carlo simulations which provides the basis to neutron fluence, neutron spectra and radiation transport simulations. To calculate the nuclide specific 3-Dimensional (3D) activity distribution of the entire facility, a facility-dependent activation cross section library is produced which focuses on recent nuclear databases (ENDF/B-VIII.0). A highly resolved and space-dependent 3D activity distribution of the entire facility is obtained using a modular program package, developed at ELS, including the activation code ORIGEN2. The results are produced in the form of detailed 3D activity maps. The source terms are generated on the basis of the space-dependent 3D activity distribution using an additional module of the program package. The combination of recent nuclear databases focusing on ENDF/B-VII.1 and complemented by JEFF-3.3 ensures a comprehensive characterisation of source terms. Subsequently, source terms are prepared for 3D radiation transport simulation using the Monte-Carlo method and the computer code MCNP. The simulations are conducted separately for each individual component obtaining the partial contribution of all in-core and out-core structures as well as the dose rate distribution of the entire facility. Similar to the activity calculation, the simulation results are used to generate 3D gamma flux and dose rate maps using the graphic module of the whole program system. On the basis of the radiological characterisation and in view of a high-level radiation protection these maps allow the optimum planning and realisation of the decommissioning and dismantling process of the nuclear power plant.

APA, Harvard, Vancouver, ISO, and other styles

33

Nash, R. S., and P. B. Woollam. "The potential benefits and drawbacks of deferring the decommissioning and dismantling of nuclear facilities." Nuclear Energy 41, no. 5 (October 2002): 325–31. http://dx.doi.org/10.1680/nuen.41.5.325.38997.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Cecchi, Savéria, Pierre Daniel, Nadine Gabor, Sascha Gentes, Yoann Guntzburger, Natalia Jubault Krasnopevtseva, Renata Kaminska, et al. "Nuclear decommissioning: project management and leadership." Safety of Nuclear Waste Disposal 2 (September 6, 2023): 5–6. http://dx.doi.org/10.5194/sand-2-5-2023.

Full text

Abstract:

Abstract. Management and leadership for safety relate to managerial competencies necessary to develop, promote and sustain a safety culture and to set goals, lead others and manage knowledge and projects to enhance safety performance. The development of these competencies is needed to enrich and complement the predominant technical background and skills of engineers and/or managers involved in the nuclear sector and particularly in decommissioning and dismantling (D&D) projects. The recent recognition of the importance of managing for safety led the International Atomic Energy Agency (IAEA) to develop formal safety requirements that are now implemented by its member states. This includes the need to develop training and education for beginning- and mid-career managers with nuclear safety responsibilities and, considering the time frame of D&D projects, for future generations of managers. Training and education challenges are acute in all Instrument for Nuclear Safety Cooperation (INSC) and European countries, where managers need to develop knowledge and comprehensive safety-related competencies to run the D&D projects of nuclear facilities in a context where the generational change of managers in the nuclear field is happening fast. In 2016/2017 the IAEA and the European Commission (EC) developed a cooperative framework to jointly address a similar challenge related to operation and regulatory oversight of nuclear installations. The development of these projects was possible by funding from the European Union (EU) through its INSC instrument. The first project, led by the IAEA in 2017, was the development of a pilot school for safety leadership at the University Côte d'Azur (UCA), France. Encouraged by this success, the agency has since then developed the syllabus into a 2-week programme, still based on experiential learning, which is offered to IAEA member states who wish to organise sessions for their managers (regulatory bodies or industry). The second project, named ELSE, was operated by UCA and aimed to develop training to help managers acquire leadership for safety capabilities, which are key professional requirements in complex, high-risk and highly regulated sectors such as the nuclear sector. The originality of the ELSE project stemmed from its science-based approach, integrating the most recent findings of management and other social sciences. The dedicated ELSE training programme is composed of a massive online open course (MOOC), a 10 d of face-to-face training and an individually tutored project. Based on the success of these experiences, the EU decided to prolong these actions in the field of nuclear D&D, leading to the start-up, in 2023, of the Decommissioning Management and Leadership for Safety Education (DMaLSE) project. This project has also been entrusted to UCA, in partnership with SKEMA Business School, the Karlsruhe Institute of Technology (KIT) and Jacques Repussard Conseil. DMaLSE has two main objectives, namely to develop a science-based training programme for future D&D project managers and to extend the impact of the project through bachelor-degree-level on-site training for operators involved in D&D projects.

APA, Harvard, Vancouver, ISO, and other styles

35

Meyer, Franz, and Ferdinand Steger. "Decommissioning of the ASTRA research reactor: Dismantling of the biological shield." Nuclear Technology and Radiation Protection 21, no. 2 (2006): 79–91. http://dx.doi.org/10.2298/ntrp0602079m.

Full text

Abstract:

The paper describes the dismantling of the inactive and activated areas of the biological shield of the ASTRA research reactor at the Austrian Research Center in Seibersdorf. The calculation of the parameters determining the activated areas at the shield (reference nuclide, nuclide vector in the barite concrete and horizontal and vertical reduction behaviors of activity concentration) and the activation profiles within the biological shield for unrestricted release, release restricted to permanent deposit and radioactive waste are presented. Considerations of located activation anomalies in the shield, e.g. in the vicinities of the beam-tubes, were made according to the reactor's operational history. Finally, an overview of the materials removed from the biological shield is given.

APA, Harvard, Vancouver, ISO, and other styles

36

Bachmann, Madeleine, and Sascha Gentes. "Explanations for the development of a novel universally inside pipe separator for dismantling (contaminated) pipelines." Safety of Nuclear Waste Disposal 1 (November 10, 2021): 19–20. http://dx.doi.org/10.5194/sand-1-19-2021.

Full text

Abstract:

Abstract. During the operation and dismantling of nuclear facilities, individual pipelines must always be removed due to leaks because of the end of their maximum service life or the dismantling of the plant. In practice, this activity, which at first glance appears simple, is associated with many challenges due to limited space or the fact that the pipelines run through walls, despite various solutions that are available on the market. Therefore, the aim of the joint research project “RoTre” (Development of a novel universally inside pipe separator for dismantling contaminated pipelines) between KIT, Siempelkamp NIS Ingenieurgesellschaft mbH and RWE Nuclear GmbH is the development of an innovative and competitive inside pipe separator for use in decommissioning and dismantling of nuclear facilities with a wide range of applications for various pipe diameters, wall strengths and materials (Fig. 1). An amendment will be the forward cleaning, whereby metal chips or other components can be captured continuously. Besides the dismantling in areas which are difficult to access, such as pipelines set in concrete or pipelines that cannot be drilled over their full length, dismantling should be possible in air and under water. After application, the system can be decontaminated. In order to separate pipes made out of different materials with various wall thicknesses, the development of a universally applicable test stand is planned in order to achieve the scientific work objectives. Among other things, it should be determined whether a sawing or an abrasive cutting process is more suitable for cutting inside pipes. Building on this, the parameters of the separation process are tested in a parameter study to achieve the smallest possible process forces with a universal applicability. Relevant parameters are the geometry parameters of the cutting unit like the saw tooth shape, the composition of the cutting wheel, as well as the process parameters in the form of infeed, cutting speed and tool speed. The cutting quality achieved by the different tools with the setting of the machine parameters is also an evaluation criterion for the selection of the cutting process.

APA, Harvard, Vancouver, ISO, and other styles

37

Santos, Pedro, Jörg Recknagel, Martin Knuth, Klaus Steinbacher, Martin Ritz, Burkhard Wassmann, and Dieter Fellner. "ROBBE – Robot-aided processing of assemblies during the dismantling of nuclear power plants." EPJ Nuclear Sciences & Technologies 8 (2022): 20. http://dx.doi.org/10.1051/epjn/2022016.

Full text

Abstract:

For a successful decommissioning and dismantling of an NPP (Nuclear Power Plant), correct and controlled processing of all components is necessary, whereby a large part of the work relates to coated (mainly painted) steel components, which make up a significant proportion of the total inventory of the power plant to be processed. The contamination of these components is reduced by removing the surface coating using UHP (Ultra-High-Pressure) water jet blasting technology. Thus, the decontaminated material is released to be recycled conventionally after receiving clearance in accordance with Chap. 3 StrlSchV (German Federal Law Gazette 2018 No. 41: StrlSchV, 2018). The manual processing of these individual parts is cost-intensive, so that an autonomous, automated solution is more economical while increasing throughput at repeatable high quality. ROBBE aims at implementing a robot-assisted, automated and autonomous decoating procedure of component groups using UHP water jet blasting technology and implements it ata German NPP in Biblis on an industrial, productive scale.

APA, Harvard, Vancouver, ISO, and other styles

38

Pieraccini, Michel, and Sylvain Granger. "A nuclear owner/operator perspective on ways and means for joint programming on predisposal activities." EPJ Nuclear Sciences & Technologies 6 (2020): 20. http://dx.doi.org/10.1051/epjn/2019039.

Full text

Abstract:

Nuclear decommissioning is a worldwide competitive market. It is also the main source of radioactive waste from the nuclear energy field. In order to reduce the waste volume it is necessary to sort the actual radioactive waste to be disposed of and to separate them from other materials that could be recycled. Since 2015, Electricité de France (EDF) has gathered the waste management and dismantling (WM&D) projects, the related competences and human resources in the WM&D field, in a dedicated directorate (DP2D) and a company group called Cyclife (including waste treatment facilities). Taking into account the experience gained by carrying out its own WM&D projects as well as contributing to international cooperation, EDF considers that integrating collaborative research and development (R&D) on pre-disposal and waste management could be carried out following four main objectives: (1) alignment of the application of regulatory frameworks through appropriate definition of criteria and rules for radioactive waste to enable sensible worldwide comparison of technics; (2) improvement of technical and organisational aspects of nuclear reactors decommissioning using a demonstrator facility to be in operation, at first for graphite reactors, by 2022; (3) development of new techniques to decontaminate/homogenize metallic materials through a dedicated recycling route. These technics will be implemented in a new treatment facility foreseen to be available by 2030; and (4) increased training of decommissioning operators with the help of new technologies. All these improvements are aiming, beyond technical and experimental aspects, at reducing environmental impacts of nuclear activities as well as preserving the radioactive disposal volumes, as they are considered by EDF as rare resources.

APA, Harvard, Vancouver, ISO, and other styles

39

Mostečak, Ana, and Gordan Bedeković. "METAL WASTE MANAGEMENT AND RECYCLING METHODS IN THE NUCLEAR POWER PLANT DECOMMISSIONING AND DISMANTLING PROCESS." Rudarsko-geološko-naftni zbornik 33, no. 1 (December 16, 2017): 25–33. http://dx.doi.org/10.17794/rgn.2018.1.4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Lafon, Maxence, Vincent Chapurlat, Jean‐François Milot, and Cyril Moitrier. "A Model‐Based Approach to Design, Organize, and Monitor Dismantling and Decommissioning of Nuclear Facilities." INSIGHT 22, no. 4 (December 2019): 31–33. http://dx.doi.org/10.1002/inst.12272.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Hyun, Dongjun, Ikjune Kim, Sungmoon Joo, Jaehyun Ha, and Jonghwan Lee. "Remote dismantling system using a digital manufacturing system and workpiece localization for nuclear facility decommissioning." Annals of Nuclear Energy 195 (January 2024): 110182. http://dx.doi.org/10.1016/j.anucene.2023.110182.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Aspe, Frederic, Raquel Idoeta, Gregoire Auge, and Margarita Herranz. "Classification and categorization of the constrained environments in nuclear/radiological installations under decommissioning and dismantling processes." Progress in Nuclear Energy 124 (June 2020): 103347. http://dx.doi.org/10.1016/j.pnucene.2020.103347.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Manna, Giustino, Irina Kuzmina, and Jaroslav Holy. "Outcomes of an international initiative for harmonization of low power and shutdown probabilistic safety assessment." Nuclear Technology and Radiation Protection 25, no. 3 (2010): 222–28. http://dx.doi.org/10.2298/ntrp1003222m.

Full text

Abstract:

Many probabilistic safety assessment studies completed to the date have demonstrated that the risk dealing with low power and shutdown operation of nuclear power plants is often comparable with the risk of at-power operation, and the main contributors to the low power and shutdown risk often deal with human factors. Since the beginning of the nuclear power generation, human performance has been a very important factor in all phases of the plant lifecycle: design, commissioning, operation, maintenance, surveillance, modification, decommissioning and dismantling. The importance of this aspect has been confirmed by recent operating experience. This paper provides the insights and conclusions of a workshop organized in 2007 by the IAEA and the Joint Research Centre of the European Commission, on Harmonization of low power and shutdown probabilistic safety assessment for WWER nuclear power plants. The major objective of the workshop was to provide a comparison of the approaches and the results of human reliability analyses and gain insights in the enhanced handling of human factors.

APA, Harvard, Vancouver, ISO, and other styles

44

Soós, Róbert, Bence Balogh, Gergely Dobos, Szabolcs Szávai, and Judit Dudra. "Innovative technologies in training and education for maintenance team of NPPs." EPJ Nuclear Sciences & Technologies 5 (2019): 21. http://dx.doi.org/10.1051/epjn/2019053.

Full text

Abstract:

Many industries, such as nuclear power plants, chemical industry, oil and gas industry have dangerous working environments and hazardous conditions for employees. Maintenance, inspection and decommissioning activities in these safety-critical areas mean a serious risk, downtime is a significant financial loss. The Virtual Reality Training Platform is reflecting on this shortcoming, by providing the possibility for maintenance workers to be trained and prepared for unexpected scenarios, and to learn complex maintenance protocols without being exposed to unnecessary danger, like high temperature, radiation, etc. Employees can have training for equipment maintenance, dismantling of facilities at closed NPP Units. One of the most significant and unique added value of the immersive virtual reality solution is that the operator can experience lifelike emergencies (detonation, shutdown) under psychological pressure, while all of the physiology indicators can be monitored like eye-tracking. Users can work together anywhere in the world. A huge financial outage in industrial production is the preparation and maintenance downtime, which can be significantly reduced by the Virtual Training platform. This method can increase the accuracy, safety, reliability, and accountability of the maintenance and decommissioning procedures, while operational costs can be reduced as well.

APA, Harvard, Vancouver, ISO, and other styles

45

Ritter, Guillaume, Romain Eschbach, Richard Girieud, and Maxime Soulard. "CESAR5.3: Isotopic depletion for Research and Testing Reactor decommissioning." EPJ Nuclear Sciences & Technologies 4 (2018): 10. http://dx.doi.org/10.1051/epjn/2018008.

Full text

Abstract:

CESAR stands in French for “simplified depletion applied to reprocessing”. The current version is now number 5.3 as it started 30 years ago from a long lasting cooperation with ORANO, co-owner of the code with CEA. This computer code can characterize several types of nuclear fuel assemblies, from the most regular PWR power plants to the most unexpected gas cooled and graphite moderated old timer research facility. Each type of fuel can also include numerous ranges of compositions like UOX, MOX, LEU or HEU. Such versatility comes from a broad catalog of cross section libraries, each corresponding to a specific reactor and fuel matrix design. CESAR goes beyond fuel characterization and can also provide an evaluation of structural materials activation. The cross-sections libraries are generated using the most refined assembly or core level transport code calculation schemes (CEA APOLLO2 or ERANOS), based on the European JEFF3.1.1 nuclear data base. Each new CESAR self shielded cross section library benefits all most recent CEA recommendations as for deterministic physics options. Resulting cross sections are organized as a function of burn up and initial fuel enrichment which allows to condensate this costly process into a series of Legendre polynomials. The final outcome is a fast, accurate and compact CESAR cross section library. Each library is fully validated, against a stochastic transport code (CEA TRIPOLI 4) if needed and against a reference depletion code (CEA DARWIN). Using CESAR does not require any of the neutron physics expertise implemented into cross section libraries generation. It is based on top quality nuclear data (JEFF3.1.1 for ∼400 isotopes) and includes up to date Bateman equation solving algorithms. However, defining a CESAR computation case can be very straightforward. Most results are only 3 steps away from any beginner's ambition: Initial composition, in core depletion and pool decay scenario. On top of a simple utilization architecture, CESAR includes a portable Graphical User Interface which can be broadly deployed in R&D or industrial facilities. Aging facilities currently face decommissioning and dismantling issues. This way to the end of the nuclear fuel cycle requires a careful assessment of source terms in the fuel, core structures and all parts of a facility that must be disposed of with “industrial nuclear” constraints. In that perspective, several CESAR cross section libraries were constructed for early CEA Research and Testing Reactors (RTR’s). The aim of this paper is to describe how CESAR operates and how it can be used to help these facilities care for waste disposal, nuclear materials transport or basic safety cases. The test case will be based on the PHEBUS Facility located at CEA − Cadarache.

APA, Harvard, Vancouver, ISO, and other styles

46

Tran, Quoc Duong, Nhi Dien Nguyen, Kien Cuong Nguyen, Ton Nghiem Huynh, Ba Vien Luong, Minh Tuan Nguyen, Quang Huy Pham, Doan Hai Dang Vo, Minh Phong Do, and Nguyen Thanh Vinh Ho. "Evaluation of neutron flux distribution in structural components and activation products in aluminum alloy at 13-2 channel of the DNRR." Nuclear Science and Technology 11, no. 3 (September 30, 2021): 1–10. http://dx.doi.org/10.53747/nst.v11i3.364.

Full text

Abstract:

The estimation of radiological properties of activated structural components of a nuclear reactor due to irradiation of neutron produced by fission is a very important task for radiation safety and reasonable cost of dismantling and radioactive waste management in the decommissioning plan of the reactor. In this work, the calculation approach was carried out by using three-dimensional neutron transport model with the Monte Carlo code MCNP5 to evaluate neutron fluxes and reaction rates. The Bateman equation was solved with neutron absorption reactions (fission and capture) and disintegration by ORIGEN2 code to obtain the activity of materials in reactor structures. This paper presents the evaluation results of the neutron flux distribution and the radioactivity of long-lived key activation products such as 60Co, 55Fe, 59Ni, 63Ni, etc. isotopes in the structural components of the Dalat Nuclear Research Reactor (DNRR). The validation of calculation methodology of the two codes was implemented by comparing calculation results with measured neutron fluxes at irradiation positions in the reactor core as well as specific activities at the bottom part of the aluminum guiding tube at 13-2 channel, which has been removed from the reactor core about six years. The calculation results were in good agreement under 7% difference with the experimental neutron flux value of (6.05±0.52) × 1012 n/cm2.s, and under 33% difference with the experimental specific activities of 60Co isotope being 1.86×104, 9.99×104, and 1.28×105 Bq/g at the positions of -32.5, -17.5 and -2.1 cm (the centerline of the reactor core is at 0 cm), respectively, in the aluminum guiding tube of irradiation channel 13-2. The neutron flux distributions in other structural components such as the graphite reflector, thermal column, thermalizing column, concrete shielding, etc. of the reactor were also evaluated. The obtained calculation results and experimental data are very valuable for the development of a suitable decommissioning plan and a reasonable dismantling strategy for the DNRR.

APA, Harvard, Vancouver, ISO, and other styles

47

Bach, Fr W., W. Pfeifer, R. Versemann, P. Wilk, L. Valencia, B. Eisenmann, and G. Hammer. "Decommissioning technologies, including recent developments and special features of the dismantling of nuclear research and prototype facilities." Kerntechnik 70, no. 1-2 (February 2005): 31–46. http://dx.doi.org/10.3139/124.100223.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Шандала, Н., N. Shandala, Д. Исаев, D. Isaev, А. Титов, A. Titov, В. Шлыгин, et al. "Radiation Survey in the Vicinity of the Shipyards Involved in Decommissioning and Dismantlement of Nuclear Ships." Medical Radiology and radiation safety 64, no. 5 (October 21, 2019): 9–14. http://dx.doi.org/10.12737/1024-6177-2019-64-5-9-14.

Full text

Abstract:

Purpose: To study radiation and health physics situation in the vicinity of the shipyards “The 10th Shipyard, a Holder of Order of the Red Banner of Labor” (JSC “10 SRZ”) and “The Nerpa Shipyard” – a branch of the JSC “The Shipyard Center “Zvezdochka” (SRZ “Nerpa”) after the completion of the main stage of nuclear submarine dismantling and to assess potential effect of on-going activities to the environment and population. Material and methods: The following methods were used in radiation survey: pedestrian gamma survey of the site using portable gamma spectrometry complexes, gamma spectrometry and radiochemistry methods to determine the activity of manmade radionuclides in samples of environmental media. Results: Radiation and health physics studies were carried out from 2013 till 2017. It was shown that gamma dose rate within the health protection zones and supervision areas (SA) of the shipyards including the territories of the nearest cities – Snezhnogorsk and Polyarnyi – was at the level of regional values and did not exceed 0.14 µSv/h. The activities of radionuclides in soil from the surveyed sites did not exceed 23 Bq/kg for 90Sr and 100 Bq/kg for 137Cs. Concentrations of 90Sr and 137Cs in plants (mosses) at the surveyed sites did not exceed 70 and 48 Bq/kg, respectively, this is a bit higher than the background levels of the reference village of Belokamenka (1 and 20 Bq/kg, respectively, for 90Sr and 137Cs). The activity of seawater (Barents Sea) in 2016–2018 reached 60 mBq/l for 90Sr and 4 mBq/l for 137Cs, at mean values from 2 to 4 mBq/l over the period between 1990 and 2000 for the studied radionuclides. Data for 137Cs and 90Sr measured in samples of local wild plants, in particular, mushrooms, did not exceed 100 Bq/kg, this is much lower than the established permissible specific activities. Conclusion: Considerable impact of the work on the dismantling of nuclear submarines, maintenance ships and ships with a nuclear energy installation on the radiation situation in the areas of shipyards and health effects in the population of Snezhnogorsk and Polyarnyi was not revealed. However, along the external border of the surveyed shipyards some local parts of the sites of 5500 m2 area were found, where the specific activities of 90Sr and 137Cs in soil exceeded background levels and bordered by the level of permissible specific activity for unlimited use of solid materials (137Cs – 100 Bq/kg).

APA, Harvard, Vancouver, ISO, and other styles

49

Lee, Taewoong, Seongmin Jo, Sunkyu Park, Nakjeom Kim, Kichul Kim, Seongjun Park, and Changyeon Yoon. "A Study on Estimation of Radiation Exposure Dose During Dismantling of RCS Piping in Decommissioning Nuclear Power Plant." Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT) 19, no. 2 (June 30, 2021): 243–53. http://dx.doi.org/10.7733/jnfcwt.2021.19.2.243.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Jeong, KwanSeong, ByungSeon Choi, JeiKwon Moon, Dongjun Hyun, Jonghwan Lee, IkJune Kim, GeunHo Kim, et al. "An evaluation on the scenarios of work trajectory during installation of dismantling equipment for decommissioning of nuclear facilities." Annals of Nuclear Energy 91 (May 2016): 25–35. http://dx.doi.org/10.1016/j.anucene.2016.01.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Nuclear decommissioning and dismantling'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles