scholarly journals Evaluation of Approaches for Well Abandonment and Temporary Shutdown at the "Yeniseiskiy" Site (Krasnoyarsk Territory, Nizhnekanskiy Massif)

2020 ◽  
Vol 13 (4) ◽  
pp. 30-41
Author(s):  
V. S. Gupalo ◽  
◽  
K. S. Kazakov ◽  
V. Yu. Konovalov ◽  
G. D. Neuvazhaev ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Development Project ◽  
The State ◽  
Natural Conditions ◽  
Term Operation ◽  
Entire Complex ◽  
Well Abandonment ◽  
Current Stage ◽  
Geological Research

Rock mass is considered as a natural barrier impeding the release of radioactive waste into the environment, being part of a multi-barrier system designed to ensure the safety of deep disposal facilities for radioactive waste (DDF RW). A number of regulatory documents [1] and recommendations [2, 3] states the importance of the geological medium, namely, its characteristics for the long-term safety of RW disposal. Current stage of URL development project is specifically focused on providing the opportunities for geological research covering target RW disposal horizons solely via borehole methods before the entire complex of underground excavations is formed. Due to long-term operation of wells and their initial design features, the state of some of these wells has appeared to be unsatisfactory requiring reconstruction. In addition, in accordance with certain legislative requirements, all wells shall be abandoned after relevant operations have been completed. The article discusses the reconstruction and abandonment of wells drilled at the Yeniseiskiy site. It demonstrates the feasibility of proposed designs providing the opportunities for further expansion of studies to investigate the state of rocks under natural conditions and to arrange for monitoring. The paper provides an evaluation and comparative analysis of plugging materials proposed to be applied under well abandonment operations.

Research and Development of Practical Industrial Cogeneration Technology in Japan

2000 ◽  
Author(s):  
Toshiaki Abe ◽  
Takashi Sugiura ◽  
Shuji Okunaga ◽  
Katsuhiro Nojima ◽  
Yasukata Tsutsui ◽  
...  
Keyword(s):  
Research And Development ◽  
Gas Turbine ◽  
High Temperatures ◽  
Gas Turbines ◽  
High Efficiency ◽  
Development Project ◽  
Term Operation ◽  
Resistance To Heat

This paper presents an overview of a development project involving industrial cogeneration technology using 8,000-kW class hybrid gas turbines in which both metal and ceramics are used in parts subject to high temperatures in order to achieve high efficiency and low pollution. The development of hybrid gas turbines focuses mainly on the earlier commercialization of the turbine system. Stationary parts such as combustor liners, transition ducts, and first-stage turbine nozzles (stationary blades) are expected to be fabricated from ceramics. The project aims at developing material for these ceramic parts that will have a superior resistance to heat and oxidation. The project also aims at designing and prototyping a hybrid gas turbine system to analyze the operation in order to improve the performance. Furthermore, the prototyped hybrid gas turbine system will be tested for long-term operation (4,000 hours) to verify that the system can withstand commercialization. Studies will be conducted to ensure that the system’s soundness and reliability are sufficient for industrial cogeneration applications.

scholarly journals Experience Obtained and Lessons Learnt from the Transition of Ukrainian NPPs to Long-Term Operation

2020 ◽  
pp. 15-29
Author(s):  
O. Shugailo ◽  
Yu. Grebenyuk ◽  
O. Zelenyі ◽  
D. Ryzhov ◽  
Ol-r Shugaylo ◽  
...  
Keyword(s):  
The State ◽  
Highly Qualified ◽  
Safety Review ◽  
Term Operation ◽  
Lessons Learnt ◽  
Periodic Safety ◽  
Scientific Potential ◽  
Unique Experience ◽  
Review Reports

Nuclear energy is a strategic Ukrainian industry that produces more than 50% of electricity at present. Over the last decade during the operation of Ukrainian NPPs, the set of technical matters have been found and corresponding tasks shall be decided with engaging of scientific potential of the country. One of such matter is a safety justification of NPP components and structures for the period that is bigger than an initial design one and that is defined as transition from design operation to the long-term operation (LTO). From the end of 2010 to the beginning of 2020, the State Nuclear Regulatory Inspectorate of Ukraine granted 11 licenses for 11 power units based on positive results of the state assessment and review of Periodic Safety Review Reports considering mandatory safety review each ten years. These results became possible due to the coordinated, conscientious and longstanding work of thousands of highly qualified nuclear experts, which led to the fact that Ukraine now has a unique experience in preparation for a transition of various types of WWER-1000 and WWER-440 reactors to LTO. The summarized results and lessons learnt from the practice of transition to LTO are presented in this paper.

Third National Inventory of Nuclear Liabilities: Main Findings, Lessons Learned

2013 ◽  
Author(s):  
Jacques Cantarella ◽  
Brigitte Roger
Keyword(s):  
Radioactive Waste ◽  
The State ◽  
Lessons Learned ◽  
Financial Resources ◽  
National Inventory ◽  
Article 9 ◽  
Radioactive Substances ◽  
Safe Management

The safe management of a country’s radioactive substances in both the short and the long term implies a cost to its present society and necessitates financial resources to cover these costs. Once they are needed, these financial resources may prove to be insufficient or even completely lacking, leading to a nuclear liability. By virtue of article 9 of the Belgian law of 12th December 1997, the Belgian Government wishes to avoid the occurrence of such nuclear liabilities. This law charges ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials with the mission to draw up a register of the localisation and the state of all nuclear sites and all sites containing radioactive substances, to estimate the costs of their decommissioning and remediation, to evaluate the existence and adequacy of the provisions for financing these future or current operations and to update the resulting inventory of nuclear liabilities on a five-yearly basis. This paper outlines the methodology put in place by ONDRAF/NIRAS to accomplish this assignment and highlights some of the results of this third inventory. It then focuses on the main recommendations ONDRAF/NIRAS made to the Belgian Government on the field of avoiding potential nuclear liabilities.

The NAGRA investigation project for the assessment of repositories for high-level radioactive waste in geological formations

1985 ◽  
Vol 49 (351) ◽  
pp. 281-288 ◽  
Author(s):  
Werner Balderer
Keyword(s):  
Radioactive Waste ◽  
Research Programme ◽  
Natural Conditions ◽  
Northern Switzerland ◽  
Hydrogeological Study ◽  
First Results ◽  
Granite Basement ◽  
High Level ◽  
Geological Formations ◽  
Geological Research

AbstractThe first results of isotopic investigations as a part of the hydrogeological study of northern Switzerland are presented. This study is part of the global geological research project of the NAGRA (National Co-operative for the Storage of Radioactive Waste) which is intended to provide the scientific knowledge required for the assessment of the feasibility of safe disposal of highly radioactive waste in the geological formations of the area. The aim of the hydrogeological research programme is to assess the natural conditions in the sedimentary sequence and the underlying granite basement, by regional investigation of hydraulic parameters, isotopic composition, and hydrogeochemistry at all existing wells (boreholes and natural thermal springs) and in 11 to 12 deep-drilled boreholes (to final depth of 1500–2500 m).

The Inventory of Nuclear Liabilities: A Mission of Public Interest

2009 ◽  
Author(s):  
Christian Cosemans ◽  
Jacques Cantarella ◽  
Gerda Bal
Keyword(s):  
Radioactive Waste ◽  
Public Interest ◽  
The State ◽  
Financial Resources ◽  
Article 9 ◽  
Radioactive Substances ◽  
Safe Management

The safe management of a country’s radioactive substances in both the short and the long term implies a cost to its present society and necessitates financial resources to cover these costs. Once they are needed, these financial resources may prove to be insufficient or even completely lacking, leading to a nuclear liability. By virtue of article 9 of the Belgian law of 12th December 1997, the Belgian Government wishes to avoid the occurrence of such nuclear liabilities. This law charges ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials with the mission to draw up a register of the localisation and the state of all nuclear sites and all sites containing radioactive substances, to estimate the costs of their decommissioning and remediation, to evaluate the existence and adequacy of the provisions for financing these future or current operations and to update the resulting inventory of nuclear liabilities on a five-yearly basis. This paper outlines the methodology put in place by ONDRAF/NIRAS to accomplish this assignment and highlights some of the results of this exercise. It than focuses on the main recommendations ONDRAF/NIRAS made to the Belgian Government on the field of avoiding potential nuclear liabilities.

scholarly journals Strengthening the Capabilities of the State Nuclear Regulatory Inspectorate of Ukraine through Interaction of Ukrainian and International Technical Safety Organizations under Licensing of Long-Term Operation of South Ukraine-1

2015 ◽  
pp. 27-30
Author(s):  
O-i Shugailo ◽  
O-r Shugailo ◽  
D. Ryzhov
Keyword(s):  
Technical Support ◽  
The State ◽  
Energy Strategy ◽  
Term Operation ◽  
Support Organizations ◽  
Technical Safety ◽  
Made In

The Energy Strategy of Ukraine for the period until 2030 foresees that about half of the Ukrainian NPP units will constitute those with extended lifetime (long term operation) over the next 10 years. The first “pilot” plants for long-term operation were Rivne units 1 and 2 (VVER-440/213) in 2010. South Ukraine NPP unit 1 (VVER-1000/V-302) is the next step in gaining long-term operation experience in Ukraine (appropriate decision was made in 2012). In both cases, the decision was preceded by many-year comprehensive activities performed by the operator, regulator and national and international scientific and technical support organizations, which were involved in safety justification from the operator and regulator sides.

scholarly journals Application of Interval Analysis Methods for NPP Power Units Safety and Reliability Assessment

2018 ◽  
pp. 23-29
Author(s):  
T. Potanina ◽  
O. Yefimov ◽  
T. Harkusha ◽  
T. Yesypenko
Keyword(s):  
Initial Data ◽  
Interval Analysis ◽  
Reliability Assessment ◽  
The State ◽  
Data Uncertainty ◽  
Unit Operation ◽  
Term Operation ◽  
State Program ◽  
Safety And Reliability

The study analizes the requirements for instrumentation and control systems of NPP units, which are currently under modernization in accordance with the state program for long-term operation of Ukrainian NPP units. The requirements established in the documents that regulate reliability and quality of performing functions by these systems emphasize the importance of developing methods to improve the accuracy of parameter measurements, methods to increase reliability of assessing safety and reliability indexes of NPP unit operation, as well as the accuracy of personnel decisions in the presence of many uncertainties and inaccuracies in the description of initial data that affect implementing necessary management actions by personnel. The paper presents the examples of the impact of initial data uncertainty on solving the tasks of safety and reliability assessment for NPP units. The study analyzes existing methods to account and describe initial data uncertainty and modeling uncertainty in the tasks of safety and operational reliability assessment for NPP units. The possibility of applying mathematical methods and tools of interval analysis to improve reliability of solving the issues of assessing safety, reliability and efficiency of NPP unit operation under conditions of initial data uncertainty was justified. The study presents the basic principles of interval calculations, which allow considering inaccuracies when specifying the initial data, parameter uncertainties and multi-mode nature of functioning of such complex technical systems as NPP units. The prospects of applying the main theoretical provisions of interval analysis and their implementation in the form of numerical methods and models to solve current issues of assessing safety, reliability and efficiency of accident-free operation of NPP units in compliance with the state program for long-term operation were specified.

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