Analysis of the Cause of Damage to the Steam Generator Cold Collector’s Dissimilar Weld Joint at Slovak Nuclear Power Plant

2020 ◽  
Vol 405 ◽  
pp. 165-170
Author(s):  
Michal Kapusňák ◽  
Michal Hajas ◽  
Marek Adamech
Keyword(s):  
Steam Generator ◽  
Weld Joint ◽  
Nuclear Power ◽  
Metallographic Analysis ◽  
Destructive Testing ◽  
Term Operation ◽  
Dissimilar Weld ◽  
Root Position ◽  
Non Destructive

By the non-destructive testing of a dissimilar weld joint (DWJ) of cold collector DN 1100 (CC) on a steam generator, indications were found on inner-side cold collector’s surface at the root position of the examined weld. All the identified indications were very similar in shape and form, therefore, it was decided to cut out a part of the damaged site from this type of DWJ DN 1100 and get the obtained ring (real piece of material) for complex metallographic analysis. This paper briefly describes the results and recommendations found for the future reference during the next long‑term operation induced ageing and degradation of critical steam generator parts in NPP Bohunice Unit 4. There are summarized the results obtained from evaluation of original DWJ material.

Implementation of Performance Demonstration Programs for Steam Generator Tubing Analysts

2006 ◽  
Vol 321-323 ◽  
pp. 1750-1753
Author(s):  
Chan Hee Cho ◽  
Min Woo Nam ◽  
Dong Hyun Jee ◽  
Jee Hong Jung ◽  
Hee Jong Lee
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Data Analyst ◽  
Testing Data ◽  
Steam Generator Tubing ◽  
Non Destructive ◽  
Performance Demonstration

The Korea Electric Power Research Institute (KEPRI) has developed performance demonstration programs for non-destructive testing personnel who analyze ECT (eddy current testing) data for steam generator tubing since 2001. The purpose of these performance demonstration programs is to ensure a uniform knowledge and skill level of data analysts and contribute to safe operation of nuclear power plants. Many changes have occurred in non-destructive testing of steam generator tubing such as inspection scope, plugging criteria and qualification requirements in Korea. According to the Notice 2004-13 revised by the Ministry of Science and Technology (MOST), the analyst for steam generator tubing shall be qualified as the qualified data analyst (QDA), and the site specific performance demonstration (SSPD) program shall be implemented. KEPRI developed these performance demonstration programs and they are being successfully implemented. The analyst's performance is expected to be improved by the implementation of these programs.

The Geometry of Steam Generator Tube and Its Relevance to the Occurrence of Stress Corrosion Cracking in Operating Nuclear Power Plants

2010 ◽  
Author(s):  
Deok Hyun Lee ◽  
Do Haeng Hur ◽  
Myung Sik Choi ◽  
Kyung Mo Kim ◽  
Jung Ho Han ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Steam Generator ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Corrosion Cracking ◽  
Location Type ◽  
Steam Generator Tubes ◽  
Non Destructive

Occurrences of a stress corrosion cracking in the steam generator tubes of operating nuclear power plants are closely related to the residual stress existing in the local region of a geometric change, that is, expansion transition, u-bend, ding, dent, bulge, etc. Therefore, information on the location, type and quantitative size of a geometric anomaly existing in a tube is a prerequisite to the activity of a non destructive inspection for an alert detection of an earlier crack and the prediction of a further crack evolution [1].

scholarly journals Safety assurance through advances in long-term operation

2020 ◽  
Vol 6 ◽  
pp. 44
Author(s):  
Kevin James Mottershead ◽  
Christian Robertson ◽  
Sebastian Lindqvist ◽  
Francisco Javier Perosanz Lopez ◽  
Eija Karita Puska
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Economies Of Scale ◽  
European Research ◽  
Term Operation ◽  
Environmental Consequences ◽  
Safety Assurance ◽  
Research And Innovation ◽  
Areas Of Interest

Mindful of the challenges to long-term operation, especially the severe safety and environmental consequences shown through historical nuclear power plant accidents (e.g. Fukoshima, Chernobyl, etc), it is imperative that European research and innovation focuses on demonstrating reliable long-term operation. Five examples of European Commission supported projects meeting such objectives are INCEFA+, SOTERIA, ATLAS+, MEACTOS and NUGENIA+. There are economies of scale within, and synergies across these projects which enable further advantage to be gained. Additionally, since researchers are well engaged internationally, this brings into European Organisations latest developments in understanding from further afield (e.g. USA, Japan), further enabling safety assurance advances, and enabling work overseas to be influenced consistent with European requirements. Through examples, this paper provides evidence of the advances claimed, whilst being careful to also declare areas of interest for which further work is still a priority.

Guided Waves as an Online Monitoring Technology for Long-Term Operation in Nuclear Power Plants: Experimental Results on a Steam Discharge Pipe

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Francesco Bertoncini ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Complex Structure ◽  
Theoretical Background ◽  
Guided Wave ◽  
Experimental Results ◽  
Term Operation

Guided wave (GW) testing is regularly used for finding defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). By using magnetostrictive sensors, some issues, which usually limit the application to nuclear power plants (NPPs), can be fixed. The authors have already shown the basic theoretical background and simulation results concerning a real steel pipe, used for steam discharge, with a complex structure. On the basis of such theoretical framework, a new campaign has been designed and developed on the same pipe, and the obtained experimental results are now here presented as a useful benchmark for the application of GWs as nondestructive techniques. Experimental measures using a symmetrical probe and a local probe in different configurations (pulse-echo and pitch-catch) indicate that GW testing with magnetostrictive sensors can be reliably applied to long-term monitoring of NPPs components.

Cyclic vs. Static Loading Behaviour of Masonry Blocks: An Approach to Evaluate the Long-Term Behaviour

2010 ◽  
Vol 452-453 ◽  
pp. 129-132
Author(s):  
Paola Antonaci ◽  
Pietro G. Bocca ◽  
Davide Masera
Keyword(s):  
Fatigue Behaviour ◽  
Non Destructive Testing ◽  
Static Displacement ◽  
Destructive Testing ◽  
Testing Laboratory ◽  
Cyclic Displacement ◽  
Non Destructive ◽  
Compressive Tests

The paper presents the results of an experimental investigation conducted on bricks. Prism-shaped specimens were produced. Laboratory tests were carried out at the Non-Destructive Testing Laboratory of the Politecnico di Torino. They were subjected to static compressive tests for the determination of their mechanical properties and cyclic compressive tests for the analysis of their fatigue behaviour. The aim of this work is to apply a failure criterion based on the observation of the static and cyclic curves to estimate the fatigue life and the long-term behaviour of the brick. Subsequently, it will be possible to give a relation between the static-displacement and cyclic-displacement of the material tested.

Lifetime Management of EDF PWR Pressure Vessels and Pipings

2004 ◽  
Author(s):  
F. Hedin ◽  
J. C. Legendre
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Pressure Vessels ◽  
Destructive Testing ◽  
Key Points ◽  
Cast Stainless Steel ◽  
Non Destructive

Lifetime management of EDF PWR vessels and pipings are one of the main technical key points of safety and competitivness. This paper describes the EDF global approach in this field, which is applied to the nuclear fleet i.e 58 nuclear power plants, and particularly to the first 34 three loops, as far as lifetime is concerned: • operating procedures and routine maintenance, special maintenance and ten years safety reassessment, • engineering analysis, based on feed back experience, scientific knowledge, degradations mechanisms, causes and consequences management, • operating loadings decrease, • complementary deterministic and cost-benefit analysis, • fit for service justifications, • anticipation strategy to prepare future, based on Non Destructive Testing investigations, ability to repair and/or to replace components, in situ expertises, ... Some examples are given: lifetime management of reactor vessels heads and bottom penetrations of pressure vessels, fit for service of cast stainless steel primary pipings, primary nozzles and auxiliary pipings special maintenance.

Research Activities in the European Union on Ageing Management for Long Term Operation of Nuclear Power Plants

2010 ◽  
Author(s):  
Oliver Martin ◽  
Antonio Ballesteros ◽  
Christiane Bruynooghe ◽  
Michel Bie`th
Keyword(s):  
Energy Supply ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Age Distribution ◽  
Term Operation ◽  
Research Activities ◽  
Ageing Management ◽  
The Eu

The energy supply of the future in the EU will be a mix of renewable, fossil and nuclear. There are 145 nuclear power reactors in operation in 15 out of the 27 EU countries, with installed power ∼132 GWe. The age distribution of current nuclear power plants in EU is such that in 2010 most of them will have passed 20-years and approximately 25% of them 30 years of age. The decrease of energy supply from nuclear generated electricity can not always be compensated in a reliable and economical way within a short time span. For this situation utilities may be keen to upgrade the reactor output and /or to ask their regulatory bodies for longer term operation. Under the research financed in the Euratom part of the Research Directorate (RTD) of the European Commission several projects explicitly address the safe long term operation of nuclear power plants (NULIFE, LONGLIFE) and the topics proposed in the 2010 call explicitly address issues concerning component ageing, in particular non metallic components, i.e. instrumentation and cables (I&C) and concrete ageing. This paper presents an overview of the plans for long term operation (LTO) of nuclear power plants in the EU. Special emphasis is given on research activities on component ageing management and long term operation issues related to safety.

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