scholarly journals Demonstration of Fatigue for LTO License of NPP Borssele

2015 ◽  
Author(s):  
M. H. C. Hannink ◽  
F. J. Blom ◽  
P. W. B. Quist ◽  
A. E. de Jong ◽  
W. Besuijen
Keyword(s):  
Environmental Effects ◽  
Nuclear Power ◽  
Power Plants ◽  
Integrated Approach ◽  
Temperature Measurements ◽  
Fatigue Assessment ◽  
Term Operation ◽  
Load Monitoring ◽  
Number Of Cycles ◽  
Ageing Management

Long Term Operation (LTO) of nuclear power plants (NPPs) requires an ageing management review and a revalidation of Time Limited Ageing Analyses (TLAAs) of structures and components important for nuclear safety. An important ageing effect to manage is fatigue. Generally, the basis for this is formed by the fatigue analyses of the safety relevant components. In this paper, the methodology for the revalidation of fatigue TLAAs is demonstrated for LTO of NPP Borssele in the Netherlands. The LTO demonstration starts with a scoping survey to determine the components and locations having relevant fatigue loadings. The scope was defined by assessment against international practice and guidelines and engineering judgment. Next, a methodical review was performed of all existing fatigue TLAAs. This also includes the latest international developments regarding environmental effects. In order to reduce conservatism, a comparison was made between the number of cycles in the analyses and the number of cycles projected to the end of the intended LTO period. The projected number of cycles is based on transient counting. The loading conditions used in the analyses were assessed by means of temperature measurements by the fatigue monitoring system (FAMOS). As a result of the review, further fatigue assessment or assessment of environmental effects was necessary for certain locations. New analyses were performed using state-of-the-art calculation and assessment methods. The methodology is demonstrated by means of an example of the surge line. The model includes the piping, as well as the nozzles on the pressurizer and the main coolant line. The thermal loadings for the fatigue analysis are based on temperature measurements. Fatigue management of the NPP is ensured by means of the fatigue concept where load monitoring, transient counting and fatigue assessment are coupled through an integrated approach during the entire period of LTO.

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.

INCEFA-PLUS Project: Lessons Learned From the Project Data and Impact on Existing Fatigue Assessment Procedures

2020 ◽  
Author(s):  
Sam Cuvilliez ◽  
Alec McLennan ◽  
Kevin Mottershead ◽  
Jonathan Mann ◽  
Matthias Bruchhausen
Keyword(s):  
Surface Finish ◽  
Environmental Effects ◽  
Nuclear Power ◽  
Power Plants ◽  
Lessons Learned ◽  
Fatigue Assessment ◽  
Data Points ◽  
Project Data ◽  
Assessment Procedures ◽  
Surface Finish Effect

Abstract The INCEFA+ project (INcreasing Safety in nuclear power plants by Covering gaps in Environmental Fatigue Assessment) is a five year project supported by the European Commission HORIZON2020 programme, which will conclude in June 2020. This project aims to generate and analyse Environmental Assisted Fatigue (EAF) experimental data (approximately 230 fatigue data points generated on austenitic stainless steel), and focuses on the effect of several key parameters such as mean strain, hold times and surface finish, and how they interact with environmental effects (air or PWR environment). This work focuses on the analysis of the data obtained during the INCEFA+ project. More specifically, this paper discusses how the outcome of this analysis can be used to evaluate existing fatigue assessment procedures that incorporate environmental effects in a similar way to NUREG/CR-6909. A key difference between these approaches and the NUREG/CR-6909 is the reduction of conservatisms resulting from the joint implementation of the adjustment sub-factor related to surface finish effect (as quantified in the design air curve derivation) and a Fen penalization factor for fatigue assessment of a location subjected to a PWR primary environment. The analysis presented in this paper indicates that the adjustment (sub-)factor on life associated with the effect of surface finish in air (as described in the derivation of the design air curve in NUREG/CR-6909) leads to substantial conservatisms when it is used to predict fatigue lifetimes in PWR environments for rough specimens. The corresponding margins can be explicitly quantified against the design air curve used for EAF assessment, but may also depend on the environmental correction Fen factor expression that is used to take environmental effects into account.

Incefa-Plus Project: Lessons Learned From the Project Data and Impact on Existing Fatigue Assessment Procedures

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Sam Cuvilliez ◽  
Alec McLennan ◽  
Kevin Mottershead ◽  
Jonathan Mann ◽  
Matthias Bruchhausen
Keyword(s):  
Surface Finish ◽  
Environmental Effects ◽  
Nuclear Power ◽  
Power Plants ◽  
Lessons Learned ◽  
Pressurized Water ◽  
Fatigue Assessment ◽  
Horizon 2020 ◽  
Project Data ◽  
Assessment Procedures

Abstract This work focuses on the analysis of the data generated during the INCEFA+ project (INcreasing safety in nuclear power plants (NPPs) by Covering gaps in Environmental Fatigue Assessment, a five-year project supported by the European Commission Horizon 2020 program). More specifically, this paper discusses how the outcome of this analysis can be used to evaluate existing fatigue assessment procedures that incorporate environmental effects in a similar way to NUREG/CR-6909. A key difference between these approaches and the NUREG/CR-6909 is the reduction of conservatisms resulting from the joint implementation of the adjustment subfactor related to surface finish effect (as quantified in the design air curve derivation) and a Fen penalization factor for fatigue assessment of a location subjected to a pressurized water reactor (PWR) primary environment. The analysis presented in this paper indicates that the adjustment (sub-) factor on life associated with the effect of surface finish in air (as described in the derivation of the design air curve in NUREG/CR-6909) leads to substantial conservatisms when it is used to predict fatigue lifetimes in PWR environments for rough specimens. The corresponding margins can be explicitly quantified against the design air curve used for environmentally assisted fatigue (EAF) assessment, but may also depend on the environmental correction Fen factor expression that is used to take environmental effects into account.

Fatigue Management During LTO of Nuclear Power Plant Borssele

2016 ◽  
Author(s):  
M. H. C. Hannink ◽  
C. G. M. de Bont ◽  
F. J. Blom ◽  
P. W. B. Quist ◽  
A. E. de Jong ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Measurement Data ◽  
Management Approach ◽  
Term Operation ◽  
Thermal Transients ◽  
Fatigue Management ◽  
Safety Margins ◽  
Load Monitoring ◽  
Load Evaluation

Fatigue is an important ageing effect to manage for long term operation (LTO) of nuclear power plants (NPPs). One of the steps in the process of LTO assessment is the revalidation of TLAAs (time limited ageing analyses). The safety margins of NPP Borssele with respect to fatigue were demonstrated by projecting the fatigue analyses to the end of the intended period of LTO. Besides this, it has to be ensured that the analyses remain valid during the entire period of LTO. Periodic verification of the load assumptions that are made in the analyses is therefore an important aspect of adequate fatigue management. In this paper, an integrated fatigue management approach is presented, coupling load monitoring, transient counting and fatigue assessment. The approach for periodic verification of the load assumptions in the fatigue analyses consists of two parts. First, it is verified whether the occurred numbers of cycles of the different load cases remain smaller than the numbers of cycles assumed in the fatigue analyses. Secondly, it is verified whether the thermal transients defined for the load cases in the fatigue analyses conservatively represent the occurred thermal transients. For the verification, the application LEAF (Load Evaluation Application for Fatigue) was developed. At NPP Borssele, thermal transients occurring during different load cases (e.g. start-up, shutdown, reactor trip) are registered by a temperature monitoring system. The load evaluation application processes the measurement data and verifies the conservatism of the load conditions in the fatigue analysis of the fatigue relevant components in the system. This paper explains the steps that are followed for the load evaluation and gives a demonstration of the results. The presented procedure is an essential part of adequate fatigue management during LTO.

OECD/NEA Activities to Support Long Term Operation

2010 ◽  
Vol 5 (6) ◽  
pp. 707-711
Author(s):  
Andrei Blahoianu ◽  
◽  
Alejandro Huerta ◽  
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Energy ◽  
State Of The Art ◽  
Integrated Approach ◽  
Energy Agency ◽  
Term Operation ◽  
Plant Life

The Integrity and Aging of Components and Structures Working Group (IAGE) of the Organisation for Economic Cooperation and Development (OECD)/Nuclear Energy Agency (NEA) was established under the Committee on the Safety of Nuclear Installations (CSNI) for three reasons: (i) to advance the current understanding of those aspects relevant to ensuring the integrity of structures, systems, and components ; (ii) to provide for guidance in choosing the optimal ways to handle challenges to the integrity of operating as well as new nuclear power plants, and (iii) to take an integrated approach to design, safety, and nuclear power plant life management. The group operates through annual plenary meetings and technical workshops and by issuing state-of-the-art reports and topical opinion papers. This paper details some recent IAGE activities and products, focusing on those dealing with the degradationmechanisms of metal and concrete components.

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.

scholarly journals Reactor performance, system reliability, instrumentation and control

2020 ◽  
Vol 6 ◽  
pp. 43
Author(s):  
Andreas Schumm ◽  
Madalina Rabung ◽  
Gregory Marque ◽  
Jary Hamalainen
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Lessons Learned ◽  
Software Systems ◽  
Reactor Performance ◽  
Horizon 2020 ◽  
Term Operation ◽  
In The Beginning ◽  
Electrical Cables

We present a cross-cutting review of three on-going Horizon 2020 projects (ADVISE, NOMAD, TEAM CABLES) and one already finished FP7 project (HARMONICS), which address the reliability of safety-relevant components and systems in nuclear power plants, with a scope ranging from the pressure vessel and primary loop to safety-critical software systems and electrical cables. The paper discusses scientific challenges faced in the beginning and achievements made throughout the projects, including the industrial impact and lessons learned. Two particular aspects highlighted concern the way the projects sought contact with end users, and the balance between industrial and academic partners. The paper concludes with an outlook on follow-up issues related to the long term operation of nuclear power plants.

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