AREVA’s Modularized Fatigue Monitoring for Lifetime Extension and Flexible Plant Operation

2014 ◽  
Author(s):  
Benedikt Heinz ◽  
David Wu
Keyword(s):  
Fatigue Assessment ◽  
Plant Operation ◽  
Thermal Transients ◽  
Plant Behavior ◽  
Load Following ◽  
Load Monitoring ◽  
Flexible Plant ◽  
Fatigue Estimation ◽  
The Impact ◽  
Lifetime Extension

For plant lifetime extension programs, AREVA provides a customized solution for thermal load monitoring and fatigue calculation. Requirements like environmental assisted fatigue effects or flexible plant operation (load following) have crucial impacts for a detailed fatigue assessment. With a modularized monitoring concept and automated simplified fatigue estimation technique, plant components can be monitored very cost efficiently with validated methodologies, providing flexible, fast and accurate results. The layout of the modularized monitoring system is simplified and different options can be added on demand. With the automated fatigue assessment, thermal transients can be classified and a cumulative usage factor can be estimated on-line. With the help of this method, the impact of thermal transients to the component fatigue can be evaluated just in time. That can be a piece of important information to get for a better knowledge about the plant behavior during flexible operating (load following) modes.

Fatigue Monitoring and Assessment: Different Approaches Combined for Lifetime Extension Challenges

2015 ◽  
Author(s):  
Tim Gilman ◽  
Mark Gray ◽  
Jürgen Rudolph ◽  
Benedikt Heinz
Keyword(s):  
Thermal Loading ◽  
Thermal Response ◽  
Engineering Practice ◽  
Extension Programs ◽  
Fatigue Assessment ◽  
Fatigue Monitoring ◽  
Load Monitoring ◽  
Time Histories ◽  
Flexible Plant ◽  
Lifetime Extension

For plant lifetime extension programs, several products provide a customized solution for thermal load monitoring and fatigue calculation. Requirements like the consideration of Environmentally Assisted Fatigue (EAF) effects or flexible plant (e.g. load follow) operation have a crucial impact on the engineering practice of a detailed fatigue assessment considering the realistically occurring loads. Several fatigue monitoring products are available on the market, some with local instrumentation added and some with transfer function approaches using existing plant instrumentation. The regulator in Germany requires thermal loading to be evaluated as realistically as practical, and thus additional instrumentation is typically added to measure the thermal response close to the monitored location. Elsewhere, and specifically in the U.S., the regulator has not required the addition of instrumentation, and thus utilities typically do not choose to add instruments. It is one purpose of the paper to explain in detail the different engineering approaches and the methodology of fatigue assessment, also under consideration of Environmentally Assisted Fatigue (EAF) and the calculation of the complete six terms stress tensor for given load-time histories. Considering the fatigue analysis of given input data (stress-time-histories) the comparability of fatigue calculations constitutes a challenging item. Recommendations will be given how to harmonize the approaches based on the technical and regulatory requirements. Finally, the issue of design code based fatigue monitoring guidelines and approaches is discussed. In this context, the German Nuclear Safety Standard KTA 3201.4 is addressed.

scholarly journals Application of Operational Load Monitoring System for Fatigue Estimation of Main Landing Gear Attachment Frame of an Aircraft

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6564
Author(s):  
Michal Dziendzikowski ◽  
Artur Kurnyta ◽  
Piotr Reymer ◽  
Marcin Kurdelski ◽  
Sylwester Klysz ◽  
...  
Keyword(s):  
Landing Gear ◽  
Fatigue Wear ◽  
Operational Load ◽  
Load Monitoring ◽  
Management Paradigms ◽  
Optimal Maintenance ◽  
Fatigue Estimation ◽  
The Individual ◽  
Vertical Landing ◽  
The Impact

In this paper, we present an approach to fatigue estimation of a Main Landing Gear (MLG) attachment frame due to vertical landing forces based on Operational Loads Monitoring (OLM) system records. In particular, the impact of different phases of landing and on ground operations and fatigue wear of the MLG frame is analyzed. The main functionality of the developed OLM system is the individual assessment of fatigue of the main landing gear node structure for Su-22UM3K aircraft due to standard and Touch-And-Go (T&G) landings. Furthermore, the system allows for assessment of stress cumulation in the main landing gear node structure during touchdown and allows for detection of hard landings. Determination of selected stages of flight, classification of different types of load cycles of the structure recorded by strain gauge sensors during standard full stop landings and taxiing are also implemented in the developed system. Based on those capabilities, it is possible to monitor and compare equivalents of landing fatigue wear between airplanes and landing fatigue wear across all flights of a given airplane, which can be incorporated into fleet management paradigms for the purpose of optimal maintenance of aircraft. In this article, a detailed description of the system and algorithms used for landing gear node fatigue assessment is provided, and the results obtained during the 3-year period of system operation for the fleet of six aircraft are delivered and discussed.

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.

Strain Rate Evaluation of Some Typical Nuclear Power Plant Components During Plant Operation

2010 ◽  
Author(s):  
Koji Dozaki ◽  
Hiromasa Chitose ◽  
Hiroshi Ogawa ◽  
Hideo Machida
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Strain History ◽  
Strain Rates ◽  
Peak Strain ◽  
Plant Operation ◽  
Thermal Transients ◽  
Reactor Water ◽  
Rate Evaluation ◽  
Reactor Internals

The dynamic aspects of loading conditions for reactor internals, piping and the like, are thought to play important roles in the initiation of failures due, for example, to stress corrosion cracking (SCC) and fatigue. Some reports show that a strain rate on the order of 10−7 s−1 most affects susceptibility to SCC in the BWR reactor water environment. Environmental fatigue, which exhibits a shorter fatigue life in reactor water than that in air, is considered to have a remarkable correlation with strain rate and its affect on fatigue life. Despite its significant affect on SCC and fatigue, the actual strain rate of components is not known and practical evaluation methods have not been developed; consequently, such failure modes as SCC and fatigue are not evaluated in design. For this paper, strain rates induced by dynamic loading during such operations as plant start-up were calculated at typical points, such as reactor internals, piping and so on. The finite element method was applied to calculate the strain history of each point, and the strain rate was evaluated. The strain rate evaluation results clearly demonstrated that thermal transients provide greater peak strain rate values than pressure transients. Strain rates on the order of 10−7 s−1 were obtained for most points of major components during such thermal transients as plant start-ups. The major factors determining the strain rate magnitude were discussed, based on the calculation results. It was shown that the rate of temperature rise was the most important parameter, because it exhibited much larger sensitivity than the other parameters on the strain rate and could be controlled by plant operation procedures. In addition, a simple strain rate evaluation method based on Green’s function was developed for a specific point with a given design condition.

External Training Load Monitoring and the Impact on Training Load Management in Collegiate Male Soccer Players

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Jacob R. Gdovin ◽  
Riley Galloway ◽  
Lorenzo S. Tomasiello ◽  
Michael Seabolt ◽  
Robert Booker
Keyword(s):  
Training Load ◽  
Soccer Players ◽  
Load Management ◽  
Load Monitoring ◽  
External Training ◽  
The Impact

Investigations on the Environmentally Assisted Fatigue Behavior of Steel Specimens for a Better Understanding of Component Fatigue in Nuclear Applications

2021 ◽  
Author(s):  
Christian Swacek ◽  
Ludwig Stumpfrock ◽  
Stefan Weihe
Keyword(s):  
Power Plant ◽  
Fatigue Behavior ◽  
Environmental Influences ◽  
Uniaxial Tensile ◽  
Loading Conditions ◽  
Ongoing Research ◽  
Fatigue Assessment ◽  
Plant Operation ◽  
Power Plant Operation ◽  
Nuclear Applications

Abstract The fatigue assessment of pressurized components is of high importance for the operation of nuclear power plants. However, the environmental influences on the fatigue behavior are highly discussed. On the one hand, laboratory specimens tested in high temperature water (HTW) conditions show a significant drop in fatigue lifetime, compared to tests at air environment, and question the conservatism of modern standards. On the other hand, the fatigue assessment methods based on uniaxial tensile testing seems to overestimate the fatigue damage of components during operation. To overcome these discrepancies, the environmental influences on material fatigue have to be better understood. Laboratory testing setups have to be adapted to the relevant loading conditions during power plant operation. Therefore, MPA Stuttgart is investigating the environmentally assisted fatigue (EAF) of steels under various loading conditions for smooth and notched specimens, as well as full scale component testing at HTW conditions. In this paper the results of ongoing research are presented. The low cycle fatigue experiments on steel materials for relevant nuclear applications are performed at air and under pressurized water reactor (PWR) environment. The shape of specimens, the loading spectra, loading rate and the multiaxiality of load are derived from piping components in power plant operation.

Fatigue Assessment of SLWR Riser in Brazilian Pre-Salt: The Impact of Slope Changing Point in SN Curve

2019 ◽  
Author(s):  
Stael F. Senra ◽  
Ludimar L. Aguiar ◽  
Eduardo Hippert ◽  
Alexandre G. Garmbis ◽  
Marcelo Dos Santos ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Limit State ◽  
Base Case ◽  
Load Spectrum ◽  
Internal Wall ◽  
Case Scenario ◽  
Fatigue Assessment ◽  
Variable Amplitude ◽  
Riser Design ◽  
The Impact

Abstract One of the main challenges in rigid riser design for Brazilian Pre-salt is the fatigue limit state. At this new production frontier, some key points are imposed as a challenge for riser designers, mainly due to the high level of motions imposed by the FPSO at the riser top in a coupled system with water depth around 2200 meters, and thicker riser’s thermal insulation demanded for flow assurance (which worsens the dynamic response of production risers). Additionally, high contaminant levels in the fluid (CO2 & H2S) demands CRA materials. Within this context, Petrobras has been considering Steel Lazy Wave Riser (SLWR) configuration as a base case scenario for rigid riser projects, since this configuration is able to absorb part of the FPSO motions that would reach the touch down zone (TDZ) and, consequently, making this region much less demanded when compared against Steel Catenary Risers (SCR). In its pioneer deepwater SLWR [1], Petrobras adopted a conservative approach for fatigue assessment that involved degenerated SN curves from DNV-RP-C203, i.e. D curve in cathodic protection with the slope changing point (SCP) shifted to 5 × 106 for external wall and F1 curve in air with SCP at 5 × 107 for internal wall. More recently, both DNVGL and BSI have reviewed their fatigue assessment codes and no longer holds parity between SN curves. BS-7608 Ed. 2014 introduced different SCPs in order to account for a possible non-conservativeness in the assessment of low stresses under variable amplitude in the loading spectra. DNVGL-RP-C203 Ed. 2016 now presents three different bilinear SN curves for the internal wall of pipelines and risers that depends on weld misalignment, while it keeps SCP unchanged. This paper presents a recent case study for a typical SLWR configuration in pre-salt, in order to evaluate the impact of the changes proposed by the new versions of these design codes in the fatigue life of riser girth welds. Results of this work showed that the impact of different positioning of slope changing points in SN curves can have a great importance for riser design, since typical load spectrum lies around this region. Fatigue life could be increased up to twice or three times if one of these codes are adopted instead of the Shifted SN curves. However, the effect of low stresses under variable amplitude loading spectra is still a concern and it should be further investigated.

Grid-Connected Nuclear Power Plant Key Issues Summary

2014 ◽  
Vol 521 ◽  
pp. 530-535
Author(s):  
Meng Wang ◽  
Jian Ding ◽  
Tian Tang ◽  
Zhang Sui Lin ◽  
Zhen Da Hu ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Large Scale ◽  
Power Modeling ◽  
Modeling Simulation ◽  
Load Following ◽  
Key Issues ◽  
The Impact

The current situation of nuclear power plants at home and abroad is described, and the impact of large-scale nuclear power accessing to the grid is analyzed, specifically in the aspects of nuclear power modeling, simulation, load following, reliability, fault diagnosis, etc. Nuclear power accessing to the grid will bring a series of problems, the causes of each problem, the main solutions and future development directions are summarized.

The impact of algogenic organic matter on water treatment plant operation and water quality: A review

2015 ◽  
Vol 46 (4) ◽  
pp. 291-335 ◽  
Author(s):  
M. Pivokonsky ◽  
J. Naceradska ◽  
I. Kopecka ◽  
M. Baresova ◽  
B. Jefferson ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Plant Operation ◽  
The Impact
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