Nuclear power plant instabilities analysis

Moreno, Carlos Julián Gavilán; Prieto‐Guerrero, Alfonso; Espinosa-Paredes, Gilberto

doi:10.1016/j.anucene.2015.05.029

Cited by 9 publications

(10 citation statements)

References 11 publications

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“…In this instability the main frequency found is 0.5 Hz and it is an in phase type or core wide oscillation 5 …”

Section: Resultsmentioning

confidence: 83%

“…The event shown occurred at Cofrentes Nuclear Power Plant in Valencia (Spain) on January 29th, 1991, during a normal startup sequence, right before the transfer to high speed of the recirculation pumps. 5,35 As can be seen in Refs. 5, 12, this instability has two main frequencies; one at 0.5 Hz and another one at 1 Hz.…”

Section: Cofrentesmentioning

confidence: 74%

“…The instability event from Cofrentes can be seen through a Low Power Range Monitor (LPRM) detector time series (Figure 4). The event shown occurred at Cofrentes Nuclear Power Plant in Valencia (Spain) on January 29th, 1991, during a normal startup sequence, right before the transfer to high speed of the recirculation pumps 5,35 . As can be seen in Refs.…”

Section: Resultsmentioning

confidence: 99%

“…In this instability the main frequency found is 0.5 Hz and it is an in phase type or core wide oscillation. 5 The Hilbert spectrum obtained with VMD is plotted in Figure 8. Note there is an increase in the amplitude at 0.5 Hz and the 1 Hz mode is visible and very well defined after 400 seconds.…”

Section: Laguna Verdementioning

confidence: 99%

“…Up to now, most of the publications regarding the study of BWR instabilities where focused on its detection 4,5,12,19 and several methodologies have been tested to do that. Nevertheless, not all the instabilities are connected to the same harmonics, that is, there are instabilities where there is a prevalence of the 1 Hz harmonic and, in other cases, is the 0.5 Hz one.…”

Section: Backbone Plots For Discriminating Instabilitiesmentioning

confidence: 99%

See 4 more Smart Citations

Resolving mode mixing in boiling water reactors instability analysis using variational mode decomposition

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Gavilan

Garcı́a-Berrocal

et al. 2020

Intl J of Energy Research

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In dynamic, complex and nonlinear systems, the analysis of transients, instabilities or unusual events is fundamental, as well as the knowledge of the system's behavior in the frequency space. What is usual in this type of study is to have discrete and digitally acquired data, due to a sampling process with a determined period or frequency. Extracting information from this data set is done by numerical methods, such as the Fourier Transform (FFT), the Hilbert-Huang Transform (HHT) or techniques from chaos mathematics (Attractors). In this way we have scarce data, with some loss of information, analyzed with numerical techniques that introduce, also, some dilution of the information. In particular, the techniques of analysis in the frequency space, by their very nature, blur, frequencies and bandwidths. This leads in some cases to the identification of unsuitable or very wide frequencies or intervals, which make the extracted information unusable. To this effect, we have studied the VMD technique that provides more real and representative frequencies of the system as well as narrower bandwidths that make possible better identification of phenomena and influences. This technique has been applied to the analysis of thermohydraulic instabilities in nuclear boiling water reactors (BWR). The cases had already been analyzed with STFT and HHT techniques. The results of the application of the VMD shows that the mode mixing is solved, so modes obtained are monofrequency and these frequency bands are narrower than in previous methodologies. This improved performance allows using backbone plots for identifying which modes are excited in instabilities events.

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“…In this instability the main frequency found is 0.5 Hz and it is an in phase type or core wide oscillation 5 …”

Section: Resultsmentioning

confidence: 83%

Section: Cofrentesmentioning

confidence: 74%

Section: Resultsmentioning

confidence: 99%

Section: Laguna Verdementioning

confidence: 99%