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Arkadov, G. V.; Ovcharov, O. V.; Pavelko, V. I.; Usanov, A. I.; Liptak, P.; Slovak, R.

doi:10.1023/a:1013378215566

Cited by 6 publications

(2 citation statements)

References 1 publication

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“…Here, the limits for the permissible resonance amplitude, frequency and quality changes are much greater than in the event of natural oscillations. The occurrence nature and specifics of the ASW as the key oscillation excitation source for the internals, the reactor vessel and the RCP had been explored for quite a long time (Arkadov et al 2001a(Arkadov et al , 2001b(Arkadov et al , 2004(Arkadov et al , 2010, but it relatively recently that information has been systematized, a classification has been developed and the key characteristics have been identified as applied to the VVER-1200 reactor (Arkadov et al 2018, Arkadov et al 2021. Information on the ASW resonances is extracted largely from the PPD signals.…”

Section: Experimental Determination Of the Asw Properties For Vver-12...mentioning

confidence: 99%

“…At the same time, the poorly engineered RP designs are known, in which the vibroacoustic effects resulted in the equipment failures or early expiration of the equipment service life (Arkadov et al 2010). Vibrations are deceptive because when the vibration amplitude is rather small, the contribution of vibrations to life expiration of the equipment is negligible, but they can play a crucial role in resonant vibration phenomena (Arkadov et al 2001a(Arkadov et al , 2001b. The resonant excitation of vibrations is considered to be unallowable for any RP design.…”

Section: Introductionmentioning

confidence: 99%

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Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

Arkadov¹,

Pavelko²,

Povarov³

et al. 2022

NUCET

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The insufficiently studied issues of acoustic standing waves (ASW) in the main circulation circuits of the VVER reactor plants are considered. For a long time no proper attention has been given to this phenomenon both by the researchers and NPP experts. In general, generation of ASWs requires the acoustic inhomogeneities of the medium in the planes perpendicular to the direction of propagation of the longitudinal wave, in which a jump in acoustic resistance occurs, this is shown by the authors based on an example of the wave equation solution (D’Alembert equation) for a certain function of two variables. The ASW classification has been developed based on the obtained experimental material, 6 ASW types have been described, and their key parameters have been specified. The amplitude distributions have been plotted for all major ASW types proceeding from the phase relations of signals from the pressure pulsation detectors and accelerometers installed on the MCC pipelines. The nature of these distributions is general and they are valid for all VVER types. For the first time the globality of all lowest ASW types is identified. Four attribute properties of the ASWs have been formulated. The first attribute is the regular ASW temperature dependences, which is the source of the diagnostic information in the process of heating/cooling of the VVER unit. The linear experimental dependences of the ASW frequencies on coolant temperature have been obtained. The frequencies, at which the MCC resonant excitation due to coincidence of the ASW frequencies with the RCP rotational frequency harmonics, have been found experimentally. The ASW energy, which origin has resulted from the RCP operation, is estimated. The RCP operation can be presented as continuous generation of pressure pulsations, which fall onto the acoustic path inhomogeneities in the form of a traveling wave and generate a standing wave after reflection from them.

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Section: Experimental Determination Of the Asw Properties For Vver-12...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

Arkadov¹,

Pavelko²,

Povarov³

et al. 2022

NUCET

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Assessment of the correlation method for determining the parameters of two-phase coolant in a vk-50 core

et al. 2011

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Measurements of the propagation velocity of small perturbations of the neutron flux along the height of the core of a VK-50 boiling water vessel reactor are presented. The method of measurement is based on the evaluation of the delay time of a signal between the axially positioned sensitive elements of a moving double direct-charge detector. The measurements are compared with calculations for the parameters of two-phase coolant in the measurement channels. It is shown that the agreement between the measurements and the calculations is best for the velocity of an interphase surface.Correlation methods of measuring coolant flow, which are based on evaluating the delay time of the signal between the axially positioned sensors, are widely used in in-core systems monitoring boiling-water vessel reactors. One of the most widely used schemes for such measurements is to determine the mutual probabilistic characteristics of neutron flux fluctuations using stationary local neutron intensity sensors based on, for example, direct-charge detectors [1,2].Another variant is to use mobile paired detectors separated by a relatively small distance. Such sensors make it possible to determine the dependence of the propagation velocity of a neutron flux perturbation over the height of the core from the local flow structure of the steam-water mixture. The results of height measurements with in-core monitoring of the energy release in VK-50 are presented in the present article [3].Review of Foreign Studies. The cross-correlation function of the currents of sensors distributed over height was first used to determine the parameters of the steam-water flow in the core of boiling-water vessel reactors at the beginning of the 1970s, when publications appeared concerning measurements performed on the Lingen (West Germany) [4], Garigliano (Italy) [5], Fukushima-1 (Japan) [6], and other reactors. These studies were based on a methodology presented in [7] and developed in subsequent publications, for example, [8,9].A two-component model of neutron-flux noise was examined in [7]. The local component of the noise was attributed to the generation and motion of steam bubbles, while the global component was due to the general effect of the coolant density on the reactivity of the system. Hence it is natural to suppose that the velocity determined by means of the cross-correlation function of the currents is the velocity of the steam phase, as done in the very early studies [10].

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Algorithms for the measurement of liquid metal coolant flow velocity with correlated thermal signals

Moazzeni

Jiang

et al. 2008

2008 International Conference on Communications, Circuits and Systems

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The flow velocity of liquid metal coolant can be determined through the measurements of temperature fluctuation recorded by a pair of temperature sensors placed certain distance apart along the flow. Traditionally, this was done using a cross-correlation algorithm to estimate the transit time of the coolant, and thus its velocity. This widely used cross-correlation algorithm, however, suffers from the ambiguity in reading of measurements. To alleviate this problem, the transfer function estimation approach was recently proposed which tends to give more accurate results. In this paper, we introduce a new algorithm that can further improve the accuracy in the transit time estimation using an adaptive inverse system model at a higher cost of computation. When real-time computation is a concern, we propose a second algorithm based on an adaptive filtering approach which makes a sound trade-off between accuracy and computation cost. This algorithm incurs less processing time than the first proposed algorithm with higher accuracy than the two aforementioned conventional algorithms.

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Cited by 6 publications

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Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

Assessment of the correlation method for determining the parameters of two-phase coolant in a vk-50 core

Algorithms for the measurement of liquid metal coolant flow velocity with correlated thermal signals

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Untitled

Cited by 6 publications

References 1 publication

﻿Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

﻿Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

Assessment of the correlation method for determining the parameters of two-phase coolant in a vk-50 core

Algorithms for the measurement of liquid metal coolant flow velocity with correlated thermal signals

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Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant

Phenomenology of acoustic standing waves as applied to the VVER-1200 reactor plant