Localization of loose part impacts on the general 3D surface of the nuclear power plant coolant circuit components

Liška, Jindřich; Kunkel, Sven

doi:10.1016/j.pnucene.2017.05.004

Cited by 7 publications

(8 citation statements)

References 8 publications

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“…To date, a large number of studies have been carried out on impact source localization methods (GOST R ISO 13379-1-2015, Olma 1985, Szappanos et al 1999, Kim et al 2003, Figedy and Oksa 2005, Park and Kim 2006, Choi et al 2011, Ki et al 2017, Liska and Kunkel 2017. The traditional and most trivial method localizes the source of the acoustic anomaly up to the equipment controlled by the sensor that first recorded the impact.…”

Section: Introductionmentioning

confidence: 99%

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Experience of using loose parts monitoring systems at Novovoronezh NPP

Voronov¹,

Slepov²

2022

NUCET

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In VVER reactor plants, it is impossible to completely exclude the appearance of loose, loosely fixed and foreign objects in the main circulation circuit. Operational experience shows that early detection and estimation of the parameters of such incidents can provide the time required to eliminate or minimize damage to the main equipment of the reactor plant. For this reason, most modern power units with pressurized water reactors (PWR, VVER) are equipped with a loose parts monitoring system (LPMS). At the units under construction, these systems are laid down as standard ones; the power units put into commercial operation in the Soviet period were also equipped with them. The requirements for them are established by international standards. Ongoing research work in this area is aimed at determining the root cause of the acoustic anomaly and the localization of its epicenter. Also, no less significant are the works aimed at determining the mass of a loose object (LO). The most precise definition of this parameter will make it possible to have an idea of the nature of the LO before its withdrawal from the primary circuit and to conclude about whether this object is accidentally found or it is a detached part of the steam generators, main circulation pumps, internal devices or shut-off and control valves.

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Section: Introductionmentioning

confidence: 99%

“…The algorithm has a simple analytical solution for the plane, but it is not adapted for the complex surface of the primary reactor circuit. Another method (Szappanos et al 1999, Figedy and Oksa 2005, Liska and Kunkel 2017 is based on the search for the closest match to the recorded ATDs calculated earlier.…”

Section: Introductionmentioning

confidence: 99%

Experience of using loose parts monitoring systems at Novovoronezh NPP

Voronov¹,

Slepov²

2022

NUCET

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“…To date, a large number of studies on impact source localization methods have been performed (Olma 1985, Szappanos et al 1999, Kim Jung Soo et al 2003, Choi et al 2011, Park and Kim 2006, Park Gee Yong et al 2006, Ki HI et al 2017, Figedy and Oksa 2005, Liska and Kunkel 2017, Zheng et al 2008. The traditional and most trivial method localizes the source of the acoustic anomaly to the equipment controlled by the sensor that first detected the impact.…”

Section: Introductionmentioning

confidence: 99%

“…Another method (Szappanos et al 1999, Figedy and Oksa 2005, Liska and Kunkel 2017 is based on the search for the closest match to the recorded TDOAs calculated earlier. To do this, the primary circuit is divided into segments of a small area or control points.…”

Section: Introductionmentioning

confidence: 99%

“…When an acoustic anomaly is recorded, its location is selected from the database as the nearest stored vector to the measured one in accordance with the Euclidean distance. In (Liska and Kunkel 2017), the errors of the localization method and its structural limitations are analyzed. To determine the time of arrival, it is necessary to know the acoustic wave velocity.…”

Section: Introductionmentioning

confidence: 99%

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A localization method for loose parts monitoring system of VVER reactor plants

Maksimov¹,

Perevezentsev²

2020

NUCET

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As operational experience shows, it can hardly be excluded that some detached or loosened parts and even foreign objects (hereinafter referred to as the ‘loose parts’) may appear in the main circulation loop of VVER reactor plants. Naturally, the sooner such incidents are detected and evaluated, the more time will be available to eliminate or at least minimize damage to the reactor plant main equipment. The paper describes a method for localizing the impact of loose parts located in the coolant circulation circuit of a VVER reactor plant. To diagnose malfunctions of the reactor plant main equipment, it is necessary to accurately determine the place where the acoustic anomaly occurred. Therefore, if some loose parts make themselves felt, it is important to track the path of their movement along the main circulation circuit as well as their location using physical barriers. The method is based on the representation of the surface, along which an acoustic wave travels, as a 3D model of the reactor plant (RP) main circulation circuit. The model has the form of a graph in which the vertices characterize the control points on the RP surface and the edges are the distances between them. The method uses information about the acoustic wave velocity and the time difference of arrivals (TDOAs) of the signal received by various sensors. It is shown that, when the effect is received by more than three sensors, along with an estimate of the impact coordinate, it becomes possible to estimate the average acoustic wave velocity. To determine time of arrival, the signal dispersion change point detection method is used. Provided that the average size between the control points on the RP surface was 300 mm, the average localization error was about 600 mm. The developed algorithm can be easily adapted to any VVER reactor plant. The obtained deviation values are acceptable for practical use.

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