Comparing the Consequences Pressure Waves due to MCP pump stops and LOCA in VVER-1000
https://doi.org/10.1134/S2304487X19040023
Abstract
Consider the propagation of pressure waves in emergency situations on the equipment of the circuit for reactor VVER-1000. Here we discuss two situations: an instant rupture (10 –4 ) in the main circulation pipelines of the primary circuit with a double End Break (DEB) and instantaneous stop (10 –4 ) of the main circulating pump. The considered emergency situations are included in the list of different types of reports necessary for VVER safety justification [1]. As a model for investigation we chose the 3 rd unit of Kalinin NPP (VVER-1000, model 320). All thermohydraulic and physics data for this are taken from the international stander problem Kalinin-3 [2, 3]. The first analysis for those emergency situations was made in works [4, 5]. For the calculations, the code of improved evaluation ATHLET [6] was used, which is included in the AC2 software package, officially obtained by the national research Nuclear University of MEPhI on the basis of a license agreement with Gesellschaft fur Anlagen-und Reaktorsicherheit (GRS) GmbH, Germany [7]. The ATHLET code is certified in Russia for calculations of stationary and transient regimes at reactors with water coolant [8]. We consider in detail the initial period of the accidents, because only at this stage we can observe the strongest amplitude and frequency of pressure fluctuations on NPP elements, which can lead to significant dynamic loads on the structural elements of these objects. This can be estimated either by: joint strength and hydrodynamic calculations, or it is possible to use the results obtained in this work as boundary conditions for the calculation of dynamic loads. The basic reason for the pressure waves in case of instant pump stop was the instant stop of the MCP. But in the case of instant rupture in the pipelines of the first circuit, the main reason is the instant boiling (superheated) of the coolant.
About the Authors
D. A. Amer
Alexandria University; National Research Nuclear University MEPhI (Moscow Engineering Physics Institute)
Egypt
Egypt
Dina Ali Amer
21526
Russian Federation
115409
Alexandria
Moscow
S. P. Nikonov
National Research Nuclear University MEPhI (Moscow Engineering Physics Institute)
Russian Federation
Russian Federation
115409
Moscow
References
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Review
For citations:
Amer D.A., Nikonov S.P. Comparing the Consequences Pressure Waves due to MCP pump stops and LOCA in VVER-1000. Vestnik natsional'nogo issledovatel'skogo yadernogo universiteta "MIFI". 2019;8(4):309-320. https://doi.org/10.1134/S2304487X19040023
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