PSI - Issue 54

ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 54 (2024) 241–249

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers Abstract The article deals with the influence of the water hammer event resulting from the rupture of the main circulation pipeline, for the Core Barrel of VVER-1000 reactor. The assumption of a double-ended pipe break in the main coolant loop piping of a nuclear power reactor followed by blowdown (a rapid loss of coolant through the break) has been considered as the worst possible loss-of coolant accident (Large Break LOCA). Such event is called a design basis accident or DBA and should be analyzed for the reactor's safe long-time operation. Research in this area has been conducted since the 80s of the XX century and one of the most difficult issues is the calculation of thermohydraulic parameters during a LB LOCA in the reactor, which determines the dynamic loads. To overcome this issue in previous authors' works a special CFD model was developed to obtain loads during hot leg break and cold leg break. Nevertheless, an important point remains CFD results transfer for mechanical analysis, especially since it might be an issue for shell which have both surfaces loaded. In the present work the calculations are performed using two models: the first one is an analytical shell model, the second one is 3D FE model of the Core Barrel. As the first step, both models are compared using a free vibration analysis. Next, pressure loading in time is applied for both models to get a dynamic response and resulting stresses. Finally structural integrity analysis is performed using failure assessment diagram (FAD). As a result, comparison between the speed, accuracy and computational cost of two different models (approaches) is performed to provide an insight of the perspective use of analytical shell models compared to well-known FE computational tools. © 2023 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers Keywords: LB LOCA, Core Barrel, CFD-analysis, SPCM, Failure assessment diagram. International Conference on Structural Integrity 2023 (ICSI 2023) Dynamic transient analysis of the Reactor Core Barrel during LB LOCA Oleksii Ishchenko a,b *, Vladislav Filonov a , Yaroslav Dubyk a a LLC “IPP - Centre”, Kyiv 01013, Ukraine b «Igor Sikorsky Kyiv Polytechnic Institute», Kyiv 03056, Ukraine Abstract The article deals with the influence of the water hammer event resulting from the rupture of the main circulation pipeline, for the Core Barrel of VVER-1000 reactor. The assumption of a double-ended pipe break in the main coolant loop piping of a nuclear power reactor followed by blowdown (a rapid loss of coolant through the break) has been considered as the worst possible loss-of coolant accident (Large Break LOCA). Such event is called a design basis accident or DBA and should be analyzed for the reactor's safe long-time operation. Research in this area has been conducted since the 80s of the XX century and one of the most difficult issues is the calculation of thermohydraulic parameters during a LB LOCA in the reactor, which determines the dynamic loads. To overcome this issue in previous authors' works a special CFD model was developed to obtain loads during hot leg break and cold leg break. Nevertheless, an important point remains CFD results transfer for mechanical analysis, especially since it might be an issue for shell which have both surfaces loaded. In the present work the calculations are performed using two models: the first one is an analytical shell model, the second one is 3D FE model of the Core Barrel. As the first step, both models are compared using a free vibration analysis. Next, pressure loading in time is applied for both models to get a dynamic response and resulting stresses. Finally structural integrity analysis is performed using failure assessment diagram (FAD). As a result, comparison between the speed, accuracy and computational cost of two different models (approaches) is performed to provide an insight of the perspective use of analytical shell models compared to well-known FE computational tools. © 2023 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers Keywords: LB LOCA, Core Barrel, CFD-analysis, SPCM, Failure assessment diagram. International Conference on Structural Integrity 2023 (ICSI 2023) Dynamic transient analysis of the Reactor Core Barrel during LB LOCA Oleksii Ishchenko a,b *, Vladislav Filonov a , Yaroslav Dubyk a a LLC “IPP - Centre”, Kyiv 01013, Ukraine b «Igor Sikorsky Kyiv Polytechnic Institute», Kyiv 03056, Ukraine

* Corresponding author. Tel.: +38-044-502-45-70. E-mail address: dubyk-yr@ipp-centre.com.ua. * Corresponding author. Tel.: +38-044-502-45-70. E-mail address: dubyk-yr@ipp-centre.com.ua.

2452-3216 © 2023 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers 2452-3216 © 2023 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers 10.1016/j.prostr.2024.01.079