Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5
The safety performance of nuclear power plants (NPPs) is a very important factor in evaluating nuclear energy sustainability. Safety analysis of passive and active safety systems have a positive influence on reactor transient mitigation. One of the common transients is primary coolant leg rupture. T...
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| Format: | Article |
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MDPI AG
2021-12-01
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| Series: | Journal of Nuclear Engineering |
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| Online Access: | https://www.mdpi.com/2673-4362/2/4/35 |
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| author | Fabiano Gibson Daud Thulu Ayah Elshahat Mohamed H. M. Hassan |
| author_facet | Fabiano Gibson Daud Thulu Ayah Elshahat Mohamed H. M. Hassan |
| author_sort | Fabiano Gibson Daud Thulu |
| collection | DOAJ |
| description | The safety performance of nuclear power plants (NPPs) is a very important factor in evaluating nuclear energy sustainability. Safety analysis of passive and active safety systems have a positive influence on reactor transient mitigation. One of the common transients is primary coolant leg rupture. This study focused on guillotine large break loss of coolant (LB-LOCA) in one of the reactor vessels, in which cold leg rupture occurred, after establishment of a steady-state condition for the VVER-1000. The reactor responses and performance of emergence core cooling systems (ECCSs) were investigated. The main safety margin considered during this simulation was to check the maximum value of the clad surface temperature, and it was then compared with the design licensing limit of 1474 K. The calculations of event progression used the engineering-level RELAP5/SCDAPSIM/MOD3.5 thermal-hydraulic program, which also provide a more detailed treatment of coolant system thermal hydraulics and core behavior. The obtained results show that actuation of ECCSs at their actuation set points provided core cooling by injecting water into the reactor pressure vessel, as expected. The peak cladding temperature did not overpass the licensing limit during this LB-LOCA transient. The primary pressure above the core decreased rapidly from 15.7 MPa to 1 MPa in less than 10 s, then stabilizes up to the end of transient. The fuel temperature decreased from 847 K to 378 K during the first 30 s of the transient time. The coolant leakage reduced from 9945 kg/s to approximately 461 kg/s during the first 190 s in the transient. Overall, the study shows that, within the design of the VVER-1000, safety systems of the have inherent robustness of containing guillotine LB-LOCA. |
| first_indexed | 2024-03-10T03:47:32Z |
| format | Article |
| id | doaj.art-181b093b7a42457e9dfc5a0319e1f21f |
| institution | Directory Open Access Journal |
| issn | 2673-4362 |
| language | English |
| last_indexed | 2024-03-10T03:47:32Z |
| publishDate | 2021-12-01 |
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| record_format | Article |
| series | Journal of Nuclear Engineering |
| spelling | doaj.art-181b093b7a42457e9dfc5a0319e1f21f2023-11-23T09:04:18ZengMDPI AGJournal of Nuclear Engineering2673-43622021-12-012451653210.3390/jne2040035Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5Fabiano Gibson Daud Thulu0Ayah Elshahat1Mohamed H. M. Hassan2Physics Department, The Malawi Polytechnic, University of Malawi, Private Bag 303, Blantyre 312225, MalawiNuclear and Radiation Engineering Department, Faculty of Engineering, Alexandria University, Alexandria 21544, EgyptNuclear and Radiation Engineering Department, Faculty of Engineering, Alexandria University, Alexandria 21544, EgyptThe safety performance of nuclear power plants (NPPs) is a very important factor in evaluating nuclear energy sustainability. Safety analysis of passive and active safety systems have a positive influence on reactor transient mitigation. One of the common transients is primary coolant leg rupture. This study focused on guillotine large break loss of coolant (LB-LOCA) in one of the reactor vessels, in which cold leg rupture occurred, after establishment of a steady-state condition for the VVER-1000. The reactor responses and performance of emergence core cooling systems (ECCSs) were investigated. The main safety margin considered during this simulation was to check the maximum value of the clad surface temperature, and it was then compared with the design licensing limit of 1474 K. The calculations of event progression used the engineering-level RELAP5/SCDAPSIM/MOD3.5 thermal-hydraulic program, which also provide a more detailed treatment of coolant system thermal hydraulics and core behavior. The obtained results show that actuation of ECCSs at their actuation set points provided core cooling by injecting water into the reactor pressure vessel, as expected. The peak cladding temperature did not overpass the licensing limit during this LB-LOCA transient. The primary pressure above the core decreased rapidly from 15.7 MPa to 1 MPa in less than 10 s, then stabilizes up to the end of transient. The fuel temperature decreased from 847 K to 378 K during the first 30 s of the transient time. The coolant leakage reduced from 9945 kg/s to approximately 461 kg/s during the first 190 s in the transient. Overall, the study shows that, within the design of the VVER-1000, safety systems of the have inherent robustness of containing guillotine LB-LOCA.https://www.mdpi.com/2673-4362/2/4/35nuclear safetysevere accidentLOCARELAP5/SCDAPSIM/MOD3.5emergency core cooling system |
| spellingShingle | Fabiano Gibson Daud Thulu Ayah Elshahat Mohamed H. M. Hassan Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5 Journal of Nuclear Engineering nuclear safety severe accident LOCA RELAP5/SCDAPSIM/MOD3.5 emergency core cooling system |
| title | Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5 |
| title_full | Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5 |
| title_fullStr | Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5 |
| title_full_unstemmed | Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5 |
| title_short | Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5 |
| title_sort | simulation of vver 1000 guillotine large break loss of coolant accident using relap5 scdapsim mod3 5 |
| topic | nuclear safety severe accident LOCA RELAP5/SCDAPSIM/MOD3.5 emergency core cooling system |
| url | https://www.mdpi.com/2673-4362/2/4/35 |
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