Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor
In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference betw...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-05-01
|
| Series: | Nuclear Engineering and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1738573323000657 |
| _version_ | 1797823775386894336 |
|---|---|
| author | Donkoan Hwang Nakjun Choi WooHyun Jung Taeil Kim Yohan Lee HangJin Jo |
| author_facet | Donkoan Hwang Nakjun Choi WooHyun Jung Taeil Kim Yohan Lee HangJin Jo |
| author_sort | Donkoan Hwang |
| collection | DOAJ |
| description | In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference between the atmosphere and the inside of the pipe, which in a postulated pipe break scenario can lead to the breakdown of the cooling pump. In this study, a plant-scale experiment was conducted to study air inflow in large piping systems by considering the actual operational conditions of an advanced research reactor. The air inflow rate was measured, and the entrained air was visualized to investigate the behavior of air inflow and flow regime depending on the pipe break size. In addition, the developed drift-flux model for a large vertical pipe with a diameter of 600 mm was compared with other correlations. The flow regime transition in a large vertical pipe under downward flow was also studied using the newly developed drift-flux model. Consequently, the characteristics of two-phase flow in a large vertical pipe were found to differ from those in small vertical pipes where liquid recirculation was not dominant. |
| first_indexed | 2024-03-13T10:28:57Z |
| format | Article |
| id | doaj.art-772b38ec7d924467a7bad67060d79744 |
| institution | Directory Open Access Journal |
| issn | 1738-5733 |
| language | English |
| last_indexed | 2024-03-13T10:28:57Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Engineering and Technology |
| spelling | doaj.art-772b38ec7d924467a7bad67060d797442023-05-19T04:45:13ZengElsevierNuclear Engineering and Technology1738-57332023-05-0155516041615Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactorDonkoan Hwang0Nakjun Choi1WooHyun Jung2Taeil Kim3Yohan Lee4HangJin Jo5Division of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of KoreaDivision of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of KoreaDepartment of Mechanical Engineering, POSTECH, Pohang, 790-784, Republic of KoreaDepartment of Mechanical Engineering, POSTECH, Pohang, 790-784, Republic of KoreaDivision of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of KoreaDivision of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of Korea; Department of Mechanical Engineering, POSTECH, Pohang, 790-784, Republic of Korea; Corresponding author. Division of Advanced Nuclear Engineering, Department of Mechanical Engineering, POSTECH, Pohang, 790-784, South Korea.In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference between the atmosphere and the inside of the pipe, which in a postulated pipe break scenario can lead to the breakdown of the cooling pump. In this study, a plant-scale experiment was conducted to study air inflow in large piping systems by considering the actual operational conditions of an advanced research reactor. The air inflow rate was measured, and the entrained air was visualized to investigate the behavior of air inflow and flow regime depending on the pipe break size. In addition, the developed drift-flux model for a large vertical pipe with a diameter of 600 mm was compared with other correlations. The flow regime transition in a large vertical pipe under downward flow was also studied using the newly developed drift-flux model. Consequently, the characteristics of two-phase flow in a large vertical pipe were found to differ from those in small vertical pipes where liquid recirculation was not dominant.http://www.sciencedirect.com/science/article/pii/S1738573323000657Two-phase flowResearch reactorLarge vertical pipeDrift-flux modelPipe breakVoid fraction |
| spellingShingle | Donkoan Hwang Nakjun Choi WooHyun Jung Taeil Kim Yohan Lee HangJin Jo Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor Nuclear Engineering and Technology Two-phase flow Research reactor Large vertical pipe Drift-flux model Pipe break Void fraction |
| title | Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor |
| title_full | Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor |
| title_fullStr | Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor |
| title_full_unstemmed | Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor |
| title_short | Plant-scale experiments of an air inflow accident under sub-atmospheric pressure by pipe break in an open-pool type research reactor |
| title_sort | plant scale experiments of an air inflow accident under sub atmospheric pressure by pipe break in an open pool type research reactor |
| topic | Two-phase flow Research reactor Large vertical pipe Drift-flux model Pipe break Void fraction |
| url | http://www.sciencedirect.com/science/article/pii/S1738573323000657 |
| work_keys_str_mv | AT donkoanhwang plantscaleexperimentsofanairinflowaccidentundersubatmosphericpressurebypipebreakinanopenpooltyperesearchreactor AT nakjunchoi plantscaleexperimentsofanairinflowaccidentundersubatmosphericpressurebypipebreakinanopenpooltyperesearchreactor AT woohyunjung plantscaleexperimentsofanairinflowaccidentundersubatmosphericpressurebypipebreakinanopenpooltyperesearchreactor AT taeilkim plantscaleexperimentsofanairinflowaccidentundersubatmosphericpressurebypipebreakinanopenpooltyperesearchreactor AT yohanlee plantscaleexperimentsofanairinflowaccidentundersubatmosphericpressurebypipebreakinanopenpooltyperesearchreactor AT hangjinjo plantscaleexperimentsofanairinflowaccidentundersubatmosphericpressurebypipebreakinanopenpooltyperesearchreactor |