Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors
Near the supercritical thermodynamic point, coolant density is very sensitive to temperature which gives potential to several instabilities in the supercritical water-cooled nuclear reactors. The flow stability features of the U.S. reference Supercritical Water- Cooled Reactor (SCWR) have been in...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Technical Report |
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Massachusetts Institute of Technology. Center for Advanced Nuclear Energy Systems. Advanced Nuclear Power Program
2011
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| Online Access: | http://hdl.handle.net/1721.1/67673 |
| _version_ | 1811079091342802944 |
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| author | Zhao, J. Saha, P. Kazimi, Mujid S. |
| author2 | Advanced Nuclear Power Technology Program (Massachusetts Institute of Technology) |
| author_facet | Advanced Nuclear Power Technology Program (Massachusetts Institute of Technology) Zhao, J. Saha, P. Kazimi, Mujid S. |
| author_sort | Zhao, J. |
| collection | MIT |
| description | Near the supercritical thermodynamic point, coolant density is very sensitive to
temperature which gives potential to several instabilities in the supercritical water-cooled
nuclear reactors. The flow stability features of the U.S. reference Supercritical Water-
Cooled Reactor (SCWR) have been investigated. Single channel stability features were
studied by the decay ratio calculations for Density Wave Oscillations (DWO). The
system response matrix was developed through perturbation and linearization of the
conservation equations in the time domain. Then, the DWO decay ratio was calculated
from the dominant eigenvalue of the system response matrix. It was found that the U. S.
reference SCWR will satisfy the stability criterion at steady state if an inlet orifice
coefficient was properly chosen. Simplified stability maps that define the onset of DWO
instability have also been constructed based on a frequency domain method for both the
single channel and the channel-to-channel DWO. At supercritical pressure, a three-region
model consisting of heavy fluid region, heavy-light fluid mixture region and light fluid
region has been used. New non-dimensional governing parameters, namely, the
Expansion Number and the Pseudo-Subcooling Number have been identified. It has been
found that the U.S. reference SCWR will be stable at full power operating condition with
large margin.
Although the SCWR operates in the supercritical pressure region at steady state,
operation at subcritical pressure will occur during a sliding pressure startup process. At
subcritical pressure, the stability maps have been developed based on the traditional
Subcooling Number and Phase Change Number (also called as Zuber Number). The
sensitivity of stability boundaries due to different two phase flow models has been
studied. It has been found that the Homogenous-Nonequilibrium model (HNEM) yields
more conservative results at high subcooling numbers while the Homogenous
Equilibrium (HEM) model is more conservative at low subcooling numbers. Based on
these stability maps, a stable sliding pressure startup procedure has been suggested for the
reference SCWR design. |
| first_indexed | 2024-09-23T11:09:54Z |
| format | Technical Report |
| id | mit-1721.1/67673 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T11:09:54Z |
| publishDate | 2011 |
| publisher | Massachusetts Institute of Technology. Center for Advanced Nuclear Energy Systems. Advanced Nuclear Power Program |
| record_format | dspace |
| spelling | mit-1721.1/676732019-04-11T03:07:05Z Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors Zhao, J. Saha, P. Kazimi, Mujid S. Advanced Nuclear Power Technology Program (Massachusetts Institute of Technology) Zhao, J. Saha, P. Kazimi, Mujid S. Near the supercritical thermodynamic point, coolant density is very sensitive to temperature which gives potential to several instabilities in the supercritical water-cooled nuclear reactors. The flow stability features of the U.S. reference Supercritical Water- Cooled Reactor (SCWR) have been investigated. Single channel stability features were studied by the decay ratio calculations for Density Wave Oscillations (DWO). The system response matrix was developed through perturbation and linearization of the conservation equations in the time domain. Then, the DWO decay ratio was calculated from the dominant eigenvalue of the system response matrix. It was found that the U. S. reference SCWR will satisfy the stability criterion at steady state if an inlet orifice coefficient was properly chosen. Simplified stability maps that define the onset of DWO instability have also been constructed based on a frequency domain method for both the single channel and the channel-to-channel DWO. At supercritical pressure, a three-region model consisting of heavy fluid region, heavy-light fluid mixture region and light fluid region has been used. New non-dimensional governing parameters, namely, the Expansion Number and the Pseudo-Subcooling Number have been identified. It has been found that the U.S. reference SCWR will be stable at full power operating condition with large margin. Although the SCWR operates in the supercritical pressure region at steady state, operation at subcritical pressure will occur during a sliding pressure startup process. At subcritical pressure, the stability maps have been developed based on the traditional Subcooling Number and Phase Change Number (also called as Zuber Number). The sensitivity of stability boundaries due to different two phase flow models has been studied. It has been found that the Homogenous-Nonequilibrium model (HNEM) yields more conservative results at high subcooling numbers while the Homogenous Equilibrium (HEM) model is more conservative at low subcooling numbers. Based on these stability maps, a stable sliding pressure startup procedure has been suggested for the reference SCWR design. 2011-12-14T19:21:33Z 2011-12-14T19:21:33Z 2004-09 Technical Report http://hdl.handle.net/1721.1/67673 MIT-ANP;TR-105 application/pdf Massachusetts Institute of Technology. Center for Advanced Nuclear Energy Systems. Advanced Nuclear Power Program |
| spellingShingle | Zhao, J. Saha, P. Kazimi, Mujid S. Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors |
| title | Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors |
| title_full | Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors |
| title_fullStr | Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors |
| title_full_unstemmed | Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors |
| title_short | Analysis Of Flow Instabilities In Supercritical Watercooled Nuclear Reactors |
| title_sort | analysis of flow instabilities in supercritical watercooled nuclear reactors |
| url | http://hdl.handle.net/1721.1/67673 |
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