Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor
Control rod calibration experiment results for the Oregon State TRIGA<sup>®</sup> Reactor (OSTR) immediately following LEU conversion in 2008, and MCNP<sup>®</sup> 5 predicted rod worths from the 2008 LEU Conversion Safety Analysis Report (CSAR) are discussed. The reactivity...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-01-01
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| Series: | Journal of Nuclear Engineering |
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| Online Access: | https://www.mdpi.com/2673-4362/5/1/2 |
| _version_ | 1797240437461745664 |
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| author | Tracey Spoerer Robert Schickler Steven Reese |
| author_facet | Tracey Spoerer Robert Schickler Steven Reese |
| author_sort | Tracey Spoerer |
| collection | DOAJ |
| description | Control rod calibration experiment results for the Oregon State TRIGA<sup>®</sup> Reactor (OSTR) immediately following LEU conversion in 2008, and MCNP<sup>®</sup> 5 predicted rod worths from the 2008 LEU Conversion Safety Analysis Report (CSAR) are discussed. The reactivity worth of the four OSTR control rods is measured using the rod-pull method. Reactor power and period measurements in this method rely on the fission chamber power detector on the north side of the reflector. It is proposed that the location of the fission chamber and the neutron flux distribution in the core may result in an inaccurate reactor period measurement due to the asymmetry of the neutron flux distribution in the OSTR core. The asymmetry of the flux is believed to be more pronounced during super-criticality, resulting in errors in the time-of-power-rise measurements. As a result, control rod calibration experiments may under-predict or over-predict the reactivity worth of certain control rods. A time-independent Monte–Carlo method for the quantification of these effects is presented. Thermal flux maps at the core axial mid-plane are obtained from the model to inform discrepancies between predicted and observed results. |
| first_indexed | 2024-04-24T18:07:25Z |
| format | Article |
| id | doaj.art-cd4d609491104f3a9295be0e531093a4 |
| institution | Directory Open Access Journal |
| issn | 2673-4362 |
| language | English |
| last_indexed | 2024-04-24T18:07:25Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Nuclear Engineering |
| spelling | doaj.art-cd4d609491104f3a9295be0e531093a42024-03-27T13:49:32ZengMDPI AGJournal of Nuclear Engineering2673-43622024-01-0151132510.3390/jne5010002Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> ReactorTracey Spoerer0Robert Schickler1Steven Reese2School of Nuclear Science and Engineering, Oregon State University, Corvallis, OR 97331, USASchool of Nuclear Science and Engineering, Oregon State University, Corvallis, OR 97331, USASchool of Nuclear Science and Engineering, Oregon State University, Corvallis, OR 97331, USAControl rod calibration experiment results for the Oregon State TRIGA<sup>®</sup> Reactor (OSTR) immediately following LEU conversion in 2008, and MCNP<sup>®</sup> 5 predicted rod worths from the 2008 LEU Conversion Safety Analysis Report (CSAR) are discussed. The reactivity worth of the four OSTR control rods is measured using the rod-pull method. Reactor power and period measurements in this method rely on the fission chamber power detector on the north side of the reflector. It is proposed that the location of the fission chamber and the neutron flux distribution in the core may result in an inaccurate reactor period measurement due to the asymmetry of the neutron flux distribution in the OSTR core. The asymmetry of the flux is believed to be more pronounced during super-criticality, resulting in errors in the time-of-power-rise measurements. As a result, control rod calibration experiments may under-predict or over-predict the reactivity worth of certain control rods. A time-independent Monte–Carlo method for the quantification of these effects is presented. Thermal flux maps at the core axial mid-plane are obtained from the model to inform discrepancies between predicted and observed results.https://www.mdpi.com/2673-4362/5/1/2control rod calibrationcontrol rod shadowingMonte Carlo methodOregon State University TRIGA<sup>®</sup> Reactor |
| spellingShingle | Tracey Spoerer Robert Schickler Steven Reese Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor Journal of Nuclear Engineering control rod calibration control rod shadowing Monte Carlo method Oregon State University TRIGA<sup>®</sup> Reactor |
| title | Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor |
| title_full | Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor |
| title_fullStr | Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor |
| title_full_unstemmed | Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor |
| title_short | Effects of Neutron Flux Distribution and Control Rod Shadowing on Control Rod Calibrations in the Oregon State TRIGA<sup>®</sup> Reactor |
| title_sort | effects of neutron flux distribution and control rod shadowing on control rod calibrations in the oregon state triga sup r sup reactor |
| topic | control rod calibration control rod shadowing Monte Carlo method Oregon State University TRIGA<sup>®</sup> Reactor |
| url | https://www.mdpi.com/2673-4362/5/1/2 |
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