Review Article
Overview and Discussion of the OECD/NRC Benchmark Based on NUPEC PWR Subchannel and Bundle Tests
Table 10
Sources of error for void distribution measurement.
| | Error source | Chordal averaged |
CT averaged | | Steady state | Transient |
| | γ-ray measurement | | | | Effect of surrounding condition (magnetic field and temperature)
on measurement system | 0.1% | 0.1% | 0.1% | | Randomness of γ-ray source decay | 0.02% | 0.2% | 0.1% | | Correction error due to background | 0.0% | 0.0% | 0.0% | | Correction error due to counting loss | <0.5% | <0.5% | <0.1% | | Calibration error | 0.1% | 0.1% | 0.1% | | Correction error due to attenuation by surrounding water | 0.0% | 0.0% | — | | Correction error due to scattering from multi-γ-rays | <0.2% | <0.2% | — |
| | Total | <0.55% | <0.6% | <0.2% |
| | Subchannel density | | | | | Transfer to density | <9 kg/m3 | <10 kg/m3 | <15 kg/m3 | | Distribution error to subchannel | <5 kg/m3 | <5 kg/m3 | — | | Correlation error from chordal averaged to CT averaged | <6 kg/m3 | <6 kg/m3 | — |
| | Subchannel density | <20 kg/m3 | <21 kg/m3 | <15 kg/m3 | | Subchannel void* | 0.040 | 0.042 | 0.030 | | Uncertainty (1σ) | 4% | 5% | 3% |
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*Reference averaged density is 500 kg/m3.
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