Multi-Feeder Stress Analysis With Interlinked Spacers for a CANDU Reactor
Bibliographic record
Abstract
In one Ontario CANDU reactor unit, the horizontal feeders are interlinked with feeder spacer rods, which are installed to prevent the contact between adjacent feeders. In the normal operating conditions, spaces do not carry any loads. Therefore, the individual feeder model is used without spacers for the horizontal feeders. This reactor unit is under extensive fuel channel shifting in order to extend the life time. The axial shifting of channels is expected to put additional loads on spacers and may constrain feeder movement. In order to determine how the spacer affects the feeder stress and feeder movement due to the extensive fuel channel shifting, multifeeder models that include spacers are created for stress analysis. Multi-feeder modelling capability is not readily available in AUTOPIPE. A novel approach of inter connecting feeders with structural elements is developed for AUTOPIPE. A significant increase in feeder stress under the extensive fuel channel shift loading condition is found when the feeder spacers are included in the model. However, the feeder stresses for Design, Level A&B loading under fuel channel shift configuration meet the ASME B&PV Code NB-3600 stress limit requirements. The feeder spacer assessment results also show that the structural integrity of feeder spacers is not affected by the fuel channel shifting. In addition, this study confirmed that it is unnecessary to release the feeder spacers to prevent spacer break or feeder overstress during the post fuel channel sifting operation, thus saving significant outage time to achieve shifting configuration.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".