Investigation of the feasibility of DRAGON/DONJON codes with CARR neutronics calculations
Bibliographic record
Abstract
BackgroundThe unique core and reflector structure of the inverse flux trap research reactors has raised a challenge to the traditional deterministic neutronics calculation methods applicable to power reactors. The deterministic codes DRAGON/DONJON with powerful geometric modeling capabilities have been maturely applied to power reactor types such as CANDU (Canadian Deuterium Uranium) and pressurized water reactors (PWR), but not been performed neutronics calculations and feasibility analysis on the China Advanced Research Reactor (CARR) with inverse flux trap design.PurposeThis study aims to verify the feasibility of the DRAGON/DONJON codes in CARR neutronics calculations and analysis.MethodsFirstly, when performing homogenization calculation using DRAGON/DONJON codes on various assemblies of CARR, the multi-assembly method was adopted to improve the surrounding impact. The OPTEX reflector optimization method was used to modify the homogenization constants of the reflector. Then, the commonly used multigroup cross-section libraries in DARGON were compared and screened, and SHEM-295 group-structure library was selected. Finally, the calculation results of DRAGON/DONJON codes were compared with the Monte Carlo references and the conventional three-step method, and analysis was conducted on the reasons for the significant deviation in the calculation results.ResultsThe results indicate that the deviation of parameters such as keff eigenvalue near critical operating condition, thermal neutron flux distribution in the active zone of the core and the middle position of the heavy water tank, and power distribution of standard fuel assemblies are relatively small whilst significant deviations in the calculation results appear at the junction of the core and heavy water tank, the vacuum boundary outside the pool, and the follower assemblies.ConclusionsThis study verifies that it is feasible to use the DRAGON/DONJON codes for CARR neutronics calculations and achieve a certain degree of accuracy, meeting the needs of experimental schemes design and rapid calculation and analysis of operating parameters.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".