Understanding Equivalent Margins Analysis for Required Upper Shelf Energy
Bibliographic record
Abstract
Equivalent Margins Analysis (EMA) involves the calculation of an alternative minimum reactor pressure vessel (RPV) upper shelf energy (USE) when the projected value falls below current limits codified in Title 10, Code of Federal Regulations, Part 50 (10 CFR 50), Appendix G. One set of calculation methodologies for performing the analysis are provided in the Nuclear Regulatory Commission’s (NRC’s) Regulatory Guide (RG) 1.161 and American Society of Mechanical Engineers Boiler & Pressure Vessel Code (ASME Code), Section XI, nonmandatory Appendix K. Careful application of fracture mechanics principles is necessary in order to properly carry out the evaluation. This is particularly the case for demonstrating compliance with the ductile crack growth stability criterion. This paper discusses robust implementation of EMA calculations and identifies recommended changes to RG 1.161 and ASME Code, Section XI, nonmandatory Appendix K.
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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) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.013 | 0.002 |
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".