ICONE23-1053 OPPORTUNITIES AND NEED TO FURTHER UPGRADE CANDU REACTORS FOR IMPROVED SEVERE ACCIDENT MITIGATION AND REDUCTION OF RISK
Notice bibliographique
Résumé
Independent deterministic analyses of system response and severe accident progression after a station blackout scenario for CANDU single and multi-unit reactors have unveiled a number of design vulnerabilities that cause uncontrolled pressure boundary ruptures; premature expulsion of coolant from main loops and from the moderator heat sink; direct exposure of core debris and fission product releases to the containment; thermo-mechanical failure of the thin shell Calandria vessel welds; accelerated production of hydrogen with containment boundary failures by steaming as well as by sparsely populated PARS units potentially exposed to high concentration deuterium/hydrogen they are unable to adequately mitigate. A number of design enhancements can however be undertaken to minimize risk from a severe accident by eliminating or avoiding some of the undesirable system responses. Engineered design measures to also avoid some the undesirable accident progression paths have been summarized in the paper. The Canadian regulatory body CNSC prepared a number of design enhancement requests as part of post Fukushima reviews but then accepted measures and submissions that do not meet the public expectations for risk reduction after Fukushima on all counts. Without thoughtful and timely design changes, consequences of a severe core damage in a CANDU reactor can pose risks that are still unacceptable especially after the hype that surrounded the utility 'Stress Tests' and regulatory 'Action Items' that followed Fukushima disaster in 2011. It is stressed that operating CANDU and other similar PHWRs in India are unique; have an enviable safety record; have maintained very high operational loads and the observations in this paper relate to requirements for mitigating a range of potential severe accidents whose probability has been demonstrated to be relatively high given that less than 15000 reactor years of operation have resulted in 3 severe accidents that have caused more off-site damage than ever anticipated. That is something the founding fathers did not consider within the design basis and the current regulating bodies have a difficult time wrapping their head around. Utilities that operate the plants have shown no visible leadership in self assessments; have rejected any attempts to enlighten them and the risk posed by continued operation of these plants can only be minimized by an open discussion of the totality of issues as attempted in this paper.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».