Status of severe accident studies at the end of the conceptual design of astrid feedback on mitigation features
Autor: | Frédéric Bertrand, X. Manchon, Jean-Baptiste Droin, A. Bachrata, Bernard Carluec, B. Farges, V. Brun-Magaud, D. Lemasson, K. Herbreteau, Nathalie Marie, S. Poumerouly |
---|---|
Přispěvatelé: | CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), AREVA, Groupe AREVA, European RandD Specific Action SESSA, affiliation inconnue, Département Etude des Réacteurs (DER), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), EDF (EDF) |
Jazyk: | angličtina |
Rok vydání: | 2017 |
Předmět: |
Nuclear and High Energy Physics
Engineering Operability Mitigation [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] 020209 energy Nuclear engineering 02 engineering and technology [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] 7. Clean energy Conceptual design CFV core Boiling 0202 electrical engineering electronic engineering information engineering General Materials Science Safety Risk Reliability and Quality Waste Management and Disposal Severe accident Mechanical energy Simulation Leakage (electronics) business.industry Mechanical Engineering ASTRID Nuclear Energy and Engineering business Core catcher Thermal energy Low sodium |
Zdroj: | FR 17 FR 17, Jun 2017, Yekaterinburg, Russia |
Popis: | International audience; The ASTRID reactor developed by the CEA with its industrial partners, will be used for demonstration of the safety and operability, at the industrial scale, of sodium fast reactors of the 4th generation. Among the goals assigned to ASTRID, one is to improve the safety and the reliability of such reactor (compared to previous built sodium-cooled fast reactors). Regarding the innovations promoted in the ASTRID design, a low sodium void worth core concept (CFV core) has been developed. By means of various design provisions enhancing the neutron leakage in case of sodium draining, the overall sodium void effect of the ASTRID core is near zero and could even be negative. Additionally, mitigation devices should be implemented into the core in order to limit the calorific energy released in the fuel during the secondary phase of the severe accident. This paper deals with a synthesis of severe accident studies performed during the second period of the pre-conceptual design stage of the ASTRID project (2013-2015). The main insights of the studies in term of mitigation strategy and of mitigation device design are highlighted in the paper. The CFV core transient behavior has been investigated in case of generalized core melting situations initiated by postulated reactivity insertion ramps (UTOP) and unprotected loss of flow (ULOF). In case of UTOP transients, the mechanical energy released by molten fuel vapor expansion does not exceed several tenths of megajoule. Simulated ULOF transients do not lead to energetic power excursions thanks to the mitigation provisions and to the core design. Regarding ULOF transients, early boiling phase leads to core power decrease and the primary phase of the accident is not governed by a power excursion. The paper deals with the approach and the presentation of preliminary findings regarding mitigation provisions. Those provisions are investigated by considering a postulated core degraded state representative of the end of the transition phase. The possible scenario evolutions from this degraded state provide the following parameters mass and temperature of molten materials, mass and flow rates of materials relocated on the core catcher and possible ejected material mass above the core Those parameters are used for the determination of approximate loadings for the primary vessel and for the core catcher. |
Databáze: | OpenAIRE |
Externí odkaz: |