Investigation of the hot-channel calculation methodology in case of shroud-less assemblies

Autor:	I. Panka, A. Keresztúri, Á. Tóta, A. Molnár, E. Temesvári
Rok vydání:	2014
Předmět:	Nuclear and High Energy Physics Radiation Computer science Nuclear engineering Scram Coolant Thermal hydraulics Nuclear Energy and Engineering Operation safety Acceptance testing General Materials Science Shroud Transient (oscillation) Safety Risk Reliability and Quality Communication channel
Zdroj:	Kerntechnik. 79:351-358
ISSN:	2195-8580 0932-3902
DOI:	10.3139/124.110459
Popis:	The fulfillment of the safety analysis acceptance criteria and the normal operation safety related limitations are usually evaluated by using separate hot-channel or/and hot-assembly thermal hydraulic calculations, especially for the closed VVER-440 assemblies. However, the shroud-less assemblies of the expected new NPP units in Hungary or even those of some recently foreseen VVER-440 are raising several questions; like what is the role of the coolant mixing between the neighboring assemblies and can the closed assembly approximation be regarded as conservative for DBA analyses. Focusing an anticipated transient without scram (ATWS) event, the paper evaluates the thermal hydraulic calculation methodology of the shroud-less assemblies by supplementing the computational domain step by step with the closest pins and subchannels of the neighboring assemblies. We concluded that assembly-wise coolant cross-flows and significant changes in the hot-channel DNBR can appear in case of shroud-less assemblies.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b289920e2928a2707dc63638ed4df3db https://doi.org/10.3139/124.110459 Zobrazit plný text záznamu