Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment

In order to improve the safety of nuclear power plants, it is necessary to make sure measures against their severe accidents. Especially, in the case of a sodium-cooled fast reactor, there is a possibility that molten core material would be discharged through control rod guide tubes into the inlet c...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Kai IGARASHI, Takaaki SAKAI, Shinya KATO, Ken-ichi MATSUBA, Kenji KAMIYAMA
Formato:	article
Lenguaje:	EN
Publicado:	The Japan Society of Mechanical Engineers 2021
Materias:	sodium-cooled fast reactor core disruptive accident relocation of molten core material simmer-iii Mechanical engineering and machinery TJ1-1570
Acceso en línea:	https://doaj.org/article/2b733b23142447b898c29f235e84eb23
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:2b733b23142447b898c29f235e84eb23
record_format	dspace
spelling	oai:doaj.org-article:2b733b23142447b898c29f235e84eb232021-11-29T06:09:58ZValidation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment2187-974510.1299/mej.21-00172https://doaj.org/article/2b733b23142447b898c29f235e84eb232021-08-01T00:00:00Zhttps://www.jstage.jst.go.jp/article/mej/8/4/8_21-00172/_pdf/-char/enhttps://doaj.org/toc/2187-9745In order to improve the safety of nuclear power plants, it is necessary to make sure measures against their severe accidents. Especially, in the case of a sodium-cooled fast reactor, there is a possibility that molten core material would be discharged through control rod guide tubes into the inlet coolant plenums beneath the rector cores in the event of a core disruptive accident (CDA). It is important to ensure in-vessel retention that keeps and confines damaged core material in the reactor vessel even if the CDA occurs. In this study, effective cooling of the melt in coolant was confirmed by comparing the experiment and analysis. CDA scenario initiated by a unprotected loss of flow condition , which is a typical cause of core damage, is generally categorized into four phases according to the progression of core-disruptive status, which are the initiating, early-discharge, material-relocation and heat-removal phases for the latest design in Japan. During the material-relocation phase, the molten core material flows down mainly through the control rod guide tube and is discharged into the inlet coolant plenum below the bottom of the core. The discharged molten core material collides with the bottom plate of the inlet plenum. Clarification of the accumulation behavior of molten core material with such a collision on the bottom plate is important to reduce uncertainties in the safety assessment of CDA. In present study, in order to make clear behavior of core melt materials during the CDAs of sodium-cooled fast reactors, analysis was conducted using the SIMMER-III code for melt discharge simulation experiments by Imaizumi et al. in which low-melting-point alloy was discharged into a shallow water pool. As the result, temperature and pressure behaviors during the discharge almost coincided between the analysis and the experiment. Therefore, it can be concluded that the validity of the analysis cell system model was confirmed.Kai IGARASHITakaaki SAKAIShinya KATOKen-ichi MATSUBAKenji KAMIYAMAThe Japan Society of Mechanical Engineersarticlesodium-cooled fast reactorcore disruptive accidentrelocation of molten core materialsimmer-iiiMechanical engineering and machineryTJ1-1570ENMechanical Engineering Journal, Vol 8, Iss 4, Pp 21-00172-21-00172 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	sodium-cooled fast reactor core disruptive accident relocation of molten core material simmer-iii Mechanical engineering and machinery TJ1-1570
spellingShingle	sodium-cooled fast reactor core disruptive accident relocation of molten core material simmer-iii Mechanical engineering and machinery TJ1-1570 Kai IGARASHI Takaaki SAKAI Shinya KATO Ken-ichi MATSUBA Kenji KAMIYAMA Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
description	In order to improve the safety of nuclear power plants, it is necessary to make sure measures against their severe accidents. Especially, in the case of a sodium-cooled fast reactor, there is a possibility that molten core material would be discharged through control rod guide tubes into the inlet coolant plenums beneath the rector cores in the event of a core disruptive accident (CDA). It is important to ensure in-vessel retention that keeps and confines damaged core material in the reactor vessel even if the CDA occurs. In this study, effective cooling of the melt in coolant was confirmed by comparing the experiment and analysis. CDA scenario initiated by a unprotected loss of flow condition , which is a typical cause of core damage, is generally categorized into four phases according to the progression of core-disruptive status, which are the initiating, early-discharge, material-relocation and heat-removal phases for the latest design in Japan. During the material-relocation phase, the molten core material flows down mainly through the control rod guide tube and is discharged into the inlet coolant plenum below the bottom of the core. The discharged molten core material collides with the bottom plate of the inlet plenum. Clarification of the accumulation behavior of molten core material with such a collision on the bottom plate is important to reduce uncertainties in the safety assessment of CDA. In present study, in order to make clear behavior of core melt materials during the CDAs of sodium-cooled fast reactors, analysis was conducted using the SIMMER-III code for melt discharge simulation experiments by Imaizumi et al. in which low-melting-point alloy was discharged into a shallow water pool. As the result, temperature and pressure behaviors during the discharge almost coincided between the analysis and the experiment. Therefore, it can be concluded that the validity of the analysis cell system model was confirmed.
format	article
author	Kai IGARASHI Takaaki SAKAI Shinya KATO Ken-ichi MATSUBA Kenji KAMIYAMA
author_facet	Kai IGARASHI Takaaki SAKAI Shinya KATO Ken-ichi MATSUBA Kenji KAMIYAMA
author_sort	Kai IGARASHI
title	Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
title_short	Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
title_full	Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
title_fullStr	Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
title_full_unstemmed	Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
title_sort	validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment
publisher	The Japan Society of Mechanical Engineers
publishDate	2021
url	https://doaj.org/article/2b733b23142447b898c29f235e84eb23
work_keys_str_mv	AT kaiigarashi validationofanalysismodelsonrelocationbehaviorofmoltencorematerialsinsodiumcooledfastreactorsbasedonthemeltdischargeexperiment AT takaakisakai validationofanalysismodelsonrelocationbehaviorofmoltencorematerialsinsodiumcooledfastreactorsbasedonthemeltdischargeexperiment AT shinyakato validationofanalysismodelsonrelocationbehaviorofmoltencorematerialsinsodiumcooledfastreactorsbasedonthemeltdischargeexperiment AT kenichimatsuba validationofanalysismodelsonrelocationbehaviorofmoltencorematerialsinsodiumcooledfastreactorsbasedonthemeltdischargeexperiment AT kenjikamiyama validationofanalysismodelsonrelocationbehaviorofmoltencorematerialsinsodiumcooledfastreactorsbasedonthemeltdischargeexperiment
_version_	1718407576617484288

Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment

Ejemplares similares