Loss-of-coolant accident (original) (raw)
يعد حادث فقد المبرد النووي أحد أشكال فشل المفاعل النووي؛ إذا لم تتم إدارتها بشكل فعال، فقد تؤدي نتائج حادث فقد المبرد النووي إلى تلف في قلب المفاعل. يوجد نظام التبريد الأساسي للطوارئ لكل محطة نووية على وجه التحديد للتعامل مع حادث فقد المبرد النووي.
| Property | Value |
|---|---|
| dbo:abstract | يعد حادث فقد المبرد النووي أحد أشكال فشل المفاعل النووي؛ إذا لم تتم إدارتها بشكل فعال، فقد تؤدي نتائج حادث فقد المبرد النووي إلى تلف في قلب المفاعل. يوجد نظام التبريد الأساسي للطوارئ لكل محطة نووية على وجه التحديد للتعامل مع حادث فقد المبرد النووي. (ar) Havárie se ztrátou chladiva (LOCA, Loss of Coolant Accident) je hypotetickou projektovou havárií jaderných elektráren s tlakovodními reaktory. Projekt uvažuje nejzávažnější porušení primárního okruhu a slouží především k hodnocení bezpečnosti bezpečnostními analýzami jaderných elektráren. Tato původně maximální projektová havárie je způsobena prasknutím primárního potrubí. Dle velikosti trhliny se havárie LOCA dělí na LB-LOCA (Large Break LOCA) a SB-LOCA (Small Break LOCA). Při havárii SB-LOCA jsou předpokládané dosažené teploty a doba trvání zahřívání paliva výrazně nižší. Iniciační událostí LB-LOCA je gilotinový řez na studené větvi hlavního primárního potrubí v místech mezi reaktorovou nádobou a hlavním cirkulačním čerpadlem s následným neomezeným oboustranným výtokem chladiva do prostoru ochranné obálky jaderné elektrárny a rychlým odpařováním chladiva. Průběh havárie má ve zjednodušeném modelu, předpokládajícím úspěšný zásah nouzových dochlazovacích systémů, čtyři fáze a vykazuje dva teplotní píky palivového pokrytí. Prasknutí studené větve smyčky primárního okruhu (cs) Als Kühlmittelverluststörfall (englisch loss-of-coolant accident, LOCA) wird in der Kerntechnik ein Störfall bezeichnet, der zum Austreten von Kühlmittel aus dem Kühlkreislauf des Kernreaktors führt. (de) A loss-of-coolant accident (LOCA) is a mode of failure for a nuclear reactor; if not managed effectively, the results of a LOCA could result in reactor core damage. Each nuclear plant's emergency core cooling system (ECCS) exists specifically to deal with a LOCA. Nuclear reactors generate heat internally; to remove this heat and convert it into useful electrical power, a coolant system is used. If this coolant flow is reduced, or lost altogether, the nuclear reactor's emergency shutdown system is designed to stop the fission chain reaction. However, due to radioactive decay, the nuclear fuel will continue to generate a significant amount of heat. The decay heat produced by a reactor shutdown from full power is initially equivalent to about 5 to 6% of the thermal rating of the reactor. If all of the independent cooling trains of the ECCS fail to operate as designed, this heat can increase the fuel temperature to the point of damaging the reactor. * If water is present, it may boil, bursting out of its pipes. For this reason, nuclear power plants are equipped with pressure-operated relief valves and backup supplies of cooling water. * If graphite and air are present, the graphite may catch fire, spreading radioactive contamination. This situation exists only in AGRs, RBMKs, Magnox and weapons-production reactors, which use graphite as a neutron moderator (see Chernobyl disaster and Windscale fire). * The fuel and reactor internals may melt; if the melted configuration remains critical, the molten mass will continue to generate heat, possibly melting its way down through the bottom of the reactor. Such an event is called a nuclear meltdown and can have severe consequences. The so-called "China syndrome" would be this process taken to an extreme: the molten mass working its way down through the soil to the water table (and below) – however, current understanding and experience of nuclear fission reactions suggests that the molten mass would become too disrupted to carry on heat generation before descending very far; for example, in the Chernobyl disaster the reactor core melted and core material was found in the basement, too widely dispersed to carry on a chain reaction (but still dangerously radioactive). * Some reactor designs have passive safety features that prevent meltdowns from occurring in these extreme circumstances. The Pebble Bed Reactor, for instance, can withstand extreme temperature transients in its fuel. Another example is the CANDU reactor, which has two large masses of relatively cool, low-pressure water (first is the heavy-water moderator; second is the light-water-filled shield tank) that act as heat sinks. Another example is the Hydrogen Moderated Self-regulating Nuclear Power Module, in which the chemical decomposition of the uranium hydride fuel halts the fission reaction by removing the hydrogen moderator. The same principle is used in TRIGA research reactors. Under operating conditions, a reactor may passively (that is, in the absence of any control systems) increase or decrease its power output in the event of a LOCA or of voids appearing in its coolant system (by water boiling, for example). This is measured by the coolant void coefficient. Most modern nuclear power plants have a negative void coefficient, indicating that as water turns to steam, power instantly decreases. Two exceptions are the Soviet RBMK and the Canadian CANDU. Boiling water reactors, on the other hand, are designed to have steam voids inside the reactor vessel. Modern reactors are designed to prevent and withstand loss of coolant, regardless of their void coefficient, using various techniques. Some, such as the pebble bed reactor, passively slow down the chain reaction when coolant is lost; others have extensive safety systems to rapidly shut down the chain reaction, and may have extensive passive safety systems (such as a large thermal heat sink around the reactor core, passively-activated backup cooling/condensing systems, or a passively cooled containment structure) that mitigate the risk of further damage. (en) Una pérdida accidental de refrigerante (en inglés: Loss-Of-Coolant Accident, LOCA) es una forma de falla de un reactor nuclear, que si no es manejada efectivamente podría tener como resultado un daño al núcleo del reactor. El (en inglés: Emergency Core Cooling System, ECCS) de cada planta nuclear existe específicamente para enfrentar esta falla. (es) 냉각재 상실사고(loss-of-coolant accident, LOCA)는 원자로에서 발생하는 사고중 하나로, 원자로에 냉각수를 공급하는 원자로냉각재계통의 배관이 파단되고 파단부위를 통하여 냉각수가 상실되는 사고이다. 효과적으로 대응하지 못하면 노심 내부의 열이 급격히 상승하여 최악의 경우 노심 용융 사고가 발생할 수 있다. 대부분의 발전소에서는 LOCA때 효율적으로 대비할 수 있게 비상노심냉각장치(ECCS)를 갖추고 있다. 원자로는 내부에서 열을 발생시켜, 냉각재를 이용하여 열을 배출시키고 그 열을 이용하여 발전을 한다. 만약 냉각재가 부족하거나, 아예 없어져 버리면 SCRAM(원자로 비상 정지)이 발동되어, 연쇄반응을 중단시킨다. 그러나 연료의 방사능 붕괴열로 인해, 일정량의 열이 원자로에 남게 된다. 이때 ECCS가 설계대로 작동되지 않는다면 열은 다음과 같이 원자로에 큰 손상을 입히게 된다. * 물이 LOCA때 존재하면, 물은 강력한 압력으로 냉각체제의 파이프를 폭발시킬수 있다. 이를 대비하여 원자력 발전소에서는 압력을 빼내는 압력밸브와, 여분의 냉각수를 더 공급할 수 있는 체제를 갖추고 있다. * 흑연과 공기가 LOCA때 만나면 흑연에서 불이 붙고, 방사능 오염을 뿌린다. 이런 상황은 흑연을 감속재로 쓰는 개량형 가스냉각 원자로, RBMK, 마그녹스, 그리고 여러 무기제조용 플루토늄 생산 원자로에서 일어날수 있다. * 연료와 원자로가 내부에서 계속 열을 받아 녹을 시 문제가 더 커질 수 있는데, 이 용융물은 열을 계속해서 생성하여, 원자로 바닥으로 내려갈 수 있다. 이런 현상을 가리켜 노심용융(Nuclear Meltdown)이라 하며, 발생시 혹독한 결과를 초래한다. 이걸 지칭하는 말 중 하나가 "차이나 신드롬"(China Syndrome, 미국의 원자력발전소에서 노심용융사고가 일어나면, 그 녹은 방사성물질이 지각밑을 타고 반대편 중국으로 갈 수 있다는 생각)이라는 극단적인 생각이다. 그러나, 현재 여러 사례와 실험을 바탕으로 볼 때, 용융물이 바닥을 녹이기 전에 용융물들의 열생산이 방해를 받게 된다. 예를 들어 체르노빌 사고때 원자로 노심이 녹아, 노심 잔류물이 기반에서 발견되었는데, 발견된 노심 잔류물은 넓게 퍼져 연쇄반응을 더이상 할 수 없게 되었었다(그러나, 여전히 방사능 수치는 위험한 수치였다). * 몇몇 원자로는 설계에서부터 수동적 안전장치(Passive Safety)를 적용해 노심용융에서 일어나는 극단적 상황을 예방했다. 페블베드 원자로의 경우엔 연료를 피복으로 둘러싸, 연료가 극단적인 열에 보호받도록 되어 있다. 다른 예로는 CANDU에서 찾을 수 있는데, CANDU에선 2개의 비교적 차가운 물질들(첫 번째로는 중성자 감속재인 중수, 두 번째는 경수로 가득찬 경수차폐 탱크)로 인해서 열은 쉽게 사그라진다. 대한민국 대부분의 원전에 해당하는 가압경수로에서 대형냉각재상실사고가 발생할 때 진행되는 사고 상태는 다음과 같다. 1. * 원자로냉각재 배관 내에서 높은 온도와 압력 상태에 있던 액체 상태의 냉각수가 배관 파단 직후 원자로격납건물 대기로 방출된다. 2. * 냉각수가 방출된 후 압력이 낮아진 원자로에 비상노심냉각계통에서 공급하는 냉각수가 유입된다. 3. * 비상노심냉각수가 원자로를 채우고 파단부위를 통해 방출되는 순환유로를 통해 붕괴열을 제거하게 된다. 따라서 비상노심냉각계통은 대형냉각재상실사고를 포함한 다양한 파단 크기의 냉각재상실사고를 분석하여, 원자로 냉각재를 보충하고 핵연료 붕괴열을 충분히 냉각시킬 수 있도록 설계되어야 한다. 냉각재상실사고에 대비한 핵연료 냉각기능 평가와 함께, 냉각재상실사고로 인한 원자로시설 인근 주민의 방사선 피폭선량에 대한 평가도 수행된다. 방사선 피폭선량 평가는 방사선 관점에서 가장 심각한 사고인 대형냉각재상실사고에 대하여 수행되며, 이때 적용되는 발전소 경계에서의 일반 주민에 대한 방사선 피폭 제한치는 미국의 10 CFR 100.11에서 규정하는 전신선량 250mSv 및 갑상선 선량 3,000mSv를 적용한다. (ko) 冷却材喪失事故（れいきゃくざいそうしつじこ、英語: loss-of-coolant accident, LOCA）とは、軽水炉において冷却材および減速材として用いられる軽水が配管の破損等によって流出し、炉心の冷却機能が損なわれる事故をいう。 (ja) Een Loss-of-coolant accident of LOCA is een referentie-ongeval bij een kerncentrale die tot schade aan de reactorkern kan leiden. Bij een LOCA valt (een deel van) het koelingssysteem uit door verlies van primair koelwater. Dit kan onrechtstreeks het gevolg zijn bij verlies van het extern net (LOOP, Loss of Offsite Power), zoals gebeurde in Fukushima. Andere risico's met inwendige oorzaak zijn een SGPB of Stoomgeneratorpijpbreuk (breuk van een buisje in een stoomgenerator) of een SLB of Stoomleidingsbreuk (breuk van een stoomleiding van het secundaire circuit).Elke kerncentrale bezit noodsystemen om de koeling van de kern te verzekeren, onder andere het 'Emergency Core Cooling System' (ECCS). (nl) L'acronimo LOCA (dall'inglese loss-of-coolant accident) indica l'incidente dovuto alla perdita del fluido refrigerante dal circuito primario di raffreddamento di un reattore nucleare a fissione. Senza l'intervento dei sistemi di sicurezza, tale incidente può facilmente condurre alla fusione del nocciolo. (it) 冷卻劑流失事故或稱「失水事件」、「冷卻水流失事故」，簡稱「LOCA」（Loss-Of-Coolant Accident），即核子反應爐的冷卻劑因故流失，未能將熱能帶出反應爐。若緊急爐心冷卻系統未能及時冷卻反應爐，反應爐內的核燃料可能會因為過熱而發生爐心熔毀。三哩島事件即因未能即使冷卻反應爐而導致部分爐心熔毀。 (zh) |
| dbo:thumbnail | wiki-commons:Special:FilePath/LWR_Meltdown.gif?width=300 |
| dbo:wikiPageID | 918900 (xsd:integer) |
| dbo:wikiPageLength | 13816 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1059460676 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Neutron_moderator dbr:Passive_nuclear_safety dbr:Nuclear_safety dbr:Boiling_water_reactor dbr:Uranium_hydride dbr:Decay_heat dbr:CANDU dbr:SCRAM dbr:Nuclear_reactor dbr:Zirconium_alloy dbc:Nuclear_reactor_safety dbr:Containment_building dbr:Coolant dbr:Lucens_reactor dbr:Combustion dbr:Fukushima_Daiichi_nuclear_disaster dbr:Pebble_Bed_Reactor dbr:Pebble_bed_reactor dbr:Pressurized_water_reactor dbr:Water_table dbr:CANDU_reactor dbr:Windscale_fire dbr:Nuclear_fission dbr:Nuclear_fuel dbr:Nuclear_meltdown dbr:Nuclear_power dbr:Nuclear_power_plant dbr:Graphite dbr:Radioactive_contamination dbr:Relief_valve dbc:Civilian_nuclear_power_accidents dbr:Atucha_I_Nuclear_Power_Plant dbr:Chernobyl_disaster dbr:Advanced_gas-cooled_reactor dbr:TRIGA dbr:Emergency_core_cooling_system dbr:Radioactive_decay dbr:Magnox dbr:Scram dbr:Void_coefficient dbr:LOFT_(LOCA) dbr:RBMK dbr:Light_water_reactors dbr:Hydrogen_Moderated_Self-regulating_Nuclear_Power_Module dbr:Nuclear_accidents_in_the_United_States dbr:Nuclear_fuel_response_to_reactor_accidents dbr:Nuclear_safety_in_the_U.S. dbr:Pressurised_heavy_water_reactor dbr:File:LWR_Meltdown.gif |
| dbp:wikiPageUsesTemplate | dbt:Authority_control dbt:More_citations_needed dbt:Portal_bar dbt:Reflist dbt:Short_description |
| dct:subject | dbc:Nuclear_reactor_safety dbc:Civilian_nuclear_power_accidents |
| gold:hypernym | dbr:Mode |
| rdf:type | owl:Thing yago:WikicatNuclearReactors yago:Apparatus102727825 yago:Artifact100021939 yago:Equipment103294048 yago:Instrumentality103575240 yago:NuclearReactor103834040 yago:Object100002684 yago:PhysicalEntity100001930 dbo:Single yago:Whole100003553 |
| rdfs:comment | يعد حادث فقد المبرد النووي أحد أشكال فشل المفاعل النووي؛ إذا لم تتم إدارتها بشكل فعال، فقد تؤدي نتائج حادث فقد المبرد النووي إلى تلف في قلب المفاعل. يوجد نظام التبريد الأساسي للطوارئ لكل محطة نووية على وجه التحديد للتعامل مع حادث فقد المبرد النووي. (ar) Als Kühlmittelverluststörfall (englisch loss-of-coolant accident, LOCA) wird in der Kerntechnik ein Störfall bezeichnet, der zum Austreten von Kühlmittel aus dem Kühlkreislauf des Kernreaktors führt. (de) Una pérdida accidental de refrigerante (en inglés: Loss-Of-Coolant Accident, LOCA) es una forma de falla de un reactor nuclear, que si no es manejada efectivamente podría tener como resultado un daño al núcleo del reactor. El (en inglés: Emergency Core Cooling System, ECCS) de cada planta nuclear existe específicamente para enfrentar esta falla. (es) 冷却材喪失事故（れいきゃくざいそうしつじこ、英語: loss-of-coolant accident, LOCA）とは、軽水炉において冷却材および減速材として用いられる軽水が配管の破損等によって流出し、炉心の冷却機能が損なわれる事故をいう。 (ja) Een Loss-of-coolant accident of LOCA is een referentie-ongeval bij een kerncentrale die tot schade aan de reactorkern kan leiden. Bij een LOCA valt (een deel van) het koelingssysteem uit door verlies van primair koelwater. Dit kan onrechtstreeks het gevolg zijn bij verlies van het extern net (LOOP, Loss of Offsite Power), zoals gebeurde in Fukushima. Andere risico's met inwendige oorzaak zijn een SGPB of Stoomgeneratorpijpbreuk (breuk van een buisje in een stoomgenerator) of een SLB of Stoomleidingsbreuk (breuk van een stoomleiding van het secundaire circuit).Elke kerncentrale bezit noodsystemen om de koeling van de kern te verzekeren, onder andere het 'Emergency Core Cooling System' (ECCS). (nl) L'acronimo LOCA (dall'inglese loss-of-coolant accident) indica l'incidente dovuto alla perdita del fluido refrigerante dal circuito primario di raffreddamento di un reattore nucleare a fissione. Senza l'intervento dei sistemi di sicurezza, tale incidente può facilmente condurre alla fusione del nocciolo. (it) 冷卻劑流失事故或稱「失水事件」、「冷卻水流失事故」，簡稱「LOCA」（Loss-Of-Coolant Accident），即核子反應爐的冷卻劑因故流失，未能將熱能帶出反應爐。若緊急爐心冷卻系統未能及時冷卻反應爐，反應爐內的核燃料可能會因為過熱而發生爐心熔毀。三哩島事件即因未能即使冷卻反應爐而導致部分爐心熔毀。 (zh) Havárie se ztrátou chladiva (LOCA, Loss of Coolant Accident) je hypotetickou projektovou havárií jaderných elektráren s tlakovodními reaktory. Projekt uvažuje nejzávažnější porušení primárního okruhu a slouží především k hodnocení bezpečnosti bezpečnostními analýzami jaderných elektráren. Tato původně maximální projektová havárie je způsobena prasknutím primárního potrubí. Dle velikosti trhliny se havárie LOCA dělí na LB-LOCA (Large Break LOCA) a SB-LOCA (Small Break LOCA). Při havárii SB-LOCA jsou předpokládané dosažené teploty a doba trvání zahřívání paliva výrazně nižší. (cs) A loss-of-coolant accident (LOCA) is a mode of failure for a nuclear reactor; if not managed effectively, the results of a LOCA could result in reactor core damage. Each nuclear plant's emergency core cooling system (ECCS) exists specifically to deal with a LOCA. (en) 냉각재 상실사고(loss-of-coolant accident, LOCA)는 원자로에서 발생하는 사고중 하나로, 원자로에 냉각수를 공급하는 원자로냉각재계통의 배관이 파단되고 파단부위를 통하여 냉각수가 상실되는 사고이다. 효과적으로 대응하지 못하면 노심 내부의 열이 급격히 상승하여 최악의 경우 노심 용융 사고가 발생할 수 있다. 대부분의 발전소에서는 LOCA때 효율적으로 대비할 수 있게 비상노심냉각장치(ECCS)를 갖추고 있다. 원자로는 내부에서 열을 발생시켜, 냉각재를 이용하여 열을 배출시키고 그 열을 이용하여 발전을 한다. 만약 냉각재가 부족하거나, 아예 없어져 버리면 SCRAM(원자로 비상 정지)이 발동되어, 연쇄반응을 중단시킨다. 그러나 연료의 방사능 붕괴열로 인해, 일정량의 열이 원자로에 남게 된다. 이때 ECCS가 설계대로 작동되지 않는다면 열은 다음과 같이 원자로에 큰 손상을 입히게 된다. 대한민국 대부분의 원전에 해당하는 가압경수로에서 대형냉각재상실사고가 발생할 때 진행되는 사고 상태는 다음과 같다. (ko) |
| rdfs:label | حادث فقد المبرد النووي (ar) Havárie se ztrátou chladiva (cs) Kühlmittelverluststörfall (de) Pérdida accidental de refrigerante (es) LOCA (it) Loss-of-coolant accident (en) 냉각재 상실사고 (ko) 冷却材喪失事故 (ja) Loss-of-coolant accident (nl) 冷卻劑流失事故 (zh) |
| owl:sameAs | freebase:Loss-of-coolant accident yago-res:Loss-of-coolant accident http://d-nb.info/gnd/4165868-1 wikidata:Loss-of-coolant accident dbpedia-ar:Loss-of-coolant accident dbpedia-cs:Loss-of-coolant accident dbpedia-de:Loss-of-coolant accident dbpedia-es:Loss-of-coolant accident dbpedia-it:Loss-of-coolant accident dbpedia-ja:Loss-of-coolant accident dbpedia-ko:Loss-of-coolant accident dbpedia-nl:Loss-of-coolant accident dbpedia-zh:Loss-of-coolant accident https://global.dbpedia.org/id/9Yed |
| prov:wasDerivedFrom | wikipedia-en:Loss-of-coolant_accident?oldid=1059460676&ns=0 |
| foaf:depiction | wiki-commons:Special:FilePath/LWR_Meltdown.gif |
| foaf:isPrimaryTopicOf | wikipedia-en:Loss-of-coolant_accident |
| is dbo:wikiPageDisambiguates of | dbr:Loca |
| is dbo:wikiPageRedirects of | dbr:Loss_of_Coolant_Accident dbr:LOCA_(nuclear) dbr:Loss_of_coolant dbr:Loss_of_coolant_accident dbr:Loss_of_coolant_accident_(LOCA) |
| is dbo:wikiPageWikiLink of | dbr:Behavior_of_nuclear_fuel_during_a_reactor_accident dbr:Rolls-Royce_PWR dbr:List_of_civilian_nuclear_accidents dbr:Neutron_moderator dbr:Passive_nuclear_safety dbr:Boiling_water_reactor dbr:Davis–Besse_Nuclear_Power_Station dbr:List_of_small_modular_reactor_designs dbr:Decay_heat dbr:Light-water_reactor dbr:Nuclear_power_debate dbr:Nuclear_power_in_Canada dbr:Nuclear_power_in_the_United_States dbr:Nuclear_safety_in_the_United_States dbr:Pressurizer_(nuclear_power) dbr:Timeline_of_the_Fukushima_Daiichi_nuclear_disaster dbr:S8G_reactor dbr:Zirconium_alloy dbr:Loss_of_Coolant_Accident dbr:Fukushima_nuclear_disaster dbr:Lenin_(1957_icebreaker) dbr:Liquid_metal_cooled_reactor dbr:Lucens_reactor dbr:Madras_Atomic_Power_Station dbr:Pressurized_water_reactor dbr:Supercritical_water_reactor dbr:B&W_mPower dbr:Bruce_Nuclear_Generating_Station dbr:Three_Mile_Island_Nuclear_Generating_Station dbr:Three_Mile_Island_accident dbr:Windscale_fire dbr:January_1969 dbr:Nuclear_fuel dbr:Nuclear_meltdown dbr:Nuclear_submarine dbr:Flooding_(nuclear_reactor_core) dbr:International_Nuclear_Event_Scale dbr:Astute-class_submarine dbr:Chernobyl_disaster dbr:George_Rankine_Irwin dbr:Donald_C._Cook_Nuclear_Plant dbr:Auxiliary_feedwater dbr:CAREM dbr:Soviet_submarine_K-8 dbr:Filtered_Containment_Venting_System dbr:Integral_fast_reactor dbr:Onagawa,_Miyagi dbr:RELAP5-3D dbr:Sequoyah_Nuclear_Plant dbr:Nuclear_and_radiation_accidents_and_incidents dbr:Loss-of-pressure-control_accident dbr:Two-phase_flow dbr:European_Community_Urgent_Radiological_Information_Exchange dbr:Loca dbr:WR-1 dbr:LOCA_(nuclear) dbr:Loss_of_coolant dbr:Loss_of_coolant_accident dbr:Loss_of_coolant_accident_(LOCA) |
| is foaf:primaryTopic of | wikipedia-en:Loss-of-coolant_accident |
