통합 검색 | Korea Science

Containment Closure Time Following Loss of Cooling Under Shutdown Conditions of YGN Units 3&4

Seul, Kwang-Won;Bang, Toung-Seok;Kim, Se-Won;Kim, Hho-Jung
- 한국원자력학회:학술대회논문집
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- 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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- pp.647-652
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- 1998
The YGN Units 3&4 plant conditions during shutdown operation were reviewed to identified the possible even scenarios following the loss of shutdown cooling. The Thermal hydraulic analyses were performed for the five cases of RCS configurations under the worst event scenario, unavailable secondary cooling and no RCS inventory makeup, using the RELAP5/MOD3.2 code to investigate the plant behavior, From the analyses results, times to boil, times to core uncovery and times to core heat up were estimated to determined the containment closure time to prevent the uncontrolled released of fission products to atmosphere, These data provide useful information to the abnormal procedure to cope with event.
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원자로 노심 용융물의 고압분출 및 비산 현상에 대한 수치해석적 연구 (MOLTEN CORIUM DISPERSION DURING HYPOTHETICAL HIGH-PRESSURE ACCIDENTS IN A NUCLEAR POWER PLANT)

김종태;김상백;김희동;정재식
- 한국전산유체공학회:학술대회논문집
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- 한국전산유체공학회 2009년 추계학술대회논문집
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- pp.121-128
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- 2009
During a hypothetical high-pressure accident in a nuclear power plant (NPP), molten corium can be ejected through a breach of a reactor pressure vessel (RPV) and dispersed by a following jet of a high-pressure steam in the RPV. The dispersed corium is fragmented into smaller droplets in a reactor cavity of the NPP by the steam jet and released into other compartments of the NPP by a overpressure in the cavity. The fragments of the corium transfer thermal energy to the ambient air in the containment or interact chemically with steam and generate hydrogen which may be burnt in the containment. The thermal loads from the ejected molten corium on the containment which is called direct containment heating (DCH) can threaten the integrity of the containment. DCH in a NPP containment is related to many physical phenomena such as multi-phase hydrodynamics, thermodynamics and chemical process. In the evaluation of the DCH load, the melt dispersion rates depending on the RPV pressure are the most important parameter. Mostly, DCH was evaluated by using lumped-analysis codes with some correlations obtained from experiments for the dispersion rates. In this study, MC3D code was used to evaluate the dispersion rates in the APR1400 NPP during the high-pressure accidents. MC3D is a two-phase analysis code based on Eulerian four-fields for melt jet, melt droplets, gas and water. The dispersion rates of the corium melt depending on the RPV pressure were obtained from the MC3D analyses and the values specific to the APR1400 cavity geometry were compared to a currently available correlation.
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