Modelling of External Cooling for In-Vessel Corium Retention in VVER-440/213 Type Nuclear Power Plants

2010 ◽  
Author(s):  
Gyo¨rgy E´zso¨l ◽  
Ga´bor Baranyai ◽  
La´szlo´ Perneczky ◽  
La´szlo´ Szabados ◽  
Iva´n To´th
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
External Surface ◽  
Cooling System ◽  
Natural Circulation ◽  
Development Programs ◽  
Flow Measurements ◽  
Experimental Modelling ◽  
External Cooling

Research and development programs of high safety significance have been going on for nuclear power plants of VVER-440/213 type to apply the in-vessel corium retention concept. The in-vessel retention (IVR) concept is based on the external reactor vessel cooling (ERVC) with the main objective to prove that the reactor pressure vessel (RPV) integrity can be preserved in accident sequences leading to core melt. One of the bases of programs was the SARNET project of European Commission, which focused on confirming the capability of the ASTEC code to simulate IVR, calculating thermal load caused by the corium. The ERVC concept is applied to the Paks nuclear power plant of VVER-440/213 type. For the experimental modelling of the ERVC, the CERES (Cooling Effectiveness on Reactor External Surface) facility was designed and constructed. The facility is a scaled down model of the cooling system intended to apply to the Paks NPP with 1:40 scaling ratio for the vessel external surface and 1:1 for the elevations giving the driving force for natural circulation. The heat load supplied to the model is provided by electric heaters. A large number of temperature, pressure, level, void and flow measurements are installed. A RELAP model of the CERES facility was developed and tested by pre-test results.

scholarly journals Ensembles of climate change models for risk assessment of nuclear power plants

2017 ◽  
Vol 232 (2) ◽  
pp. 185-200
Author(s):  
Matteo Vagnoli ◽  
Francesco Di Maio ◽  
Enrico Zio
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Climate Models ◽  
Cooling System ◽  
Future Projections ◽  
Change Models ◽  
Temperature And Pressure

Climate change affects technical systems, structures and infrastructures, changing the environmental context for which systems, structures and infrastructure were originally designed. In order to prevent any risk growth beyond acceptable levels, the climate change effects must be accounted for into risk assessment models. Climate models can provide future climate data, such as air temperature and pressure. However, the reliability of climate models is a major concern due to the uncertainty in the temperature and pressure future projections. In this work, we consider five climate change models (individually unable to accurately provide historical recorded temperatures and, thus, also future projections) and ensemble their projections for integration in a probabilistic safety assessment, conditional on climate projections. As case study, we consider the passive containment cooling system of two AP1000 nuclear power plants. Results provided by the different ensembles are compared. Finally, a risk-based classification approach is performed to identify critical future temperatures, which may lead to passive containment cooling system risks beyond acceptable levels.

Environmental Considerations for Preparing Permit Applications of New Nuclear Power Plants Located in Greenfield Sites

2010 ◽  
Author(s):  
Ping K. Wan ◽  
Desmond W. Chan ◽  
Alice C. Carson
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Fossil Fuels ◽  
Cooling System ◽  
The United States ◽  
Attractive Alternative ◽  
Socioeconomic Impacts ◽  
Power Generators ◽  
Available Technology

Nuclear power generation has become an increasingly attractive alternative in the United States (U.S.) power market due to several factors: growing demand for electric power, increasing global competition for fossil fuels, concern over greenhouse gas emissions and their potential impact on climate change, and the desire for energy independence. Assuring the protection of people and the environment are of paramount concern to nuclear power generators and regulators as we move towards a possible nuclear renaissance. Thus, sound engineering design is of utmost important and potential environmental and safety concerns must be carefully evaluated and disposition during permitting of the new nuclear power plants. Areas to be considered in order to alleviate these concerns include the following: • Site meteorology and dispersion conditions of the area; • Evaluation of radiological consequence during normal plant operation and emergency conditions; • Water availability for plant cooling system; • Evaluation of potential land use, water use, ecological and socioeconomic impacts of the proposed action. This paper focuses on site suitability evaluation for greenfield sites through site characterization, examination of challenges/constraints in deployment of available technology/plant systems, and mapping of permitting compliance strategy. Case studies related to selection of plant systems based on the environmental site conditions, preferred compliance plan, and public acceptance, are included.

scholarly journals A pre-test analysis of ATLAS SBO with RCP seal leakage using MARS code

2021 ◽  
Vol 7 (4) ◽  
pp. 26-33
Author(s):  
Quang Huy Pham ◽  
Sang Yong Lee ◽  
Seung Jong Oh
Keyword(s):  
Coping Strategies ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Cooling System ◽  
Water Injection ◽  
Cooling Water ◽  
Feed Water ◽  
Test Loop ◽  
Station Blackout

The accident in Fukushima Daiichi nuclear power plants shows the important of developing coping strategies for extended station blackout (SBO) scenarios of the nuclear power plants (NPPs). Many NPPs in United State of America are applying FLEX approach as main coping strategies for extended station blackout (SBO) scenarios. In FLEX strategies, outside water injection to reactor cooling system (RCS) and steam generators (SGs) is considered as an effective method to remove residual heat and maintain the inventory of the systems during the accident. This study presents a pretest calculation using MARS code for the Advanced Thermal-hydraulic Test Loop for Accident Simulation (ATLAS) SBO experiment with RCP seal leakage scenario. In the calculation, the turbinedriven auxiliary feed water pumps (TDAFPs) are firstly used after SBO initiation. Then, the outside cooling water injection method is used for long term cooling. In order to minimize operator actions and satisfy requirements of APR1400 emergency operation procedure (EOP), the SGs Atmospheric Dump Valve (ADV) opening ratio, auxiliary feed water (AFW) and outside cooling water injection flow rates were investigated to have suitable values. The analysis results would be useful for performing the experiment to verify the APR 1400 extended SBO optimum mitigation strategy using outside cooling water injection.

Innovation structure combining inter-story isolation with passive cooling effect for AP1000 nuclear power plants

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gangling Hou ◽  
Yu Liu ◽  
Tao Wang ◽  
Binsheng Wang ◽  
Tianshu Song ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Cooling System ◽  
Design Method ◽  
Passive Cooling ◽  
Original Design ◽  
Seismic Safety ◽  
Lower Altitude ◽  
Content Type

PurposeAn inter-story isolation structure (IIS) for AP1000 nuclear power plants (NPPs) is provided to resolve the conflict of seismic safety and the optimal location of air intakes.Design/methodology/approachThe effect of passive cooling system (PCS) is better with lower altitude of air intakes than that in the original design of AP1000 NPPs. Seismic performances of IIS NPPs, including the seismic responses, damping frequency bandwidth and seismic reduction robustness, are improved by combining the position of air intakes lower and the optimal design method.FindingsTheoretical analysis and numerical simulation are illustrated that the seismic reduction failure of IIS NPPs is the lowest probability of occurrence when PCS has highest working efficiency.Originality/valueThe IIS NPPs can transfer the contradiction between PCS work efficiency and seismic safety of NPPs to the mutual promotion of them.

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