scholarly journals Electrical and Thermomechanical Co-Simulation Platform for NPP

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 939
Author(s):  
Poria Hasanpor Divshali ◽  
Pasi Laakso ◽  
Seppo Hänninen ◽  
Robert John Millar ◽  
Matti Lehtonen
Keyword(s):  
Power Systems ◽  
Nuclear Power ◽  
Power Plants ◽  
Electrical Power ◽  
Simulation Platform ◽  
Electrical System ◽  
Electrical Power Systems ◽  
Electrical Grid ◽  
Simulation Tools ◽  
Initial Survey

In order to analyze the safety of nuclear power plants (NPP), interactions between thermomechanical and automation processes, the on-site electrical grid, and the off-site transmission system should be studied in detail. However, an initial survey of simulation tools used for the modelling and simulation of NPP shows that existing simulation tools have some drawbacks in properly simulating the aforementioned interactions. In fact, they simulate detailed electrical power systems and thermomechanical systems but neglect the detailed interactions of the electrical system with thermomechanical and automation processes. To address this challenge, this paper develops an open-source co-simulation platform which connects Apros, a proprietary simulator of the thermomechanical and automation processes in NPP, to power system simulators. The proposed platform provides an opportunity to simulate both the electrical and thermomechanical systems of an NPP simultaneously, and study the interactions between them without neglecting any details. This detailed analysis can identify critical faults more accurately, and provides better support for probabilistic risk analyses (PRA) of NPP. To investigate the effectiveness of the proposed platform, detailed thermomechanical and electrical models of an NPP, located in Finland, are cosimulated. The preliminary results emphasize that neglecting the detailed interactions between domains of NPP may lead to inaccurate simulation results and may affect NPP safety.

Earthquake Experience Data Point to Benefit of Diverse Backup Power

2014 ◽  
Author(s):  
David J. Calhoun ◽  
Mark A. Gake
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Nuclear Power ◽  
Power Plants ◽  
Electrical Power ◽  
Electrical Power Systems ◽  
Common Mode ◽  
Failure Risk ◽  
Diesel Generators ◽  
The Individual

Operating nuclear power plants typically have backup electrical power supplied by diesel generators. Although backup power systems are designed with redundant trains, each capable of supplying the power requirements for safe shutdown equipment, there is a common-mode seismic failure risk inherent in these customary backup power arrangements. In an earthquake, multiple equipment trains with similar, if not identical, components located side-by-side are exposed to inertial forces that are essentially identical. In addition, because of their similar subcomponent configurations, seismic fragilities are approximately equal. In that case, the probability of multiple backup power system failures during an earthquake is likely to be dependent on, and nearly the same as, the individual seismic failure probability of each equipment train. Post-earthquake inspections at conventional multiple unit power stations over the last 40 years identified this common-mode seismic failure risk long before the tsunami-related common-mode failures of diesel generators at Fukushima Daiichi in March 2011. Experience data from post-earthquake inspections also indicate that failure probabilities of diverse sets of power generation equipment are independent and inherently less susceptible to common-mode failures. This paper demonstrates that employing diverse backup power designs will deliver quantifiable improvements in electrical system availability following an earthquake. These improvements are illustrated from available literature of post-earthquake inspection reports, along with other firsthand observations. A case study of the seismic performance of similarly configured electrical power generation systems is compared to the performance of diverse sets of electrical power systems. Seismic probabilistic risk analyses for several system configurations are presented to show the benefit of improved post-earthquake availability that results from designing new backup power systems with greater diversity.

Sign in / Sign up

Export Citation Format

Share Document