scholarly journals Systematic evaluation program review of NRC Safety Topic VI-7. 3 associated with the electrical, instrumentation and control portions of the ECCS actuation system for the Dresden II Nuclear Power Plant

1980 ◽  
Author(s):  
G. St. Leger-Barter
Author(s):  
John T. Kitzmiller ◽  
Richard G. Anderson ◽  
Laura L. Genutis ◽  
Dennis M. Popp

Core Damage Frequency (CDF) and Large Release Frequency (LRF) can be greatly affected by the application of Instrumentation and Control (I&C) within the control and safety systems utilized in the operations of a nuclear power plant. It is important that the modeling of these systems be an accurate representation of the I&C design to capture the effects of the I&C on the operations of the nuclear power plant as far as control and safety that are needed for the effective and safe operation of power generation. Various sensitivities can be performed on I&C modeling in the AP1000 Probabilistic Risk Assessment (PRA) to determine the impact on CDF. These sensitivities can be in the areas of base reliability values (probabilities), common cause failures (CCF) of software as well as common cause (CC) factors of computer modules. Insights can be found as to the effects of these CCFs by varying the modeled probabilities in the most conservative direction to determine how the model will respond. The model response, i.e., CDF and cutset importance orders will provide insights as to how sensitive I&C modeling is to CCF and how sensitive the rest of the PRA model is to I&C. Increasing failure probability of the Protection and Safety Monitoring System (PMS) and Plant Control System (PLS), and Diverse Actuation System (DAS) to explore the minimum reliability that would support favorable CDF and LRF values, as well as, the effect of total failure of the PMS (no credit taken for PMS in core damage sequences) and PLS (no credit taken for PLS in core damage sequences) on CDF values are explored. Sensitivity analyses show that the CDF increases if no credit is taken for operator actions. For AP1000, this sensitivity study indicated a decrease in dependence on operator actions over conventional nuclear plants. This conclusion is likely a result of the increased reliability of the PMS to automatically actuate the given systems and components. For this reason, the most important system is PMS, in the case where no credit is taken for PMS in core damage sequences.


Robotica ◽  
2020 ◽  
Vol 39 (1) ◽  
pp. 165-180
Author(s):  
Zhang Zhonglin ◽  
Fu Bin ◽  
Li Liquan ◽  
Yang Encheng

SUMMARYThe particularity of nuclear power plant environment requires that the nuclear power inspection robot must be remote control operation. The main purpose of the inspection robot is to carry out inspection, prevention, reporting, and safety emergency operation on the instruments, so as to provide guarantee for the safe operation of the nuclear power plant. Based on the representative configuration of nuclear power robot at home and abroad, this paper develops a small and lightweight nuclear power plant inspection robot, including walking mechanism, lifting mechanism, operating mechanism, image acquisition, information communication and control system, etc., to carry on the statics analysis to the key components of the inspection robot and verify that the stiffness and strength of the mechanical structure meet the requirements of lightweight design. Modal analysis is carried out to verify that the motor does not cause resonance when working. The kinematic model of the robot has been established and can provide the theoretical basis for the controller design. A hierarchical control system based on LabVIEW upper computer monitoring and control operation interface is established, which uses adaptive fuzzy Proportional Integral Derivative (PID) control to simulate the walking control, and then realizes the control of walking mechanism through software programming, and the adaptive fuzzy PID control has better effect than the conventional PID control. The S-type acceleration and deceleration algorithm is used to realize the accurate control of the position location of the lifting mechanism. Finally, combined with the experiment of 5MS robot comprehensive experimental platform, it is proved that the inspection robot can realize remote control function operation.


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