Measuring the Release Time and Total Drop Time of a Control Rod

1959 ◽  
Vol 6 (4) ◽  
pp. 328-332 ◽  
Author(s):  
Charles Zucker ◽  
Lewis Haring
Keyword(s):  
Release Time ◽  
Control Rod ◽  
Drop Time

Research of the Rod Drop Time Based on the Control Rod System of TMSR-SF1

2017 ◽  
Author(s):  
Zuokang Lin ◽  
Lin Zhu ◽  
Chunfeng Zhao ◽  
Yun Cao ◽  
Xiao Wang
Keyword(s):  
Molten Salt ◽  
Similarity Criterion ◽  
Maximum Error ◽  
Driving Mechanism ◽  
Control Rod ◽  
Water Condition ◽  
Rod System ◽  
Drop Time ◽  
Control Rods ◽  
Reactor Accidents

The reactor scram function realized by the rapidly dropping of control rods ensures safety when the reactor accidents (loss of electricity and earthquake, etc.) happen. In the thorium base molten salt reactor (TMSR - SF1), the rod drop time is obviously affected by the resistance which produced in the molten salt as its high density and viscosity. In this paper, the drop time of the control rod is obtained by the theoretical and experimental methods for comparison. Firstly, the drop time is analyzed both in air and water condition with calculation and experiment. And the method used for the resistance calculation of the rod during dropping is verified. Secondly, the similarity criterion is adopted to calculate the drop time in molten salt condition. The study shows that: 1) In air and water condition, the calculation is coincidence with the experimental results within the maximum error less than 2 %. 2) The drop time of the rod in molten salt is 2.8 s with a dropping height 2.4m in reactor, which satisfy the safety requirement of the control system. 3) It is necessary to use another buffer beside the disc spring to protect the driving mechanism of the rod during the rod dropping.

A Method for RCCA Drop Analysis

2013 ◽  
Author(s):  
Tong Liu ◽  
Heng Huang ◽  
Peng Li ◽  
Wei Xu ◽  
Yuemin Zhou ◽  
...  
Keyword(s):  
Computer Program ◽  
Equations Of Motion ◽  
Control Rod ◽  
Structure Interaction ◽  
Fluid Resistance ◽  
Fuel Assemblies ◽  
Control Assembly ◽  
Drop Time ◽  
The Impact ◽  
Fluid Interaction

The control rod drop time is one of the most important parameters for safety analysis. The calculation accuracy of control rod drop time will be affected if ignoring the transverse vibration, which is mainly caused by the fluid-structure interaction between the RCCA (rod cluster control assembly)s, guide tubes and the fluid interaction. A new method for RCCA drop analysis is presented in this paper. The transverse equations of motion are established considering fluid-elastic structure interaction, assuming the fluid is incompressible laminar flow. And the vertical equations of motion are established considering the gravity force of RCCAs, the fluid resistance, and the friction force led by collision. A computer program based on this method is used to calculate the control rod drop time, the impact and the dynamic response of RCCA. The analysis results are compared with those of the in-house code, which is used for commercial design. It shows the computer program using the new models provides a useful tool in the design of RCCAs and fuel assemblies.

Drop Time Evaluation for SMART Control Rod Assembly

2011 ◽  
Vol 14 (2) ◽  
pp. 25-28
Author(s):  
Kyoung-Rean Kim ◽  
Ki-Jong Jang ◽  
Jin-Seok Park ◽  
Won-Jae Lee
Keyword(s):  
Control Rod ◽  
Smart Control ◽  
Drop Time ◽  
Time Evaluation

Control rod drop-time reduction in typical swimming pool research reactors

2018 ◽  
Vol 106 ◽  
pp. 146-152
Author(s):  
M.R. Salmanpour Paean Afrakati ◽  
M. Gharib ◽  
S.M. Mirvakili
Keyword(s):  
Swimming Pool ◽  
Control Rod ◽  
Research Reactors ◽  
Drop Time ◽  
Time Reduction

scholarly journals R&D on a Nonlinear Dynamics Analysis Code for the Drop Time of the Control Rod

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Daogang Lu ◽  
Yuanpeng Wang ◽  
Qingyu Xie ◽  
Huimin Zhang ◽  
Muhammed Ali
Keyword(s):  
Nonlinear Dynamics ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Response Analysis ◽  
Safe Operation ◽  
Control Rod ◽  
Long Time ◽  
Drop Time ◽  
Dynamics Response

Whether the control rod can drop down in time is one of the important guarantees for the safe operation of the nuclear power plant. The drop-down process of the control rod is very complicated. For a long time, the researchers have done a lot of work on that, but it is hard to consider all the nonlinear factors. This paper considers the main factors together. Based on the theoretical analysis, we developed the nonlinear dynamics response analysis software for the nuclear power plant, which can be used to calculate the rod’s drop-down time. Compared with the results of the experiments, the software we developed proves to be applicable and reliable.

scholarly journals Control Rod Drop Hydrodynamic Analysis Based on Numerical Simulation

2020 ◽  
Vol 8 ◽  
Author(s):  
Jie Cheng ◽  
Zhenying Wang ◽  
Chuan Lu ◽  
Jibin Zhang ◽  
Shumao Bi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Nuclear Power ◽  
Power Plants ◽  
Degrees Of Freedom ◽  
Nuclear Reactor ◽  
Three Dimensional ◽  
Guide Tube ◽  
Control Rod ◽  
Drop Time ◽  
Maximum Impact Force

The drop time of the control rod plays an important role in judging whether a nuclear reactor can be safely shut down in an emergency condition and has become one of the most important parameters for the safety analysis of nuclear power plants. Exact assessment of the drop time is greatly dependent on the forces acting on the control rod. In this research, a three-dimensional numerical simulation of the control rod in a low-temperature heating reactor was established based on 6DOF (6 degrees of freedom) model using dynamic meshing technology, and it was used to analyze the control rod dropping experiment. The behavior of dropping the control rod was obtained, including the velocity, the displacement, and the pressure distribution on the control rod guide tube. The comparison between the simulation and the experiment results indicated that the simulation was capable of simulating the dropping characteristic of the control rod. Some important parameters can be calculated, such as the time of control rod dropping process and the maximum impact force. Based on this, useful information could be provided for the design of control rod driveline structure.

Effect of coating method on release of Glimepiride from porosity osmotic pump tablets (POPTs)

2020 ◽  
pp. 37-45
Keyword(s):  
In Vitro Release ◽  
Osmotic Pump ◽  
Release Time ◽  
Once Daily ◽  
Coating Solution ◽  
Continuous Release ◽  
Red Color ◽  
Coating Method ◽  
Osmotic Agent

In this study, once-daily porosity osmotic pump tablets (POPTs) of Glimepiride were prepared using HPMC K100M (61%), osmotic agent (30% NaCl) coated using two different coating techniques spraying and dipping methods. The coating solution composed of ethyl cellulose (7.5%) w\w in ethanol (90%), castor oil (2%) as water-insoluble plasticizer and Gingo red color (0.5% w\w). In both techniques, the coating level was adjusted to give a 10% increase in the weight of the tablets. The effect of the coating by dipping technique with an increase in the weight of tablet (10 %, 20% & 50%) was also investigated to see the effect coating level on the percentage of drug release from POPTs. The results of the in vitro release of Glimepiride from tablets coated by the spraying method showed longer release time (24 hrs) than those coated with dipping method. On the other hand, increasing the coating level by dipping method retarded the release of the drug from tablets. However, the same retardation effect on release as shown with the spraying technique was only obtained by increasing the coating level with a 50% increase in the weight of the tablet. Thus, coating by spraying is more efficient to prepare POPTs to give a continuous release of Glimepiride from once daily table with the lowest increase in the total weight of the tablet.

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