[en] CRDM stepping loads act on the parts of CRDM during stepping motions. In this study the CPR1000 CRDM stepping loads are calculated through kinematics analysis and Adams dynamic simulation. The stepping loads of latch, pin, and coupling are got. Conclusions show that the method is an effective method to calculate CRDM stepping loads and the results are consistent with engineering experience. At the same time comparison and analysis of the impact of hydraulic camping force on insertion motion are studied. (authors)

[en] The ventilation heat transfer of CPR1000 Control Rod Drive Mechanism (CRDM) is simulated when CRDM continuous insertion action by using the ANSYS CFX software. The CRDM coils temperature, the relationship between cooling air flow and the CRDM coils temperature, CRDM air flow pressure drop in cooling channel, CRDM heat dissipating capacity and heat transfer coefficient are analyzed. The comparison between the simulated results and the test results shows that the numerical simulation method is acceptable. (authors)

[en] In gamma spectroscopy analysis, in order to improve the accuracy of the radionuclide activity, the net count of the radionuclide characteristic peaks is particularly important. The paper adopted the Gaussian function fitting the peak shape of the peak area after subtracting the background of the peak area, and the paper gets the peak shape parameters by solving the fitting equation according to the Levenberg-Marquardt method, this method takes the pretreatment resultant peak height, peak position and peak width as the initial value, and adaptive computes step size to iterate until the iteration is completed. Analyzing according to the computational simulation results, this method can fit mono-energetic peak to the best state, and the overlapped peaks can be separated into multiple single peak then do fitting. Through the experiment, the relative error between the above method measured nuclides characteristic peak area and the HPGe spectrometer measured peak area is less than 8%, the experimental results show that this method can rapidly and accurately calculate the characteristic peak area. (authors)

[en] Function expressions of kinematic pair force with latch dimensions, friction coefficient, link angle and external load was obtained by theoretical analysis, and the expression was verified by the motion analysis software. Key parameters of kinematic pair were confirmed, and their effect trends with force of parts were obtained. They show that the available method of kinematic pair optimization is increasing the space of latch holes. Using the motion analysis software, the forces of parts before and after optimization was compared. The result shows that the forces of parts were improved after the optimization. (authors)

[en] Control rod drive mechanism (CRDM) lower Canopy welding zone could leak under the influence of certain factors in some pressurized water reactors. The plugging assembly mounted on the welding externally can prevent and seal the leakage. According to the structure characteristics of the components, the stress conditions of key components were analyzed and the plugging effect of the assembly was verified by using the finite element software. The results show that the component can effectively reduce the stress of welding zone. At the same time, the stress level trends due to different pre-tightening forces, contact surface angle and friction were analyzed, so that the relationship curves and the optimum parameters were educed. The analysis data can be applied to the structure design, manufacture and assembly process, for making the component to achieve the best effect of plugging. (authors)

[en] The lift and withdraw of Control Rod Drive Mechanism (CRDM) need three coils working together, which demands a strict process of coil current's dynamic response. The paper built a rod control system and its equivalent circuit by Simulink, calculated the influence of coil current response time from the aspects of coil resistance inductor, voltage and other factors, and simulated the current in moving coils by MAGNET. Finally, the paper concluded with the influence on CRDM coil current response time by coil voltage, coil equivalent inductance, resistance and rod control circuit. (authors)

[en] Based on the working principle of the releasing critical current of CRDM movable armature, academic analysis and experimentation were combined to study the relationship between releasing critical current and electromagnetic force. Some influencing factors were analyzed by investigation tests about the non-confirmation of movable armature releasing critical current. In conclusion, a new proper acceptance criterion and some improving advice of CRDM movable armature releasing critical current were proposed. (authors)

[en] The technology of virtual instruments and blue tooth communication can be applied to the design of gamma spectrometer. The hardware of system includes portable gamma spectrometer, blue tooth module and PC. The software of system includes the composed of acquisition system by the MCU and analysis system by PC. The design of acquisition system includes the design of main program, the design of liquid crystal display module, the design of keyboard module, the design of blue tooth communication module and the design of data acquisition module. The design of analysis system includes the design of serial communication module, the design of data storage module and the design of data processing module. Practice shows that the system has a user-friendly, flexible, low cost and easy to expand. It can greatly improve the analysis capabilities of energy spectrum and it is a new development direction of gamma energy spectrum. (authors)

[en] The stepping motion of the control rod drive mechanism is a complicated dynamic process combined with electromagnetic field, flow field, and motion. It is not accurate to analyze the process by static method or partial technique. Magnet software, Fluent software, and Adams software were combined to conduct the coupling calculation of gravity, electromagnetic force, hydraulic resistance, and spring force during the stepping motion of the control rod drive mechanism. The electromagnetic force, hydraulic resistance, displacement and velocity of movable parts, and stepping loads were calculated quantitatively. The calculated values of the movable pole closing time, critical current and stepping loads were compared with the corresponding experimental values. The calculated values were in consistence with the experimental values. It is proved that the united simulation is an effective dynamic analysis method for the stepping motion of the control rod drive mechanism. (authors)

[en] The core apartment of a handhold electric productions designing is the designing of the power. It is a general requirement that the handhold electronic productions can work a long time in field operation, so it calls for the power has the higher conversion efficiency, low power's quiescent dissipation, good load characteristics and small power source ripple. Furthermore, the system has to make weak signal amplified transformed filtered and processed. For reducing the quiescent dissipation of the system, so it is necessary to exist for the ambipolar power. The paper precisely elaborated on development of power, it was used on one handhold radioactive environmental monitoring instrument, this power has a good characteristic, simultaneously has a formidable compatibility, may be suitable for other handhold electronic products. (authors)