[en] The pulsed operation experiment in Xi'an Pulsed Reactor with the steady core arrangement was performed and the experimental result was analyzed. It indicates that this operation mode is safe and feasible, and some important operation parameters of the reactor with steady core arrangement at pulsed operation mode were obtained. The theoretical and experimental results were compared and both deviations were analyzed. (authors)

[en] There are some differences between the software and hardware of the digital power regulation system and the previous analog systems, thus a new method for the automatic power regulation needs to be studied. The control model of digital power regulation system is built and the basic idea of the automatic control method is proposed. The key technical issues including avoiding short period problem and enhancing the stability of the motion of the control rod are studied. The automatic control method of the digital power regulation system is designed through iterative calculations. The simulation code of Xi'an Pulsed Reactor (XAPRSC) is applied to verify the design method, and the results show that the new method meets the design index and is beneficial to the operation safety of Xi'an Pulsed Reactor. (authors)

[en] Reactivity is an important physical parameter of the reactor. Adding the reactivity real-time monitoring function in Xi'an Pulsed Reactor can provide operators with the real-time responsiveness and trends, which is conducive to its safe operation. The inverse dynamic method is widely used in the reactivity measurement because of its good real-time performance, which is capable to measure any reactivity introduction. However, due to the movement of the control rod, the spatial distribution of the neutron injection rate is inconsistent, and the deviation occurs. In this paper, the inverse dynamic method and the static spatial effect factor are analyzed theoretically, and the corresponding calculation method is given. Taking Xi'an Pulsed Reactor as the research object, the three-dimensional response function of the detector is calculated by using Monte Carlo (MCNP) program, and the normalized nodal power density is calculated, thus the static spatial effect factor is obtained. Finally, the experiment of interpolating the control rod at different rod speeds is carried out on the pulsed reactor and the integral value curve of the control rod is obtained by processing the experimental data. The results show that it is necessary to correct the spatial effect. The value curve of the control rod is more stable and the error between the calculation result and the real value is smaller. (authors)

[en] Steady Control Rod Drive Mechanism (CRDM) in Xi'an Pulsed Reactor is the key equipment to implement start-up, shutdown reactor and adjust power of reactor. It takes ball screws as drive machine, engaged electromagnet to drive steady control rod up and down, disengaged electromagnet to drop the control rod rapidly. The structure characteristics, the parameter of design and the test results of CRDM are presented. The machine has been used for Xi'an Pulse Reactor successfully

[en] A semi-physical simulation system of Xi'an Pulsed Reactor is developed for the purpose of providing the analog signal source, verifying the power regulation method and personnel training for the digital instrument and control system of Xi'an pulse reactor under construction. The design philosophy of semi-physical simulation system is proposed and the system frame is presented. The core physical simulation model is improved and the real-time core simulation program is coded by MATLAB. The human-machine interface is programmed by the software Kingview, and the rod control and rod position measurement are carried out by programmable controller S7-200. A series of hardware equipments, including the control rod driving mechanism simulator, the signal generator and the manual operation board, are developed. And the internal communication of the system is established. The change of the core power when the control rod is raised or lowered, and the pulse parameters after the pulsed rod is emitted are simulated with the semi-physical simulation system. The results are in good agreement with the experimental data on the reactor. The output of the signal generator is measured and the consequence is in accordance with the expectation. It is shown that the semi-physical simulation system can realize the design purpose and has good performance. (authors)

[en] In order to solve the problem of multi-dimensional uncertainty parameters and small probability of functional failure, an innovative functional reliability estimation method named Data Mining Technology was presented. In the presented method, with the combination of the bootstrap response surface model and optimization line sampling design, the functional failure probability can be evaluated with high efficiency. This method was applied in the natural circulation cooling in Xi'an Pulsed Reactor (XAPR). Combined with Medium Break Loss of Coolant Accident (MLOCA), the uncertainties related to the input parameters and the model were considered. And then the probability of functional failure was estimated with the presented method. The numerical results show that the bootstrap response surface model has a high degree of fitting, and the optimized line sampling technique has a high computational efficiency and an excellent computational accuracy. In addition, the evaluation method in this paper has strong adaptability to the implicit nonlinear functional failure analysis of the passive systems. (authors)

[en] The instrument and control system of Xi'an Pulsed Reactor is under the digitized reconstruction, and the code for analyzing the dynamic characteristics of non-pulse transient conditions is essential to provide the real-time variety parameters such as power and fuel temperature. Based on the previous classical analysis code of UHZr Pulsed Reactor, the model for analyzing the dynamic characteristics is built by optimizing the reactor physical model of the previous code and adding new models, and the Xi'an Pulsed Reactor Dynamic Characteristic Analysis Code (XPRDCA) is developed for non-pulse transient analysis. The experiment on the Xi'an Pulsed Reactor is performed. The calculation results of the code and the data obtained from the experiment are compared, and the effect of the temperature reactivity coefficient and the gap heat transfer coefficient on the dynamic characteristics is studied. The calculation results are in good agreement with the experiment data, and the computation speed of the code with optimized model is remarkably improved, and the code could be applied to the design and debugging of the digital instrument and control system. (authors)

[en] The mode and characteristics of the debugging management of the Xi'an Pulsed Reactor (XAPR) is discussed. The special group takes charges of daily debugging work, and the system called 'debugging test ticket' is adopted to control start-up of the test items. The code is programmed in Technology and management character, the duty of each department of join in debugging is defined, the fundamental of debug work is constituted. The test time and area is respectively controlled in test. The debugging of XAPR is assured by the measures

[en] Functional failure becomes an important factor in the natural circulation system operation failure, which needs to be considered in the system reliability analysis. In order to solve the problem of multi-dimensional uncertainty parameters and small functional failure probability of passive system, an efficient functional reliability estimation method based on improved response surface and importance sampling subset simulation methods was presented. This method was applied in natural circulation cooling in Xi'an Pulsed Reactor (XAPR) core. Combined with MLOCA, the uncertainties related to the input parameters and the model were considered. And then the probability of functional failure and the sensitivity measures were estimated. The assessment results show that the functional failure probability of natural circulation for XAPR core is 3.796 × 10^-3, and the functional failure in the passive system reliability analysis should be fully considered. This method has high computed efficiency and excellent computed accuracy compared with traditional probability analysis methods, and it is robust to nonlinear functional function of natural circulation for XAPR core. (authors)

[en] This article introduced a software which can help experimenter to operate the XI'AN Pulse Reactor(XAPR). This software provide some experiential formula to help the user to confirm some physical parameter of XAPR. The software has a friendly interface and is helpful for the experimenter. (authors)