[en] The calculation on radionuclide concentration in the helium of primary loop for the module high temperature gas-cooled reactor (MHTGR) is the basis of radiation protection design and environment impact assessment. Based on the original and removal mechanisms of radionuclides in the helium of primary loop of the module reactor, the calculation models on radionuclide concentration in the helium are derived and the calculation formulas are given

[en] A 10 mm-diameter miniature annular centrifugal contactor suitable for laboratory use in radiochemical separation has been designed. The tests for both hydraulic performance and mass transfer efficiency have been performed. The 100 mm contactor can operate with residence times of 5∼20 s per stage and holdup volume of 4 mL per stage. It works well for aqueous-organic flow ratio ranged from 0.1 to 15. Europium mass transfer efficiencies of 90% were attained for tributyl phosphate (TBP)-nitric acid system. The laboratory equipment was suitable for remote operation with highly radioactive solutions, and study of fission product behavior in solvent extraction at short residence times. The satisfactory results were obtained in hot tests of TRPO extraction process that were performed by means of the 10 mm miniature centrifugal contactor

[en] At the air duct of Xi'an Jiaotong University, which was established on the design parameters of steam generator for the 200 MW high temperature gas cooled reactor (HTR), the experimental study on the behavior of helical tube bundles vibration in steam generator, which was induced by low density cross flow, has been done. The problem such as the critical flow velocity at which fluid elastic instability phenomenon begin to occur, the reciprocal action on neighboring tubes in different helical radius, and that in the same helical radius etc., has been discussed in detail. The results provide bases for designing helium steam generator for HTR, and bases to advance theoretical study on flow induced helical tube bundles vibration too

[en] The dynamic response of the fuel assembly and fuel channel interaction during a seismic event is analyzed to study the structural characteristics of the reactor fuel assembly as part of the Daqing NHR-200 project. The finite element program for automatic dynamic increment nonlinear analysis (ADINA) is used to predict the nonlinear dynamic response due to collisions between the fuel assembly and the fuel channel during seismic events. The results are used to analyze factors affecting the dynamic response, such as boundary support conditions and changes of the main model parameters. Curves are presented for the forces and frame displacements following the seismic excitation. the results verify the structural integrity of the fuel assembly including the channel in the NHR-200 design when subjected to seismic loading and verify that the cruciform control rod can still be inserted

[en] The Fuzzy-Smith pre-estimate controller to solve the control of the big delay system is developed, accompanied with the development of the mathematical model of the 10 MW high temperature gas cooled test reactor (HTR-10) and the design of its control system. The simulation results show the Fuzzy-Smith pre-estimate controller has the advantages of both fuzzy control and Smith pre-estimate controller; it has better compensation to the delay and better adaptability to the parameter change of the control object. So it is applicable to the design of the control system for the high temperature gas cooled reactor

[en] The use of the third harmonic wave (355 nm) of a Q-switch yttrium-aluminum garner laser to facilitate human gastric cancer cells gene transfection is reported. The laser beam is focused by the objective lenses (Nikon UVF-100) of the microscope (Zeiss Axiovert 10). At the specimen plane, the area of the laser beam is very small (microbeam). Calcein and IgG-FITC are applied to simulate DNA molecules. When the laser microbeam shoots at a cell, it produces a self-healing hole on the membrane. At the same time, calcein or IgG-FITC transfuses into the irradiated cell. Irradiated cells emit green fluorescence excited by blue light under fluorescence microscope. The energy for human gastric cancer cell irradiation is about 200 μJ/pulse and the pulse duration less than 10 ns

[en] Photon attenuation within the body causes the quantitative errors in a single photon emission tomography (SPECT) image. The attenuation map must be known for proper attenuation correction. A shifted line source and slice collimator were used to obtain oblique fan-beam transmission projection data on a three-detector SPECT system. Hi-quality projection data were acquired, and 3D attenuation maps were reconstructed using three methods. The experiments show that 360 degree scanning can compensate projection truncation of an oblique fan-beam and that a special analytic algorithm, convolution back-projection reconstruction inferred for oblique fan-beam projection, can accurately reconstruct the 3D attenuation

[en] Analysis of the dynamic features of steam generators is fundamental to the design and analysis of control systems to improve its performance. A dynamic model of the steam generator in the HTR-10 high temperature gas-cooled reactor was developed to accurately model the distributed, non-linear, and dynamic features of the once-through steam generator running at full power. The results show that static emulation of this model agrees with its static design and experimental results. The dynamic emulation modeled the thermal-hydraulic principle. The results well improve design of steam generator control systems

[en] The characteristics of the RF (radio frequency) resonance method of ion extraction were analyzed to improve atomic vapor laser isotope separation (AVLIS) by using the PIC-MCC code to simulate the RF resonance. The movements of the charged particles in the plasma were simulated by PIC and the collisions were simulated by the Monte Carlo method. Among other interactions, charge exchange is the primary collision type which affects the loss of the aimed isotope. The results show that to rapidly extract ions of the aimed isotope with low losses, RF voltage amplitude must be greater, electrode spacing must be narrower, and the electrode temperature should be increased. The atom density should be chosen as a trade-off between the production rate and the collision loss

[en] The author investigates the behavior of two-phase flow and flow instability in a 5 MW nuclear heating reactor test loop HRTL-5, which simulates the geometry and system design of the 5 MW reactor. It points out that the chose of distribution parameter C₀ and drift velocity V_vj may have significant effect on the result of static and dynamic analysis of the system, when one-dimensional two-phase flow drift model with conservation equations for mass, steam, energy and momentum was used. C₀ has no great effect on the steady mass flow rate, usually it can be ignored. In the range of V_vj = 0.0∼0.6 m/s, V_vj has about 6% effect on the steady mass flow rate, but has 53% effect on the void fraction at the exit of the heated section. The result by drift model (C₀ = 1.1, V_vj = 0.48) shows 15% difference from that by homogeneous model (C₀ = 1.0, V_vj = 0.0) on the predicting of instability boundary. In this analysis C₀ = 1.1 and V_vj 0.48 are used. Calculated results of both static and dynamic states by drift model agree with experimental data well under the 5 MW nuclear reactor conditions