Adjustment of the Parameters in the Calculations of the γ-Production Data

Introduction The γ-production data are very important for the nuclear engineering, especially for the calculations of the radiation shielding. Because the experimental values of the γ-production data can not satisfy the needs of the nuclear engineering both in the quantity of the nuclei and in the energy region covered by them, as the supplement, the theoretical calculations of the γ-production data are indispensable. The γ-production data in the nuclear reactions induced by neutrons include the γ-production cross sections, the γ-energy spectra, the γ-multiplicities and the reaction cross sections of the (n,γ) and the (n,xγ) reactions, where the (n,xγ) reactions mean     

Substantiation of the Choice of Threshold Parameters for the System Monitoring the Fuel-Containing Materials in the Object “Cover”

A substantiation is given for the choice of threshold values of the neutron flux density (threshold-1 – Attention and threshold-2 – Danger), and formulas are derived for calculating these values for systems which are being designed and are currently in operation for monitoring the state of fuel-containing materials in the object Cover at the Chernobyl nuclear power plant.     

Mass-Spring Model Used to Simulate the Sloshing of Fluid in the Container Under the Earthquake

The fluid in the container interacts with the container structure under the earthquake, and the bottom and the side walls are subjected to the pressure because of the fluid sloshing. This pressure is called hydrodynamic pressure. The one dimensional lumpe…     

Study on the Manufacture Technology of the Zirconia Tubes Ⅲ.Research on the Slip Casting Process of the Zirconia Tubes

ThepropertiesofZrO2·Y2O3·Gd2O3slipwithintermediatediameter(therawmateri-alsunder1μmindiameterexceed60%)arestudiedinthepaper.Theslipcastingisper-formedusingplastermould.Itisfoundthatseveralfactors,includingthepHvalueofsus-pensionslip,theconcentrationofd…     

Mass-Spring Model Used to Simulate the Sloshing of Fluid in the Container Under the Earthquake

The fluid in the container interacts with the container structure under the earthquake, and the bottom and the side walls are subjected to the pressure because of the fluid sloshing. This pressure is called hydrodynamic pressure. The one dimensional lumped mass-spring model（LMSM） is presented in ＂Seismic Analysis of Safety related Nuclear Structures and Commentary on Standard for Seismic Analysis of Safety related Nuclear Structures＂ （ASCE 4—86）. This model, which is simple but valid, is described in detail. This paper develops 3-D mass-spring model based on the LMSM in the ASCE 4—86.     

Investigation of the radiation characteristics of the masonry in the ai uranium–graphite reactor

The results of investigations of the nuclear safety of the masonry in the AI uranium–graphite (Industrial Association Mayak) reactor are presented. It is concluded on the basis of these results that the masonry is nuclear safe and a radiation certificate is composed. The radiation examination made it possible to determine the level, composition, and distribution of the radioactive contamination of the masonry as well as the level and distribution of the neutron and γ radiation, and to construct a forecast of the change in the activity of radionuclides in graphite as a function of the holding time. These data are necessary for safety analysis and for making decisions about the subsequent stages of decommissioning of the reactor. Translated from Atomnaya énergiya, Vol. 105, No. 5, pp. 266–269, November, 2008.     

Experiment for the Flow Distribution in the CARR Fuel Assembly

CARR fuel assembly is a plate type fuel element, which has twenty rectangle coolant channels formatted by twenty-one fuel plates. The breadths of channel are symmetrically distribution along the     

Research of the CICC Stability by the Numerical Code Gandalf

1. IntroductionIn this zpaper, we introduce cable--in-conduit conductor (i.e. CICC) which is used in the HT--7U superconducting TOkamak to obtain an effective andstable superconductor design for large magnets. Thedesign of the HT-7U superconducting TOkamak incorporates superconducting magnets of the toroidalfield (TF) and poloidal field (PF) systems [1]. TheCICC is cooled with a forced -flow supercritical helium at 4.5K. One of the most key problems relatedto conductor and coil prote…     

Determination of the Trigger-Electrode Position for the Field-Distortion Spark Gap

The optimal axial position of the trigger-electrode of the field-distortion spark gap is investigated through electric field calculation.The electric fields of the gap are calculated when locating trigger-electrode at different positions.It is shown that if the distance d between the trigger electrode and the low electric potential electrode is greater than 1.3mm,the maximum field intensity occurs at the edge of the trigger-electrode ,which will facilitate the generation of multi-channel discharge.According to calculated results,the working characteristics of the gap is investigated and it shows that when d=1.4mm the field distortion gap can be triggered reliably.     

A Comparison of the Maximum Entropy Method of Analysis with the Exciton Model Plus the Master Equation

The maximum entropy method of analysis is successful in fitting experimental data.In order to reveal the underlying physics,this method is applied in comparison with the conventional approach,i.e the exciton model plus the master equation,to three cases.It is found that both approaches produce almost equally good fits to spectra,and yield almost the same average exciton numbers. This implies that there must be similar physical ideas behind the two approaches,and it should be safe to use the maximum entropy method of analysis to fit data or to estimate reaction cross sections.     

Influence of the Gas Mixture Ratio on the Correlations Between the Excimer XeCl Emission and the Sealed Gas Temperature in DIelectric Barrier Discharge Lamps

For dielectric barrier discharge lamps filled with various gas mixture ratios,the correlations between the excimer XeCl emission and the sealed gas temperature have been founded,and a qualitative explication is presented.For gas mixture with chlorine larger than 3%,the emission intensity increases with the sealed gas temperature,while with chlorine about 2%,the emission intensity decreases with the increase in the gas temperature,and could be improved by cooling water .However,if chlorine is less than 1.5% ,the discharge appears to be a mixture mode with filaments distributed in a diffused glow-like discharge,and the UV emission is independent on the gas temperature.     

Effects of the radiative recombination on the intensity and polarization of the Ly-α emission of hydrogen-like ions

The intensity ratio of the to photon emission is analyzed for hydrogen-like Fe²⁵⁺ ions if their excitation arises in a plasma not only from the electron impact but also due to the radiative recombination (RR) of initially bare Fe²⁶⁺ ions. Under such conditions, the intensity ratio and the (degree of) linear polarization of the Ly-α₁ line are explored for collisions with an electron beam over a wide range of kinetic energies up to 50 keV. Apart from the direct population of the 2p_1/2,3/2 levels via the RR of bare ions, the contributions from radiative cascades and higher multipoles are taken into account by applying a fully relativistic theory for the motion of the electrons and the electron-photon coupling. Our calculations show an overall small effect of the RR upon the degree of the Ly-α₁ polarization as well as the intensity ratio under usual plasma conditions. However, the effects from the RR of initially bare ions may become significant at electron beam energies , for plasma conditions far away from ionization equilibrium with a relatively large proportion of bare Fe ions, as it may be realized in electron-beam ion trap experiments.     

Analysis of the Water Hammer in the Secondary Loop of CEFR

The coolant of the primary loop and secondary loop of CEFR is sodium. The reaction of sodium with water during the leakage of SG will induce the water hammer in the secondary loop. The water hammer in the loop would cause the pipeline to swing, the suppor…     

Assessment of the induced radioactivity in the treatment room of the heavy-ion medical machine in Wuwei using PHITS

Carbon-ion radiotherapy(CIRT) offers unique physical and biological advantages over photon radiotherapy. However, some materials and devices in the CIRT treatment room become radioactive under bombardment by therapeutic carbon-ion beams due to nuclear reactions, thereby leading to possible radiation hazards to medical staff and additional and unwanted doses to patients. This study assessed the level of induced radioactivity in the treatment room of the Heavy-Ion Medical Machine(HIMM) in Wuwei. M...     

Analysis of the Water Hammer in the Secondary Loop of CEFR

The coolant of the primary loop and secondary loop of CEFR is sodium. The reaction of sodium with water during the leakage of SG will induce the water hammer in the secondary loop. The water hammer in the loop would cause the pipeline to swing, the support of the pipeline to snap, the pipeline to break, even the nuclear power station to shutdown directly. The water hammer is an important issue of the design and safe analysis of CEFR.     

Accident Analysis of the Large Leakage in the SG of CEFR

ThisreportwasfinishedinAugust,1999,whichgivestheaccidentanalysisofsodium-waterreactionunderlargeleakagecaseintheSG(steamgenerator)ofCEFR.Themainresultsincludetemperatureandpressureschangeofsecondaryloopequipmentunderthisaccidentcase,andthepossibleaccident…     

The definition of the roentgen in the “Recommendations of the International Commission on Radiological Units. 1953”

The contradictions found in the definitions of the roentgen as a unit of X- and γ-radiation are expounded and criticized. The definition accepted in the USSR of the roentgen as the unit of physical dose\((\frac{{OST}}{{VKS}}7623)\) differs from those in the International Recommendations and of the Congresses (Stockholm 1928 and Chicago 1937), where the roentgen is considered as the unit of dose, and not the physical dose. This has occasioned much confusion as to the physical content of the phenomena which the roentgen was intended to measure. An attempt was made in the 1953 Recommendations to resolve these difficulties, but this cannot be considered successful. The basic fault in the definition of the roentgen, which is that it “measures the amount of X- or γ-radiation” is retained. The definition given in the Recommendations of the amount of radiation as the time-integral of the intensity leads to the concept of the amount of radiation as being a flux density at a point, i.e., it adds a third variant to the dose concept, which further confuses the issue. The paper presents the requirements which the definitions of the basic units for measuring ionizing radiations — the roentgen and its equivalents — must satisfy.