[en] The objective of this study is to explore the potential of layered zinc hydroxide nitrate modified with sodium benzoate as nanoparticle in thermoplastic polyester elastomer (TPEE). The organically modified zinc hydroxide nitrate was compounded with TPEE using solution blending method. The nanocomposite structure was characterized by means of X-ray diffraction and transmission electron microscopy. The results showed that the nanoparticle was homogenously dispersed in TPEE matrix, and partially exfoliated structure was formed. The thermal behavior, mechanical and thermal combustion properties of the novel nanocomposite were studied respectively through differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA) and microscale combustion calorimeter (MCC). For the nanocomposite containing 7 wt% nanoparticle, the crystallization temperature evaluated by DSC was increased by 10 °C. The storage modulus at −95 °C measured by DMA was improved by around 26%. The heat release capacity (an indicator of a material fire hazard) from MCC testing was reduced by about 56% (compared to the results of neat TPEE). - Highlights: • We prepare zinc hydroxide nitrate modified by sodium benzoate (SB-ZHN). • We prepare and characterize thermoplastic polyester elastomer/SB-ZHN nanocomposites. • We investigate the thermal and combustion properties of the nanocomposites. • We study the thermodynamic properties of the nanocomposites

[en] A large-scale and refined three-dimensional numerical simulation of the upper plenum flow field of the pressure vessel of the three-loop pressurized water reactor is carried out by using the commercial CFD software STAR-CCM+ code. The coolant flow at the outlet of 157 fuel assemblies is calculated by the component tracking method. A mixing matrix of the upper plenum with 3 × 157 elements is constructed, which can be used to quantitatively and accurately describe the complex flow process of the coolant flowing out from the reactor core and mixing in the upper plenum and redistributing to the hot legs. It is found that the mixing of the coolant flowing from the core is not thorough and complete in the upper plenum of pressure vessel. The coolant flowing from fuel assembly at different positions in the radial direction is with obvious corresponding relationship in the interface area between the upper plenum and the hot legs, and the difference of the radial power distribution of fuel assembly will inevitably lead to the formation of the thermal stratification of the coolant in hot legs. (authors)

[en] As a risk assessment technology based on probability, the fire PSA is accepted abroad by nuclear industry in its application in the risk assessment for nuclear power plants. Based on the industry experience, the fire-induced impact on the plant safety during low power and shutdown operation cannot be neglected, therefore fire PSA can be used to assess the corresponding fire risk. However, there is no corresponding domestic guidance/standard as well as accepted analysis methodology up to date. Through investigating the latest evolvement on fire PSA during low power and shutdown operation, and integrating its characteristic with the corresponding engineering experience, an engineering methodology to evaluate the fire risk during low power and shutdown operation for nuclear power plant is established in this paper. In addition, an analysis demonstration as an example is given. (authors)

[en] The analysis aims to research and compare different analysis methods for validity of fire barrier in nuclear power plants to provide reference for engineering application. The analysis method for validity of fire barrier in nuclear power plants is discussed including equivalent fire duration method (i.e. equal area method and equal temperature method) and computer simulation method. The fire barriers of two fire compartments (hydraulic machine compartment and electric equipment room) are analyzed by these methods. The advantages, disadvantages and scope of engineering application of these methods have been assessed according to the compare of the different evaluation results. The paper points out that the analysis method of validity of fire barrier in nuclear power plant should be selected according to practical conditions. It suggests that the preferred method is equal area method in the actual engineering design and at the same time,the computer simulation method should also be applied as far as possible to achieve more practical results or more detail fire protection features of the compartment. In the future, the computer simulation method should be improved in the aspects of code, standard, guideline and methodology to push forward the application of the method in fire protection design for nuclear power plant. (authors)

[en] Nuclear plant seismic instrument system (KIS)is used for scouting the activity of seism near nuclear plant, and providing analytical information to operators of plant according to seism data. To ensure KIS to perform properly, KIS must be installed and debugged according to standard means. This article introduced the frame, the means of installation and the means of debugging about the renewed KIS of QinShan Phase II plant which has reference to the KIS installation of other nuclear plants. (authors)

[en] Objective: To discuss the whole design and to carry through the implement project in building picture archiving and communication system (PACS). Methods: All modalities with or without DICOM were integrated into PACS to store the whole images and share those resources. Windows NT and SQL 7.0 were used on the servers to store all kinds of patient image files, and those images could be viewed on all the web-based clinical workstations and the license was up to 100. RAID 5 online HDD which had the capability to store images for 3 months and DLT long term archive storage up to 7 T in size were built in the system. The PACS already finished the integration with RIS and HIS to expand images to the whole hospital and ready to be an imaging center of one area. Results: The founded typical PACS connected hospital equipments at present and realized primary no-film mode in department of radiology. The PACS had extended to the whole hospital clinical rooms, surgery, and emergency treatment room, etc. The PACS was connected to the HIS and networks of other hospitals. The center of image data was established, realizing the connection among the center of image data together with current area and other area hospitals. The PACS was easy to use for the doctors and improved the work efficiency. Conclusion: The practice has proved that current project related PACS planning as a whold practice in step by step is viable and successful

[en] Proton beams produced by accelerators are often used to test proton single event effect cross section curve (σ-E curve) to evaluate the aerospace microelectronic device performance against proton radiation. A MLFC was manufactured to measure proton beam, and was tested at the irradiation facility on Beijing HI-13 tandem accelerator. The results show that the MLFC can measure proton energy and beam intensity, and also can measure the purity of the proton beam energy, which is very useful for determining if the beam is suitable for experiments and beam tuning. (authors)

[en] Nuclear plant seismic instrument system (KIS)is used for scouting the activity of seism near nuclear plant, recording the seismic data, and providing analytical information to operators of plant who can keep the nuclear reactor in security. The recorded seismic data can be preserved for a long time and help the design institution to validate the anti-seismic design. This article introduced the elements, function, frame and subsystems about the KIS of QinShan Phase II plant. (authors)

[en] The research is carried out based on the specific requirements for fire risk analysis and fire protection in important regulations and standards, such as HAD102/11, ASME/ANS RA-Sa-2009, NB/T 20037.4-2013, EJT 1217-2007, NFPA 804, NFPA 805 and other regulations and standards. The analysis system introduced in this paper is based on the combination of the deterministic analysis method, probabilistic analysis methods, and the application of fire modeling software. Up to now, the analysis system has been used in many project, such as the amendment of fire protection of cable gallery in Sanmen nuclear power plant, the installation of very early fire detection system in CAP1400 project, as well as the main control room (MCR) fire modeling and evacuation analysis in CAP1000 project, etc. The effectiveness of this analysis system can be verified through the development of these projects. In fact, this analysis system is not limited to the passive nuclear power plants, and also applicable to other types of power plants. With the gradual construction of nuclear power plants in China, the analysis system can play an important role in future, including the guidance or support of the fire protection design, and safety assessment, etc. (author)

[en] Due to its superior performances such as compact structure, higher heat transfer efficiency, and deeper fuel burn-up, plate-type fuel assembly has been more and more widely utilized in new type integrated reactors arid experimental research reactors of which coolant is forced passing through the typical narrow rectangular channels formed by plate-type fuel in the core. Under some postulated accident conditions, such as irradiation damage, materials debris or foreign objects dragged into the core with the coolant circulation, and coolant flow assembly blockage accidents could occur. The accident may cause the reduction of coolant flow, make the fuel plate temperature increased, result in the phenomenon of dry-out, threaten the integrity of fuel cladding, and even cause the release of radioactive material into the reactor coolant system. The transient thermal-hydraulic characteristics of plate-type fuel assembly under inlet 95% partial and total flow blockage transient accidents are numerical simulated using the commercial CFD software ANSYS FLUENT 12.1 code. The liquid-solid conjugate heat transfer between coolant and fuel-plates has been considered in this calculation, and we analyzed the three-dimensional flow field, temperature field and the influencing factors. (authors)