scholarly journals Mode-Locked CO Laser for Isotope Separation of Uranium Employing Condensation Repression

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Igor Y. Baranov ◽  
Andrey V. Koptev

In the present work, we have suggested a technical solution of a CO laser facility for industrial separation of uranium used in the production of fuel for nuclear power plants. There has been used a method of laser isotope separation of uranium, employing condensation repression in a free jet. The laser operation with nanosecond pulse irradiation can provide acceptable efficiency in the separating unit and the high effective coefficient of the laser with the wavelength of 5.3 μm. Receiving a uniform RF discharge under medium pressure and high Mach numbers in the gas stream solves the problem of an electron beam and cryogenic cooler of CO lasers. The laser active medium is being cooled while it is expanding in the nozzle; a low-current RF discharge is similar to a non-self-sustained discharge. In the present work, we have developed a calculation model of optimization and have defined the parameters of a mode-locked CO laser with an RF discharge in the supersonic stream. The CO laser average power of 3 kW is sufficient for efficient industrial isotope separation of uranium at one facility.

2007 ◽  
Author(s):  
I. Y. Baranov ◽  
A. V. Koksharov ◽  
A. V. Koptev ◽  
K. M. Romodin

2012 ◽  
Vol 260-261 ◽  
pp. 307-311 ◽  
Author(s):  
Menik Ariani ◽  
Z. Su'ud ◽  
Fiber Monado ◽  
A. Waris ◽  
Khairurrijal ◽  
...  

In this study gas cooled reactor system are combined with modified CANDLE burn-up scheme to create small long life fast reactors with natural circulation as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. Therefore using this type of nuclear power plants optimum nuclear energy utilization including in developing countries can be easily conducted without the problem of nuclear proliferation. In this paper, optimization of Small and Medium Long-life Gas Cooled Fast Reactors with Natural Uranium as Fuel Cycle Input has been performed. The optimization processes include adjustment of fuel region movement scheme, volume fraction adjustment, core dimension, etc. Due to the limitation of thermal hydraulic aspects, the average power density of the proposed design is selected about 75 W/cc. With such condition we investigated small and medium sized cores from 300 MWt to 600 MWt with all being operated for 10 years without refueling and fuel shuffling and just need natural Uranium as fuel cycle input. The average discharge burn-up is about in the range of 23-30% HM.


Author(s):  
Dennis Toebben ◽  
Piotr Luczynski ◽  
Manfred Wirsum ◽  
Wolfgang F. D. Mohr ◽  
Klaus Helbig

Abstract The changing energy landscape leads to a rising demand of more flexible power generation. A system for steam turbines warm-keeping provides the ability to shutdown conventional power plants during periods with a high share of renewable power. Simultaneously, these power plants are ready for grid stabilization on demand without an excessive consumption of lifetime during the start-up. One technical solution to keep a steam turbine warm is the use of hot air which is passed through the turbine. In addition, the air supply prevents corrosion during standstill and also enables the pre-warming after maintenance or long outages. This paper investigates the warm-keeping process of an intermediate pressure steam turbine (double shell configuration) through the use of dynamic numerical Finite-Elements (FE) simulations. As a representative test-case, warm-keeping calculations during a weekend shutdown (60h) are conducted to investigate the temperatures, their distribution and gradients within the rotor and the casing. For this purpose an improved numerical calculation model is developed. This detailed 3D FE model (including blades and vanes) uses heat transfer correlations conceived for warm-keeping with low air mass flows in gear mode operation. These analytical correlations take heat radiation, convection and contact heat transfer at the blade roots into account. The thermal boundary conditions at the outer walls of rotor and casing are determined by use of experimental natural cool-down data. The calculation model is finally compared and verified with this data set. The results offer valuable information about the thermal condition of the steam turbine for a subsequent start-up procedure. The warm-keeping operation with air is able to preserve hot start conditions for any time period. Most of the heat is transferred close to the steam inlet of the turbine, which is caused by similar flow directions of air and steam. Thus, temperatures in the last stages and in the casing stay well below material limits. This allows higher temperatures at the first blade groove of the turbine, which are highly loaded during a turbine startup and thus crucial to the lifetime.


Author(s):  
Viorel Serban ◽  
Adrian Panait ◽  
Marian Androne ◽  
George Alexandru Ciocan ◽  
Madalina Zamfir

Buildings, equipment and pipe networks, herein below called “structures”, within nuclear and classic objectives are affected by the dynamic actions of earthquake, shocks and vibrations type, herein below called“ excitations”. The repeated action of excitations on structures most often lead to important built-up of kinetic and potential energy in oscillating systems made-up of such structures. Such a built-up is leading to tens of times increase of the amplitude of the dynamic response in accelerations and displacements of structures as to the excitation amplitude. In its turn, such an increase is leading to the exceeding of the efforts and distortions of the structures material, accompanied by the occurrence of damages or destroy. Because in most cases the excitation cannot be reduced or eliminated, the only technical solution available for the engineers is to reduce the dynamic response of the structures on the existing excitations. The innovative SERB-SITON solution developed and applied within the Subsidiary of Technology and Engineering for Nuclear Projects (SITON) is based on the use of SERB-SITON isolation behavior devices with low friction and controlled stiffness on horizontal plane to cut-off the dynamic action transfer from the excitation to the structure and telescopic devices with controlled elasticity and damping both to reduce the dynamic response of the structures, as well as the dissipation of the energy transferred to the structure or the limitation of structure distortion upon the dynamic actions. The paper presents the performances of SERB-SITON mechanical devices used to protect buildings, equipment and pipe networks against dynamic actions and an adequate method to evaluate the dynamic response of structures (by using SERB-SITON devices), in real time inclusively. For large-size buildings such as nuclear power plants, old buildings, churches, bridges, etc., SERB-SITON isolation devices with friction by sliding or rolling with a very small and adjustable, stiffness installed under the structure on any horizontal direction, are presented. For reinforced concrete or metal framework buildings such as high buildings, industrial halls, towers, etc., SERB-SITON telescopic devices with controlled stiffness and damping large, force inclusively are presented. For equipment and pipe networks, SERB-SITON supports that are capable to overtake large permanent loads with relative displacements on two directions for thermal displacements, and also capable to elastically overtake and damp dynamic actions, are presented.


Author(s):  
L. Ike Ezekoye ◽  
William E. Densmore ◽  
William M. Turkowski ◽  
Robert E. Becse

Check valves are the simplest valves in power plants. Their simplicity and passive nature, combined with their relatively low maintenance requirements, often mask their relative importance in piping systems. Compared to power operated valves (POVs), such as motor operated valves or air operated valves, check valves have very few parts. The more parts a valve has, the more likely failures will occur. As such, power operated valves tend to have more stringent requirements that cover periodic verification of operability, in-service testing (IST), and scheduled preventive maintenance to assure functionality. Check valves, on the other hand, do not require nearly the same amount of rigor to assure operability. The passive nature of check valves often leads the user not to expect failures. Consequently, lacking of attention often results to inadvertent failures. One failure that has received significant attention from both the industry and the regulator is check valve body-to-bonnet joint leakage. In nuclear power plants this leakage can contaminate the general area where the valve is located, can lead to a plant shutdown, and pose personnel hazards. In this paper, the technical solutions that can be used to manage check valve body-to-bonnet joint leakage will be presented. The merits of each technical solution and the associated challenges will be discussed. Also, as some of the leakage containment solutions are appurtenances to the valve, the paper will address the interface between the appurtenances and the valve.


Author(s):  
Jiachuan Lu ◽  
Longtao Liao ◽  
Bo Feng ◽  
Yifen Chen ◽  
Junwei Hao ◽  
...  

Now Nuclear Power Plants (NPPs) design is moving toward being highly dependent on digital computers in many complex systems, especially microprocessors. As a medium between operators and NPPs for exchange and interaction which ultimate operational decisions still rely on, the Human-System Interaction has been widely concerned and become one of the focuses in NPPs design. So in order to take full advantage of operating experience, human cognitive processing abilities, and progressive technologies, it is critical to plan, design, implement, operate, and maintain a reliable HSIs. The project, funded by the Nuclear Power Institute of China (NPIC), designs and develops a set of typical and comparatively complete technical solution of Human-System Interaction based on instrumentation and control system in actual NPP. To take advantage of the design process and modules as well as templates of this technical solution provided by this project, which take HFE into account, we can achieve the realistic simulation of Human-System Interaction for digital NPPs, making the use of iFIX software, and the Human-System Interaction system can be used to design interfaces for different kinds of NPPs. In this paper, the realization of human-system interaction will be introduced, and the current research status and main challenges of Human-System Interaction are included. And at this stage we have made the processes of the cross-platform data acquisition and monitoring, processing and display of small instrument control systems come true.


2018 ◽  
Vol 11 (3) ◽  
pp. 241-246
Author(s):  
P. N. Korobets ◽  
V. V. Slovik ◽  
N. B. Karnitskiy

The policy of restructuring the generating capacities of the energy system of the Republic of Belarus assumes the introduction of the the Belarusian nuclear power plant (NPP) in the coming years. The presence of external and internal factors affecting the sale of electricity from NPP will require solving a number of problems, including power redundancy and frequency control through involvement of internal power generating facilities. These include steam-turbine state power plants and combined heat and power plants (CHPP), combined-cycle power units, special mobile electric power units, the commissioning of electric boilers and accumulator tanks. The latter is a new technical solution for the Belarusian energy system that requires careful analysis to identify the optimal system for coordinated operation of co-generation power units with electric boilers and accumulator tanks. At the same time, the heating and non-heating seasons of the CHPP operation are considered. The function of the accumulator tanks with minimum and maximum power consumption is shown. At charging of the accumulator tanks, the generation of electricity by co-generation power units with thermal regulation is increased. The operation of electric boilers and accumulator tanks is considered through the example of Grodno CHPP-2. The expediency of including electric boilers in the scheme of the CHPP as the most effective means of using co-generation turbine units in the cycling mode with unloading them by electric power during the night hours is determined, which ensures the maximum reduction of the electric power output to the power system from the Belarusian NPP.A similar approach at other industrial CHPP of the power system will, to some extent, ensure stable power supply from the Belarusian NPP. Reconstruction of the CHPP with installation of accumulator tanks will make it possible to create a flexible heat supply scheme for consumers in the conditions of night electrical unloading when the NPP power units are put into operation.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Dennis Toebben ◽  
Piotr Luczynski ◽  
Manfred Wirsum ◽  
Wolfgang F. D. Mohr ◽  
Klaus Helbig

AbstractThe changing energy landscape leads to a rising demand of more flexible power generation. A system for steam turbine (ST) warm-keeping provides the ability to shutdown conventional power plants during periods with a high share of renewable power. Simultaneously, these power plants are ready for grid stabilization on demand without an excessive consumption of lifetime during the start-up. One technical solution to keep a ST warm is the use of hot air, which is passed through the turbine. In addition, the air supply prevents corrosion during standstill and also enables the prewarming after maintenance or long outages. This paper investigates the warm-keeping process of an intermediate pressure (IP) ST (double-shell configuration) through the use of dynamic numerical finite element (FE) simulations. As a representative test case, warm-keeping calculations during a weekend shutdown (60 h) are conducted to investigate the temperatures, their distribution, and gradients within the rotor and the casing. For this purpose, an improved numerical calculation model is developed. This detailed three-dimensional FE model (including blades and vanes) uses heat transfer correlations conceived for warm-keeping with low air mass flows in gear mode operation. These analytical correlations take heat radiation, convection, and contact heat transfer at the blade roots into account. The thermal boundary conditions (BCs) at the outer walls of the rotor and casing are determined by use of experimental natural cool-down data. The calculation model is finally compared and verified with this dataset. The results offer valuable information about the thermal condition of the ST for a subsequent start-up procedure. The warm-keeping operation with air is able to preserve hot start conditions for any time period. Most of the heat is transferred close to the steam inlet of the turbine, which is caused by similar flow directions of air and steam. Thus, temperatures in the last stages and in the casing remain well below material limits. This allows higher temperatures at the first blade groove of the turbine, which is highly loaded during a turbine startup and thus crucial to the lifetime.


2021 ◽  
Author(s):  
Guilian Shi ◽  
Jikun Wang ◽  
Jingbin Gao

Abstract Turbine Control System (DEH) and Turbine Protection System (ETS) are important auxiliary systems for turbines. Normally DEH and ETS are supplied by turbine manufacturers. This paper investigates the operation experience in Nuclear Power Plants (NPPs) in China, there are many problems including information security, maintenance inconvenience, long supply cycle guarantee, high cost and so on in DEH and ETS. This paper analyzes the problems and tries to get the reasons why DEH&ETS have these problems. The Distribute Control System (DCS) technology has been widely used in nuclear power plant in now days, so this paper puts forward a technical solution based on the safety DCS and non-safety DCS platform to realize the DEH and ETS, and according to the feasibility analysis of products, and the test results based on engineering prototype, the solution can solve the problems of DEH and ETS effectively, some performances of the DEH&ETS have been improved, and the solution has a good prospect in further.


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