Research on DTS Analysis Method for 1000MWe PWR NPP

2021 ◽  
Author(s):  
Yubin Zhang
Keyword(s):  
Fluid Pressure ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Analysis Method ◽  
Steam Generators ◽  
Reactor Coolant ◽  
Plant Life ◽  
Coolant System ◽  
Reactor Pressure ◽  
Reference Document

Abstract The design transients (DTS) are intended to be used to evaluate component stress analysis, which bound the plant operation over the design plant life, and will be as a reference document regarding plant usage factor surveillance. The conditions of DTS represent bounding cases for plant events that are expected to occur, or that may occur, during the plant lifetime. For different operating conditions, DTS analysis methods would be different. This report describes the DTS analysis method to be used when designing the major reactor coolant system components of the 1000MWe PWR plant. Some of components will be considered: Reactor Pressure Vessel, Main Coolant Lines, Reactor Coolant Pumps, Pressurizer and Steam Generators. Generally, variations in fluid pressure, fluid temperature and flowrate are used to represent the parameters for DTS. This report describes the method of DTS analysis and shows the evolution process of relevant thermal hydraulic parameters.

Research on the Seismic Analysis and Optimization of High Flux Reactor Nuclear Power Piping System Based on Multi-Point Response Spectrum Method

2020 ◽  
Author(s):  
Xuan Huang ◽  
Pingchuan Shen ◽  
Shuai Liu ◽  
Jian Liu ◽  
Xiaozhou Jiang ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
High Flux ◽  
Analysis Method ◽  
Response Spectrum Method ◽  
High Flux Reactor ◽  
Reactor Coolant ◽  
Spectrum Method ◽  
Flux Reactor ◽  
Coolant System

Abstract High flux reactor is an important engineering test reactor, which can be used in irradiation research of materials, chemistry, isotopes, medicine and other fields. In the high flux reactor coolant system, there are a large number of nuclear pipes and the layout is complex. The optimization of seismic analysis method for reactor coolant system is an important part in the design process to ensure the nuclear pipes meet the design specifications. The traditional single point response spectrum method needs to envelope the response spectrum of different floors as the analysis input. This method is difficult to give the reasonable seismic load to the numerous nuclear pipes and it will increase the design cost and the difficulty of safety analysis about nuclear pipe. In this paper, an optimized seismic analysis method of reactor coolant system is proposed. By using the multi-point response spectrum method, the optimization of different excitation loading modes for different constrained support points is realized. The analysis results show that the multi-point response spectrum method can solve the problem that different support points are located at different elevation floors in the reactor coolant system, which makes the calculation results more accurate and reasonable. Compared with the traditional method, it can make the design more efficient and practical.

Enhancement of Pressurizer Safety Valve Operability by Seating Design Improvement

1995 ◽  
Vol 117 (3) ◽  
pp. 279-282
Author(s):  
N. T. Moisidis ◽  
M. D. Ratiu
Keyword(s):  
Safety Valve ◽  
Operating Conditions ◽  
Maintenance Costs ◽  
Design Improvement ◽  
Reactor Coolant ◽  
Coolant System

Operating conditions specific to pressurizer safety valves (PSVs) have led to numerous problems and have caused industry and NRC concerns regarding the adequacy of spring-loaded self-actuated safety valves for reactor coolant system (RCS) overpressure protection. Specific concerns are: setpoint drift, spurious actuations, and leakage. Based on testing and valve construction analysis of a Crosby model 6M6 PSV (Moisidis and Ratiu, 1992), it was established that the primary contributor to the valve problems is a susceptibility to weak seating. To eliminate spring instability, a new spring washer was designed, which guides the spring and precludes its rotation from the “reference” installed position (Figs. 6 and 7). Results of tests performed on a prototype PSV equipped with the modified upper spring washer has shown significant improvements in valve operability and a consistent setpoint reproducibility to less than ±1 percent of the PSV setpoint (testing of baseline, unmodified valve, resulted in a setpoint drift of ±2 percent). Enhanced valve operability will result in a significant decrease in operating and maintenance costs associated with valve maintenance and testing. In addition, the enhanced setpoint reproducibility will allow the development of a nitrogen to steam correlation for future in-house PSV testing which will result in further reductions in costs associated with valve testing.

Nonlinear Analysis Method Research of Multi-Bolt Connection Structure of Primary Equipment Support

2017 ◽  
Author(s):  
Jianrong Zou ◽  
Shaochong Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steam Generator ◽  
Support System ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Reactor Coolant ◽  
Asme Code ◽  
Bolt Connection ◽  
Coolant System

The main equipments of the reactor coolant system include the steam generator, the reactor coolant pump, the pressurizer and the reactor coolant loop. The reactor coolant system is equipped with a steam generator for each of the two loops, and pressurizer is connected with the hot leg of loop 1 using the surge line. The main loop support system design of AP series greatly simplifies the RCS loop support system. Pressurizer supports consist of columns, lower lateral supports, upper lateral support and ring girder, and the steam generator supports consist of columns, lower lateral supports, upper lateral supports and intermediate lateral supports. Ring Girder of pressurizer consists of two semi-circular girders, vertical supports and splice connection of girder and the two half-ring girders are connected with splice connection using 11 bolts. The steam generator upper lateral support is mainly composed of bracket, snubber, pin and ubar and the ubar and the steam generator is connected via 16 bolts in the initial design. These bolts are to ensure the support junction can withstand the force and torque of various conditions of the reactor coolant system, which are important components of the main equipment support. There are large numbers of bolts in the splice connection of ring girder and ubar of upper lateral support of steam generator, and the bolts load was calculated using the uniform method in the general engineering design and analysis. During the design review it was found that the bolts load was uneven and in order to determine the non-uniformity of the bolts the finite element method was used to calculate the load on each bolt, and the resulting stress ratio was greater than 1 did not meet the requirements of the ASME Code. In this paper, the calculation method was studied and the design improvements for parts was made using the nonlinear analysis method to meet the requirements of ASME Code in the case of master supports of main equipment supports have been made good. At the same time the impact of bolts load because of gap was studied. It had very good economic benefits. The calculation and research of this paper show that the finite element method can calculate the force of bolts finely, and can get a more reasonable result than the empirical formula. It can be referred to when the multi-bolt connection structure needs to be refined, such as flange connection of important equipments and valves and flange and bolt design optimization.

Hydrodynamic Factors Affecting the Design of Valve Plates and Thrust Bearings

1966 ◽  
Vol 181 (1) ◽  
pp. 653-666 ◽  
Author(s):  
J. McKeown ◽  
D. A. Milner ◽  
N. A. Shute ◽  
D. E. Turnbull
Keyword(s):  
Fluid Pressure ◽  
Operating Conditions ◽  
Fluid Viscosity ◽  
Fluid Temperature ◽  
Mechanical Seals ◽  
Approximate Methods ◽  
Factors Affecting ◽  
Thrust Bearings ◽  
Axial Piston Pumps ◽  
Axial Piston

The limitations of analyses of the characteristics of viscous flow systems based on the assumption of constant fluid viscosity have been recognized for a considerable period of time and attempts to overcome them have previously been made by suggesting the use of a ‘mean effective’ value of viscosity. It has become increasingly obvious, however, that the large changes which often occur in the value of the viscosity of most hydraulic fluids suitable for use in fluid power and lubricating systems can no longer be disregarded and a more exact study of the results of the effects produced by variations of both pressure and temperature on the viscosity of such fluids is desirable. The present work contains such an analysis, and consideration is given to a system wherein combined Couette and Poiseuille flows occur. Predictions are made of the effects produced under certain operating conditions by the variation of the viscosity of the fluid with both the instantaneous values of the fluid pressure and the fluid temperature. Methods of applying these results to studies of the operation of valve plates for axial piston pumps and motors, radial face or mechanical seals and hydrostatic thrust bearing design are indicated. Approximate methods of allowing for the effects of heat losses by conduction through the rigid boundaries of the film are suggested and some results of a computer study of these conditions are described.

Evaluation of Nozzle P-T Limit Curves for Korea Optimized Power Reactor

2020 ◽  
Author(s):  
Hyunchul Lee ◽  
Choonsung Yoo ◽  
Youngjae Maeng ◽  
Sunghoon Yoo
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Power Reactor ◽  
Nuclear Safety ◽  
Reactor Vessel ◽  
Limit Curve ◽  
Reactor Coolant ◽  
Regulatory Issue ◽  
Coolant System ◽  
Reactor Pressure

Abstract The purpose of the Pressure – Temperature (P-T) limit curve is to prevent a failure of reactor pressure vessel during operation of reactor coolant system. In Korea, P-T limit curves have to meet 10CFR50 Appendix G [1] according to Nuclear Safety and Security Commission Notification 2017-20. The P-T limit curves have been traditionally evaluated based on the beltline region which is most affected by neutron irradiation. However due to the geometric discontinuity, the inside corner regions of the vessel nozzles are the most highly stressed regions of reactor vessel. These higher stresses can potentially result in more restrictive P-T limits, even if the reference nil ductility transition temperatures (RTNDT) for these components are not as high as those of the reactor vessel beltline shell materials that have simpler geometries. In 2014, the NRC issued Regulatory Issue Summary (RIS) 2014-11 [2], which require the consideration of reactor vessel nozzles in P-T limits curve generation. In this paper, P-T limit curves for Korea optimized power reactor (OPR-1000) nozzles at the end of license were evaluated. And then these curves were compared to the traditional beltline region P-T limit curves in order to verify which curve is more limiting.

Modeling of a Fixed-Bed Reactor for the Production of Phthalic Anhydride

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Amir Rahimi ◽  
Sogand Hamidi
Keyword(s):  
Phthalic Anhydride ◽  
Fixed Bed ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Conversion Degree ◽  
Reactor Length ◽  
Reactor Temperature ◽  
Reported Data ◽  
Reactor Pressure

In this study, the performance of a fixed–bed tubular reactor for the production of phthalic anhydride is mathematically analyzed. The conversion degree and reactor temperature values are compared with the measured one in a tubular reactor applied in Farabi petrochemical unit in Iran as well as reported data in the literature for a pilot plate. The comparisons are satisfactory. The effects of some operating parameters including reactor length, feed temperature, reactor pressure, and existence of an inert in the catalytic bed are investigated. The optimum value of each parameter is determined on the basis of the corresponding operating conditions.

scholarly journals Experimental and Theoretical Analysis of a Linear Focus CPV/T System for Cogeneration Purposes

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2960 ◽  
Author(s):  
Carlo Renno
Keyword(s):  
Focal Length ◽  
Concentration Field ◽  
Operating Conditions ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Atmospheric Conditions ◽  
High Concentration ◽  
Environment Temperature ◽  
Temperature Levels ◽  
T System

The knowledge of the actual energy performances of a concentrating photovoltaic and thermal (CPV/T) system with a linear focus optics, allows to evaluate the possibility of adopting this type of system for cogeneration purposes. Hence, the main aim of this paper is the design, realization, setting and modeling of a linear focus CPV/T system in the high concentration field. An experimental linear focus CPV/T plant was created in order to determine its electrical and thermal performance under different working conditions in terms of environment temperature, sunny and cloudy conditions, focal length, etc. Moreover, a theoretical model of the linear focus CPV/T system was also studied. This model evaluates the temperatures of the working fluid that flows in the cooling circuit of the CPV/T system under several operating conditions. The temperatures of the triple junction (TJ) cells, experimentally evaluated referring to different solar radiation and atmospheric conditions, were considered as the input data for the model. The values of the fluid temperature, theoretically and experimentally determined, were thus compared with good agreement. The electrical production of the CPV/T system depends generally on the TJ cell characteristics and the concentration factor, while the thermal production is above all linked to the system configuration and the direct normal irradiance (DNI) values. Hence, in this paper the electric power obtained by the linear-focus CPV/T system was evaluated referring to the cogeneration applications, and it was verified if the TJ cell and the cooling fluid reach adequate temperature levels in this type of system, in order to match the electrical and the thermal loads of a user.

scholarly journals FATIGUE LIFE ASSESSMENT OF REACTOR COOLANT SYSTEM COMPONENTS BY USING TRANSFER FUNCTIONS OF INTEGRATED FE MODEL

2010 ◽  
Vol 42 (5) ◽  
pp. 590-599 ◽  
Author(s):  
Shin-Beom Choi ◽  
Yoon-Suk Chang ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
Myung-Jo Jhung ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Transfer Functions ◽  
Life Assessment ◽  
Fe Model ◽  
Reactor Coolant ◽  
Fatigue Life Assessment ◽  
System Components ◽  
Coolant System

A Shape Memory Alloy-Based Morphing Axial Fan Blade—Part I: Blade Structure Design and Functional Characterization

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Annalisa Fortini ◽  
Alessio Suman ◽  
Nicola Aldi ◽  
Mattia Merlin ◽  
Michele Pinelli
Keyword(s):  
Shape Memory ◽  
Solid Phase ◽  
Functional Characterization ◽  
Structure Design ◽  
Operating Conditions ◽  
Surface Pattern ◽  
Fluid Temperature ◽  
Axial Fan ◽  
Polymeric Matrices ◽  
Air Stream

The possibility to realize adaptive structures is of great interest in turbomachinery design, owing to the benefits related to enhanced performance and efficiency. To accomplish this, a challenging approach is the employment of shape memory alloys (SMAs), which can recover seemingly permanent strains by solid phase transformations whereby the so-called shape memory effect (SME) takes place. This paper presents the development of a heavy-duty automotive cooling axial fan with morphing blades activated by SMA strips that works as actuator elements in the polymeric blade structure. Concerning the fan performance, this new concept differs from a conventional viscous fan clutch solution especially during the nonstationary operating conditions. The blade design was performed in order to achieve the thermal activation of the strips by means of air stream flow. Two polymeric matrices were chosen to be tested in conjunction with a commercially available NiTi binary alloy, whose phase transformation temperatures (TTRs) were experimentally evaluated by imposing the actual operating thermal gradient. The SMA strips were then thermomechanically treated to memorize a bent shape and embedded in the polymeric blade. In a specifically designed wind tunnel, the different polymeric matrices equipped with the SMA strips were tested to assess the fluid temperature and surface pattern behavior of the blade. Upon heating, they tend to recover the memorized shape and the blade is forced to bend, leading to a camber variation and a trailing edge displacement. The recovery behavior of each composite structure (polymeric matrix with the SMA strips) was evaluated through digital image analysis techniques. The differences between the blade shape at the initial condition and at the maximum bending deformation were considered. According to these results, the best coupling of SMA strips and polymeric structure is assessed and its timewise behavior is compared to the traditional timewise behavior of a viscous fan clutch.

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