scholarly journals Simulate the effect of integral burnable absorber on the neutronic characteristics of a PWR assembly

2018 ◽  
Vol 4 (4) ◽  
pp. 287-293 ◽  
Author(s):  
Ahmed Galahom
Keyword(s):  
Power Distribution ◽  
Three Dimensional ◽  
Published Data ◽  
Pressurized Water Reactor ◽  
Three Dimensional Model ◽  
Pressurized Water ◽  
Mcnpx Code ◽  
Absorber Material ◽  
Burnable Absorber ◽  
Neutronic Characteristics

This article examines the effect of an integral burnable absorber (IBA) on the neutronic characteristics of Pressurized Water Reactor (PWR) to provide possible improvements for the fuel management. MCNPX code was used to design a three dimensional model for PWR assembly. The designed model has been validated by comparing the output data with a previously published data. MCNPX code was used to analyze the radial thermal neutron flux and the radial power distribution through PWR assembly with and without IBA. Gadolinium is burnable absorber material that was used in the IBA rods. The gadolinium element suppressed the power in the regions where they were distributed. The existence of IBA rods has a large effect on the Kinf. This effect decreases gradually with burnup due to the degradation of gadolinium. The gadolinium isotopes degradation was analyzed with burnup. Different numbers of IBA rods were investigated to optimize the suitable number that can be used in the PWR assembly. The gadolinium effect on the concentration of 135Xe and 149Sm resulting from the fission process was analyzed.

scholarly journals Effect of Axial Distribution of Gadolinium Burnable Poison in Advanced Pressurized Water Reactor Assembly

2019 ◽  
pp. 46-53 ◽  
Author(s):  
Hend M. Saad ◽  
Riham Refeat ◽  
Moustafa Aziz ◽  
H. Mansour
Keyword(s):  
Power Distribution ◽  
Length Distribution ◽  
Pressurized Water Reactor ◽  
Axial Distribution ◽  
Pressurized Water ◽  
Fuel Rods ◽  
Water Reactor ◽  
Burnable Absorber ◽  
Reactor Assembly ◽  
Power Distribution Control

The radial and axial power distribution in power reactors are determined mainly by the patterns of the fuel assembly and the burnable absorber at the beginning of cycle. In Advanced Pressurized Water Reactor (APWR), gadolinium burnable absorber is used to decrease the relative power of fresh fuel assemblies. In this paper, the effect of the axial distribution of gadolinium (Gd) on the power of the APWR assembly is studied. Three models of APWR assemblies are simulated using MCNP6 code. In the first model, UO2 fuel is distributed uniformly in all the fuel rods. In the other two models some of the UO2 fuel rods are replaced by UO2-Gd2O3 rods in part length distribution. Two gadolinium concentrations 6% and 10% are used. The main neutronic parameters are estimated for the three models: the multiplication factor (K-infinity) as a function of burnup (GWd/MTU), the radial and axial power distributions. The results show that the distribution of the gadolinium absorber in the central region of fuel rod (part-length absorber) leads to flattening of axial power, which means additional axial power distribution control.

scholarly journals Transformation of Pressurized Water Reactor (AP1000) to Fuzzy Graph

MATEMATIKA ◽  
2018 ◽  
Vol 34 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Azmirul Ashaari ◽  
Tahir Ahmad ◽  
Wan Munirah Wan Mohamad
Keyword(s):  
Nuclear Power ◽  
Ph Value ◽  
Published Data ◽  
Primary System ◽  
Fuzzy Graph ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Fission Process ◽  
Water Reactor ◽  
Dynamic Concentration

Pressurized water reactor (PWR) type AP1000 is a third generation of a nuclear power plant. The primary system of PWR using uranium dioxide to generate heat energy via fission process. The process influences temperature, pressure and pH value of water chemistry of the PWR. The aim of this paper is to transform the primary system of PWR using fuzzy autocatalytic set (FACS). In this work, the background of primary system of PWR and the properties of the model are provided. The simulation result, namely dynamic concentration of PWR is verified against published data.

Seismic Isolation for Advanced Nuclear Power Stations

1990 ◽  
Vol 6 (2) ◽  
pp. 371-401 ◽  
Author(s):  
Frederick F. Tajirian ◽  
James M. Kelly ◽  
Ian D. Aiken
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Three Dimensional ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Isolation System ◽  
Power Stations ◽  
Safety Margins ◽  
Extensive Test ◽  
The U.S

Seismic isolation offers an attractive approach for reducing seismic loads in nuclear structures, and more significantly, in reactor components. Isolation will lead to a simplification of designs, facilitate standardization, enhance safety margins, and may potentially reduce cost. To date, six large Pressurized Water Reactor units have been isolated in France and South Africa and several advanced nuclear concepts in the U.S., Japan, and Europe have incorporated this approach. It is recognized that to qualify and license an isolation system in the U.S. and in Japan, a comprehensive testing program of isolation components and systems would be required. A major seven year program was initiated in Japan in 1987 with the objective of establishing a qualified seismic isolation design for a large fast breeder reactor to be constructed at the end of this decade. In the U.S., two concepts which use steel laminated elastomeric bearings for seismic isolation have been developed. One of these concepts is a novel system which provides three-dimensional isolation. An extensive test program of scaled prototype bearings to demonstrate their feasibility and effectiveness has been carried out.

scholarly journals Finite Element Based Full-Life Cyclic Stress Analysis of 316 Grade Nuclear Reactor Stainless Steel Under Constant, Variable, and Random Fatigue Loading

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Bipul Barua ◽  
Subhasish Mohanty ◽  
Joseph T. Listwan ◽  
Saurindranath Majumdar ◽  
Krishnamurti Natesan
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Stress Analysis ◽  
Nuclear Reactor ◽  
Three Dimensional ◽  
Fatigue Loading ◽  
Cyclic Stress ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Fatigue Evaluation

Although S∼N curve-based approaches are widely followed for fatigue evaluation of nuclear reactor components and other safety critical structural systems, there is a chance of large uncertainty in estimated fatigue lives. This uncertainty may be reduced by using a more mechanistic approach such as physics based three-dimensional (3D) finite element (FE) methods. In a recent paper (Barua et al., 2018, ASME J. Pressure Vessel Technol., 140(1), p. 011403), a fully mechanistic fatigue modeling approach which is based on time-dependent stress–strain evolution of material over the entire fatigue life was presented. Based on this approach, in this work, FE-based cyclic stress analysis was performed on 316 nuclear grade reactor stainless steel (SS) fatigue specimens, subjected to constant, variable, and random amplitude loading, for their entire fatigue lives. The simulated results are found to be in good agreement with experimental observation. An elastic-plastic analysis of a pressurized water reactor (PWR) surge line (SL) pipe under idealistic fatigue loading condition was performed and compared with experimental results.

Design of Decoupled Mechanical Shim Control System for a Generation III+ Pressurized Water Reactor Based on Feedforward Compensation and Multimodel Approach

2018 ◽  
Author(s):  
Pengfei Wang ◽  
Xinyu Wei ◽  
Fuyu Zhao
Keyword(s):  
Control System ◽  
Power Distribution ◽  
Coupling Effect ◽  
Control Performance ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Decoupling Method ◽  
Control Rod ◽  
Wide Range ◽  
Decoupled Control

The advanced Mechanical Shim (MSHIM) core control strategy employs two separate and independent control rod banks, namely the MSHIM control banks (M-banks) and axial offset (AO) control bank (AO-bank), for automatic reactivity/temperature and axial power distribution control respectively. The M-banks and AO-bank are independently controlled by two closed-loop controllers called the coolant average temperature (Tavg) controller and AO controller. Since the movement of M-banks and AO-bank can both affect the Tavg and AO, the Tavg controller is coupled with the AO controller. In order to avoid the interference between the two controllers, the MSHIM control system adopts an interlock design between them to avoid the simultaneous movement of the M-banks and AO-bank and make sure the priority of the M-bank movement. This design can enhance the stability of the MSHIM control system. However, the control performance is degraded at the same time. In the present study, the feedforward compensation decoupling method and multimodel approach are used to eliminate the coupling effect between the two controllers in the MSHIM control system during a wide range of power maneuvers. A multiple feedforward compensation system is designed with integration of feedforward compensators for the Tavg and AO controllers at five power levels using the multimodel approach. By implementing it in the MSHIM control system, the interlock between the M-banks and AO-bank can be released to realize the independent and decoupled control between Tavg and AO. The effectiveness of the decoupled MSHIM control system is verified by comparing its control performance with that of the original MSHIM control system during typical load change transients of the AP1000 reactor. The obtained results show that superior and decoupled control of Tavg and AO can be achieved with the proposed decoupled MSHIM control system.

Sign in / Sign up

Export Citation Format

Share Document