Study on Optimization Design for CSR1000 Core

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Lianjie Wang ◽  
Ping Yang ◽  
Di Lu ◽  
Wenbo Zhao
Keyword(s):  
Steady State ◽  
Power Distribution ◽  
Optimization Design ◽  
Code System ◽  
Fuel Cladding ◽  
Steady State Analysis ◽  
Control Capability ◽  
Supercritical Water Cooled Reactor ◽  
Conceptual Core ◽  
Steady State Performance

An optimization design of China supercritical water-cooled reactor (SCWR) with the rated electric power of 1000 MWe (CSR1000) conceptual core is proposed. Steady-state performance of the proposed core is then studied with the SCWR core steady-state analysis code system SNTA. These key parameters such as burnup performance, reactivity control capability, power distribution, maximum fuel cladding temperature, and maximum linear power density are analyzed. The relative coolant flow rate of the second flow path, which is suited with assembly power, is also presented. The study shows that the refueling cycle of CSR1000 core can be extended effectively under the optimization design.

Development of SNTA Code System for SCWR Core Steady-State Analysis

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Lianjie Wang ◽  
Wenbo Zhao ◽  
Ping Yang ◽  
Yongqiang Ma ◽  
Di Lu
Keyword(s):  
Steady State ◽  
Three Dimensional ◽  
Concept Design ◽  
Code System ◽  
Core Concept ◽  
Steady State Analysis ◽  
Outer Iteration ◽  
The Finite Difference Method ◽  
Supercritical Water Cooled Reactor ◽  
State Analysis

A coupled neutronics/thermal-hydraulics (N/T) three-dimensional code system SNTA is developed for supercritical water-cooled reactor (SCWR) core steady-state analysis by modular coupling the improved neutronics nodal methodological code and SCWR thermal-hydraulic subchannel code. The appropriate outer iteration coupling method and self-adaptive relaxation factor are proposed for enhancing convergence, stability, and efficiency of coupled N/T calculation. The steady-state analysis for the CSR1000 core is applied to verify SNTA. The results calculated by SNTA agreed well with those by CASIR and SRAC. SNTA is more efficient than CASIR and SRAC, where the neutronics modules are based on the finite-difference method. The numeric results show that SNTA can be applied to SCWR core steady-state analysis and core concept design.

Study on Calculation Difference of the SCWR Core Steady-State Analysis Code

2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Lianjie Wang ◽  
Lei Yao ◽  
Ping Yang ◽  
Di Lu ◽  
Wenbo Zhao
Keyword(s):  
Steady State ◽  
Cross Section ◽  
Power Distribution ◽  
Group Structure ◽  
Three Dimensional ◽  
Thermal Hydraulics ◽  
Steady State Analysis ◽  
Energy Group ◽  
The Cross ◽  
State Analysis

Abstract The three-dimensional code system supercritical water-cooled reactor (SCWR) coupled neutronics/thermal-hydraulics analysis (SNTA) code is developed for SCWR core steady-state analysis by coupling neutronics/thermal-hydraulics (N/T). This paper studies the calculation difference between the SNTA code and the standard reactor analysis code (SRAC). By using the impacts exclusive method, it is confirmed that the calculation difference between these two codes is caused by different feedback of the cross section. The cross section data and the energy group structure of the SRAC code differ from the SNTA code, and the density coefficient of reactivity calculated by the SRAC code is higher, which means the feedback of the density and power distribution is bigger and the axial power distribution varies rapidly. The SNTA code with finer energy group structure is suitable for the performance analysis of SCWR core which has strong N/T coupling characteristics.

Steady-state analysis of load-balancing algorithms in the sub-Halfin–Whitt regime

2020 ◽  
Vol 57 (2) ◽  
pp. 578-596 ◽  
Author(s):  
Xin Liu ◽  
Lei Ying
Keyword(s):  
Steady State ◽  
Positive Integer ◽  
Load Balancing ◽  
Heavy Traffic ◽  
Sufficient Condition ◽  
Steady State Analysis ◽  
Server Systems ◽  
Join The Shortest Queue ◽  
Shortest Queue ◽  
Steady State Performance

AbstractWe study a class of load-balancing algorithms for many-server systems (N servers). Each server has a buffer of size $b-1$ with $b=O(\sqrt{\log N})$, i.e. a server can have at most one job in service and $b-1$ jobs queued. We focus on the steady-state performance of load-balancing algorithms in the heavy traffic regime such that the load of the system is $\lambda = 1 - \gamma N^{-\alpha}$ for $0<\alpha<0.5$ and $\gamma > 0,$ which we call the sub-Halfin–Whitt regime ($\alpha=0.5$ is the so-called Halfin–Whitt regime). We establish a sufficient condition under which the probability that an incoming job is routed to an idle server is 1 asymptotically (as $N \to \infty$) at steady state. The class of load-balancing algorithms that satisfy the condition includes join-the-shortest-queue, idle-one-first, join-the-idle-queue, and power-of-d-choices with $d\geq \frac{r}{\gamma}N^\alpha\log N$ (r a positive integer). The proof of the main result is based on the framework of Stein’s method. A key contribution is to use a simple generator approximation based on state space collapse.

An Analysis of the Steady-State Performance of the Cylindrical-Spherical Floating Ring Bearing

1987 ◽  
Vol 109 (4) ◽  
pp. 704-708 ◽  
Author(s):  
D. M. Clarke ◽  
C. Fall ◽  
G. N. Hayden ◽  
T. S. Wilkinson
Keyword(s):  
Steady State ◽  
Excellent Agreement ◽  
Power Loss ◽  
Theoretical Work ◽  
Steady State Analysis ◽  
Cavitation Inception ◽  
Inner Surface ◽  
Lubricant Films ◽  
Loss Prediction ◽  
Steady State Performance

A steady-state analysis based on the short bearing approximation is presented for the cylindrical-spherical floating ring bearing, where the inner surface of the ring is cylindrical whilst the outer is spherical. Performance characteristics are compared with Li and Rohde’s theoretical work on the conventional cylindrical-cylindrical bearing. Excellent agreement is obtained, especially for (L/D) = 0.5. The present analysis of both the inner and outer lubricant films, the thickness of the latter varying axially, takes account of striated flow downstream of cavitation inception. The importance of this is demonstrated when considering power loss prediction.

Externally-Pressurized Gas-Lubricated Floating-Ring Porous Journal Bearings: Part 1: Steady State Analysis

1984 ◽  
Vol 198 (4) ◽  
pp. 213-224 ◽  
Author(s):  
M Malik
Keyword(s):  
Steady State ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Design Parameters ◽  
Fixed Bearing ◽  
Steady State Analysis ◽  
Permeability Parameter ◽  
New Type ◽  
Bearing Design ◽  
Steady State Performance

A new type of gas-lubricated floating-ring journal bearing in which the fixed bearing and the ring are both porous, has been conceived and analysed, theoretically, for the steady state characteristics. Bearing characteristics are presented against two design parameters, namely, clearances ratio and permeability parameter. The comparison of these characteristics with those of externally-pressurized plain porous journal bearings shows that the new bearing represents, with its steady state performance, a distinctly advanced bearing design.

Influence Analysis of Coupled Neutronics and Thermo-Hydraulics on Steady-State Characteristics of Supercritical Water-Cooled Reactor

2012 ◽  
Vol 472-475 ◽  
pp. 278-283
Author(s):  
Juan Chen ◽  
Tao Zhou ◽  
Zhou Sen Hou ◽  
Wan Xu Cheng ◽  
Can Hui Sun
Keyword(s):  
Steady State ◽  
Supercritical Water ◽  
Cross Sections ◽  
Power Distribution ◽  
Coupled Model ◽  
Calculation Model ◽  
Coolant Temperature ◽  
Coupling Condition ◽  
Coupling Calculation ◽  
Supercritical Water Cooled Reactor

the coulped neutronics and thermo-hydraulics model for supercritical water-cooled reactor (SCWR) is developed by internal coupling method. It is based on the two group neutron diffusion equations and the one-dimensional junction thermal analysis mode, in which the cross sections used for SCWR are generated by Dragon tool. Compared with the calculation results based on the non-coupling calculation model, the steady state characteristics under coupling calculation condition are detailed analyzed by considering parameters feedback at each axial node. The results show that, as coupled model is chosen its axial power distribution would give an obvious deviation from the cosine function that used for non-coupled model. Although the cladding temperature at most of the axial nodes rises with a shifted power peak, the maximum cladding temperature is finally decreased. For the above coupling condition, the maximum cladding temperature would appear at the external assemblies with lower coolant temperature but not at inner assemblies with higher coolant temperature. As the detailed description for coupling characteristics of supercritical water-cooled reactor is given, a certain theory reference for its system safety could be provided.

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