Lateral Crush Strength of Nuclear Fuel Spacer Grid Considering Weld Properties

2012 ◽  
Vol 36 (12) ◽  
pp. 1663-1668 ◽  
Author(s):  
Kee Nam Song ◽  
Sang Hoon Lee
Keyword(s):  
Nuclear Fuel ◽  
Spacer Grid ◽  
Weld Properties ◽  
Crush Strength

Study on the Lateral Dynamic Crush Strength of a Spacer Grid Assembly for a LWR Nuclear Fuel Assembly

2010 ◽  
Vol 34 (9) ◽  
pp. 1175-1183 ◽  
Author(s):  
Kee-Nam Song ◽  
Sang-Hoon Lee ◽  
Soo-Bum Lee ◽  
Jae-Jun Lee ◽  
Gyung-Jin Park
Keyword(s):  
Fuel Assembly ◽  
Nuclear Fuel ◽  
Spacer Grid ◽  
Nuclear Fuel Assembly ◽  
Crush Strength

scholarly journals Effect of Weld Properties on the Crush Strength of the PWR Spacer Grid

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Kee-nam Song ◽  
Sang-hoon Lee
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Structural Component ◽  
Weld Zone ◽  
Base Material ◽  
Instrumented Indentation ◽  
Spacer Grid ◽  
Indentation Technique ◽  
Weld Properties ◽  
Crush Strength

Mechanical properties in a weld zone are different from those in the base material because of different microstructures. A spacer grid in PWR fuel is a structural component with an interconnected and welded array of slotted grid straps. Previous research on the strength analyses of the spacer grid was performed using base material properties owing to a lack of mechanical properties in the weld zone. In this study, based on the mechanical properties in the weld zone of the spacer grid recently obtained by an instrumented indentation technique, the strength analyses considering the mechanical properties in the weld zone were performed, and the analysis results were compared with the previous research.

IMPACT ANALYSIS AND TEST FOR THE SPACER GRID ASSEMBLY OF A NUCLEAR FUEL ASSEMBLY

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1228-1234 ◽  
Author(s):  
KEE-NAM SONG ◽  
SANG-HOON LEE ◽  
SOO-BUM LEE
Keyword(s):  
Fuel Assembly ◽  
Nuclear Fuel ◽  
Impact Analysis ◽  
Test Results ◽  
Lateral Loads ◽  
Spacer Grid ◽  
Element Analysis ◽  
Nuclear Fuel Assembly ◽  
Crush Strength ◽  
Good Agreement

A spacer grid assembly is one of the main structural components of the nuclear fuel assembly for a Pressurized light Water Reactor (PWR). The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during a handling and, if needed, sustains lateral seismic loads. The ability of a spacer grid assembly to resist these lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, a finite element analysis on the dynamic crush strength of spacer grid assembly specimens is carried out. Comparisons show that the analysis results are in good agreement with the test results to within about a 30 % difference range. Therefore, we could predict the crush strength of a spacer grid assembly in advance, before performing a dynamic crush test. And also a parametric study on the crush strength of a spacer grid assembly is carried out by adjusting the weld penetration depth for a sub-sized spacer grid, which also shows a good agreement between the test and analysis results.

Impact Analysis for the Egg-Crate Structure of a Nuclear Fuel Assembly by Using FEM

2007 ◽  
Vol 353-358 ◽  
pp. 2668-2671
Author(s):  
Kee Nam Song ◽  
Sang Hoon Lee ◽  
Jae Yong Kim
Keyword(s):  
Fuel Assembly ◽  
Nuclear Fuel ◽  
Impact Analysis ◽  
Lateral Loads ◽  
Spacer Grid ◽  
Element Analysis ◽  
Nuclear Fuel Assembly ◽  
Buckling Test ◽  
Crush Strength ◽  
Good Agreement

A spacer grid assembly is one of the main structural components of the nuclear fuel assembly of a Pressurized light Water Reactor (PWR). The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during a handling and, if needed, sustains lateral seismic loads. The ability of a spacer grid assembly to resist these lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, a finite element analysis on the dynamic crush strength of spacer grid assembly specimens is carried out. Comparisons show that the analysis results are in good agreement with the test results within an 8 % difference range. Therefore, we could predict the crush strength of a spacer grid assembly in advance, before performing the dynamic buckling test. And also a parametric study on the crush strength of a spacer grid assembly is carried out by adjusting the weld penetration depth for a sub-sized spacer grid, which also shows a good agreement between the test and analysis results.

Study on the Spacer Grid Dynamic Crush Strength According to Cell Sizes

2020 ◽  
Author(s):  
Jooyoung Ryu ◽  
Hangil Woo ◽  
Chaeyoung Nam ◽  
Youngik Yoo ◽  
Namgyu Park ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Impact Load ◽  
Lateral Impact ◽  
Spacer Grid ◽  
Manufacturing Method ◽  
Spacer Grids ◽  
Seismic Loss ◽  
Limiting Load ◽  
Long Pulse ◽  
Crush Strength

Abstract A spacer grid is one of the primary components of the PWR nuclear fuel. Spacer grid maintains proper pitches between the fuel rods and enables the fuel rod to cool down by providing coolant flow path. However, when the nuclear fuel is subjected to an unexpected excessive load during shipping, handling, manufacturing and operating, it could lead to fuel failure such as spacer grid buckling and cladding tube deformation. The most limiting load acting on the spacer grid is the lateral impact load during seismic/loss-of-coolant accidents. Dynamic crush strength of the spacer grid greatly contributes to the nuclear fuel integrity throughout the fuel lifetime [1]. This buckling strength tends to become weak in end of life (EOL) condition. KEPCO NF (KNF) carried out dynamic crush tests of the spacer grid and analyzed its characteristics. Spacer grids were prepared with three groups that have different cell sizes according to beginning of life (BOL), EOL and enlarged EOL simulated conditions. In addition, two kinds of dynamic crush tests were performed. One is pendulum impact test that drops a hammer to the grid in a short time. And the other is hydraulic long-pulse test that pushes impact plate to the grid in longer time. These tests and analysis results were compared in each group and discussed to explore key factors for improving crush strength of the spacer grid. In this paper, the spacer grid manufactured by additive manufacturing (AM) technology [2] is also introduced to verify the buckling performance. AM is a method to make designed shape with metal powder and built-up technology that is different from conventional manufacturing. Through the study, it could be a good alterative solution that the new manufacturing method might be helpful to improve dynamic impact characteristics.

ICONE15-10366 Optimization of a Nuclear Fuel Spacer Grid Spring Using Homology Constraints

2007 ◽  
Vol 2007.15 (0) ◽  
pp. _ICONE1510-_ICONE1510
Author(s):  
Moon-Kyun Shin ◽  
Hyun-Ah Lee ◽  
Jae-Jun Lee ◽  
Ki-Nam Song ◽  
Gyung-Jin Park
Keyword(s):  
Nuclear Fuel ◽  
Spacer Grid
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