SURET calculation of a new type of nuclear fuel assembly having spacer grid with mixing vane

Abstract The purpose of this study is to develop a finite element model that accurately describes the buckling behavior of a spacer grid. The spacer grid is the most important component of a nuclear fuel assembly and supports the fuel rod with a structurally sufficient buckling strength. Therefore, the development of a reliable spacer grid model is essential to evaluate the mechanical integrity of a nuclear fuel assembly. To achieve this objective, a three-dimensional finite element model was proposed to simulate the buckling characteristics and mechanical behavior of a PWR spacer grid. To simulate the exact mechanical properties of the spacer grid cell, the parameter values required for the model were determined by conducting a fuel rod drag test and spacer grid spring/dimple stiffness test. Finally, a spacer grid static compression test and dynamic impact test were performed according to the gap size of the spacer grid cell, and the model was verified by comparing the test and analysis results. The results obtained using the developed spacer grid finite element model agreed well with the mechanical test results, and it was confirmed that both the buckling characteristics and mechanical behaviors of the model were accurately simulated by the proposed model.

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

International Journal of Modern Physics B ◽

10.1142/s021797920804658x ◽

2008 ◽

Vol 22 (09n11) ◽

pp. 1228-1234 ◽

Cited By ~ 4

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.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.2668 ◽

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.

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