Evaluation of U10Mo Fuel Plate Irradiation Behavior via Numerical and Experimental Benchmarking

Abstract

This article analyzes dimensional changes due to irradiation of monolithic plate-type nuclear fuel and compares results with finite element analysis of the plates during fabrication and irradiation. Monolithic fuel plates tested in the Advanced Test Reactor (ATR) at Idaho National Lab (INL) are being used to benchmark the performance of proposed fuel for several high power research reactors. Post-irradiation metallographic images of plates sectioned at the mid-plane were analyzed to determine dimensional changes of the fuel and the cladding response. A constitutive model of the fabrication process and irradiation behavior of the tested plates was developed using the general purpose commercial finite element analysis package, ABAQUS. Using calculated burn-up profiles of irradiated plates to model the power distribution and including irradiation behaviors such as swelling and irradiation enhanced creep, model simulations allow analysis of plate parameters that are either impossible or infeasible in an experimental setting. The development and progression of fabrication induced stress concentrations at the plate edges was of primary interest, as these locations have a unique stress profile during irradiation. Additionally, comparison between 2D and 3D models was performed to optimize analysis methodology. In particular, the ability of 2D and 3D models to account for out of plane stresses which result in 3-dimensional creep behavior that is a product of these components. Results show that assumptions made in 2D models for the out-of-plane stresses and strains cannot capture the 3-dimensional physics accurately and thus 2D approximations are not representative. Stress-strain fields are dependent on plate geometry and irradiation conditions, thus, if stress based criteria is used to predict plate behavior (as opposed to material impurities, fine micro-structural defects, or sharp power gradients), unique 3D finite element formulation for each plate is required.

Thermo-mechanical behavior simulation coupled with the hydrostatic-pressure-dependent grain-scale fission gas swelling calculation for a monolithic UMo fuel plate under heterogeneous neutron irradiation

“…N is calculated with the analytical solution [12], which was obtained through solving the governing equations for diffusion of fission gas atoms in the equivalent spherical grain, where re-solution of the intergranular fission gas atoms is considered. So, ∂Rb∂p=hsbvNbRb2−4π3Rb516π3γRb3+4πRb4p+2γhsbvNb (14) with which the hydrostatic pressure can be solved through nonlinear iterations, as stated in the next section.…”

“…Cui et al [12] further improved the fission gas swelling model with consideration of hydrostatic pressure and re-solution of intergranular gas atoms, and it was used to simulate the in-pile behavior in a monolithic fuel plate under uniform neutron irradiation [12]. The simulation researches [7,13,14] on the in-pile thermomechanical behavior in monolithic and dispersion UMo fuel plates tend to increase gradually. As we know, fuel plates in the reactor core are under a heterogeneous irradiation condition [7].…”

Analisis Cacat Blister Pada Kelongsong Bahan Bakar U3Si2/Al Menggunakan Ultrasonic Test

“…Uji tak merusak pada pelat elemen bakar pasca iradiasi menggunakan UT dalam kegiatan PIE di IRM bertujuan untuk mendeteksi adanya anomali atau cacat. Pengaruh iradiasi pada pelat elemen bakar dapat menimbulkan terjadinya fenomena swelling (pembengkakan) [6] dan terbentuknya blister (lepuhan) [7] pada permukaan pelat elemen bakar. Uji tak merusak dilakukan di dalam hot cell IRM, sebelum alat UT dipasang di dalam hot cell, perlu dilakukan optimasi parameter pengoperasian yang tepat agar alat pengujian tersebut nantinya dapat dengan mudah dioperasikan oleh operator dari operating area menggunakan tangan manipulator serta mampu memperoleh data hasil pengujian yang akurat.…”

Swelling of U-7Mo/Al-Si dispersion fuel plates under irradiation – Non-destructive analysis of the AFIP-1 fuel plates

“…[Insert Figure 20] This behavior is not expected to significantly impact overall fuel behavior. However, the fuel meat within the region located just inside the fuel meat thickness ridge is subjected to a tensile stress due to differential fuel meat growth [37]. The net stress on the fuel meat is dependent on the magnitude of external pressure applied by the coolant.…”