Horizon 2020 Marie Skłodowska-Curie Innovative Training Network

Alberto González Merino

MSc
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Alberto González Merino 2017-12-02T04:20:17+00:00
Early Stage Researcher
Equipos Nucleares SA (Spain)

Project 3: Reduction of uncertainty in design of free standing nuclear spent fuel rack

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Research Interests:

Structural engineering; Finite element method (FEM); Computational fluid dynamics (CFD); Fluid-structure interaction (FSI); Physical models; Structural safety; Hydraulic structures; Computer programing; Process improvement

Biography:

He studied and earned a double Master’s degree in Civil Engineering from both “Escuela de Caminos, Canales y Puertos” in Santander and “Ecole des Ponts et Chaussées” in Paris. During this exchange program, aimed at high performance students, he was focused on Structural and Hydraulic Engineering and he was granted several academic achievement awards.

Since 2012, he has worked for a multinational company dedicated to inventing, designing and manufacturing Fusegates® worldwide. During these years, he has had the chance to run several model test campaigns and develop new tailored products. This experience has made him realize that an innovative culture is among his highest interests. He joined TRUSS ITN in October 2015.

He truly believes that Research and Development is the best way to improve the reliability of existing structures and it is his desire to contribute in reaching these goals which he believes will shape his future career.

Research Outputs:

  • Beretta, M., Gonzalez Merino, A., Cazaillet, O., and Batterham, R. (2013), ”Quipolly dam: a case study on customizing Fusegates® design for adverse spillway conditions” in ICOLD Seattle and PKW II. -> Link to presentation
  • Beretta, M., Gonzalez Merino, A. and Cazaillet, O. (2013), ”Barrage de Quipolly : Les hausses fusibles (Fusegates ®) adaptées aux conditions extrêmes de l’évacuateur de crues” CFBR, Chambéry. -> Link to full text
  • Kovalev, S., Onipchenko, G., Zyuzin, G., and Mathis, N. (2012) ”Automatic adjustable valve”, Patent No. WO 2013175102 A1. -> Link to patent 
Presentation in 1st TRUSS Symposium

Publications in TRUSS

Spent fuel racks are steel structures designed to store the spent fuel assemblies removed from the nuclear power reactor. They rest in free-standing conditions submerged in the depths of the spent fuel pool. During a strong-motion earthquake, racks undergo large displacements subjected to inertial forces. An accurate estimation of their response is essential to achieve a safe pool layout and a reliable structural design. A transient analysis with direct integration of the equation of motion throughout the whole earthquake duration becomes therefore unavoidable. The computational cost associated to this analysis leads to the use of simplified finite element models giving rise to a certain dose of uncertainty. This paper carries out a parametric analysis of the key modelling properties for a two-rack system. This technique examines the behavior of the main transient outputs as a modelling parameter is systematically varied. Numerical results provide a source of insight into the general behavior of the rack system and an effective tool to propose an efficient and reliable modeling and meshing. The trade-off between outputs and computational cost and is also discussed. [DOI] -> Link to full text in repository

High Density Spent Fuel Storage (HDSFS) racks are structures designed to hold nuclear spent fuel assemblies removed from the nuclear power reactor after having been irradiated. They are used in the first step of the waste management process, during the wet storage. The underwater seismic response of HDSFS racks is a troubling safety issue. Since they are 12 m submerged free standing multi-body structures loaded with radioactive fuel, their design remains as complex as crucial. The design deals with a Fluid-Structure Interaction problem, a transient dynamic response and a very highly nonlinear behaviour. Several cost-effective industrial approaches have been used in these calculations to date, but some dispersion of results still exists. Therefore, the regulatory authorities are requiring an evaluation of the uncertainties in the methodology. Equipos Nucleares, S.A. (ENSA) is a worldwide expert in racks design and construction and has recently launched a research project to improve the understanding of the phenomena. The latter is funded by the European Commission and aimed to identify, evaluate and reduce the uncertainties involved in the calculations. In this paper, the state of the art and the current sources of uncertainty are discussed. -> Link to full text in repository
High Density Spent Fuel Storage racks are steel structures designed to hold nuclear spent fuel assemblies removed from the nuclear power reactor. Weighing around 60 tons, they are 5m high free standing structures resting on the floor of a 12 m depth pool and separated by only a few centimetres. Their underwater seismic response is a troubling safety issue, especially after Fukushima nuclear disaster. However, only limited basic guidelines have been provided as regulatory design criteria to date. The racks’ design deals with a very highly nonlinear behaviour, a transient dynamic response and a fluid-structure interaction problem. Industry is currently using available computer-aided finite element analysis software to solve the design problem in a cost-effective manner but some dispersion of results still exists. Hence, the nuclear regulatory authorities are requiring an evaluation of the current uncertainty associated to the assessment of rack displacements, rocking and maximum forces on supports. This paper discusses the main difficulties faced during the seismic analysis and presents an ad-hoc analysis methodology based on the hydrodynamic mass concept which takes advantage of a simplifying thermal analogy. The methodology, implemented in ANSYS FE Mechanical is hereby described for a reduced scale 2-rack model where the coupling effect of water in the dynamic motion of immersed racks is quantified and displacements and forces are provided. Finally, methodology assumptions are discussed and lessons learnt about the behaviour trends are summarized. -> Link to full text in repository