scholarly journals SERPENT/SUBCHANFLOW COUPLED CALCULATIONS FOR A VVER CORE AT HOT FULL POWER

2021 ◽  
Vol 247 ◽  
pp. 04006
Author(s):  
Diego Ferraro ◽  
Manuel García ◽  
Uwe Imke ◽  
Ville Valtavirta ◽  
Riku Tuominen ◽  
...  
Keyword(s):  
High Performance ◽  
Neutron Transport ◽  
Coupling Scheme ◽  
High Fidelity ◽  
Reactor Physics ◽  
Coupled Calculation ◽  
Final Goal ◽  
Wide Range ◽  
Computational Resources ◽  
Full Core

An increasing interest on the development of highly accurate methodologies in reactor physics is nowadays observed, mainly stimulated by the availability of vast computational resources. As a result, an on-going development of a wide range of coupled calculation tools is observed within diverse projects worldwide. Under this framework, the McSAFE European Union project is a coordinated effort aimed to develop multiphysics tools based on Monte Carlo neutron transport and subchannel thermal-hydraulics codes. These tools are aimed to be suitable for high-fidelity calculations both for PWR and VVER reactors, with the final goal of performing pin-by-pin coupled calculations at full core scope including burnup. Several intermediate steps are to be analyzed in-depth before jumping into this final goal in order to provide insights and to identify resources requirements. As part of this process, this work presents the results for a pin-by-pin coupling calculation using the Serpent 2 code (developed by VTT, Finland) and the subchannel code SUBCHANFLOW (SCF, developed by KIT, Germany) for a full-core VVER model. For such purpose, a recently refurbished master-slave coupling scheme is used within a High Performance Computing architecture. A full-core benchmark for a VVER-1000 that provides experimental data is considered, where the first burnup step (i.e. fresh core at hot-full rated power state) is calculated. For such purpose a detailed (i.e. pin-by-pin) coupled Serpent-SCF model is developed, including a simplified equilibrium xenon distribution (i.e. by fuel assembly). Comparisons with main global reported results are presented and briefly discussed, together with a raw estimation of resources requirements and a brief demonstration of the inherent capabilities of the proposed approach. The results presented here provide valuable insights and pave the way to tackle the final goals of the on-going high-fidelity project.

scholarly journals SERPENT/SUBCHANFLOW COUPLED BURNUP CALCULATIONS FOR VVER FUEL ASSEMBLIES

2021 ◽  
Vol 247 ◽  
pp. 04005
Author(s):  
Diego Ferraro ◽  
Manuel García ◽  
Uwe Imke ◽  
Ville Valtavirta ◽  
Riku Tuominen ◽  
...  
Keyword(s):  
Neutron Transport ◽  
Nuclear Industry ◽  
Hydraulic Calculation ◽  
Coupling Scheme ◽  
Published Data ◽  
High Fidelity ◽  
Thermal Hydraulics ◽  
Vver Fuel ◽  
Safety Standards ◽  
Wide Range

The continuous improvement in nuclear industry safety standards and reactor designers’ and operators’ commercial goals represent a push for the development of highly accurate methodologies in reactor physics. This fact, combined with the availability of vast computational resources, allowed the development of a wide range of coupled state-of-the-art neutronic-thermal-hydraulic calculation tools worldwide during last decade. Under this framework, the McSAFE European Union project is a coordinated effort aimed to develop multiphysics tools based on Monte Carlo neutron transport and subchannel thermal-hydraulics codes, suitable for high-fidelity calculations for PWR and VVER reactors. This work presents the results for a pin-by-pin coupled burnup calculation using the Serpent 2 code (developed by VTT, Finland) and the subchannel thermal-hydraulics code SUBCHANFLOW (SCF, developed by KIT, Germany) for two different VVER-type fuel assembly types. For such purpose, a recently refurbished master-slave coupling scheme is considered, which provides several new features such as burnup and transient calculations capabilities for square and hexagonal geometries. Main aspects of this coupling are presented for this burnup case, showing some of the capabilities now available. On top of that, the obtained global results are compared with available published data from a similar high-fidelity approach for the same FA design, showing a good agreement. Finally, a brief analysis of the main resources requirement and main bottlenecks identification are also included. The results presented here provide valuable insights and pave the way to tackle the final goals of the McSAFE project, which includes full-core pin-by-pin depletion calculation within a fully coupled MC-TH approach.

scholarly journals Optimizing the RMC Code Using the Decay Chain Method for Large-Scale Decay Calculations

2021 ◽  
Vol 9 ◽  
Author(s):  
Hao Li ◽  
Ganglin Yu ◽  
Shanfang Huang ◽  
Kan Wang
Keyword(s):  
Monte Carlo ◽  
Large Scale ◽  
Trajectory Analysis ◽  
Linear Complexity ◽  
Neutron Transport ◽  
Decay Chain ◽  
High Fidelity ◽  
Reactor Physics ◽  
Transport Code ◽  
Full Core

Decay calculations play an important role in reactor physics simulations. In particular, the isotopic decay of the burned fuel during refueling is important for predicting the startup reactivity of the following burn-up cycle. In addition, there is a growing interest in high-fidelity simulations where the mesh in the burn-up region can involve millions of regions. However, existing models repeatedly solve the same Bateman equations for each region, which is a waste of calculational resources. RMC is a Monte Carlo neutron transport code developed for advanced reactor physics analysis including criticality calculations and burn-up calculations. This paper presents a decay calculation method named the Decay Chain Method (DCM) to optimize the RMC code for large-scale decay calculations. Unlike traditional methods, the Decay Chain Method solves the Bateman equations one decay chain at a time rather than one region at a time. The decay calculation in the burn-up mode then treats the decay steps as zero power burn-up steps with some optimized calculational methods to further reduce the calculational time. These methods were evaluated for a single pin example and for a Virtual Environment for Reactor Applications (VERA) full-core example. The calculations for the single pin example verify the accuracy of the decay step treatment in the burn-up mode and show the improved efficiency. The single pin is divided into 1–1,000,000 decay regions to study the efficiency differences between the Transmutation Trajectory Analysis (TTA) and DCM methods. Both methods have a linear complexity with respect to the number of regions but DCM costs just one-sixtieth of the TTA time. In the simplified VERA full core example, the DCM method reduces the decay calculation time to 0.32 min from 75.26 min while the accuracy remains unchanged.

scholarly journals Flexible composition and execution of high performance, high fidelity multiscale biomedical simulations

2013 ◽  
Vol 3 (2) ◽  
pp. 20120087 ◽  
Author(s):  
D. Groen ◽  
J. Borgdorff ◽  
C. Bona-Casas ◽  
J. Hetherington ◽  
R. W. Nash ◽  
...  
Keyword(s):  
High Performance ◽  
Multiscale Simulation ◽  
High Fidelity ◽  
Biomedical Domain ◽  
Multiscale Simulations ◽  
Total Execution Time ◽  
Stent Restenosis ◽  
Single Scale ◽  
Wide Range ◽  
In Stent Restenosis

Multiscale simulations are essential in the biomedical domain to accurately model human physiology. We present a modular approach for designing, constructing and executing multiscale simulations on a wide range of resources, from laptops to petascale supercomputers, including combinations of these. Our work features two multiscale applications, in-stent restenosis and cerebrovascular bloodflow, which combine multiple existing single-scale applications to create a multiscale simulation. These applications can be efficiently coupled, deployed and executed on computers up to the largest (peta) scale, incurring a coupling overhead of 1–10% of the total execution time.

Hierarchical Multiscale Modeling of Tire–Soil Interaction for Off-Road Mobility Simulation

2019 ◽  
Vol 14 (6) ◽  
Author(s):  
Hiroki Yamashita ◽  
Guanchu Chen ◽  
Yeefeng Ruan ◽  
Paramsothy Jayakumar ◽  
Hiroyuki Sugiyama
Keyword(s):  
High Performance ◽  
Computational Models ◽  
Computational Cost ◽  
Interaction Model ◽  
High Fidelity ◽  
Wheel Load ◽  
Mobility Performance ◽  
Wide Range ◽  
Computationally Intensive ◽  
Soil Bin

A high-fidelity computational terrain dynamics model plays a crucial role in accurate vehicle mobility performance prediction under various maneuvering scenarios on deformable terrain. Although many computational models have been proposed using either finite element (FE) or discrete element (DE) approaches, phenomenological constitutive assumptions in FE soil models make the modeling of complex granular terrain behavior very difficult and DE soil models are computationally intensive, especially when considering a wide range of terrain. To address the limitations of existing deformable terrain models, this paper presents a hierarchical FE–DE multiscale tire–soil interaction simulation capability that can be integrated in the monolithic multibody dynamics solver for high-fidelity off-road mobility simulation using high-performance computing (HPC) techniques. It is demonstrated that computational cost is substantially lowered by the multiscale soil model as compared to the corresponding pure DE model while maintaining the solution accuracy. The multiscale tire–soil interaction model is validated against the soil bin mobility test data under various wheel load and tire inflation pressure conditions, thereby demonstrating the potential of the proposed method for resolving challenging vehicle-terrain interaction problems.

scholarly journals Fabrication and testing of high-performance all-metal neutron guides and axisymmetric mirrors by electrochemical replication

MRS Advances ◽  
2020 ◽  
Vol 5 (29-30) ◽  
pp. 1513-1528
Author(s):  
B. Khaykovich ◽  
S. Romaine ◽  
A. Ames ◽  
R. Bruni ◽  
H. A. Ambaye ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
High Performance ◽  
State Of The Art ◽  
Neutron Transport ◽  
Optical Devices ◽  
High Fidelity ◽  
Single Piece ◽  
Critical Components ◽  
Structure Of Matter ◽  
Neutron Guides

ABSTRACTNeutron scattering is one of the most useful methods of studying the structure of matter, with applications to biomedical, structural, magnetic and energy-related materials. Neutron-scattering instruments are installed around research reactors or accelerator-based neutron sources, and neutron guides are critical components of these facilities. They are neutron-transport optical devices consisting of state-of-the-art mirrors often tens of meters long. Here we demonstrate a novel fabrication method of all-metallic neutron guides and axisymmetric mirrors by electroplating from precision mandrels. The process allows for the fabrication of single-piece all-metal guides of prismatic and axisymmetric shapes. We also demonstrate supermirror guides and axisymmetric focusing supermirrors produced with the same technology. We present the fabrication and tests of the multilayer-coated replicated guides and optic and show that the mandrel is reproduced with high fidelity and reliability. Such supermirror optics will provide game-changing improvements in neutron techniques.

Combined Microstructure and Heat Conduction Modeling of Heterogeneous Interfaces and Materials

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Ishan Srivastava ◽  
Sridhar Sadasivam ◽  
Kyle C. Smith ◽  
Timothy S. Fisher
Keyword(s):  
Transport Properties ◽  
High Performance ◽  
Energy Transport ◽  
Heterogeneous Materials ◽  
Operating Conditions ◽  
High Fidelity ◽  
Energy Materials ◽  
Wide Range ◽  
Material State ◽  
Random Structures

Heterogeneous materials are becoming more common in a wide range of functional devices, particularly those involving energy transport, conversion, and storage. Often, heterogeneous materials are crucial to the performance and economic scalability of such devices. Heterogeneous materials with inherently random structures exhibit a strong sensitivity of energy transport properties to processing and operating conditions. Therefore, improved predictive modeling capabilities are needed that quantify the detailed microstructure of such materials based on various manufacturing processes and correlate them with transport properties. In this work, we integrate high fidelity microstructural and transport models, which can aid in the development of high performance energy materials. Heterogeneous materials are generally comprised of nanometric or larger length scale domains of different materials or different phases of the same material. State-of-the-art structural optimization models demonstrate the predictability of the microstructure for heterogeneous materials manufactured via powder compaction of variously shaped and sized particles. The ability of existing diffusion models to incorporate the essential multiscale features in random microstructures is assessed. Lastly, a comprehensive approach is presented for the combined modeling of a high fidelity microstructure and heat transport therein. Exemplary results are given that reinforce the importance of developing predictive models with rich stochastic output that connect microstructural information with physical transport properties.

scholarly journals DEVELOPMENT OF MPACT FOR FULL-CORE SIMULATIONS OF MAGNOX GAS-COOLED NUCLEAR REACTORS

2021 ◽  
Vol 247 ◽  
pp. 06041
Author(s):  
Brian J. Ade ◽  
Nicholas P. Luciano ◽  
Andrew J. Conant ◽  
Cole A. Gentry ◽  
Shane G. Stimpson ◽  
...  
Keyword(s):  
Neutron Transport ◽  
National Laboratory ◽  
Test Problems ◽  
High Fidelity ◽  
Validation Data ◽  
Oak Ridge ◽  
Section Data ◽  
Axial Dimension ◽  
And Performance ◽  
Full Core

The MPACT code, jointly developed by Oak Ridge National Laboratory and University of Michigan, is designed to perform high-fidelity light water reactor (LWR) analysis using wholecore pin-resolved neutron transport calculations on modern parallel-computing hardware. MPACT uses the subgroup method for resonance self-shielding, while the primary neutron transport solver uses a 2D/1D method that is based on the method of characteristics (MoC) for the x-y planes coupled with a 1D diffusion or transport solver in the axial dimension. Additional geometry capabilities are currently being developed in MPACT to support hexagonal-pitched lattices, as well as interstitial geometry (i.e., control rods at the corner of four adjacent pin cells). In this research, the MPACT method is tested on gas-cooled reactors by applying MPACT to full-core MAGNOX reactor test problems. MAGNOX test problems were chosen due to the availability of high-quality reactor design and validation data (available through an ongoing collaboration with the National Nuclear Laboratory in the United Kingdom) and the existence of a relatively complex axial power shape that is expected to challenge the MPACT method. MPACT’s convergence for partial- and full-core problems will be tested and verified. MPACT will be compared with high-fidelity continuous-energy Monte Carlo simulations to verify core reactivity, power distributions, and performance of the available cross section data libraries and energy group structures.

scholarly journals MULTILEVEL CMFD ACCELERATION METHODS FOR WHOLE CORE REACTOR SIMULATION IN VERA

2021 ◽  
Vol 247 ◽  
pp. 02037
Author(s):  
Luke Cornejo ◽  
Benjamin Collins ◽  
Shane Stimpson
Keyword(s):  
Finite Difference ◽  
Finite Difference Method ◽  
Virtual Environment ◽  
Difference Method ◽  
Neutron Transport ◽  
Coarse Mesh ◽  
Reactor Physics ◽  
Acceleration Methods ◽  
Solver Performance ◽  
Full Core

Ongoing efforts are being made to improve the performance of MPACT as the deterministic neutron transport solver in the Virtual Environment for Reactor Analysis (VERA). As other parts of the code have been improved, the coarse mesh finite difference method (CMFD) has come to take up a significant portion of the runtime. Multilevel-in-energy CMFD and multilevel-in-space CMFD solvers have been used to improve CMFD solver performance. A new multilevel-in-space-and-energy CMFD solver is being introduced that combines components of these two methods. W-Cycles and partial W-Cycles are being investigated to further improve the efficiency of the multilevel-in-energy CMFD solver. The performance of these methods is demonstrated on full core reactor physics problems of interest to VERA.

High Performance Reconfigurable Hardware Acceleration on Neutron Transport Computation Based on AGENT Methodology

2010 ◽  
Author(s):  
Shanjie Xiao ◽  
Tatjana Jevremovic
Keyword(s):  
High Performance ◽  
Neutron Transport ◽  
Three Dimensional ◽  
Hardware Acceleration ◽  
Reconfigurable Hardware ◽  
Reactor Physics ◽  
Von Neumann ◽  
Acceleration Techniques ◽  
High Efficient ◽  
Field Programmable

A high performance hardware acceleration coprocessor built on field programmable arrays (FPGAs) is designed to accelerate neutron transport computation for three dimensional whole reactor cores. The acceleration coprocessor is designed based on the reconfigurable computation techniques and adopts the dataflow-driven non von Neumann architecture for high efficient parallel computation. The hardware acceleration coprocessor supports much more intensive available computation power compare with the same-era CPUs, and is compatible with existing software acceleration methods. It reaches about 20 times speed up in simulation validations. It is the first time that the reconfigurable hardware acceleration techniques are used to improve the computational efficiency of the reactor physics and neutron transport simulations.

scholarly journals High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems

2014 ◽  
Vol 372 (2021) ◽  
pp. 20130381 ◽  
Author(s):  
Vijay S. Mahadevan ◽  
Elia Merzari ◽  
Timothy Tautges ◽  
Rajeev Jain ◽  
Aleksandr Obabko ◽  
...  
Keyword(s):  
Nuclear Reactor ◽  
Neutron Transport ◽  
High Fidelity ◽  
Design Problems ◽  
Flexible Coupling ◽  
Physics Simulation ◽  
Software Interfaces ◽  
Coupling Strategy ◽  
Reactor Models ◽  
Computational Resources

An integrated multi-physics simulation capability for the design and analysis of current and future nuclear reactor models is being investigated, to tightly couple neutron transport and thermal-hydraulics physics under the SHARP framework. Over several years, high-fidelity, validated mono-physics solvers with proven scalability on petascale architectures have been developed independently. Based on a unified component-based architecture, these existing codes can be coupled with a mesh-data backplane and a flexible coupling-strategy-based driver suite to produce a viable tool for analysts. The goal of the SHARP framework is to perform fully resolved coupled physics analysis of a reactor on heterogeneous geometry, in order to reduce the overall numerical uncertainty while leveraging available computational resources. The coupling methodology and software interfaces of the framework are presented, along with verification studies on two representative fast sodium-cooled reactor demonstration problems to prove the usability of the SHARP framework.

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