The Paramak: automated parametric geometry construction for fusion reactor designs.

Abstract

During the conceptual design process of fusion reactors it is useful to rapidly prototype different design concepts and assess their suitability against a range of high level requirements. Rapid prototyping allows the 'fail early' mantra of other fields to be applied to engineering design. Furthermore, the rapid generation of low fidelity analysis allows fast exploration of design space, which enables better decisions to be made during concept selection and the detailed design phase. The Paramak is an open-source tool that aims to provide automated parameter driven 3D CAD models for fusion reactor components and magnetic fusion reactors. The geometry produced is compatible with several analysis workflows and this allows iterative automated model building and analysis to help steer the design concept optimisation process. The Paramak uses CadQuery 2 to create the 3D CAD model. The Paramak framework is used to create a few example reactor configurations including: a spherical reactor, a regular large radius tokamak and a compact submersion tank reactor. Input parameters for the various reactors that the Paramak can generate generally fall into three categories: continuous ranges such as blanket thickness, integer ranges such as number of toroidal field coils and categorical parameters such as type of divertor. The Paramak facilitates parameter studies where users can investigate the impact of input design parameters on the reactor performance. The use of modern software practices allows the geometry to be continuously tested in analysis workflows to ensure it is fit for purpose. The generation of output metrics from input parameters lends itself to the use of data science and machine learning approaches in order to steer the design. The Paramak provides rapid construction of analysis ready CAD in a manner that allows the designer to save time when exploring the design space for design studies and facilitate automated generative design.

ARC reactor neutronics multi-code validation*

“…The automated back-end scripts read and standardize the data from each code for comparison. The files and scripts used in this study are version controlled in a Github repository 4 . This work does not include a conjecture about realistic limits of the reactor, considering the design received from CFS is preliminary.…”

“…The original CAD model of ARC was provided by Commonwealth Fusion Systems (CFS) and coordinates extracted from this model were used as a basis for a new parameter driven CAD model. The parameter driven model defines all the CAD parts using a combination of coordinates, parameters, design intent, relationships between components using Paramak [3]. This allows for changes to components to be codified and the a new geometry to be automatically generated via a Python API.…”

“…The motivation for programmable CAD and the drive towards reproducible, less brittle automated cad that conveys design intent is discussed in detail by Mathur et al [19]. The reactor components-consisting of the plasma, first wall, inner and outer vacuum vessels, vessel cooling channel, Be multiplier, FLiBe blanket [20], blanket tank, neutron shielding, poloidal field (PF) coils, and vertical stability coils, PF coils, TF coils-were all generated with the open-source Paramak code [3] to be consistent with the major dimensions and radial build of ARC, originally published by Sorbom et al [1]. While the ARC reactor model created is typical of the level of detail found in concept design stage this level of detail is not a limitation of the approach.…”

“…To address these challenges, advances to neutronics codes should be pursued to simplify how the calculations are performed. This article presents the first high-fidelity neutronics results for the affordable, robust, compact (ARC) reactor concept using new CAD models consistent with the geometry presented in previous work [1,2] and created with the Paramak code [3,4]. These analyses were performed with three independent Monte Carlo (MC) transport codes with CAD frontends (MCNP6.2 using Attila4MC [5], Shift using DAGMC, and OpenMC using DAGMC) and demonstrate that the resulting neutron spectra in many important regions throughout the reactor are within the statistical uncertainties, confirming that there are numerous accurate approaches to fusion neutronics analysis for reactor designs suitable for industry needs.…”

ParaStell: parametric modeling and neutronics support for stellarator fusion power plants

“…In the fusion space, the python package Paramak was developed as a low-to-medium fidelity parametric modeling toolset for tokamak FWBS systems (Shimwell et al, 2021). Because it is designed for tokamaks, the toolset assumes toroidal symmetry.…”