IAPWS95 System Requirements Specification
This template follows INL template TEM-135, "IT System Requirements Specification".
This document serves as an addendum to Framework System Requirements Specification and captures information for SRS specific to the IAPWS95 application.
Introduction
System Purpose
IAPWS95 is a module to compute the fluid properties of water using Spline-Based Table lookups (SBTL) for MOOSE applications. SBTL is a fast method of computing properties from pre-generated tables of fluid properties. The IAPWS95 can compute properties such as density, specific heat, or viscosity over the range of validity in pressure and temperature that the input data was defined on. Water fluid properties are useful to perform thermal hydraulic simulations of Light Water Reactors (LWRs) and certain coolant loops in advanced nuclear reactors. LWRs are currently the only type of civilian commercial nuclear reactors in the United States.
System Scope
IAPWS95's scope is somewhat open-ended, as fluid properties are an important but generally not central part of a given simulation.
System Overview
System Context
The IAPWS95 application is command-line driven. Like MOOSE, this is typical for a high-performance software that is designed to run across several nodes of a cluster system. As such, all usage of the software is through any standard terminal program generally available on all supported operating systems. Similarly, for the purpose of interacting through the software, there is only a single user, "the user", which interacts with the software through the command-line. IAPWS95 does not maintain any back-end database or interact with any system daemons. It is an executable, which may be launched from the command line and writes out various result files as it runs.
Figure 1: Usage of IAPWS95 and other MOOSE-based applications.
System Functions
Since IAPWS95 is a command-line driven application, all functionality provided in the software is operated through the use of standard UNIX command line flags and the extendable MOOSE input file. IAPWS95 is completely extendable so individual design pages should be consulted for specific behaviors of each user-defined object.
User Characteristics
Like MOOSE, there are three kinds of users working on the IAPWS95 application:
IAPWS95 application Developers: These are the core developers of the IAPWS95 application. They are responsible for following and enforcing the software development standards of the application, as well as designing, implementing, and maintaining the software.
Developers: A scientist or engineer that uses the IAPWS95 application alongside MOOSE and the IAPWS95 dependencies to build their own application. This user will typically have a background in modeling or simulation techniques (and perhaps numerical analysis) but may only have a limited skillset when it comes to code development using the C++ language. This is the primary focus group of the application. In many cases, these developers will be encouraged to contribute generally-appropriate code back to IAPWS95 application, or to one of its dependencies.
Analysts: These are users that will run the code and perform analysis on the simulations they perform. These users may interact with developers of the system requesting new features and reporting bugs found and will typically make heavy use of the input file format.
Assumptions and Dependencies
The IAPWS95 application is developed using MOOSE and is based on various modules, as such the SRS for IAPWS95 is dependent upon the files listed at the beginning of this document. Any further assumptions or dependencies are outlined in the remainder of this section.
The IAPWS95 application is designed with the fewest possible constraints on hardware and software. It inherits the assumptions and dependencies for its own dependencies - namely, the MOOSE framework, MOOSE physics modules, and IAPWS95 submodule applications - which are listed at the beginning of this document. Any physics-based assumptions in code simulations and code objects are highlighted in their respective documentation pages.
References
Definitions and Acronyms
This section defines, or provides the definition of, all terms and acronyms required to properly understand this specification.
Definitions
Verification: (1) The process of: evaluating a system or component to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase. (2) Formal proof of program correctness (e.g., requirements, design, implementation reviews, system tests) (24765:2010(E), 2010).
Acronyms
| Acronym | Description |
|---|---|
| INL | Idaho National Laboratory |
| MOOSE | Multiphysics Object Oriented Simulation Environment |
| NQA-1 | Nuclear Quality Assurance Level 1 |
| POSIX | Portable Operating System Interface |
| SRS | Software Requirement Specification |
System Requirements
In general, the following is required for MOOSE-based development:
A POSIX compliant Unix-like operating system. This includes any modern Linux-based operating system (e.g., Ubuntu, Fedora, Rocky, etc.), or a Macintosh machine running either of the last two MacOS releases.
| Hardware | Information |
|---|---|
| CPU Architecture | x86_64, ARM (Apple Silicon) |
| Memory | 8 GB (16 GBs for debug compilation) |
| Disk Space | 30GB |
| Libraries | Version / Information |
|---|---|
| GCC | 8.5.0 - 12.2.1 |
| LLVM/Clang | 10.0.1 - 16.0.6 |
| Intel (ICC/ICX) | Not supported at this time |
| Python | 3.9 - 3.11 |
| Python Packages | packaging pyaml jinja2 |
Functional Requirements
No requirements of this type exist for this application, beyond those of its dependencies.Usability Requirements
No requirements of this type exist for this application, beyond those of its dependencies.Performance Requirements
No requirements of this type exist for this application, beyond those of its dependencies.System Interfaces
No requirements of this type exist for this application, beyond those of its dependencies.System Operations
Human System Integration Requirements
The IAPWS95 application is command line driven and conforms to all standard terminal behaviors. Specific human system interaction accommodations shall be a function of the end-user's terminal. MOOSE (and therefore IAPWS95) does support optional coloring within the terminal's ability to display color, which may be disabled.
Maintainability
The latest working version (defined as the version that passes all tests in the current regression test suite) shall be publicly available at all times through the repository host provider.
Flaws identified in the system shall be reported and tracked in a ticket or issue based system. The technical lead will determine the severity and priority of all reported issues and assign resources at their discretion to resolve identified issues.
The software maintainers will entertain all proposed changes to the system in a timely manner (within two business days).
The core software in its entirety will be made available under the terms of a designated software license. These license terms are outlined in the LICENSE file alongside the IAPWS95 application source code.
Reliability
The regression test suite will cover at least 50% of all lines of code within the IAPWS95 application at all times. Known regressions will be recorded and tracked (see Maintainability) to an independent and satisfactory resolution.
System Modes and States
MOOSE applications normally run in normal execution mode when an input file is supplied. However, there are a few other modes that can be triggered with various command line flags as indicated here:
| Command Line Flag | Description of mode |
|---|---|
-i <input_file> | Normal execution mode |
--split-mesh <splits> | Read the mesh block splitting the mesh into two or more pieces for use in a subsequent run |
--use-split | (implies -i flag) Execute the simulation but use pre-split mesh files instead of the mesh from the input file |
--yaml | Output all object descriptions and available parameters in YAML format |
--json | Output all object descriptions and available parameters in JSON format |
--syntax | Output all registered syntax |
--registry | Output all known objects and actions |
--registry-hit | Output all known objects and actions in HIT format |
--mesh-only (implies -i flag) | Run only the mesh related tasks and output the final mesh that would be used for the simulation |
--start-in-debugger <debugger> | Start the simulation attached to the supplied debugger |
The list of system-modes may not be extensive as the system is designed to be extendable to end-user applications. The complete list of command line options for applications can be obtained by running the executable with zero arguments. See the command line usage.
Physical Characteristics
The IAPWS95 application is software only with no associated physical media. See System Requirements for a description of the minimum required hardware necessary for running the IAPWS95 application.
Environmental Conditions
Not Applicable
System Security
MOOSE-based applications such as IAPWS95 have no requirements or special needs related to system-security. The software is designed to run completely in user-space with no elevated privileges required nor recommended.
Information Management
The IAPWS95 application and all dependencies in their entirety will be made available on an appropriate repository hosting site accessible to IAPWS95 licensees, commensurate to their access level. Day-to-day backups and security services will be provided by the hosting service.
Polices and Regulations
MOOSE-based applications must comply with all export control restrictions.
System Life Cycle Sustainment
MOOSE-based development follows various agile methods. The system is continuously built and deployed in a piecemeal fashion since objects within the system are more or less independent. Every new object requires a test, which in turn requires an associated requirement and design description. The IAPWS95 development team follows the NQA-1 standards.
Packaging, Handling, Shipping and Transportation
All export control restrictions must be adhered to when packaging and shipping media containing the IAPWS95 application or its dependencies.
Verification
The regression test suite will employ several verification tests using comparison against known analytical solutions, the method of manufactured solutions, and convergence rate analysis.