Engineering topics
Publications and source records attributed to Moon, Brandon L.
The objective of this document is to provide relevant information about the verification and validation (V&V) status of RELAP5-3D for the MARVEL microreactor design and safety analysis and to provide indications about needed V&V activities before MARVEL microreactor operation.
The objective of this Engineering Calculations and Analysis Report (ECAR) is to provide documentation and highlight relevant information regarding the verification and validation (V&V) of the commercial computational fluid dynamics (CFD) code STAR-CCM+ for the thermal and fluids analyses performed for the MARVEL microreactor.
This report demonstrates that the MARVEL Reactor Primary Coolant Boundary (herein referred to as the Primary Coolant System, or PCS) is designed to meet ASME BPVC Section III Division 5 elevated temperature service design-by-analysis criteria. The analysis approach that delineates division of responsibilities to meet project objectives is discussed herein. In short, Design and Service Level A, B, and C code calculations are detailed in ECAR-6580 [9] for the majority of the PCS with complex geometry, while the Lower Downcomers, Bottom Head, and Reactor Core Barrel are analyzed in ANL-24/36. Service Level D code calculations are detailed in this document.
This ECAR encompasses the design-by-equation requirements in ASME BPVC Section III Division 5 Subsection HCB, in addition to the service level and design-by-analysis requirements of Subsection HBB, as they apply to the Guard Vessel.
The purpose of this Engineering Calculations and Analysis Report (ECAR) is to document the structural evaluation for part of the Microreactor Applications Research Validation and Evaluation (MARVEL) Primary Coolant System (PCS) and Guard Vessel System (GVS). For the PCS this relates specifically to the Distribution Plenum (DP), The Intermediate Heat Exchanger (IHX), and the Upper Downcomer (UD). For the GVS, this will include only the top corner that is machined into the DP Top Plate. These components will be evaluated using the 2021 version of ASME Section III, Division 5 [1] which is a design code that governs the construction of vessels, storage tanks, piping, pumps, valves, supports, core support structures and nonmetallic core components for use in high temperature reactor systems and their supporting systems. Materials at high temperature are subject to creep and fatigue mechanisms that require additional analyses that aren’t covered in ASME Section III, Division 1 rules. Division 5 contains two approaches: elastic or inelastic, however, additional Code Cases specific to Division 5, allow for an Elastic-Perfectly Plastic (EPP) approach. The components analyzed in this ECAR will use a combination of the elastic and EPP approach. Only Design and Service Levels A and B are evaluated in this ECAR. Service Level D evaluations for the entire PCS are documented in ECAR-6564, “MARVEL Project Primary Coolant System Pressure Vessel Stress Documentation” [2] and for the entire GVS are documented in ECAR-6574, “MARVEL Guard Vessel System FEA and ASME Analysis” [3]. The Design and Service Level A and B analyses for the PCS Downcomer piping and Core Barrel are documented in ANL-24/36, "Engineering Calculations and Analysis of the Core Barrel and Downcomer Piping in the MARVEL PCS” [4], and the GVS (except for the top corner) is in ECAR-6574, “MARVEL Guard Vessel System FEA and ASME Analysis.” See Section 2.0 for more detail on the analysis boundaries.
This evaluation determines the expected service lifetime for the Stirling Engines in the Power Generation Subsystem (PGS) based on the radiation resistance of the organic materials, electrical components, and magnets, along with the projected radiation dose rate. Components that are not projected to last for a six-month operational period are discussed in more detail, including their associated risk due to failure and possible remedial actions.
This report documents the verification and validation (V&V) efforts of the Monte Carlo N-Particle transport code (MCNP) version 6.2 on the Sawtooth supercomputer for the Microreactor Applications Research Validation and Evaluation (MARVEL) microreactor required for the preliminary documented safety analysis. This document records V&V for a safety, hazards, analysis, and design software used for design and analysis of safety class structures, system and components (SSC)s.
The purpose of this document is to perform a single-failure analysis through the use of a Failure Modes and Effects Analysis (FMEA) for the Safety Related components of the MARVEL Instrumentation and Control (I&C) System. The intent is that this document will meet the requirements for a single-failure analysis described in IEEE-379, “IEEE Standard for Application of the Single-Failure Criterion to Nuclear Power Generating Station Safety Systems”, to verify that this design does indeed meet the single failure criterion. Principles of IEEE-352, “IEEE Guide for General Principles of Reliability Analysis of Nuclear Power Generating Station Safety Systems” are followed to ensure the analysis is consistent with industry standards.
This specification establishes the requirements for the design of the MARVEL Primary Coolant System (PCS) Boundary, Guard Vessel System (GVS) Boundary, Core Support Structure (CSS), and Internal Heat Exchanger (IHX) Liner to provide a complete basis for ASME BPVC Section III Division 5 construction. All information in this section is generic and applicable to all metallic components unless otherwise specified.
In the previous work (ECAR-7210), the peak cladding temperature of the MARVEL microreactor has been evaluated by steady-state Reynolds-Averaged Navier-Stokes (RANS) based computational fluid dynamics (CFD) simulations. Although numerical uncertainties of RANS-based CFD simulations has been assessed in ECAR-7210, the model uncertainty of RANS turbulence models must be investigated to resolve the issues related to inaccurate prediction of turbulent heat flux and flow pulsation in a tight lattice rod bundle using the steady-state RANS simulations. Consequently, this ECAR conducted a high-fidelity CFD analysis utilizing Large Eddy Simulation (LES) to generate reference data and investigated the model uncertainty of RANS-based CFD simulations.
This report documents a bounding post-shutdown dose rates over time in the upper confinement area and above the top of the TREXc Pit Shield at the end of two years of operation of the MARVEL microreactor. The dose rates take into consideration the doses from the core fission products, the sodium-potassium coolant (NaK), the steel components, the Stirling engines, and the gallium eutectic (EGaInSn) secondary coolant. The MCNP model in this analysis is based on the 90% design of the MARVEL reactor from ECAR- 7447. Neutron fluence used as inputs to this analysis were calculated in ECAR-7447.
As part of the Microreactor Applications Research Validation and Evaluation Project (MARVEL) design effort, an enveloping end of life radiological source term for the reactor fuel and sodiumpotassium (NaK) eutectic coolant is calculated in support of the MARVEL preliminary hazard evaluation. The source term calculation assumes slightly more than two-years of uninterrupted operations at a power of about 120 kW for a total energy of 7,600,000 MJ which exceeds the planned two-year operation at 100 kW. The Reactor modeling was performed with MCNP6 Version 1.0 and the depletion was performed using the COUPLE and ORIGEN modules from the SCALE Version 6.2 code package.
A. Idaho National Laboratory (INL) is developing a microreactor to produce electrical power utilizing a small nuclear core and Stirling engines under the Microreactor Application Research Validation and Evaluation (MARVEL) program. This procurement specification defines the requirements for fabrication of the MARVEL AL-30 Secondary Support Standoff Blocks manufactured by Zircar. The design requires twelve blocks; however, the requested quantity shall be 16 to account for required testing after receipt of materials. B. Any conflict between this specification and referenced Codes and Standards, or any supplementary specifications in the procurement documents requires written clarification from the Contractor prior to proceeding with any work. Any deviation from the procurement documents requires approval by the Contractor with the change request process.
This ECAR analyzes the Secondary Coolant System liner, otherwise known as the Intermediate Heat Exchanger (IHX) Liner, as an ASME Section VIII, Division 1 pressure vessel. This analysis is only necessary in the event of a failure of the primary coolant boundary, in which case the IHX liner acts as a secondary confinement boundary to prevent primary coolant leakage. The liner main body or vessel is analyzed, as well as the liner flange ring.
The purpose of this ECAR is to document compliance with best engineering practices, ANSI/AISC N690 and the seismic requirements of IBC-2015 for the Reflector Support Structure of the MARVEL microreactor.
This document reports the steady-state thermal-hydraulic and static mechanical analyses of the MARVEL micro-reactor core. The objective of this work is to investigate whether fuel-to-fuel contact could occur due to the thermal deformation of the fuel cladding during the normal operation and to assess the resulting impact on the peak cladding temperatures (PCT) if contact occurs. The scope of the work consists of three computational tasks. First, a conjugate heat transfer analysis using computational fluid dynamics (CFD) model was performed to evaluate the PCTs during normal operating conditions. Second, a finite element analysis (FEA) using the cladding temperature field obtained from the CFD analysis was performed to evaluate the thermal deformation of cladding and determine the occurrence of fuel-to-fuel contact. Finally, a CFD analysis of FEA-informed fuel-to-fuel gap (represented by a conservative 0.05 mm uniform gap) was performed to evaluate whether the PCT exceeds the safety criteria.
This ECAR encompasses and documents compliance to the pressure safety requirements of the Microreactor Applications Research Validation and Evaluation (MARVEL) Reactor Primary Coolant Boundary (referred to herein as the Primary Coolant System, or PCS, which includes the outer boundary of the Central Insurance Absorber (CIA)) as a Class A system (equivalent to a Section III Division 1 Class 1 system) for high temperature reactors subjected to elevated temperature service.
The Microreactor Applications Research Validation and Evaluation (MARVEL) microreactor generates electricity using four Stirling cycle engines. Each Stirling engine, along with its mounting system, is called a Secondary Support Structure (SSS). An individual SSS consists of a Secondary Output Structure (SOS), a Secondary Support Structure Base, an insulation block, and assorted hardware. The SOS consists of the Stirling engine, the Secondary Output Structure Ring, a vibration isolator, and hardware. The purpose of this analysis is to show that the SSS is appropriately designed to meet structural, mechanical, and maintenance requirements for specified operating conditions.