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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Outreach to Industry on Safeguards by Design Concept for Small Modular Reactors

"Safeguards by Design" (SBD) is the process of incorporating safeguards features into the design of a nuclear facility during the design stage. The goal of SBD is to increase the safeguardability of a facility, which is a qualitative measure of the degree of ease with which a nuclear energy system can be effectively and efficiently placed under international safeguards. During the past decade, the National Nuclear Security Administration's (NNSA) Next Generation Safeguards Initiative funded the Pacific Northwest National Laboratory (PNNL), Brookhaven National Laboratory, and several consultants to develop the Facility Safeguardability Assessment (FSA) process. FSA is a screening process used by a facility designer to focus attention on the aspects of their facility or process design that would most benefit from application of SBD principles and practices. The process identifies the most relevant guidance within the SBD tools for enhancing the safeguardability of the design. During FY 2014, NNSA sponsored BNL and LANL to introduce the FSA to Westinghouse designers of their small modular nuclear power plant design. This report documents the interactions with Westinghouse Electric Company LLC ("Westinghouse") staff. The report describes the Westinghouse safeguards design concept with a view towards eventual application of the FSA to their design.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2024

Nuclear waste attributes of near-term deployable small modular reactors

The nuclear waste attributes of near-term deployable SMRs were assessed using established nuclear waste metrics, which are the DU mass, SNF mass, volume, activity, decay heat, radiotoxicity, and decommissioning LLW volumes. Metrics normalized per unit electricity generation were compared to a reference large PWR. Three SMRs, VOYGR, Natrium, and Xe-100, were selected because they represent a range of reactor and fuel technologies and are active designs deployable by the decade’s end. The SMR nuclear waste attributes show both some similarities to the PWR and some significant differences caused by reactor-specific design features. The DU mass is equivalent to or slightly higher than the PWR. Back-end waste attributes for SNF disposition vary, but the differences have a limited impact on long-term repository isolation. SMR designs can vary significantly in SNF volume (and thus heat generation density). However, these differences are amenable to design optimization for handling, storage, transportation, and disposal technologies. Nuclear waste attributes from decommissioning vary depending on design and decommissioning technology choices. Given the analysis results in this study and assuming appropriate waste management system and operational optimization, there appear to be no major challenges to managing SMR nuclear wastes compared to the reference PWR.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Use of Radiofrequency Tamper Indicating Devices (RFTID) to Enhance Remotely Monitoring the Security of Advanced and Small Modular Reactors (A/SMRs)

A/SMRs will likely be deployed in remote locations that are difficult to access, thereby requiring limited on-site staff. • Vendors are considering remote monitoring as a solution to enhance nuclear security. RFTIDs are a candidate technology for maintaining nuclear security of A/SMRs but need to be evaluated for feasibility and implementation into the wider physical protection system.

O'Dowd, Kevin [Savannah River National Laboratory ↗
NASA NTRS2012

Curved Waveguide Based Nuclear Fission for Small, Lightweight Reactors

The focus of the presented work is on the creation of a system of grazing incidence, supermirror waveguides for the capture and reuse of fission sourced neutrons. Within research reactors, neutron guides are a well known tool for directing neutrons from the confined and hazardous central core to a more accessible testing or measurement location. Typical neutron guides have rectangular, hollow cross sections, which are crafted as thin, mirrored waveguides plated with metal (commonly nickel). Under glancing angles with incoming neutrons, these waveguides can achieve nearly lossless transport of neutrons to distant instruments. Furthermore, recent developments have created supermirror surfaces which can accommodate neutron grazing angles up to four times as steep as nickel. A completed system will form an enclosing ring or spherical resonator system to a coupled neutron source for the purpose of capturing and reusing free neutrons to sustain and/or accelerate fission. While grazing incidence mirrors are a known method of directing and safely using neutrons, no method has been disclosed for capture and reuse of neutrons or sustainment of fission using a circular waveguide structure. The presented work is in the process of fabricating a functional, highly curved, neutron supermirror using known methods of Ni-Ti layering capable of achieving incident reflection angles up to four times steeper than nickel alone. Parallel work is analytically investigating future geometries, mirror compositions, and sources for enabling sustained fission with applicability to the propulsion and energy goals of NASA and other agencies. Should research into this concept prove feasible, it would lead to development of a high energy density, low mass power source potentially capable of sustaining fission with a fraction of the standard critical mass for a given material and a broadening of feasible materials due to reduced rates of release, absorption, and non-fission for neutrons. This advance could be applied to direct propulsion through guided fission products or as a secondary energy source for high impulse electric propulsion. It would help meet national needs for highly efficient energy sources with limited dependence on fossil fuels or conflict materials, and it would improve the use of low grade fissile materials which would help reduce national stockpiles and waste.

Coker, Robert↗
DOE OSTI2021

Comparison of Attila Transport Code with MCNP in the Analysis of Small Modular Reactor Shielding

Of great importance in the design of a nuclear power plant is the evaluation of shielding from the ionizing radiation produced in the core of the nuclear reactor. This requires simulation software to predict the dose rates in the areas of interest. These problems are referred to as deep penetration problems, as they involve the reduction of a radiation field by two or three orders of magnitude or more. This makes accurate analyses difficult for Monte Carlo based solutions that rely on enough particles being sampled in an area of interest. Comparing the simulation of the same modeled system with more than one computer application, especially one that uses a different algorithmic approach, is a way to gain confidence in the results. In this research, two models were created, one in Monte Carlo N Particle (MCNP) which uses a stochastic algorithmic approach, and the other in Attila, which uses a deterministic algorithmic approach to test the validity of the model and to estimate the dose rates in the area of interest. Successful comparison of the two models is a way we can validate the model used for that estimation.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

Xe-100 Pebble Bed Small Modular Reactor: Solving Critical Challenges to Enable the Xe-100 Pebble Bed Advanced Reactor Concept (ARC) (Final Scientific and Technical Report)

This is the final progress report for the Department of Energy (DOE) – X Energy, LLC cooperative agreement DENE0008472. This report provides a high-level summary of the work performed during the entire period of performance, running from July 1, 2016 – June 30, 2022. This span of time covers the original 5-year award and a one year no-cost extension. There were four tasks within this project: (1) project management, (2) reactor design furtherance, (3) fuel development, and (4) Nuclear Regulatory Commission (NRC) engagement. Detailed reporting during execution of the project was provided by a total of 23 quarterly reports, 42 X-energy technical reports, and voluntary monthly update presentations. Other technical work products include 2 white papers and 2 Topical Report submitted to the Nuclear Regulatory Commission, 15 Potential Inventions documented, 4 patents issued, 3 patents pending, 8 peer reviewed journal articles, and 2 Oak Ridge National Laboratory Technical Manuscripts. All the X Energy milestones/deliverables were met early or on time and are archived in the DOE Office of Nuclear Energy’s Program Information Control System: Nuclear Energy under Fiscal Year 2016, Work Breakdown Structure 2.07 – X-Energy. All other work products are available to DOE upon request.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗