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DOE OSTI2025

Basis for Dose and Reactor Safety Design Criteria for Army Regulation AR 50–7 and DA Pamphlet

This report describes the basis used to develop the radiological dose acceptance and design criteria contained in the draft updates to Army Regulation 50–7 (AR 50–7) Army Reactor Program and its accompanying draft Department of the Army (DA) Pamphlet (PAM), Army Reactor Program Procedures. These criteria will apply to Army nuclear reactors that fall under AR 50–7 and its accompanying DA PAM and ensure alignment with the overall objectives of the Army Reactor Program. The development basis for the radiological dose and design criteria supports a modern, technology-neutral, risk-informed, and performance-based approach to Army regulation of reactors and the demonstration of “adequate protection of the public.” To establish these criteria that support the Army’s unique operational requirements, multiple well-known and well-established standards and their supporting documentation were reviewed to ensure consistency with existing regulatory safety levels, including guidance from U.S. and international sources. These include the U.S. Nuclear Regulatory Commission’s (NRC’s) regulations and policy, the Canadian Nuclear Safety Commission’s (CNSC’s) regulatory documents, the International Atomic Energy Agency’s (IAEA’s) safety standards, as well as industry input that is tailored specifically to advanced microreactors. This report walks through the key definitions and associated references used for these criteria, which are outlined in Section 2.0. Based on these definitions, the dose acceptance criteria were established for various receptors for routine reactor operations (Section 3.2), design basis accidents (Section 3.3), and beyond design basis accidents (Section 3.4). Comparisons of multiple national and international dose limits are provided in these sections. Lastly, Section 4.0 outlines the reactor safety design criteria contained in the draft DA PAM and their associated bases.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2025

FY24 – FY25 Efforts to Revive the ANS-54.8 Liquid Metal Fire Protection in LMR Plants Standard

The current multi-year effort seeks to utilize national laboratory support from Argonne to expedite revival of the ANS-54.8 standard titled “Liquid Metal Fire Protection in LMR Plants.” To achieve that objective, the following tasks were identified: Task 1 involves working directly with ANS to revive the ANS-54.8 Working Group. This was to be accomplished by completing necessary paperwork, submitting that paperwork to ANS for approval, enlisting potential working group members from industry, the NRC, national laboratories, and universities, and organizing and leading Working Group activities. The overall purpose of the Working Group is to develop an updated draft of ANS-54.8 for review and approval by ANS consensus committees, the ANS Standards Board, and certification from ANSI. Task 2 focuses on leveraging historical information and expertise at Argonne related to sodium fire protection systems and strategies. For more than a decade, Argonne has worked on both international and domestic projects related to sodium fire protection system development and evaluation. The goal of this task is to utilize that experience to help inform the ANS-54.8 Working Group on important considerations that may be addressed in an updated draft of ANS-54.8. Task 3 focuses on leveraging Argonne experience in the development of and use of analysis methods and tools for the simulation of sodium fire scenarios and evaluation of the effectiveness of sodium fire protection systems and strategies. For more than a decade, Argonne has recovered, modified, and utilized several historical sodium fire analysis software tools. The goal of this task is to utilize that experience to help inform the ANS-54.8 Working Group of best practices for sodium fire progression analysis that may be addressed in an updated draft of ANS-54.8.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

NASA NTRS1974

Current issues of space law before the United Nations

The United Nations' activities in the area of space law and the accomplishments of the Outer Space Committee are discussed. Two draft conventions, the draft treaty on the moon and the draft treaty on the registration of space objects are considered. Other issues covered include the direct broadcast by satellite, the boundary between air space and outer space, and remote sensing from space.

Hosenball, S. N.↗

NASA NTRS1987

Statistical properties of a cloud ensemble - A numerical study

The statistical properties of cloud ensembles under a specified large-scale environment, such as mass flux by cloud drafts and vertical velocity as well as the condensation and evaporation associated with these cloud drafts, are examined using a three-dimensional numerical cloud ensemble model described by Soong and Ogura (1980) and Tao and Soong (1986). The cloud drafts are classified as active and inactive, and separate contributions to cloud statistics in areas of different cloud activity are then evaluated. The model results compare well with results obtained from aircraft measurements of a well-organized ITCZ rainband that occurred on August 12, 1974, during the Global Atmospheric Research Program's Atlantic Tropical Experiment.

Tao, Wei-Kuo↗

NASA NTRS2012

Lessons Learned in Decadal Planning in Space Science

This summary has been prepared by the workshop rapporteurs as a factual summary of what occurred at the workshop. The planning committee's role was limited to planning and convening the workshop. The views contained in the report are those of individual workshop participants and do not necessarily represent the views of all workshop participants, the planning committee, or the National Research Council. This summary was written using video recordings of the entire workshop proceedings. Speakers attributed in this summary were not asked to review the workshop summary before its release. This workshop summary has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the NRC's Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the summary meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this summary: George Paulikas, The Aerospace Corporation (retired), Marcia Rieke, University of Arizona, Kunio Sayanagi, Hampton University, Marcia Smith, Space and Technology Policy Group, LLC, and Warren Washington, National Center for Atmospheric Research. Although the reviewers listed above have provided many constructive comments and suggestions, they did not see the final draft of the workshop summary before its release. The review of this report was overseen by Kenneth Kellermann, National Radio Astronomy Observatory. Appointed by the NRC, he was responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authors and the institution.

Groswald, Lewis↗

NASA NTRS2013

Plant Habitat Telemetry / Command Interface and E-MIST

Plant Habitat (PH) is an experiment to be taken to the International Space Station (ISS) in 2016. It is critical that ground support computers have the ability to uplink commands to control PH, and that ISS computers have the ability to downlink PH telemetry data to ground support. This necessitates communication software that can send, receive, and process, PH specific commands and telemetry. The objective of the Plant Habitat Telemetry/ Command Interface is to provide this communication software, and to couple it with an intuitive Graphical User Interface (GUI). Initial investigation of the project objective led to the decision that code be written in C++ because of its compatibility with existing source code infrastructures and robustness. Further investigation led to a determination that multiple Ethernet packet structures would need to be created to effectively transmit data. Setting a standard for packet structures would allow us to distinguish these packets that would range from command type packets to sub categories of telemetry packets. In order to handle this range of packet types, the conclusion was made to take an object-oriented programming approach which complemented our decision to use the C++ programming language. In addition, extensive utilization of port programming concepts was required to implement the core functionality of the communication software. Also, a concrete understanding of a packet processing software was required in order to put aU the components of ISS-to-Ground Support Equipment (GSE) communication together and complete the objective. A second project discussed in this paper is Exposing Microbes to the Stratosphere (EMIST). This project exposes microbes into the stratosphere to observe how they are impacted by atmospheric effects. This paper focuses on the electrical and software expectations of the project, specifically drafting the printed circuit board, and programming the on-board sensors. The Eagle Computer-Aided Drafting (CAD) software was used to draft the E-MIST circuit. This required several component libraries to be created. Coding the sensors and obtaining sensor data involved using the Arduino Uno developmental board and coding language, and properly wiring peripheral sensors to the microcontroller (the central control unit of the experiment).

Walker, Uriae M.↗

NASA NTRS2014

Ontology Engineering in Provenance Enablement for the National Climate Assessment

The National Climate Assessment of the U.S. Global Change Research Program (USGCRP) analyzes and presents the impacts of climate change on the United States. The provenance information in the assessment is important because the assessment findings are of great public and academic concern and are used in policy and decision-making. By applying a use case-driven iterative methodology, we developed information models and ontology to represent the content structure of the recent National Climate Assessment draft report and its associated provenance information. We tested the ontology by using it in pilot systems serving information about instances of chapters, scientific findings, figures, tables, images, datasets, references, people, and organizations, etc. in the draft report, as well as interrelationships among those instances. The results successfully help users trace provenance in the draft report, such as finding all the journal articles from which a figure in the report was derived. The provenance information in our work was maintained in the context of the "Web of Data". In addition to the pilot systems we developed, other tools and services are also able to retrieve and utilize the provenance information. Our work is part of a Global Change Information System coordinated by the USGCRP that will eventually cover provenance information for the entire scope of global change research. Such a system will greatly increase understanding, credibility and trust in the global change research and foster reproducibility of scientific results and conclusions.

Ontology engineering↗

NASA NTRS2015

Analysis of UAS DAA Alerting in Fast-Time Simulations without DAA Mitigation

Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of performance standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements for DAA alerting system performance. A recent study conducted using NASA's ACES (Airspace Concept Evaluation System) simulation capability begins to address questions surrounding the development of draft MOPS for DAA alerting systems. ACES simulations were conducted to study the performance of alerting systems proposed by the SC-228 DAA Alerting sub-group. Analysis included but was not limited to: 1) correct alert (and timeliness), 2) false alert (and severity and duration), 3) missed alert, and 4) probability of an alert type at the time of loss of well clear. The performance of DAA alerting systems when using intent vs. dead-reckoning for UAS ownship trajectories was also compared. The results will be used by SC-228 to inform decisions about the surveillance standards of UAS DAA systems and future requirements development and validation efforts.

alerting↗

NASA NTRS2015

Analysis of UAS DAA Surveillance in Fast-Time Simulations without DAA Mitigation

Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of performance standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements for DAA surveillance system performance. A recent study conducted using NASA's ACES (Airspace Concept Evaluation System) simulation capability begins to address questions surrounding the development of draft MOPS for DAA surveillance systems. ACES simulations were conducted to study the performance of sensor systems proposed by the SC-228 DAA Surveillance sub-group. Analysis included but was not limited to: 1) number of intruders (both IFR and VFR) detected by all sensors as a function of UAS flight time, 2) number of intruders (both IFR and VFR) detected by radar alone as a function of UAS flight time, and 3) number of VFR intruders detected by all sensors as a function of UAS flight time. The results will be used by SC-228 to inform decisions about the surveillance standards of UAS DAA systems and future requirements development and validation efforts.

unmanned aircraft systems↗

NASA NTRS2014

ACES Study of DAA-Mitigated UAS Operations SC-228 Requirements Sub Group

Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of performance standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements as well as the safety substantiation and end-to-end assessment of DAA system performance. A recent study conducted using NASA's ACES (Airspace Concept Evaluation System) simulation capability begins to address questions surrounding the development of draft MOPS for DAA systems by assessing DAA performance in a NAS-wide context. ACES analyses were conducted to determine the impact of varying elements of UAS pilot performance and uncertainty mitigations on DAA system performance. Simulations were conducted with recorded cooperative and non-cooperative VFR (Visual Flight Rules) traffic to accurately model UAS encounters with other NAS traffic (ATC (Air Traffic Control) being responsible for separation with other IFR (Instrument Flight Rules) aircraft) and with roughly 25, 000 simulated UAS operations The number of Loss of Well Clear (LoWC) events were recorded across the range of independent variables: pilot response time, horizontal LoWC prediction buffer and horizontal LoWC resolution buffer. The number of LoWC events was compared to the unmitigated case (without the benefit of a DAA system) to determine the resultant risk-ratio for each of 8 simulation conditions. The parameter trades presented by the resultant DAA system performance (risk ratio) will be used by SC 228 to inform decisions about future requirements development and validation efforts.

Detect-and-Avoid↗

NASA NTRS2014

Airspace Safety Threshold Study: Status Update to SC-228 DAA Safety Sub-Group

Risk ratio↗

DOE OSTI2019

Development of a Technical Standard for Radiological Characterization of DAW - 19552

Since the Manhattan Project, the U.S. Department of Energy (DOE) and its predecessor agencies have performed a wide mission involving nuclear materials and weapons development, production, testing, and modernization. While the initial mission components relied heavily upon reactor physics and chemistry, the environmental programs have increasingly relied upon development of more accurate and effective measurement methodologies to determine the radiological and chemical properties of the unique waste streams that were generated during the weapons production and testing mission. During the ongoing site cleanup program, the DOE laboratories and former production sites have developed a wide range of site-specific processes and procedures for conducting radiological characterization of dry active waste (DAW) that is managed as low-level radioactive waste. This has resulted in a Complex-wide variability among sites with respect to the methodologies and instrumentation used to characterize individual waste streams. The DAW-type waste was selected for development of a characterization standard since it is a simple, voluminous, and repetitive waste stream with a substantial knowledge base, established experience history at multiple site locations, and the potential for realization of programmatic benefits though standardization. Implementation of a consistent, standardized approach to DAW characterization will take advantage of multiple applications for a technology that is both mature and stable. The DAW characterization process is repetitive and lends itself to implementation at a wide range of operating locations - resulting in economies of scale, compliance with regulatory requirements, and consistent implementation of procedures which support design, operations, maintenance, and management of facilities, activities and environmental restoration programs. In response to a request from DOE, the Energy Facility Contractors Group (EFCOG) Waste Management Working Group (WMWG) is supporting the development of a new DOE Technical Standard for Radiological Characterization of DAW. The purpose of the proposed new standard is to provide a technical resource that integrates and enhances the utilization of current site-specific methodologies and processes. An EFCOG/WMWG technical team has prepared a Technical Basis Document (TBD) to support the development and utilization of the new standard. The TBD provides detailed reference information for use by site personnel when implementing the guidance to be provided in the standard. It also provides the rationale for and details concerning the recommended technical approaches for radiological characterization of representative DAW-type waste streams. The TBD is an essential resource and will be included as an appendix to the proposed standard. Formulation of the new standard will draw upon the information contained in the TBD in order to integrate and improve the utilization of current site-specific methodologies and processes. It will also include a comparison of current radiological characterization methodologies to determine which ones are most reliable and effective in producing relevant and valid data. In view of the long history and participation by several agencies in the regulation of nuclear programs, existing Voluntary Consensus Standards have also been identified in the TBD and will be referenced for relevancy and applicability to the new proposed standard. A Project Justification Statement (PJS) was also developed by the EFCOG/WMWG Team. Following internal Team review and approval by EFCOG, the draft PJS was submitted through Argonne National Laboratory (ANL) and the DOE Argonne Site Office Technical Standards Managers for review and approval by the DOE Argonne Site Office Manager. After resolution of comments and approval by the Manager, the PJS will be submitted to the DOE/HQ Technical Standards Program Manager (TSPM) for formal coordination. Following resolution of technical comments received during the PJS coordination process and receipt of a technical standards project number assigned by the TSPM, the Team will confirm the overall preparation schedule and develop an Internal Draft Technical Standard for coordination with the DOE Argonne Site Office. Following comment resolution, the Team will then prepare a Coordination Draft for submittal to the DOE Technical Standards RevCom review process and will respond to comments generated during this Complex-wide review. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2020

Expedited Walkdowns and Preparation of Cost Estimates for Decontamination and Demolition of Excess Facilities - 20335

Lawrence Livermore National Security, LLC (LLNS) is the prime contractor responsible for managing and operating Lawrence Livermore National Laboratory (LLNL). The mission of the LLNL is to strengthen security of the United States through development and application of world-class science and technology to enhance the nation's defense, reduce the global threat from terrorism and weapons of mass destruction, and respond with vision, quality, integrity, and technical excellence to scientific issues of national importance. To accomplish its mission, LLNL must plan and manage its campus space and facilities to optimize use of its relatively small one-square-mile footprint. LLNL currently has numerous excess facilities that require decontamination and demolition (D and D). The LLNL Legacy Facility Program is responsible for stewardship and risk reduction programs to effectively manage these excess assets at LLNL. The Legacy Facility Program identified 10 excess facilities at LLNL that were candidates for demolition based on risks from further degradation of the facilities, potential exposure to hazardous materials, or need for removal to make way for new program facilities. The buildings range from a structure built in 1943 to serve as a US Navy drill hall during World War II, to a facility that provided neutrons to study material properties for the fusion energy program. The National Nuclear Security Administration (NNSA) appropriated FY19 funding for the development of Class 3 estimates for these 10 excess facilities that would be used to develop a Program Management Plan for funding consideration. Class 3 estimates are not conceptual, nor overly detailed, but adequate to be used for budget and appropriation purposes. Using existing strategic sourcing agreements, LLNL was able to organize a team of senior subject matter experts (SMEs) with diverse technical backgrounds across the Department of Energy (DOE) Complex to complete extensive process knowledge (PK) reviews and walk-downs of each excess facility and to deliver accurate and complete estimates under an expedited schedule (i.e., within eight weeks). To facilitate the expedited schedule, LLNL was fully prepared for the arrival of the JGMS team, which consisted of the following companies: J.G. Management Systems, Inc. (JGMS); Strata-G, LLC; and Michael Baker International. LLNL provided background and PK information on the excess facilities, pictures, supporting historical documentation, and radiological survey history as well as escorted access to the facilities. The JGMS team has previous experience supporting Program Management Plans for excess facilities at the Y-12 National Security Complex. The team mobilized to LLNL and performed the facility walk-downs from January 22-25, 2019. Using a methodical evaluation process, expertise, and experience, the team was able to deliver walk-down draft reports and estimates to LLNL before their February 8, 2019 deadline. LLNL then in turn reviewed, completed the estimates by adding waste management costs and other LLNL costs, and delivered the estimates to NNSA by February 15, 2019. The completed final reports, including draft D and D estimates, were delivered to LLNL before their March 6, 2019 deadline. The work was successfully completed ahead of the expedited schedule required by LLNL, resulting in a commendation from the client. This paper describes how the partnership and collaboration as a fully integrated team comprised of the prime contractor, LLNS, and the JGMS team successfully met the needs of the US government, resulting in the performance of expedited site walk-downs, the development of summary evaluation reports, and the preparation of draft Class 3 estimates and preliminary schedules for the D and D of 10 excess facilities at LLNL. The efforts of the team will enable the D and D of the first excess facility in the 2020-2021 time frame. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

Cooling efficiency of a spot-type personalized air-conditioner

Here, this study defined Cooling Efficiency ( CE ) of a Spot-type Personalized Air-Conditioning (SPAC) device as the ratio of the additional sensible heat removal from human body induced by SPAC and the device's cooling capacity. CE enabled the investigation of SPAC performance on the occupant's sensible heat loss (Q s ) and thermal sensation by its quantitative relation with the change of PMV level ( ΔPMV ). Three round nozzles with the diameter of 0.08 m, 0.105 m, and 0.128 m, respectively, discharged air jets at airflow rates from 11.8 L s –1 to 59.0 L s –1 , toward the chest of a seated or standing human body with a clothing of 0.48 clo. This study developed a validated CFD model coupled with the Fanger's thermoregulation model, to calculate Q s in a room of 26 °C ventilated at a rate of 3 ACH. According to the results, Q s , CE and draft risk ( DR ) at face had significant positive linear correlation with the SPAC device's supply airflow rates (R2 >0.96), and a negative linear correlation for ΔPMV. With DR = 20% at face, CE was always under 0.3, and ΔPMV was around -1.0–1.1. Interestingly, both CE and ΔPMV had the least favorable values for the air jet produced by the nozzle with the diameter of 0.105 m independent of body posture. In conclusion, although SPAC could lead to additional Q s by sending air at a higher airflow rate from a smaller nozzle, the improvement in cooling efficiency and thermal sensation had a limit due to draft risk.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2024

OpenFAST Modeling of the T-Omega Wind Floating Offshore Wind Turbine System

To reduce the cost of offshore wind energy through a more efficient design of the floating support structure, T-Omega Wind developed a novel lightweight and shallow-draft platform concept that aims to achieve a wave-following behavior without resonance amplification. The rotor and generator are carried by four tower legs with each leg supported by a shallow-draft float at the base. In preparation for a more detailed analysis, a coupled aero-hydro-elastic model of the proposed concept is developed in OpenFAST. The detailed modeling approach is presented, including a novel application of the SubDyn substructure dynamics module of OpenFAST to approximate the loads on the axle tube at the tower top from the rotor hub bearings. Preliminary results obtained with the OpenFAST model by rigidifying the substructure and blades indicate that the original sizing of the design can lead to large hub acceleration in the axial/surge and pitch directions due to platform-pitch motion. The high axial acceleration also potentially leads to large bending moments in the four tower legs. To address these issues, an updated design is developed with, among other changes, increased float spacing at the tower base and improved shear-transmitting geometry of the tower legs. The new design suggests significantly reduced extreme hub accelerations under the same conditions even with structural flexibility and will be further analyzed in the future through full aero-hydro-servo-elastic simulations.

FOWT↗

DOE OSTI2016

Berkeley Lighting Cone

A lighting cone is a simple metal cone placed on the fuel bed of a stove during ignition to act as a chimney, increasing the draft through the fuel bed. Many stoves tend to be difficult to light due to poor draft through the fuel bed, so lighting cones are used in various parts of the world as an inexpensive accessory to help with ignition.

42 ENGINEERING↗

DOE OSTI2024

OpenFAST Modeling of the T-Omega Wind Floating Offshore Wind Turbine System

ENGINEERING,WIND ENERGY↗

DOE OSTI2024

OpenFAST Modeling of the T-Omega Wind Floating Offshore Wind Turbine System: Preprint

To reduce the cost of offshore wind energy through a more efficient design of the floating support structure, T-Omega Wind developed a novel lightweight and shallow-draft platform concept that aims to achieve a wave-following behavior without resonance amplification. The rotor and generator are carried by four tower legs with each leg supported by a shallow-draft float at the base. In preparation for a more detailed analysis, a coupled aero-hydro-elastic model of the proposed concept is developed in OpenFAST. The detailed modeling approach is presented, including a novel application of the SubDyn substructure dynamics module of OpenFAST to approximate the loads on the axle tube at the tower top from the rotor hub bearings. Preliminary results obtained with the OpenFAST model by rigidifying the substructure and blades indicate that the original sizing of the design can lead to large hub acceleration in the axial/surge direction and in the pitch direction due to platform-pitch motion. The high hub acceleration also potentially leads to large bending moments in the four tower legs. To address the issue identified, an updated design is developed with, among other changes, increased float spacing at the tower base and improved geometry of the tower legs. The new design suggests significantly reduced extreme platform pitch angles under the same conditions and will be further analyzed in the future through full aero-hydro-servo-elastic simulations.

FOWT↗