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DOE OSTI2020

Oak Ridge National Laboratory Technical Input for the Nuclear Regulatory Commission Review of the 2017 Edition of ASME Section III, Division 5, ‘High Temperature Reactors’

To assist the Nuclear Regulatory Commission in its decision making on endorsement of the American Society for Mechanical Engineers Boiler and Pressure Vessel Code Section III, Division 5 (2017 Edition) for development of advanced non-light water reactors, the following Division 5 portions were reviewed: Article HBB-2000 Material; Article HCB-2000 Material; Article HGB-2000 Material; Mandatory Appendix HBB-I-14 Tables and Figures; and, Nonmandatory Appendix HBB-U Guidelines for Restricted Material Specifications to Improve Performance in Certain Service Applications. In addition to the 2017 Edition, the same parts of the 2019 Edition have also been reviewed as indicated in various sections of the report. This review was conducted by a collaboration of national laboratory and private sector participants with significant industrial experience, including some heavy lifting and deep diving from Clarus Consulting, LLC., all intended to achieve an objective, independent, and practical perspective. The report provides recommendations, descriptions of the evaluation methods, and the source references for the data used. To build confidence required for endorsement of the Code, this review was conducted as a verification and validation of the above Code contents. The objective of verification is to ensure that the Code is free of error – direct or implied; contains the information needed for its use, including proper coverage of the Code-specified materials for the intended application, and completeness and adequacy of references to other portions of the Code. The objective of validation is to authenticate that the Code tabulations and graphs represent design inputs consistent with what are determined using rules and methods specified by the Code. The authentication process used data that were assembled and/or generated independent of Code development, while the methods of analysis followed Code-specified methods where appropriate. The designated portions for this review cover the five alloys codified for high temperature reactor applications in Division 5, i.e. 316 SS, 304 SS, 800H, 2¼Cr-1Mo, and 9Cr-1Mo-V, regarding their general requirements, permitted specifications and design stress intensity values for pressure-retaining applications, deterioration in service, fatigue acceptance test, permissible weld materials, tensile and yield strength, expected minimum stress-to-rupture values (including for Alloy 718), weld stress rupture factors, permissible materials for bolting use, and restricted specifications in certain service applications. Additionally, stress intensity values for bolting materials including 316 SS, 304 SS and alloy 718 were reviewed. Analysis and discussion are also provided on contents outside of these designated Code portions where it was deemed relevant and necessary to develop a technically sound understanding of issues relating to the designated portions. Due to unavailability of sufficient test data on welds during the review period, the weld stress rupture factors in Tables HBB-I-10.14A to E, which cover a total of ten tables for the five alloys welded with twenty-eight different weld metals (some with similar properties), have been deferred to a future review effort. The review identified mainly two types of issues. The first type includes instances where the Code is found factually incomplete or incorrect, such as obsolete materials specifications listings, missing tabulation of stresses for bolting. Changes to the Code are recommended in these cases. The second type of issue includes instances where the Code tabulations and graphs are found to be less conservative than the review analysis results. In these cases, recommendations are made for further review and consideration where the difference in conservatism exceeds 10%, which is our threshold for questioning technical adequacy, meriting a risk assessment by the Nuclear Regulatory Commission and/or reactor designers. It is noted that this effort has been executed using all available data and established methods of analysis, including methods and criteria specified and used by the Code. As such, the findings that are presented in quantitative detail, in a format for convenient comparison with the Code, and with identification of where further review is recommended, should provide a sound technical basis for decisions about quantifying the implications of the reduced design margins and technical adequacy/inadequacy to form a basis for conditioning specific Code tabulation values on endorsement. Recommendations for specific changes to the Code, however, entail design conservatism considerations beyond the scope of this review effort, and are not made in this report.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Evaluation of the Los Alamos Nuclear Material Packaging Risk Ranking Method

Repackaging nuclear material into robust containers to protect workers and the public has been ongoing at LANL and around the DOE complex for nearly two decades. The number of containers at LANL is around 5,000; limited resources for repackaging material has led to extended repackaging campaigns and the need to prioritize repackaging. Various methodologies have been used to prioritize the repackaging efforts and to demonstrate progress in risk reduction over time (e.g., Boerigter, 1997). The 2000-1 DNFSB recommendation recognized the limited DOE resources for repackaging, and acknowledged the need to “prioritize and schedule tasks to be undertaken with available funds according to consideration of risks.” Later, in DNFSB recommendation 2005-1, in addition to recommending that DOE develop a packaging standard, the Board recommended that “Characterization information should also be used to develop a surveillance program prioritized according to expected material and container risk (including, for example, material type, material form, and the age and type of container).” In response to requests and recommendations from the DOE and DNSFB to prioritize according to worker risk, a risk ranking method based on the potential consequence of dropping a container from 3 meters was developed in 2007 (Smith, 2007) and updated in 2014 (Hoffman, 2014). Various LANL implementation plans for repackaging were developed over the years using this methodology (Stone, 2014). Currently, this method is utilized in conjunction with an algorithm to mitigate programmatic risk to prioritize container repackaging and material processing (Prochnow, 2015). The purpose of this study is to document how the current risk ranking method works, how it is used and potential limitations.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2023

Computationally Guided Design of Multiple Impurities Tolerant Electrode (Final Report)

The current project was based on a combined experimental and computational approach, which can help recommend better cathode materials under multiple impurities conditions. The PI will mainly take in charge of experimental and computational thermodynamics of the selected cathode materials for the SOFC applications under multiple impurities. While the co-PI will run the electrochemical tests of the cathodes recommended and eventually the long-term degradation tests. At the end of the project, a multiple tolerant cathode material based on the combined experimental and computational approach will be recommended and the reliability of the commonly used accelerated testing will be evaluated. It will address multiple impurities poisoning effect of SO2, CO2, Cr and H2O on the LSM, LSCF and LNO cathodes by identifying the formation of the detrimental secondary phases by XRD, SEM and TEM techniques. And further recommended cathode material will be subjected to electrochemical testing and the most promising ones will be applied to long-term tests. The hybrid approach the PI proposed will not only be applied to the design of multiple impurities tolerant cathodes but will also be considered in the future oxygen electrode applications in SOECs or reversible SOCs. This hybrid computational and experimental approach includes four sections: 1) Investigation of single impurity poisoning on LSM, LSCF and LNO cathodes in the presence of SO2, CO2, Cr. In this section, LSM, LSCF cathodes from FuelCellMaterials and LNO cathodes from Sol-Gel synthesis will be heat-treated in the above single impurity. And the formation of the secondary phases as well as the corresponding simulations will be cross compared, which shows good agreement between each other. Meanwhile, the accelerated testing approach will be evaluated in these systems compared with the previous published work to understand the reliability of the approach. 2) Investigation of multiple impurities poisoning on LSM, LSCF and LNO cathodes in the presence of Cr+H2O, SO2+Cr and SO2+Cr+H2O conditions. We have also applied these 3 candidate cathodes under these multiple impurities’ conditions and the long-term degradation mechanism of the multiple impurities will be understood with the help of the combined experimental and computational approach. Meanwhile, the synergistic effect of those impurities will be compared with the individual ones in the same cathode system to further reveal the actual operating conditions. 3) Electrochemical testing and polarization of the recommended cathode. We have demonstrated very low polarization resistance in LSCF (core)-LSM (shell) electrodes using MSD process and analyzed impedance spectra using DRT analysis and confirming that the low polarization resistance in LSM infiltrated MSD cells is due to reduction in polarization resistance associated with O2-adsorption process. 4). Long-term degradation testing. We have developed a versatile MSD-based process to deposit various continuous coatings onto porous scaffolds and established baseline for longer term Cr-impurity testing in future projects.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Illustration of bunch merge simulation in RHIC

Following are examples of a 4 to 2 to 1 merge of proton bunches in RHIC obtained by running the simulation code rhic2mrg23. As the code runs, the user is prompted to enter several numbers. For these examples, RF harmonic number 1440.0 is entered. An RF frequency of 112.597 696 626 MHz at this harmonic is entered. This gives a proton energy of 100 GeV. The merge simulation starts with a uniform distribution of unbunched protons. 2.0 eV-s is entered for the longitudinal emittance of the distribution. The code will recommend a voltage to capture the unbunched protons into 4 harmonic 1440 buckets. A capture voltage of 142.390 kV is recommended. 144.0 kV is entered. It is desirable to capture the protons as “adiabatically” as possible. A capture time of 3318 ms is recommended by the code. 3320.0 ms is entered. A 4 to 2 merge time of 1659 ms is recommended by the code. 1660.0 ms is entered. A 2 to 1 merge time twice that of the 4 to 2 merge is recommended by the code. 3320.0 ms is entered. The code requests a “time fraction” FQMRG to be entered. This is a number (from 0.1 to 1.0) that determines the time at which data are recorded during the 4 to 2 merge. The number 0.5 is entered. This encodes the recording of data halfway through the 4 to 2 merge.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Illustration of bunch merge simulation in AGS

Following are examples of a 4 to 2 to 1 merge of proton bunches in AGS obtained by running the simulation code ags2mrg23. As the code runs, the user is prompted to enter several numbers. For these examples, RF harmonic number 12.0 is entered. An RF frequency of 4.453 913 448 73 MHz at this harmonic is entered. This gives proton G γ = 45.5. The merge simulation starts with a uniform distribution of unbunched protons. 2.0 eV-s is entered for the longitudinal emittance of the distribution. The code will recommend a voltage to capture the unbunched protons into 4 harmonic 12 buckets. A capture voltage of 0.0527 kV is recommended. 0.053 kV is entered. It is desirable to capture the protons as “adiabatically” as possible. Because of the long synchrotron period (372 ms), a capture time of 74,707 ms is recommended by the code. A shorter time, 10,000 ms, is entered to reduce the running time of the code. A 4 to 2 merge time of 37,353 ms is recommended by the code. 4000.0 ms is entered. A 2 to 1 merge time twice that of the 4 to 2 merge is recommended by the code. 8000.0 ms is entered. The code requests a “time fraction” FQMRG to be entered. This is a number (from 0.1 to 1.0) that determines the time at which data are recorded during the 4 to 2 merge. The number 0.5 is entered. This encodes the recording of data halfway through the 4 to 2 merge.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Quality Assessment of Molten Salt Thermochemical Property Data

Recommendations are made to enhance user confidence in property values included in the Molten Salt Thermal Database-Thermochemical Properties (MSTDB-TC). Specifically, it is recommended that all available measured values be included with a transparent assessment of each to arrive at a preferred value for each salt composition in the database. The use of a quality assessment and ranking system is recommended for data and property values compiled in the MSTDB-TC that is analogous to the approach developed for data and property values included in the MSTDB-Thermophysical Properties (TP) database. The approach includes assessments of five features of data collection: the method used to measure the property value, calibration of devices used to make the measurements, the quantified uncertainty of the results, control of the environmental conditions, and determination of the salt composition. The quality of each facet is ranked as High, Moderate, or Incomplete based on objective metrics. The overall quality of the dataset is ranked based on rankings of the five data features and traceability of the reported property value, with rankings of A and B indicating the data and property value are deemed suitable for quantitative use, C indicating the value is computed and not validated and U indicating uncertainties restrict the recommended use to qualitative purposes. Sufficient information should be provided or cited within each data set included in the database to verify the reported property value. The recommended approach is suitable for assessing data already in the MSTDB-TC and screening new entries.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

Comparing Occupant Light Exposure in Factory and Office Spaces

There is an increasing desire to provide healthy workplace environments that better serve people while minimizing the impact on the planet. Building recommendations help designers to incorporate the latest research and best practices, but translating research studies conducted in different settings to broader recommendations is challenging. This is particularly true for lighting, with researchers continuing to learn more about circadian, neuroendocrine, and neurobehavioral responses to light. The recommendations are regularly adjusting to incorporate the latest research as well as feedback from practitioners implementing these recommendations. There remains a need to better document the actual light exposure that people experience over the course of a day and across seasons, so that researchers can better understand the influence of light on people and recommendations can be refined. Thankfully, advances in sensor technology are making this more possible than ever. PNNL collaborated with ETC Inc. to understand actual occupant light exposure in factory and office spaces at ETC’s Headquarters in Middleton, WI. The primary building at ETC headquarters opened in 2004 and houses approximately 800 employees that contribute to central business functions, customer support, research and development, as well as the company’s primary 60,000 ft2 manufacturing facility. Vertical light exposure measurements including electric light and daylight were recorded in factory, research and development, and office work areas at occupant eye height. This document will focus on lighting measurements collected in six factory and office locations across work location, season, and time of day. Ultimately, detailed lighting measurements can be coupled with employee surveys to support development of satisfactory work environments.

42 ENGINEERING↗
NASA NTRS1975

CARETS: A prototype regional environmental information system. Volume 3: Toward a national land use information system

It is recommended that a national land use information system be established by an agency of the Federal Government. This recommendation comes at a time of increasing demand for scientific information in support of environmentally relevant land use planning and management at all levels of government. It is also a time when new airborne and spaceborne remote sensors, tested in cooperation with the National Aeronautics and Space Administration (NASA) and the Earth Resources Observation Systems (EROS) Program of the Department of the Interior, make possible the gathering of land use information rapidly and on an unprecedented scale. Furthermore, information handling technology is developing toward a capability to receive, store, and disseminate the huge quantities of data that would be involved. The recommendation for the national land use information system is based upon careful analysis of the results of remote sensing experiments funded by NASA, EROS, and the Geography Program of the Geological Survey, with specific examples drawn from the demonstration project known as the Central Atlantic Regional Ecological Test Site (CARETS). CARETS is cast in the framework of a regional land use information system, channeling the flow bf information generated in response to users' declaration of their needs, through stages dealing with remote sensing data gathering systems, data processing and land mensuration, calibration in-terms of environmental impact, and evaluation with feedback from users. The proposed system would develop and implement a unified approach to the description and interpretation of the changing uses of the nation's land resources, building upon the base of interagency and intergovernmental cooperation already achieved in the experimental work to date. The land use data base that is being derived from high-altitude aerial color infrared photography would be the initial component of the recommended system. High-altitude photographic coverage would immediately be extended to as much of the nation as possible as technological developments and economic considerations permit. The system would later expand to include multiple-sensor, multiple-platform data sources. Six system characteristics are recommended: (1) High capacity storage of data available for quick retrieval, inexpensive processing, and update, (2) provision of accuracy appropriate to the scale of survey or to the level of detail dictated by different types of management and decision requirements; (3) permanent, publicly accessible sensor records for historical interpretation; (4) compatibility of the recording, storage, and retrieval system with all types of inputs, from ground observer to satellite; (5) products of diverse formats and scales, responsive to user feedback; (6) and standardization of formats, scales, and storage inputs to permit nationwide comparability.

Land use mapping↗
NASA NTRS1992

Electron beam fluorescence measurements in the Boeing hypersonic shock tunnel

The Calspan electron beam fluorescence (EBF) measurement system is described along with the results of measurements made in hypersonic flow. Numerous self-emitting metallic species were identified, many of which may be associated with an aging/erosion process within the B30HST. Because there were only 16 tunnel runs, it was only possible to obtain spectral measurements over a limited range of wavelengths and time sampling periods. Many spectral features of the flow remain uninvestigated. Because flow self-emission is important to all optical diagnostic techniques, it is recommended that additional spectral studies by performed. The three electron beam-excited species that were identified are nitrogen, helium, and nitric oxide. The high metallic radiation background interfered with attempts to obtain the time-wise variation of N2 density and He radiation with the optical fiber/PMT channels. In the case of the N2 density measurements the result of interference was increased uncertainty. Unfortunately, the interference caused the time-wise He measurements to fail completely. It is recommended that the electron beam be modulated to provide discrimination against the background radiation in future N2 density measurements. Careful data reduction produced useful measurements of N2 vibrational temperature, even though the high background from metallic species significantly increased measurement uncertainty. Perhaps the recommended additional spectral studies would reveal N2(+) First Negative System band-pair regions having less background. Detection of the He arrival was easily accomplished with the spectrometer/array detector system. Because of this, it is recommended that this means of detecting He arrival be used in the future. With proper calibrations of the system an He number density could be obtained. Although the flow conditions were out of limits for the run in which the NO spectrum was recorded, the usefulness of the NO spectrum for determination of free-stream rotational temperature was demonstrated and should be exploited in future experiments. Indeed, based on the strong NO signals, it is recommended that lower resolution NO spectra be obtained to provide a measure of NO vibrational temperature in the same manner that the N2 temperature was obtained.

Price, Linwood L.↗
NASA NTRS1990

Ultraviolet, visible, and gravity astrophysics: A plan for the 1990's

NASA's Office of Space Science and Applications (OSSA) receives advice on scientific strategy and priorities from the U.S. National Academy of Sciences. Guidance to the OSSA Astrophysics Division, in particular, is provided by dedicated academy committees, ad hoc study groups, and, at ten-year intervals, by broadly mandated astronomy and astrophysics survey committees charged with making recommendations for the coming decade. Many of the academy's recommendations have important implications for the conduct of ultraviolet and visible-light astronomy from space. Moreover, these areas are now poised for an era of rapid growth. Through technological progress, ultraviolet astronomy has already risen from a novel observational technique four decades ago to the mainstream of astronomical research today. Recent developments in space technology and instrumentation have the potential to generate comparably dramatic strides in observational astronomy within the next ten years. In 1989, the Ultraviolet and Visible Astrophysics Branch of the OSSA Astrophysics Division recognized the need for a new, long-range plan that would implement the academy's recommendations in a way that yielded the most advantageous use of new technology. NASA's Ultraviolet, Visible, and Gravity Astrophysics Management Operations Working Group was asked to develop such a plan for the 1990's. Since the branch holds programmatic responsibility for space research in gravitational physics and relativity, as well as for ultraviolet and visible-light astrophysics, missions in those areas were also included. The working group met throughout 1989 and 1990 to survey current astrophysical problems, assess the potential of new technologies, examine prior academy recommendations, and develop the implementation plan. The present report is the product of those deliberations. Key astrophysical questions to be addressed cover topics such as the structure and evolution of the early universe, energetics of active galactic nuclei, stellar winds in massive stars, sources powered by accretion, composition and state of the interstellar medium, nature of the galactic halo, chromospheric activity in cool stars, and formation of stars and planetary systems. This document provides a review of these questions, program concerns, and the recommended implementation plan for the 1990's.

Source record↗
NASA NTRS1992

Future manned systems advanced avionics study

COTS+ was defined in this study as commercial off-the-shelf (COTS) products, ruggedized and militarized components, and COTS technology. This study cites the benefits of integrating COTS+ in space, postulates a COTS+ integration methodology, and develops requirements and an architecture to achieve integration. Developmental needs and concerns were identified throughout the study; these needs, concerns, and recommendations relative to their abatement are subsequently presented for further action and study. The COTS+ concept appears workable in part or in totality. No COTS+ technology gaps were identified; however, radiation tolerance was cited as a concern, and the deferred maintenance issue resurfaced. Further study is recommended to explore COTS+ cost-effectiveness, maintenance philosophy, needs, concerns, and utility metrics. The generation of a development plan to further investigate and integrate COTS+ technology is recommended. A COTS+ transitional integration program is recommended. Sponsoring and establishing technology maturation programs and COTS+ engineering and standards committees are deemed necessary and are recommended for furthering COTS+ integration in space.

Sawamura, Bob↗
NASA NTRS1998

Aerospace Safety Advisory Panel

During 1997, the Aerospace Safety Advisory Panel (ASAP) continued its safety reviews of NASA's human space flight and aeronautics programs. Efforts were focused on those areas that the Panel believed held the greatest potential to impact safety. Continuing safe Space Shuttle operations and progress in the manufacture and testing of primary components for the International Space Station (ISS) were noteworthy. The Panel has continued to monitor the safety implications of the transition of Space Shuttle operations to the United Space Alliance (USA). One area being watched closely relates to the staffing levels and skill mix in both NASA and USA. Therefore, a section of this report is devoted to personnel and other related issues that are a result of this change in NASA's way of doing business for the Space Shuttle. Attention will continue to be paid to this important topic in subsequent reports. Even though the Panel's activities for 1997 were extensive, fewer specific recommendations were formulated than has been the case in recent years. This is indicative of the current generally good state of safety of NASA programs. The Panel does, however, have several longer term concerns that have yet to develop to the level of a specific recommendation. These are covered in the introductory material for each topic area in Section 11. In another departure from past submissions, this report does not contain individual findings and recommendations for the aeronautics programs. While the Panel devoted its usual efforts to examining NASA's aeronautic centers and programs, no specific recommendations were identified for inclusion in this report. In lieu of recommendations, a summary of the Panel's observations of NASA's safety efforts in aeronautics and future Panel areas of emphasis is provided. With profound sadness the Panel notes the passing of our Chairman, Paul M. Johnstone, on December 17, 1997, and our Staff Assistant, Ms. Patricia M. Harman, on October 5, 1997. Other changes to the Panel composition during the past year were: the resignation of Mr. Dennis E. Fitch as a Consultant; the appointment of Mr. Roger D. Schaufele as a Consultant; and the assignment of Ms. Susan M. Smith as Staff Assistant.

Source record↗
NASA NTRS2002

Human Factors Process Task Analysis Liquid Oxygen Pump Acceptance Test Procedure for the Advanced Technology Development Center

A process task analysis effort was undertaken by Dynacs Inc. commencing in June 2002 under contract from NASA YA-D6. Funding was provided through NASA's Ames Research Center (ARC), Code M/HQ, and Industrial Engineering and Safety (IES). The John F. Kennedy Space Center (KSC) Engineering Development Contract (EDC) Task Order was 5SMA768. The scope of the effort was to conduct a Human Factors Process Failure Modes and Effects Analysis (HF PFMEA) of a hazardous activity and provide recommendations to eliminate or reduce the effects of errors caused by human factors. The Liquid Oxygen (LOX) Pump Acceptance Test Procedure (ATP) was selected for this analysis. The HF PFMEA table (see appendix A) provides an analysis of six major categories evaluated for this study. These categories include Personnel Certification, Test Procedure Format, Test Procedure Safety Controls, Test Article Data, Instrumentation, and Voice Communication. For each specific requirement listed in appendix A, the following topics were addressed: Requirement, Potential Human Error, Performance-Shaping Factors, Potential Effects of the Error, Barriers and Controls, Risk Priority Numbers, and Recommended Actions. This report summarizes findings and gives recommendations as determined by the data contained in appendix A. It also includes a discussion of technology barriers and challenges to performing task analyses, as well as lessons learned. The HF PFMEA table in appendix A recommends the use of accepted and required safety criteria in order to reduce the risk of human error. The items with the highest risk priority numbers should receive the greatest amount of consideration. Implementation of the recommendations will result in a safer operation for all personnel.

Diorio, Kimberly A.↗
NASA NTRS1990

ECLSS Integration Analysis: Advanced ECLSS Subsystem and Instrumentation Technology Study for the Space Exploration Initiative

In his July 1989 space policy speech, President Bush proposed a long range continuing commitment to space exploration and development. Included in his goals were the establishment of permanent lunar and Mars habitats and the development of extended duration space transportation. In both cases, a major issue is the availability of qualified sensor technologies for use in real-time monitoring and control of integrated physical/chemical/biological (p/c/b) Environmental Control and Life Support Systems (ECLSS). The purpose of this study is to determine the most promising instrumentation technologies for future ECLSS applications. The study approach is as follows: 1. Precursor ECLSS Subsystem Technology Trade Study - A database of existing and advanced Atmosphere Revitalization (AR) and Water Recovery and Management (WRM) ECLSS subsystem technologies was created. A trade study was performed to recommend AR and WRM subsystem technologies for future lunar and Mars mission scenarios. The purpose of this trade study was to begin defining future ECLSS instrumentation requirements as a precursor to determining the instrumentation technologies that will be applicable to future ECLS systems. 2. Instrumentation Survey - An instrumentation database of Chemical, Microbial, Conductivity, Humidity, Flowrate, Pressure, and Temperature sensors was created. Each page of the sensor database report contains information for one type of sensor, including a description of the operating principles, specifications, and the reference(s) from which the information was obtained. This section includes a cursory look at the history of instrumentation on U.S. spacecraft. 3. Results and Recommendations - Instrumentation technologies were recommended for further research and optimization based on a consideration of both of the above sections. A sensor or monitor technology was recommended based on its applicability to future ECLS systems, as defined by the ECLSS Trade Study (1), and on whether its characteristics were considered favorable relative to similar instrumentation technologies (competitors), as determined from the Instrumentation Survey (2). The instrumentation technologies recommended by this study show considerable potential for development and promise significant returns if research efforts are invested.

Source record↗
NASA NTRS2007

Finding Uncertainties that Cause the Age Dependence of Dose Limits to Be Immature

Space radiation permissible exposure limits (PEL) are intended to set acceptable levels of cancer risks, and avoid any clinical significant non-cancer effects. The 1989 recommendation of the National Council of Radiation Protection and Measurements (NCRP) recommended a strong age dependence of dose limits that departed drastically from the then mature 1970 dose limits recommendations from the National Academy of Science, which were independent of age. In 2000, the NCRP recommended revised limits that showed a similar trend of risk with age to the 1989 report. In this model, the cancer risk per Sv varies by more than 2-fold for ages between 30- and 50-yr. Therefore for galactic cosmic rays exposure, astronaut age has a larger influence on risk then radiation shielding mass or material composition, vehicle propulsion method, or position in the solar cycle. For considering the control of mission costs and resources, the possibility of using astronaut age as a trade variable in mission design could be considered. However, the uncertainties in describing the age dependence on risk have not been fully explored. We discuss biological factors that influence the age dependence of radiation risks, including susceptibility, expression and latency, and radiation quality. These factors depend not only on the individual s age, but also their genetic sensitivity and interaction with other environmental factors. Epidemiological data is limited in describing the age dependence on risk. The 2005, BEIR VII report recommends an age dependence for cancer risk attributable solely to the life-table disagreeing strongly with the NCRP model. However, BEIR VII also noted the limited power of human data for concomitantly describing both age and age after exposure dependences of cancer risks. Many experimental studies have shown that high LET radiation (e.g., high charge and energy (HZE) nuclei and neutrons) display reduced latency compared to low LET radiation, suggesting distinct biological factors are important. We discuss potential molecular mechanisms that would influence the age dependence of radiation risks. A probability distribution function for the uncertainties in age-dependence of risk models is described and predictions for Mars missions discussed. Our report suggests that theoretical considerations based on new experimental studies are needed to ensure the correct age dependence in space radiation risk models and the resulting Astronaut PEL.

Cucinotta, Francis A.↗
NASA NTRS2008

Issues Regarding the Assimilation of Cloud and Precipitation Data

This is the authors' response to a set of criticisms regarding a previously published work. It briefly addresses the main criticisms. In particular, it explains why some papers identified as having some fundamental flaws were referenced in the original work without detailed exposition of those flaws. It also explains why parts of the conclusion criticized as being contradictory are, in fact, not. It further highlights the need for more publishing of scientific criticisms. In the December 2007, special issue of the Journal of Atmospheric Sciences devoted to the Workshop on Assimilation of Satellite Cloud and Precipitation Observations, the authors published an article summarizing the many critical issues that render observations of cloud and precipitation difficult to analyze. Essentially, these include the inaccuracies of both current instruments and the relationships between what is actually observed (infrared or microwave energy detected at the altitude of the satellite) to what is desired (e.g., estimates of cloud drop sizes or rain rates) and the chaotic nature of atmospheric behavior and the complex mathematics describing it. The paper also included recommendations for future research and brief descriptions of many previous works concerning the subject. One reader is now attempting to publish a criticism of that paper. Her three complaints are that there was insufficient explanation of the identification of some cited works as being fundamentally flawed, that as a review the paper should have referenced some works additional to those it did, and that two recommendations were contradictory. Each of these complaints is addressed briefly in this response. First we explain why a brief list of works cited in our paper were identified as "flawed" with only a brief explanation. The design and conduct of the experiments reported in those papers violate well-established fundamentals such that, once the errors are recognized, their interpretations are no longer supported. Unfortunately, over the years, no researchers have bothered to publish criticisms of those papers, such that there are now too many to address in any single paper not devoted to that purpose. Yet, those papers are so often cited that we could not simply ignore them. Furthermore, if we had cited them without warning our readers regarding their flaws, we would have perpetrated a great disservice. In our response, however, we do offer further explanation of why some details, neglected in these papers, are critical to proper scientific evaluation. Neither did we offer insufficient references. Although we intentionally did not claim to be a "review' paper, we did cite 100 papers. That number is approximately 5 times the usual amount cited in journal articles. Although we only referenced few papers published after 2005, that was because our manuscript was submitted in January 2006, with its final, editorially-reviewed form in June 2006. We therefore could not reference papers published after this date. The problem here is that our paper was "in press" for 18 months. Finally, we explain that a careful reading of our paper reveals that our recommendations are not contradictory. Essentially, although we recommend 2 very distinct research approaches, these are complimentary and either alone is insufficient to accelerate progress. In conclusion, we recommend that the scientific community expends greater effort in publishing careful scientific criticisms so that others do not face the same dilemma we did. Likely this requires some reward system for doing so.

Errico, Ronald M.↗
NASA NTRS2012

NASA Electronic Parts and Packaging (NEPP) Program

Recent Findings from Audits, New Technology Data Reviews a) Disabled Chip Burn-ins A recent audit for a QML device discovered that the chip was disabled during the static burn-in, thus it was not drawing any current. Recommendation: For new SMDs add a statement within the burn-in paragraphs stating that the parts shall be kept in their enabled state during the burn-in. b) Class Q 160-hr/125oC Burn-in This is being interpreted as a static burn-in (even for CMOS technology). Recommendation: Provide clarification in MIL-STD-883, Test Method 5004. c) At Frequency (Dynamic) Burn-ins Test equipment limitation is being cited for not doing burn-ins at the application frequency. Recommendation: The burn-in task group to discuss and provide guidance. When the SMD says that the part can be used at 200 MHz, then doing burn-in at 6 MHz (cited as burn-in equipment limitation frequency) is not going to be meaningful! d) Two Static Burn-ins Some manufacturers are doing electrical testing between the two static burn-ins, whereas others do electricals after completing both static burn-ins. Recommendation: Provide clarification in MIL-STD-883, Test Method 5004. e) Thermal Imaging For a device with hot spots, the thermal resistance, junction-to-case, would be much higher than the guidelines given in MIL-STD-1835. One of the suppliers used thermal imaging to find hot spots on the die. Recommendation: Assign a task group to evaluate the effectiveness of thermal imaging at the product development stage.

Class Y↗
NASA NTRS2016

Absorption Cross-Sections of Ozone in the Ultraviolet and Visible Spectral Regions: Status report 2015

The activity Absorption Cross-Sections of Ozone (ACSO) started in 2008 as a joint initiative of the International Ozone Commission (IO3C), the World Meteorological Organization (WMO) and the IGACO (Integrated Global Atmospheric Chemistry Observations) O3/UV subgroup to study, evaluate, and recommend the most suitable ozone absorption cross-section laboratory data to be used in atmospheric ozone measurements. The evaluation was basically restricted to ozone absorption cross-sections in the UV range with particular focus on the Huggins band. Up until now, the data of Bass and Paur published in 1985 (BP, 1985) are still officially recommended for such measurements. During the last decade it became obvious that BP (1985) cross-section data have deficits for use in advanced space-borne ozone measurements. At the same time, it was recognized that the origin of systematic differences in ground-based measurements of ozone required further investigation, in particular whether the BP (1985) cross-section data might contribute to these differences. In ACSO, different sets of laboratory ozone absorption cross-section data (including their dependence on temperature) of the group of Reims (France) (Brion et al., 1993, 1998, 1992, 1995, abbreviated as BDM, 1995) and those of Serdyuchenko et al. (2014), and Gorshelev et al. (2014), (abbreviated as SER, 2014) were examined for use in atmospheric ozone measurements in the Huggins band. In conclusion, ACSO recommends:(a) The spectroscopic data of BP (1985) should no longer be used for retrieval of atmospheric ozone measurements.(b) For retrieval of ground-based instruments of total ozone and ozone profile measurements by the Umkehr method performed by Brewer and Dobson instruments data of SER (2014) are recommended to be used. When SER (2014) is used, the difference between total ozone measurements of Brewer and Dobson instruments are very small and the difference between Dobson measurements at AD and CD wavelength pairs are diminished.(c) For ground-based Light Detection and Ranging (LIDAR) measurements the use of BDM (1995) or SER (2014) is recommended.(d) For satellite retrieval the presently widely used data of BDM (1995) should be used because SER (2014) seems less suitable for retrievals that use wavelengths close to 300 nm due to a deficiency in the signal-to-noise ratio in the SER (2014) dataset.The work of ACSO also showed: The need to continue laboratory cross-section measurements of ozone of highest quality. The importance of careful characterization of the uncertainties of the laboratory measurements. The need to extend the scope of such studies to other wavelength ranges (particularly to cover not only the Huggins band but also the comparison with the mid-infrared region). The need for regular cooperation of experts in spectral laboratory measurements and specialists in atmospheric (ozone) measurements.

Orphal, Johannes↗