Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “INSPECTOR”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8

Johnson Space Center: Workmanship Training

Special processes require special skills, knowledge and experienced application. For over 15 years, the NASA Johnson Space Center's Receiving, Inspection and Test Facility (RITF) has provided Agency-wide NASA Workmanship Standards compliance training, issuing more than 500 to 800 training completion certificates annually. It is critical that technicians and inspectors are trained and that they maintain their proficiency to implement the applicable standards and specifications. Training services include "hands-on" training to engineers, technicians, and inspectors in the areas of electrostatic discharge (ESD), soldering, surface mount technology (SMT), crimping, conformal coating, and fiber-optic terminations.

Patterson, Ashley↗

Workmanship Training Industry

Special processes require special skills, knowledge and experienced application. For over 15 years, the NASA Johnson Space Center's Receiving, Inspection and Test Facility (RITF) has provided Workmanship Standards compliance training, issuing more than 500 to 800 training completion certificates annually. It is critical that technicians and inspectors are trained and that they maintain their proficiency to implement the applicable standards and specifications. Training services include 'hands-on' training to engineers, technicians, and inspectors in the areas of electrostatic discharge (ESD), soldering, fiber optics, lithium battery handling, torque and wire safety, and wire wrapping.

Patterson, Ashley↗

Machine Learning Based AFP Inspection: A Tool for Characterization and Integration

Automated Fiber Placement (AFP) has become a standard manufacturing technique in the creation of large scale composite structures due to its high production rates. However, the associated rapid layup that accompanies AFP manufacturing has a tendency to induce defects. We forward an inspection system that utilizes machine learning (ML) algorithms to locate and characterize defects from profilometry scans coupled with a data storage system and a user interface (UI) that allows for informed manufacturing. A Keyence LJ-7080 blue light profilometer is used for fast 2D height profiling. After scans are collected, they are process by ML algorithms, displayed to an operator through the UI, and stored in a database. The overall goal of the inspection system is to add an additional tool for AFP manufacturing. Traditional AFP inspection is done manually adding to manufacturing time and being subject to inspector errors or fatigue. For large parts, the inspection process can be cumbersome. The proposed inspection system has the capability of accelerating this process while still keeping a human inspector integrated and in control. This allows for the rapid capability of the automated inspection software and the robustness of a human checking for defects that the system either missed or misclassified.

Sacco, Christopher↗

A Survey of NASA Standard Nondestructive Evaluation (NDE)

This document provides a comprehensive review to trace the evolution of NASA’s Standard nondestructive evaluation (NDE) flaw sizes provided in NASA-STD-5009B for fracture-critical metallic spaceflight hardware. A NASA Standard NDE flaw size is considered to be conservative such that most inspectors, trained and certified in the specific method, are expected to provide the required 90/95 probability of detection (POD) for that flaw size. As such, individual certified inspectors are not required to perform POD demonstration testing to be allowed to inspect fracture-critical hardware for that specific method.

Probability of Detection↗

An Eddy Current Case Study using NASA’s Transfer Function and Limited-Sample Probability of Detection Guidebooks

Probability of detection (POD) requirements for NASA fracture-critical human-rated systems can be met by (1) claiming ‘similarity’ to NASA Standard Nondestructive Evaluation (NDE) flaw sizes or (2) by inspector-specific POD demonstration, known as NASA Special NDE. Standard NDE flaw sizes are intended to represent the detection capability of most qualified inspectors, and were primarily based on POD studies in the development of the Space Shuttle Program Orbiter fracture control plan. However, these Standard NDE flaw sizes were based on fatigue cracks in flat panels of one material alloy over a limited range of panel thicknesses. While the POD study was comprehensive, the inspection conditions are relatively narrow. An evaluation of similarity between the Standard NDE POD study and flight component conditions is required to apply Standard NDE to specific flight component inspections. A similarity evaluation may include differences in materials, surface finish, component geometry (e.g., curvature, corners, welds), and inspection access. Similarity is typically based on a qualitative engineering evaluation. Recently, NASA published a quantitative methodology to assess similarity. If similarity is not supported by test and analysis, then the methodology provides a transfer function of flaw size for Special NDE POD demonstration. NASA recommends that Special POD demonstrations use flaws that are flight-like or more difficult to detect than flight component flaws, which are commonly induced fatigue cracks. Often, it is not feasible to induce fatigue cracks in flight component geometry, and therefore, a simpler representative geometry is used, commonly a flat panel, for POD demonstration. Inducing cracks in simple geometry specimens can be time-consuming and expensive, and thus, minimizing the number of flawed specimens is desired. Traditionally, NASA Special NDE demonstration was limited to MIL-HDBK-1823A methods or the binomial point-estimate method (PEM), commonly known as 29/29. Recently, NASA published a limited-sample POD (LS-POD) methodology for signal-response NDE techniques (e.g., eddy current) that provides POD demonstration with fewer specimens than previous approaches. LS-POD suggests a minimum of 10 flawed specimens, compared to 29 in the PEM and the suggested minimum of 40 from MIL-HDBK-1823A. The methodology also includes new guidance on evaluating the probability of false calls. In this presentation, these new transfer function and LS-POD methodologies are described and illustrated through an eddy current detection capability of far-side flaws on thin welded panels. A geometry-based transfer function is developed using electro-discharge machined (EDM) notches in flight component and simple geometry to estimate the Special NDE flaw size that is representative of the critical initial flaw size required by the fracture analysis. Then, fatigue cracks are induced in simple flat panels of the transferred flaw size, and the LS-POD methodology is used for Special NDE demonstration.

P. A. Parker↗

ENVIRONMENTAL SAMPLING USING LOCATION SPECIFIC AIR MONITORING IN BULK HANDLING FACILITIES

Since the introduction of safeguards strengthening measures approved by the International Atomic Energy Agency (IAEA) Board of Governors (1992-1997), international nuclear safeguards inspectors have been able to utilize environmental sampling (ES) (e.g. deposited particulates, air, water, vegetation, sediments, soil and biota) in their safeguarding approaches at bulk uranium/plutonium handling facilities. Enhancements of environmental sampling techniques used by the IAEA in drawing conclusions concerning the absence of undeclared nuclear materials or activities will soon be able to take advantage of a recent step change improvement in the gathering and analysis of air samples at these facilities. Location specific air monitoring feasibility tests have been performed with excellent results in determining attribute and isotopic composition of chemical elements present in an actual test-bed sample. Isotopic analysis of collected particles from an Aerosol Contaminant Extractor (ACE) collection, was performed with the standard bulk sampling protocol used throughout the IAEA network of analytical laboratories (NWAL). The results yielded bulk isotopic values expected for the operations. Advanced designs of air monitoring instruments such as the ACE may be used in gas centrifuge enrichment plants (GCEP) to detect the production of highly enriched uranium (HEU) or enrichments not declared by a State. Researchers at Savannah River National Laboratory in collaboration with Oak Ridge National Laboratory are developing the next generation of ES equipment for air grab and constant samples that could become an important addition to the international nuclear safeguards inspector's toolkit. Location specific air monitoring to be used to establish a baseline environmental signature of a particular facility employed for comparison of consistencies in declared operations will be described in this paper. Implementation of air monitoring will be contrasted against the use of smear ES when used during unannounced inspections, design information verification, limited frequency unannounced access, and complementary access visits at bulk handling facilities. Analysis of technical features required for tamper indication and resistance will demonstrate the viability of successful application of the system in taking ES within a bulk handling location. Further exploration of putting this technology into practice is planned to include mapping uranium enrichment facilities for the identification of optimal for installation of air monitoring devices.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Suggestions for better election security.

Summary of Common Security Mistakes: (1) Electronic voting machines that fundamentally lack security thought and features, including an ability to detect tampering or intrusion, or to be reliably locked or sealed; (2) Failure to disassemble, inspect, and thoroughly inspect (not just test) a sufficient number of voting machines before and after elections in order to detect hardware or software tampering; (3) Assuming that tamper - indicating seals will either be blatantly ripped/smashed open, or else there is no tampering. In reality, even amateurs can spoof most seals leaving (at most) subtle evidence; (4) Inadequate seal use protocols and training of seal installers and inspectors. Failure to show examples of blatantly and subtly attacked seals to seal inspectors; (5) Over confidence in use of a voter verified paper record (VVPR), a VVPR is an excellent security countermeasure, but it is not a silver bullet, especially for an election organization with poor overall security; (6) Little or no insider thr at mitigation; and (7) A poor security culture, including denial and no a priori procedures for dealing with security questions or concerns.

99 GENERAL AND MISCELLANEOUS↗

DEVELOPMENT OF A TAMPER RESISTANT/INDICATING AEROSOL COLLECTION SYSTEM FOR ENVIRONMENTAL SAMPLING AT BULK HANDLING FACILITIES

Environmental sampling has become a key component of International Atomic Energy Agency (IAEA) safeguards approaches since its approval for use in 1996. Environmental sampling supports the IAEA's mission of drawing conclusions concerning the absence of undeclared nuclear material or nuclear activities in a Nation State. Swipe sampling is the most commonly used method for the collection of environmental samples from bulk handling facilities. However, augmenting swipe samples with an air monitoring system, which could continuously draw samples from the environment of bulk handling facilities, could improve the possibility of the detection of undeclared activities. Continuous sampling offers the opportunity to collect airborne materials before they settle onto surfaces which can be decontaminated, taken into existing duct work, filtered by plant ventilation, or escape via alternate pathways (i.e. drains, doors). Researchers at the Savannah River National Laboratory and Oak Ridge National Laboratory have been working to further develop an aerosol collection technology that could be installed at IAEA safeguarded bulk handling facilities. The addition of this technology may reduce the number of IAEA inspector visits required to effectively collect samples. The principal sample collection device is a patented Aerosol Contaminant Extractor (ACE) which utilizes electrostatic precipitation principles to deposit particulates onto selected substrates. Recent work has focused on comparing traditional swipe sampling to samples collected via an ACE system, and incorporating tamper resistant and tamper indicating (TRI) technologies into the ACE system. Development of a TRI-ACE system would allow collection of samples at uranium/plutonium bulk handling facilities in a manner that ensures sample integrity and could be an important addition to the international nuclear safeguards inspector's toolkit. This work was supported by the Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and International Security (NIS), National Nuclear Security Administration (NNSA).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Next Generation Safeguards Initiative: Analysis of Probability of Detection of Plausible Diversion Scenarios at Gas Centrifuge Enrichment Plants Using Advanced Safeguards

Over the last decade, efforts by the safeguards community, including inspectorates, governments, operators and owners of centrifuge facilities, have given rise to new possibilities for safeguards approaches in enrichment plants. Many of these efforts have involved development of new instrumentation to measure uranium mass and uranium-235 enrichment and inspection schemes using unannounced and random site inspections. We have chosen select diversion scenarios and put together a reasonable system of safeguards equipment and safeguards approaches and analyzed the effectiveness and efficiency of the proposed safeguards approach by predicting the probability of detection of diversion in the chosen safeguards approaches. We analyzed the effect of redundancy in instrumentation, cross verification of operator instrumentation by inspector instrumentation, and the effects of failures or anomalous readings on verification data. Armed with these esults we were able to quantify the technical cost benefit of the addition of certain instrument suites and show the promise of these new systems.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Next Generation Safeguards Initiative: Overview and Policy Context of UF6 Cylinder Tracking Program

Thousands of cylinders containing uranium hexafluoride (UF{sub 6}) move around the world from conversion plants to enrichment plants to fuel fabrication plants, and their contents could be very useful to a country intent on diverting uranium for clandestine use. Each of these large cylinders can contain close to a significant quantity of natural uranium (48Y cylinder) or low-enriched uranium (LEU) (30B cylinder) defined as 75 kg {sup 235}U which can be further clandestinely enriched to produce 1.5 to 2 significant quantities of high enriched uranium (HEU) within weeks or months depending on the scale of the clandestine facility. The National Nuclear Security Administration (NNSA) Next Generation Safeguards Initiative (NGSI) kicked off a 5-year plan in April 2011 to investigate the concept of a unique identification system for UF{sub 6} cylinders and potentially to develop a cylinder tracking system that could be used by facility operators and the International Atomic Energy Agency (IAEA). The goal is to design an integrated solution beneficial to both industry and inspectorates that would improve cylinder operations at the facilities and provide enhanced capabilities to deter and detect both diversion of low-enriched uranium and undeclared enriched uranium production. The 5-year plan consists of six separate incremental tasks: (1) define the problem and establish the requirements for a unique identification (UID) and monitoring system; (2) develop a concept of operations for the identification and monitoring system; (3) determine cylinder monitoring devices and technology; (4) develop a registry database to support proof-of-concept demonstration; (5) integrate that system for the demonstration; and (6) demonstrate proof-of-concept. Throughout NNSA's performance of the tasks outlined in this program, the multi-laboratory team emphasizes that extensive engagement with industry stakeholders, regulatory authorities and inspectorates is essential to its success.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

The Importance of Establishing and Maintaining Continuity of Knowledge during 21st Century Nuclear Fuel Cycle Activities

During this century, the entire nuclear fuel cycle will expand and become increasingly more global, taxing both the resources and capabilities of the International Atomic Energy Agency (IAEA) to maintain an effective Continuity of Knowledge (CoK) and its ability to provide timely detection of diversion. Uranium that currently is mined and milled in one country will be converted, enriched, and fabricated into fuel for reactors in an expanding set of new countries. This expansion will make it harder to guarantee that regional activities stay regional and that diversion detection is timely unless new and sustainable tools are developed to improve inspector effectiveness. To deal with this emerging reality, the IAEA must increase its use of unattended monitoring and employ new tools and methods that enhance CoK during all phases of the fuel cycle. This approach will help provide useful information to aid in detecting undeclared activities and create opportunities for timely and appropriate responses to events well before they enter phases of greater concern (e.g., enrichment). The systems that maintain CoK of safeguarded assets rely on containment and surveillance (C/S) technologies. The 21st century fuel cycle will require increased use of these technologies and systems, plus greater implementation of unattended systems that can securely collect data when inspectors are not present.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Technical Cross-Cutting Issues for the Next Generation Safeguards Initiative's Spent Fuel Nondestructive Assay Project

Ever since there has been spent fuel (SF), researchers have made nondestructive assay (NDA) measurements of that fuel to learn about its content. In general these measurements have focused on the simplest signatures (passive photon and total neutron emission) and the analysis has often focused on diversion detection and on determining properties such as burnup (BU) and cooling time (CT). Because of shortcomings in current analysis methods, inspectorates and policy makers are interested in improving the state-of-the-art in SF NDA. For this reason the U.S. Department of Energy, through the Next Generation Safeguards Initiative (NGSI), targeted the determination of elemental Pu mass in SF as a technical goal. As part of this research effort, 14 nondestructive assay techniques were studied . This wide range of techniques was selected to allow flexibility for the various needs of the safeguards inspectorates and to prepare for the likely integration of one or more techniques having complementary features. In the course of researching this broad range of NDA techniques, several cross-cutting issues were. This paper will describe some common issues and insights. In particular we will describe the following: (1) the role of neutron absorbers with emphasis on how these absorbers vary in SF as a function of initial enrichment, BU and CT; (2) the need to partition the measured signal among different isotopic sources; and (3) the importance of the “first generation” concept which indicates the spatial location from which the signal originates as well as the isotopic origins.

Next Generation Safeguards Initiative↗

Prototype Radiation Detector Positioning System For The Automated Nondestructive Assay Of Uf6 Cylinders

International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility’s entire cylinder inventory. These measurements are time-consuming, expensive, and assay only a small fraction of the total cylinder volume. An automated nondestructive assay system capable of providing enrichment measurements over the full volume of the cylinder could improve upon current verification practices in terms of efficiency and assay accuracy. This paper describes an approach denoted the Integrated Cylinder Verification Station (ICVS) that supports 100% cylinder verification, provides volume-averaged cylinder enrichment assay, and reduces inspector manpower needs. To allow field measurements to be collected to validate data collection algorithms, a prototype radiation detector positioning system was constructed. The system was designed to accurately position an array of radiation detectors along the length of a cylinder to measure UF6 enrichment. A number of alternative radiation shields for the detectors were included with the system. A collimated gamma-ray spectrometer module that allows translation of the detectors in the surrounding shielding to adjust the field of view, and a collimating plug in the end to further reduce the low-energy field of view, were also developed. Proof-of-principle measurements of neutron and high-energy gamma-ray signatures, using moderated neutron detectors and large-volume spectrometers in a fixed-geometry, portal-like configuration, supported an early assessment of the viability of the concept. The system has been used successfully on two testing campaigns at an AREVA fuel fabrication plant to scan over 30 product cylinders. This paper will describe the overall design of the detector positioning system and provide an overview of the Integrated Cylinder Verification Station (ICVS) approach.

assay↗

Advancements of the Hybrid Method UF6 Container Inspection System

Safeguards inspectors currently visit uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are performed with handheld high-resolution detectors on a limited number of cylinders taken to be representative of the plant’s cylinder inventory. These enrichment assay methods interrogate only a small fraction of the total cylinder volume, and are time-consuming and expensive to execute. Pacific Northwest National Laboratory (PNNL) is developing an automated UF6 cylinder verification station concept based on the combined collection of traditional enrichment-meter data (186 keV photons from 235U) and non-traditional, neutron-induced, high-energy gamma-ray signatures (3-8 MeV) with an array of collimated, medium-resolution scintillators. Previous work at PNNL (2010) demonstrated proof-of-principle that this hybrid method yields accurate, full-volume assay of the cylinder enrichment, reduces systematic errors when compared to several other enrichment assay methods, and provides simplified instrumentation and algorithms suitable for long-term, unattended operations. This system aims to increase the number of inspected cylinders at higher accuracy and with lower cost than when compared to inspectors with hand-held instruments. Several measurement campaigns of 30B cylinder populations and a refined MCNP model will be reported. The MCNP model consists of per-gram basis vectors for the different uranium isotopes and several fill geometries, enabling fast generation of any UF6 enrichment level and multiple configurations. The refined model was used to optimize collimator design and detector configuration for the hybrid method. In addition, a new field prototype based on model results was utilized in a set of field measurements.

Mace, Emily K.↗

Opportunities to more fully utilize safeguards information reported to the IAEA at Gas Centrifuge Enrichment Plants

In an effort to increase transparency and to strengthen IAEA safeguards, more countries are adopting practices that provide the IAEA with more timely, safeguards-relevant information to confirm nuclear operations are as declared. At Gas Centrifuge Enrichment Plants (GCEPs) potential examples include installing unattended IAEA instruments that transmit selected information back to Vienna, instruments that collect and store measurement information on-site, and daily facility operator submissions of material receipts, shipments, or utilization of key operational systems (e.g., UF6 feed stations) to on-site mail boxes. Recently the IAEA has implemented the use of on-site mailbox systems supplemented with short notice or unannounced inspections to maintain effectiveness without significantly increasing the number of inspection days. While these measures significantly improves the IAEA’s effectiveness, we have identified several opportunities for how the use of this information could be improved and how some additional information would further improve safeguards. This paper presents concepts for how the safeguards information currently collected at GCEPs could be more effectively utilized through enhancing the way that raw data is displayed visually so that it is more intuitive to the inspector and provides for more effective inspection planning and execution, comparing information with previous IAEA inspection activities (lists of previous verified inventory), through comparing data with operator supplied data when inspectors arrive (notional inventory change reports), and through evaluating the data over time to provide even greater confidence in the data and operations as declared in between inspections. This paper will also discuss several potential improvements to the submissions themselves, such as including occupancy information about product and tails stations and including weight information for each station.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Technology Solutions Case Study: Combustion Safety for Appliances Using Indoor Air

This case study describes how to assess and carry out the combustion safety procedures for appliances and heating equipment that uses indoor air for combustion in low-rise residential buildings. Only appliances installed in the living space, or in an area freely communicating with the living space, vented alone or in tandem with another appliance are considered here. This document is for inspectors, auditors, and technicians working in homes where energy upgrades are being conducted whether or not air infiltration control is included in the package of measures being applied. In the indoor combustion air case, guidelines summarized here are based on language provided in several of the codes to establish minimum requirements for the space using simplified prescriptive measures. In addition, building performance testing procedures are provided by testing agencies. The codes in combination with the test procedures offer comprehensive combustion safety coverage to address safety concerns, allowing inexperienced residential energy retrofit inspectors to effectively address combustion safety issues and allow energy retrofits to proceed.

Building America↗

Field trial of the enhanced data authentication system (EDAS)

The Enhanced Data Authentication System (EDAS) is means to securely branch information from an existing measurement system or data stream to a secondary observer. In an international nuclear safeguards context, the EDAS connects to operator instrumentation, and provides a cryptographically secure copy of the information for a safeguards inspectorate. However, this novel capability could be a valuable complement to inspector-owned safeguards instrumentation, offering context that is valuable for anomaly resolution and contingency.

97 MATHEMATICS AND COMPUTING↗

Automated commissioning and inspection for PV systems

An electric system includes a local power controller and solar panel system that includes a plurality of solar modules on one or more branch circuits. A method for commissioning the electric system includes an installer using a commissioning device to send and receive information from a remote system and the local power controller performing an automatic self-test of the electric system. The results of the self-test may be packaged with photographs and measurements of the electric system and sent to a remote system where an inspector can inspect the electric system remotely. After receiving approval by the inspector, the local power controller may automatically activate each branch circuit of the electric system and thus enabling the electric system to generate electricity.

14 SOLAR ENERGY↗