Active Time-Domain Reflectometry for Unattended Safeguards Systems: FY16 Report

The International Atomic Energy Agency (IAEA) continues to expand its use of unattended measurement systems. An increasing number of systems and an expanding family of instruments create challenges in terms of deployment efficiency and the implementation of data authentication measures. In collaboration with the IAEA, tamper-indicating measures to address data-transmission authentication challenges with unattended safeguards systems are under investigation. Pacific Northwest National Laboratory (PNNL) is studying the viability of active time-domain reflectometry (TDR) along two parallel but interconnected paths: (1) swept-frequency TDR as the highly flexible, laboratory gold standard to which field-deployable options can be compared, and (2) a low-cost commercially available spread-spectrum TDR technology as one option for field implementation. This report describes PNNL’s FY15 progress in the viability study including: an overview of the TDR methods under investigation; description of the testing configurations and mock tampering scenarios; results from a preliminary sensitivity comparison of the two TDR methods; demonstration of a quantitative metric for estimating field performance that acknowledges the need for high detection probability while minimizing false alarms. FY15 progress reported here sets the stage for a rigorous comparison of the candidate TDR methods, over a range of deployment scenarios and perturbing effects typical of IAEA unattended monitoring systems.

As the extent of the shortage becomes clear, an interagency task force is giving scientific users priority, but some say the material is not available at any price.

Detector characterization for quantitative spectral radiography of uranium powder samples

Analysis of an indirect neutron signature for enhanced UF6 cylinder verification

Nuclear forensics relies on the analysis of certain sample characteristics to determine the origin and history of a nuclear material. In the specific case of uranium enrichment facilities, it is the release of trace amounts of uranium hexafluoride (UF{sub 6}) gas - used for the enrichment of uranium - that leaves a process-characteristic fingerprint. When UF{sub 6} gas interacts with atmospheric moisture, uranium oxyfluoride particles or particle agglomerates are formed with sizes ranging from several microns down to a few tens of nanometers. These particles are routinely collected by safeguards organizations, such as the International Atomic Energy Agency (IAEA), allowing them to verify whether a facility is compliant with its declarations. Spectrometric analysis of uranium particles from UF{sub 6} hydrolysis has revealed the presence of both particles that contain fluorine, and particles that do not. It is therefore assumed that uranium oxyfluoride is unstable, and decomposes to form uranium oxide. Understanding the rate of fluorine loss in uranium oxyfluoride particles, and the parameters that control it, may therefore contribute to placing boundaries on the particle's exposure time in the environment. Expressly for the purpose of this study, we prepared a set of uranium oxyfluoride particles at the Institute for Reference Materials and Measurements (EU-JRC-IRMM) from a static release of UF{sub 6} in a humid atmosphere. The majority of the samples was stored in controlled temperature, humidity and lighting conditions. Single particles were characterized by a suite of micro-analytical techniques, including NanoSIMS, micro-Raman spectrometry (MRS), scanning (SEM) and transmission (TEM) electron microscopy, energy-dispersive X-ray spectrometry (EDX) and focused ion beam (FIB). The small particle size was found to be the main analytical challenge. The relative amount of fluorine, as well as the particle chemical composition and morphology were determined at different stages in the ageing process, and immediately after preparation. This report summarizes our most recent findings for each of the analytical techniques listed above, and provides an outlook on what remains to be resolved. Additional spectroscopic and mass spectrometric measurements were carried out at Pacific Northwest National Laboratory, but are not included in this summary.

Pacific Northwest National Laboratory (PNNL) provided technical assistance to NorthWrite Inc. under the Small Business Vouchers (SBV) Pilot. NorthWrite delivered services to owners of small commercial buildings, using a cloud-based service to monitor, control, and optimize building operations, saving energy and reducing operating costs for the owners while ensuring that occupant comfort needs were consistently met. NorthWrite had a longstanding desire to add a new suite of diagnostic capabilities to their service offering and had been trying, without success, to incorporate several diagnostic algorithms published by PNNL. These algorithms arise from research previously supported by BTO. Through the SBV awarded to NorthWrite, PNNL made available technical knowledge regarding the derivation and application of the following sets of algorithms for use in the NorthWrite Cloud-based service delivery system: • algorithms for monitoring rooftop packaged air conditioners and heat pumps (often referred to as rooftop units or RTUs) and diagnosing faults in these units, • advanced algorithms for automated fault detection and diagnosis of other equipment found in small buildings, and • algorithms for identifying, prioritizing, and assessing the economic effectiveness of implementing energy saving measures in small commercial buildings based on sensed data. The PNNL researchers involved were the original developers of these algorithms, had a unique understanding of the derivation of the algorithms, and had the source data used for this derivation. Further, the PNNL researchers had extensive experience using these algorithms in the laboratory, unique experience applying these algorithms in real-world small commercial buildings and could solve a number of key problems that NorthWrite and other users faced in using these algorithms at scale. In addition, PNNL had recently installed a pair of RTUs in a laboratory setting that were instrumented and connected with data acquisition systems that provided a unique test rig for validating the algorithms before NorthWrite began to deploy their new services in the field.

In 2022, researchers at Pacific Northwest National Laboratory (PNNL) used the Accelerated and Real-Time Environmental Nodal Assessment (ARENA) cable and motor test bed to characterize spread spectrum time domain reflectometry (SSTDR) and compare the responses of an SSTDR instrument to those of a frequency domain reflectometry (FDR) instrument. Results showed both techniques could detect and locate cable anomalies such as phase-to-phase low resistance and shorts, thermal insulation damage, mechanical insulation damage, and the presence or absence of water in some conditions. The SSTDR tests used a commercial instrument provided by LiveWire Innovations Inc. This commercial instrument performed tests at 6, 12, 24, and 48 MHz bandwidth. The results of these tests were compared to FDR tests where bandwidths could be extended up to 1.3 GHz, although the best responses for cable tests were from 100 to 500 MHz. Lower bandwidth signals can propagate better along the cable while higher bandwidths have higher resolution for impedance change reflections allowing more precise indication of location and separation of anomalies. The 2022 research found that FDR responses were clearer than SSTDR and speculated that a higher bandwidth SSTDR could more successfully detect and locate cable anomalies. One advantage of the SSTDR system investigated was that it was designed for energized online use up to 1,000 volts, which may be a significant advantage for nuclear power plant use. The LiveWire SSTDR instrument is an established product in the rail and aircraft industry and updating the SSTDR hardware parameters is difficult to justify without more conclusive testing. Therefore, a software adjustable laboratory SSTDR instrument was developed by PNNL and was used to test extended bandwidth SSTDR cable tests. Within the ARENA test bed, 42 cable conditions were tested with the PNNL SSTDR, FDR, and the LiveWire SSTDR—each operating at four different bandwidths. Observations and conclusions regarding the relative performance of the three instruments over different bandwidths are note below. Responses of the PNNL SSTDR (at 50 MHz) and the LiveWire SSTDR (at 48 MHz) were similar. The PNNL SSTDR higher frequency bandwidths behaved as expected showing sharper peaks and higher noise. This validated the PNNL SSTDR as a reasonable implementation of the SSTDR technology. Lower bandwidth SSTDR responses (particularly 6 and 12 MHz) may have increased value for use within longer cables but were not particularly effective at identifying anomalous cable behavior in the 100 ft cables tested here. The higher bandwidths of the PNNL SSTDR (50, 100, 200, and 400 MHz) did not provide substantially clearer cable reflectometry responses, but having the higher frequency responses available did add to the cable test evaluation. Strong responses to shorts and low impedance faults between phases were particularly evident in the higher bandwidth PNNL SSTDR and the FDR data. Measurements were repeatable, with similar responses obtained from a thermally aged cable for tests taken a month apart. Signal noise was affected in the unshielded cable by the local in-tray cable arrangement including proximity to metal edges and rungs of the cable tray. Foam isolation of the cable from the tray metal reduced in both FDR and SSTDR responses. Cable condition monitoring in nuclear power plants will likely benefit from both more informative off-line testing methods and from the development of on-line methods for continuous monitoring of cables in use. The LWRS-funded ARENA test bed was a valuable resource for this development and direct comparison of nuclear electrical cable condition monitoring technologies. Test results are targeted to guide industry advancement of testing and monitoring tools for cable aging management.

Many States are considering interim very long-term storage (VLTS) strategies for spent fuel storage while final disposition options are developed. Under the VLTS approach, spent fuel will be stored for periods that could exceed 50 to 100 years. The long-term storage of spent fuel — and the increasing stockpile of plutonium contained in this spent fuel — exacerbate the international safeguards and verification needs for spent fuel. In particular, significant delays in any verification of the contents of spent fuel assemblies prior to disposition may cause even further delays in the final disposition (or reprocessing) of spent fuel. As a result, the resources required by the International Atomic Energy Agency (IAEA) to safeguard the increasing stockpile of spent fuel will increase. Safeguarding these interim storage facilities and subsequently, the transportation of long-term stored fuel, will place additional demands on IAEA resources if the current approach, which relies heavily upon inspectors being present at the facility, is to be continued. Current IAEA approaches to safeguarding above ground dry storage sites do not take into account the challenges associated with longer-term storage and are also very dependent on inspector presence. The IAEA is moving toward remote and unattended monitoring systems for safeguards and these systems should be utilized at VLTS facilities as much as possible. The research and development of various monitoring systems should be continued.

Isotope Techniques in the Study of Environmental Change Proceedings of an International Symposium on Isotope Techniques in the Study of Past and Current Environmental Changes in the Hydrosphere and the Atmosphere Organized by the International Atomic Energy Agency and Held in Vienna, 14–18 April 1997, IAEA Vienna, 1998, 932 pp., ISBN 92-0-100598-9. Low Doses of Lonizing Radiation: Biological Effects and Regulatory Control Invited Papers and Discussions: Proceedings of a Conference, Seville, Spain, 17–21 November 1997 (Jointly Organized by IAEA and WHO) IAEA Vienna 1998, 439 pp. Radiological Conditions of the Western Kara Sea: Assessment of the Radiological Impact of the Dumping of Radioactive Waste in the Arctic Seas (Radiological Assessment Reports Series, IAEA Vienna 1998, 124 pp.). Radiological Conditions at the Semipalatinsk Test Site, Kazakhstan: Preliminary Assessment and Recommendations for Further Study (Radiological Assessment Reports Series, IAEA Vienna, 1998, 41 pp.). Rudolf Schönheimer (1898–1941), Leben und Werk H. K. Berthold, 90 S.; Reihe Biographien berühmter Ärzte, Falk Foundation e.V. Freiburg 1998.

The increase of nuclear sites entering the decommissioning phase has drawn the attention of governments, regulatory bodies, and industries to decommissioning projects. However, despite the high number of uncertainties and risks of these projects, there is a lack of dedicated risk management frameworks beyond the guidelines established by the International Atomic Energy Agency (IAEA) and the Project Management Institute (PMI). This study aims to propose an integrated framework for managing risks in Nuclear Decommissioning Projects. For the development of the framework artificial intelligence algorithms were employed, integrating models derived from the manufacturing sector capable of assessing risks, identifying an optimal set of risk mitigation actions, and predicting the additional project delay or cost based on a quantitative risk analysis. To demonstrate its validity, the model was applied to a nuclear decommissioning project currently underway in Italy, generating a forecast of the final project delay. The results showed to be promising, as the delay prediction for the analysed phase of the project differs from the current one only by an error of 4.7%. The proposed model can help project managers in managing risks and predicting delays or additional project costs during the preliminary phase. In addition, the framework is equally useful for controlling risks in the progress stages of the project by dynamically updating forecasts.

The use of Monte Carlo particle transport simulations in radiotherapy was pioneered in the earlynineteen-seventies, but it was not until the eighties that they gained recognition as an essential research tool for radiation dosimetry, health physics and later on for radiation therapy treatment planning. Since the mid-nineties, there has been a boom in the number of workers using MC techniques in radiotherapy, and the quantity of papers published on the subject. Research and applications of MC techniques in radiotherapy span a very wide range from fundamental studies of cross sections and development of particle transport algorithms, to clinical evaluation of treatment plans for a variety of radiotherapy modalities.The International Workshop on Current Topics in Monte Carlo Treatment Planning took place at Montreal General Hospital, which is part of McGill University, halfway up Mount Royal on Montreal Island. It was held from 3-5 May, 2004, right after the freezing winter has lost its grip on Canada. About 120 workers attended the Workshop, representing 18 countries. Most of the pioneers in the field were present but also a large group of young scientists. In a very full programme, 41 long papers were presented (of which 12 were invited) and 20 posters were on display during the whole meeting. The topics covered included the latest developments in MC algorithms, statistical issues, source modelling and MC treatment planning for photon, electron and proton treatments. The final day was entirely devoted to clinical implementation issues. Monte Carlo radiotherapy treatment planning has only now made a slow entrée in the clinical environment, taking considerably longer than envisaged ten years ago. Of the twenty-five papers in this dedicated special issue, about a quarter deal with this topic, with probably many more studies to follow in the near future. If anything, we hope the Workshop served as an accelerator for more clinical evaluation of MC applications. The remainder of the papers in this issue demonstrate that there is still plenty of work to be undertaken on other topics such as source modelling, calculation speed, data analysis, and development of user-friendly applications.We acknowledge the financial support of the National Cancer Institute of Canada, the Institute of Cancer Research of the Canadian Institutes of Health Research, the Research Grants Office and the Post Graduate Student Society of McGill University, and the Institute of Physics Publishing (IOPP). A final word of thanks goes out to all of those who contributed to the successful Workshop: our local medical physics students and staff, the many colleagues who acted as guest associate editors for the reviewing process, the IOPP staff, and the authors who generated new and exciting work.We are also grateful for the endorsement of the Workshop by the International Atomic Energy Agency, the Canadian Organization of Medical Physicists and the American Association of Physicists in Medicine. [This line was added to the editorial on 23 March 2005.]

In the quality assurance system for medicinal products, an important role is played by the procedure for validation of analytical methods at the stages of development, testing, technology and serial production. The need for validation at the stage of drug development is due to the fact that it is possible to promptly identify the shortcomings of the method and significantly improve it. The purpose of this study is to validate methods for testing «The authenticity» and «Quantitative determination» of acyzole in dental gel. Materials and methods. To achieve this goal, an active pharmaceutical substance of pharmacopoeial quality was used. When developing methods for testing for “Authenticity,” a reaction with oxalic acid to the zinc cation determined in the composition of acyzole was used. For the quantitative determination of acyzole, the complexometric method was used. The objects of the study were three series of gel samples. Results and discussion. As a result of the research, a method for testing «Authenticity» was developed; it was found that the proposed method is characterized by a negative analytical signal on model mixtures free of the analyte component and placebo, and a positive analytical signal on model mixtures of various compositions containing the analyte component. The validation characteristics of methods for the quantitative determination of acyzole in the gel were studied. positive results were obtained. The proposed methods can be used for inclusion in the regulatory documentation for the developed gel. Conclusion. When assessing the validation characteristics of the proposed methods, it was established that the methods for testing the «Authenticity» and «Quantitative determination» of acyzole in the gel are specific, the methods of quantitative determination are characterized by accuracy and repeatability, a linear dependence in the analytical range of ±20% of the declared amount of acyzole, which allows them to be used for a reliable assessment quality of the developed dental gel.

As the adoption of electric vehicles continues to accelerate, managing the risks as- sociated with battery technology has become critical. To ensure the safety of people and goods, it is essential to secure battery packs throughout their whole lifecycle, during charging, discharging, logistic and storage phases. However, current battery packs, which must constantly evolve to meet demands for reduced weight, volume, and cost in a competitive market, often underestimate an essential parameter: temperature reading. Temperature monitoring is a key element of battery health, yet it is typically performed at only a few points on the pack, limiting the reliability of the diagnostic. The present study proposes a novel approach based on time-domain reflectometry (TDR) to achieve real-time, distributed temperature monitoring along a single cable sensor. While optical fibbers approaches are discussed in the literature, TDR methods present easier integration, cost-efficiency, robustness, and can be installed with existing battery cables. The possibility of using readily available components such as coaxial cables and time-domain reflectometers with advanced signal processing techniques enables accurate temperature measurement. The first results comprising calibration experiments for various coaxial cable and validated temperature measurements over a range of zero to five meters. Us- ing high-frequency signals, hot spots were detected with a precision of three centimeters, which is ideal for identifying overheating cells in a battery pack. Furthermore, the sys- tem can operate across a broad temperature range, including sub-zero environments and up to a hundred degrees, which is the range for battery surveillance. This innovative solution presents a promising path forward in Structural Health Monitoring, paving the way for safer and more reliable electric vehicle batteries.

Runtime verification RV provides essential mechanisms to enhance software robustness and prevent malfunction. However, RV often entails complex and formal processes that could be avoided in scenarios in which only invariants or simple safety properties are verified, for example, when verifying input data in Graphical User Interfaces GUIs. This paper describes S-DAVER, a lightweight framework aimed at supporting separate data verification in GUIs. All the verification processes are encapsulated in an independent layer and then transparently integrated into an application. The verification rules are specified in separate files and written in interpreted languages to be changed/reloaded at runtime without recompilation. Superimposed visual feedback is used to assist developers during the testing stage and to improve the experience of users during execution. S-DAVER provides a lightweight, easy-to-integrate and dynamic verification framework for GUI data. It is an integral part of the development, testing and execution stages. An implementation of S-DAVER was successfully integrated into existing open-source applications, with promising results. Copyright © 2015John Wiley & Sons, Ltd.

The trabecular bone microstructure is a key to the early diagnosis and advanced therapy monitoring of osteoporosis. Regularly measuring bone microstructure with conventional multi-detector computer tomography (MDCT) would expose patients with a relatively high radiation dose. One possible solution to reduce exposure to patients is sampling fewer projection angles. This approach can be supported by advanced reconstruction algorithms, with their ability to achieve better image quality under reduced projection angles or high levels of noise. In this work, we investigated the performance of iterative reconstruction from sparse sampled projection data on trabecular bone microstructure in in-vivo MDCT scans of human spines. The computed MDCT images were evaluated by calculating bone microstructure parameters. We demonstrated that bone microstructure parameters were still computationally distinguishable when half or less of the radiation dose was employed.