17 research outputs found
Redundancy of Supply in the International Nuclear Fuel Fabrication Market: Are Fabrication Services Assured?
For several years, Pacific Northwest National Laboratory (PNNL) has been assessing the reliability of nuclear fuel supply in support of the U.S. Department of Energy/National Nuclear Security Administration. Three international low enriched uranium reserves, which are intended back up the existing and well-functioning nuclear fuel market, are currently moving toward implementation. These backup reserves are intended to provide countries credible assurance that of the uninterrupted supply of nuclear fuel to operate their nuclear power reactors in the event that their primary fuel supply is disrupted, whether for political or other reasons. The efficacy of these backup reserves, however, may be constrained without redundant fabrication services. This report presents the findings of a recent PNNL study that simulated outages of varying durations at specific nuclear fuel fabrication plants. The modeling specifically enabled prediction and visualization of the reactors affected and the degree of fuel delivery delay. The results thus provide insight on the extent of vulnerability to nuclear fuel supply disruption at the level of individual fabrication plants, reactors, and countries. The simulation studies demonstrate that, when a reasonable set of qualification criteria are applied, existing fabrication plants are technically qualified to provide backup fabrication services to the majority of the world's power reactors. The report concludes with an assessment of the redundancy of fuel supply in the nuclear fuel market, and a description of potential extra-market mechanisms to enhance the security of fuel supply in cases where it may be warranted. This report is an assessment of the ability of the existing market to respond to supply disruptions that occur for technical reasons. A forthcoming report will address political disruption scenarios
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Peaceful Uses Bona Fides: Criteria for Evaluation and Case Studies
This study applies a set of indicators to assess the peaceful nature of a state’s nuclear program. Evaluation of a country’s nuclear program relative to these indicators can help the international community to take appropriate actions to ensure that the growth of the global nuclear energy industry proceeds peacefully and to minimize nuclear proliferation risks
Six Years of Chandra Observations of Supernova Remnants
We present a review of the first six years of Chandra X-ray Observatory
observations of supernova remnants. From the official "first-light" observation
of Cassiopeia A that revealed for the first time the compact remnant of the
explosion, to the recent million-second spectrally-resolved observation that
revealed new details of the stellar composition and dynamics of the original
explosion, Chandra observations have provided new insights into the supernova
phenomenon. We present an admittedly biased overview of six years of these
observations, highlighting new discoveries made possible by Chandra's unique
capabilities.Comment: 82 pages, 28 figures, for the book Astrophysics Update
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Broadening Industry Governance to Include Nonproliferation
As industry is the first line of defense in detecting and thwarting illicit trade networks, the engagement of the private sector is critical to any government effort to strengthen existing mechanisms to protect goods and services throughout the supply chain. This study builds on previous PNNL work to continue to evaluate means for greater industry engagement to complement and strengthen existing governmental efforts to detect and stem the trade of illicit goods and to protect and secure goods that could be used in making a weapon of mass destruction. Specifically, the study evaluates the concept of Industry Self Regulation, defined as a systematic voluntary program undertaken by an industry or by individual companies to anticipate, implement, supplement, or substitute for regulatory requirements in a given field, generally through the adoption of best practices. Through a series of interviews with companies with a past history of non-compliance, trade associations and NGOs, the authors identify gaps in the existing regulatory infrastructure, drivers for a self regulation approach and the form such an approach might take, as well as obstacles to be overcome. The authors conclude that it is at the intersection of industry, government, and security that—through collaborative means—the effectiveness of the international nonproliferation system—can be most effectively strengthened to the mutual benefit of both government and the private sector. Industry has a critical stake in the success of this regime, and has the potential to act as an integrating force that brings together the existing mechanisms of the global nonproliferation regime: export controls, physical protection, and safeguards. The authors conclude that industry compliance is not enough; rather, nonproliferation must become a central tenant of a company’s corporate culture and be viewed as an integral component of corporate social responsibility (CSR)
Offline versus online suicide-related help seeking: changing domains, changing paradigms
Objective: Suicidal individuals are among the most reluctant help-seekers, which limits opportunities for treating and preventing unnecessary suffering and self-inflicted deaths. This study aimed to assist outreach, prevention, and treatment efforts by elucidating relationships between suicidality and both online and offline help seeking. Method: An anonymous online survey provided data on 713 participants, aged 18-71 years. Measures included an expanded General Help-Seeking Questionnaire and the Suicidal Affect-Behavior-Cognition Scale. Results: General linear modeling results showed that, as predicted, face-to-face help-seeking willingness decreased as risk level increased. However, for emerging adults help-seeking likelihood increased with informal online sources as risk increased, while other online help-seeking attitudes differed little by risk level. Linear regression modeling determined that, for suicidal individuals, willingness to seek help from online mental health professionals and online professional support sites was strongly related (ps < .001). Help seeking from social networking sites and anonymous online forums was also interrelated, but more complex, demonstrating the importance of age and social support factors (ps < .001). Conclusion: These findings show that the Internet has altered the suicide-related help-seeking paradigm. Online help seeking for suicidality was not more popular than face-to-face help seeking, even for emerging adults. However, treatment and prevention professionals have good reasons to increase their online efforts, because that is where some of the highest risk individuals are going for help with their most severe personal problems
Evaluation of a Business Case for Safeguards by Design in Nuclear Power Reactors
Safeguards by Design (SbD) is a well-known paradigm for consideration and incorporation of safeguards approaches and associated design features early in the nuclear facility development process. This paradigm has been developed as part of the Next Generation Safeguards Initiative (NGSI), and has been accepted as beneficial in many discussions and papers on NGSI or specific technologies under development within NGSI. The Office of Nuclear Safeguards and Security funded the Pacific Northwest National Laboratory to examine the business case justification of SbD for nuclear power reactors. Ultimately, the implementation of SbD will rely on the designers of nuclear facilities. Therefore, it is important to assess the incentives which will lead designers to adopt SbD as a standard practice for nuclear facility design. This report details the extent to which designers will have compelling economic incentives to adopt SbD
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Evaluation of a Business Case for Safeguards by Design in Nuclear Power Reactors
Safeguards by Design (SbD) is a well-known paradigm for consideration and incorporation of safeguards approaches and associated design features early in the nuclear facility development process. This paradigm has been developed as part of the Next Generation Safeguards Initiative (NGSI), and has been accepted as beneficial in many discussions and papers on NGSI or specific technologies under development within NGSI. The Office of Nuclear Safeguards and Security funded the Pacific Northwest National Laboratory to examine the business case justification of SbD for nuclear power reactors. Ultimately, the implementation of SbD will rely on the designers of nuclear facilities. Therefore, it is important to assess the incentives which will lead designers to adopt SbD as a standard practice for nuclear facility design. This report details the extent to which designers will have compelling economic incentives to adopt SbD
Effects of mexiletine on hyperexcitability in sporadic amyotrophic lateral sclerosis: Preliminary findings from a small phase II randomized controlled trial
BackgroundTo collect preliminary data on the effects of mexiletine on cortical and axonal hyperexcitability in sporadic amyotrophic lateral sclerosis (ALS) in a phase 2 double- blind randomized controlled trial.MethodsTwenty ALS subjects were randomized to placebo and mexiletine 300 or 600- mg daily for 4 wk and assessed by transcranial magnetic stimulation and axonal excitability studies. The primary endpoint was change in resting motor threshold (RMT).ResultsRMT was unchanged with 4 wk of mexiletine (combined active therapies) as compared to placebo, which showed a significant increase (P = .039). Reductions of motor evoked potential (MEP) amplitude (P = .013) and accommodation half- time (P = .002), secondary outcome measures of cortical and axonal excitability, respectively, were also evident at 4 wk on mexiletine.ConclusionsThe relative stabilization of RMT in the treated subjects was unexpected and could be attributed to unaccounted sources of error or chance. However, a possible alternative cause is neuromodulation preventing an increase. The change in MEP amplitude and accommodation half- time supports the reduction of cortical and axonal hyperexcitability with mexiletine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166371/1/mus27146_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166371/2/mus27146.pd
Effects of mexiletine on hyperexcitability in sporadic amyotrophic lateral sclerosis: Preliminary findings from a small phase II randomized controlled trial
© 2020 Wiley Periodicals LLC Background: To collect preliminary data on the effects of mexiletine on cortical and axonal hyperexcitability in sporadic amyotrophic lateral sclerosis (ALS) in a phase 2 double-blind randomized controlled trial. Methods: Twenty ALS subjects were randomized to placebo and mexiletine 300 or 600 mg daily for 4 wk and assessed by transcranial magnetic stimulation and axonal excitability studies. The primary endpoint was change in resting motor threshold (RMT). Results: RMT was unchanged with 4 wk of mexiletine (combined active therapies) as compared to placebo, which showed a significant increase (P =.039). Reductions of motor evoked potential (MEP) amplitude (P =.013) and accommodation half-time (P =.002), secondary outcome measures of cortical and axonal excitability, respectively, were also evident at 4 wk on mexiletine. Conclusions: The relative stabilization of RMT in the treated subjects was unexpected and could be attributed to unaccounted sources of error or chance. However, a possible alternative cause is neuromodulation preventing an increase. The change in MEP amplitude and accommodation half-time supports the reduction of cortical and axonal hyperexcitability with mexiletine