| 1. |
- Clack, Christopher T. M., et al.
(author)
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Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar
- 2017
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In: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 114:26, s. 6722-6727
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Journal article (peer-reviewed)abstract
- A number of analyses, meta-analyses, and assessments, including those performed by the Intergovernmental Panel on Climate Change, the National Oceanic and Atmospheric Administration, the National Renewable Energy Laboratory, and the International Energy Agency, have concluded that deployment of a diverse portfolio of clean energy technologies makes a transition to a low-carbon-emission energy system both more feasible and less costly than other pathways. In contrast, Jacobson et al. [Jacobson MZ, Delucchi MA, Cameron MA, Frew BA (2015) Proc Natl Acad Sci USA 112(49): 15060-15065] argue that it is feasible to provide "low-cost solutions to the grid reliability problem with 100% penetration of WWS [wind, water and solar power] across all energy sectors in the continental United States between 2050 and 2055", with only electricity and hydrogen as energy carriers. In this paper, we evaluate that study and find significant shortcomings in the analysis. In particular, we point out that this work used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions. Policy makers should treat with caution any visions of a rapid, reliable, and low-cost transition to entire energy systems that relies almost exclusively on wind, solar, and hydroelectric power.
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| 2. |
- Frisch, M, et al.
(author)
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Cultural bias in the AAP's 2012 Technical Report and Policy Statement on male circumcision
- 2013
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In: Pediatrics. - : American Academy of Pediatrics (AAP). - 1098-4275 .- 0031-4005. ; 131:4, s. 796-800
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Journal article (peer-reviewed)abstract
- The American Academy of Pediatrics recently released its new Technical Report and Policy Statement on male circumcision, concluding that current evidence indicates that the health benefits of newborn male circumcision outweigh the risks. The technical report is based on the scrutiny of a large number of complex scientific articles. Therefore, while striving for objectivity, the conclusions drawn by the 8 task force members reflect what these individual physicians perceived as trustworthy evidence. Seen from the outside, cultural bias reflecting the normality of nontherapeutic male circumcision in the United States seems obvious, and the report’s conclusions are different from those reached by physicians in other parts of the Western world, including Europe, Canada, and Australia. In this commentary, a different view is presented by non–US-based physicians and representatives of general medical associations and societies for pediatrics, pediatric surgery, and pediatric urology in Northern Europe. To these authors, only 1 of the arguments put forward by the American Academy of Pediatrics has some theoretical relevance in relation to infant male circumcision; namely, the possible protection against urinary tract infections in infant boys, which can easily be treated with antibiotics without tissue loss. The other claimed health benefits, including protection against HIV/AIDS, genital herpes, genital warts, and penile cancer, are questionable, weak, and likely to have little public health relevance in a Western context, and they do not represent compelling reasons for surgery before boys are old enough to decide for themselves.
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| 3. |
- Frazer, D., et al.
(author)
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Degradation of HT9 under simultaneous ion beam irradiation and liquid metal corrosion
- 2016
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 479, s. 382-389
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Journal article (peer-reviewed)abstract
- A potentially promising coolant/structural material pair for a liquid-metal-cooled fast reactors is lead bismuth eutectic (LBE) coolant with the ferritic/martensitic steel HT9. The challenge of deploying LBE, however, is the corrosive environment it creates for structural materials. This corrosion can be mitigated with precise oxygen content control in the LBE to allow for the growth of passive protective oxide layers on the surface of the steel. In this paper, results are reported from the Irradiation Corrosion Experiment II (ICE-II), which allowed the simultaneous irradiation of a sample while in contact with LBE. It was found that a characteristic multilayer structure with an outer Fe3O4 oxide and inner FeCr2O4 spinel was grown and the oxidation was significantly larger in the irradiated region when compared to the region that was only exposed to LBE corrosion. Possible mechanisms are discussed to help understand this irradiation enhanced corrosion behavior.
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| 4. |
- Qvist, Staffan A., et al.
(author)
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Autonomous Reactivity Control (ARC) - Principles, geometry and design process
- 2016
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In: Nuclear Engineering and Design. - : Elsevier. - 0029-5493 .- 1872-759X. ; 307, s. 249-274
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Journal article (peer-reviewed)abstract
- The Autonomous Reactivity Control (ARC) system was developed to ensure inherent safety performance of Generation-IV reactors while having a minimal impact on reactor performance and economic viability. Here we present in detail the principles of how the ARC system operates, what materials should be used, what components make up the system and how they are interconnected. The relevant equations regarding how to design the system for a certain response are developed and defined, and the most important aspects determining the speed of actuation of the systems are analyzed. Thus, this study serves as the general reference material for all of the fundamental principles behind the ARC idea. Finally, we present a step-by-step guide to how a fast reactor fuel subassembly with an ARC system installed would be manufactured, using a full 3D-CAD model. For an ARC installation in a 1000 MWth sodium-cooled oxide fueled fast reactor core, the system constitutes a relatively minor adjustment to a typical fuel assembly, increasing its total axial extent by similar to 5-10% and the total primary coolant pressure drop by similar to 1%. The main finding of this study is that it is possible to design, manufacture (using existing methods) and implement ARC systems in the fuel assemblies of fast reactor cores to provide inherent safety in all anticipated unprotected transients with only a modest increase in the length of the assembly and the pressure drop across the core.
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| 5. |
- Qvist, Staffan A., et al.
(author)
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Tailoring the response of Autonomous Reactivity Control (ARC) systems
- 2017
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In: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 99, s. 383-398
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Journal article (peer-reviewed)abstract
- The Autonomous Reactivity Control (ARC) system was developed to ensure inherent safety of Generation IV reactors while having a minimal impact on reactor performance and economic viability. In this study we present the transient response of fast reactor cores to postulated accident scenarios with and without ARC systems installed. Using a combination of analytical methods and numerical simulation, the principles of ARC system design that assure stability and avoids oscillatory behavior have been identified. A comprehensive transient analysis study for ARC-equipped cores, including a series of Unprotected Loss of Flow (ULOF) and Unprotected Loss of Heat Sink (ULOHS) simulations, were performed for Argonne National Laboratory (ANL) Advanced Burner Reactor (ABR) designs. With carefully designed ARC-systems installed in the fuel assemblies, the cores exhibit a smooth non-oscillatory transition to stabilization at acceptable temperatures following all postulated transients. To avoid oscillations in power and temperature, the reactivity introduced per degree of temperature change in the ARC system needs to be kept below a certain threshold the value of which is system dependent, the temperature span of actuation needs to be as large as possible.
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