scholarly journals Occupational safety data and casualty rates for the uranium fuel cycle. [Glossaries]

1981 ◽  
Author(s):  
F.R. O'Donnell ◽  
H.C. Hoy
Keyword(s):  
Occupational Safety ◽  
Fuel Cycle ◽  
Safety Data ◽  
Uranium Fuel

Parametric Lattice Study of a Graphite-Moderated Molten Salt Reactor

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Boris A. Hombourger ◽  
Jiří Křepel ◽  
Konstantin Mikityuk ◽  
Andreas Pautz
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Block Size ◽  
Equilibrium Composition ◽  
Reaction Rates ◽  
Point Of View ◽  
Fission Rate ◽  
Slowing Down ◽  
Channel Radius ◽  
Uranium Fuel

Molten salt reactors (MSRs) are promising advanced nuclear reactors for closure of the fuel cycle. This paper discusses the core design of graphite-moderated MSRs, thanks to a parametric study of the fuel and moderator lattice. The study is conducted at equilibrium of the thorium-uranium fuel cycle for several fuel channel radius and moderator block size combinations. The equilibrium composition for each studied configuration is derived with the help of an in-house MATLAB code, EQL0D, which uses the Serpent 2 Monte Carlo neutronics code for the calculation of reaction rates. The results include excess reactivity at equilibrium, mirroring the breeding gain, and the actinide vector composition for each configuration. Moreover, the occurence of an optimum of the excess reactivity per percent uranium-233 was observed. The investigations showed that it is systematically seen at an interchannel distance equal to the neutron slowing-down length in graphite for each configuration and does not depend on the salt channel radius beyond a certain size, which is given by the thermal fission rate reaching the levels of the fast fission rate. In this way, an exotic energy and spatial distribution of the neutrons are attained. The investigations highlight the potential attractiveness, from a neutronics/fuel cycle point of view, of both large fuel channels and moderators with a shorter neutron slowing-down length.

Burn up Study of an Innovative Natural Uranium-Thorium Fueled Reprocessing Free Fusion-Fission Hybrid Reactor Blanket with Closed Thorium-Uranium Fuel Cycle

2015 ◽  
Vol 68 (3) ◽  
pp. 566-572 ◽  
Author(s):  
S. C. Xiao ◽  
Jing Zhao ◽  
X. Heng ◽  
X. Y. Sheng ◽  
Z. Zhou ◽  
...  
Keyword(s):  
Fuel Cycle ◽  
Natural Uranium ◽  
Hybrid Reactor ◽  
Uranium Fuel

scholarly journals Risk Perceptions and Safety Cultures in the Handling of Nanomaterials in Academia and Industry

2020 ◽  
Vol 64 (5) ◽  
pp. 479-489 ◽  
Author(s):  
Marie Louise Kirkegaard ◽  
Pete Kines ◽  
Katharina Christiane Jeschke ◽  
Keld Alstrup Jensen
Keyword(s):  
Safety Culture ◽  
Risk Perceptions ◽  
Occupational Safety ◽  
Safety Management ◽  
Linguistic Diversity ◽  
Safety Data ◽  
Maturity Model ◽  
Academic Institutions ◽  
Management Tools ◽  
Limit Values

Abstract Objectives Work and research with nanomaterials (NMs) has primarily focused on innovation, toxicity, governance, safety management tools, and public perceptions. The aim of this study was to identify academia and industry occupational safety and health (OSH) managers’ perceptions and handling of NMs, in relation to safety culture. Methods Semistructured interviews were carried out with OSH managers at six academic institutions and six industrial companies. The interview statements were coded into five topics regarding NMs: risk comprehension, information gathering, actions, communication, and compliance. The statements were then coded according to a five-step safety culture maturity model reflecting increasing occupational safety maturity from passive, to reactive, active, proactive, and exemplary occupational safety. Results The safety culture maturity of the academic institutions were primarily active and proactive, whereas the industry group were primarily active and reactive. None of the statements were rated as exemplary, with the majority reflecting an active safety culture. The topics varied from a passive approach of having no focus on NMs and regarding risks as a part of the job, to applying proactive measures in the design, production, application, and waste management phases. Communication and introduction to OSH issues regarding NMs as well as compliance provided challenges in both academia and industry, given the increasing cultural and linguistic diversity of students/staff and employees. Workplace leaders played a crucial role in establishing a legitimate approach to working safely with NMs, however, the currently available OSH information for NMs were described as insufficient, impractical, and inaccessible. There was an embedded problem in solely relying on safety data sheets, which were often not nanospecific, as this may have led to underprotection. Conclusions There is a need for more structured, up-to-date, easily accessible, and user-friendly tools and information regarding toxicity and threshold limit values, relevant OSH promotion information, legislation, and other rules. The study underscores the need for politicians and engineers to collaborate with communication experts and both natural and social scientists in effectively framing information on NMs. Such a collaboration should allow for flexible deployment of multilevel and integrated safety culture initiatives to support sustainable nanotechnology and operational excellence.

Breeding of 233U in the thorium–uranium fuel cycle in VVER reactors using heavy water

2015 ◽  
Vol 78 (11) ◽  
pp. 1274-1286 ◽  
Author(s):  
V. E. Marshalkin ◽  
V. M. Povyshev
Keyword(s):  
Heavy Water ◽  
Fuel Cycle ◽  
Uranium Fuel

scholarly journals Impact on the fitness of N95 masks with extended use/limited reuse and dry heat decontamination

2021 ◽  
pp. jim-2021-001908
Author(s):  
Mengyi Zha ◽  
Jude Alsarraj ◽  
Brandon Bunch ◽  
David Venzon
Keyword(s):  
Healthcare Workers ◽  
Human Subject ◽  
Occupational Safety ◽  
Safety Data ◽  
Health Administration ◽  
Human Subject Research ◽  
Dry Heat ◽  
Safety And Health ◽  
Control And Prevention ◽  
The Impact

Substandard use of N95 masks, sometimes combined with dry heat decontamination, lacks safety data. We evaluated the impact of these practices on the fitness of N95 masks. This is a non-human subject research conducted from July to October 2020. 155 masks were used by 12 healthcare workers during 10-hour shifts. Masks were collected at the end of the shift and if the number of donnings/doffings was less than five (‘modified extended use’, ME) or whenever this number reached five (‘limited reuse’, LR), per the recommendation of the Centers for Disease Control and Prevention. Masks that passed an Occupational Safety and Health Administration qualitative fit test underwent a cycle (30 min, 75°C) of dry heat decontamination. After use, 84% (95% CI 77% to 90%) of the masks fit the users, 85% (95% CI 73% to 93%) in ME and 83% (95% CI 73% to 90%) in LR. After dry heat, 86% of the fitted masks (95% CI 78% to 91%) still fit, 93% (95% CI 80% to 98%) in ME and 82% (95% CI 70% to 89%) in LR. If a fit test was not done before decontamination, 72% (95% CI 64% to 79%) of the masks would fit, 79% (95% CI 66% to 88%) in ME and 68% (95% CI 57% to 77%) in LR. Common substandard use preserves fitness of N95 masks up to 85%. One cycle of dry heat decontamination preserves fitness of N95 masks up to 93% when donned/doffed less than five times and fitness is ensured before decontamination. If a fit test is not performed beforehand, dry heat decontamination cannot preserve the fitness of used N95 masks above 80%.

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