Dynamic Finite Element Analyses of the Primary System of the Atucha II NPP under Beyond Design Basis Earthquakes

Atucha II Nuclear Power Plant (CNA II) is a pressurized heavy water reactor (PHWR) that started its commercial operation in May 2016. Construction began during 1980, and the design licensing base, agreed between the Responsible Entity (CNEA at that time) and the designer (KWU/Siemens), did not consider the double-ended guillotine break (DEGB) event in the primary pipe loop as a requirement of the emergency core cooling systems and reactor shutdown. Instead, a 10% loss of coolant of the cross section of the primary system, which would be equivalent to a surgeline DEGB (line connecting the primary system with the pressurizer), was considered. The Autoridad Regulatoria Nuclear (nuclear regulatory body of Argentina – ARN) entrusted the realization of an independent evaluation, to assess whether a DEGB caused by a beyond design basis event could be possible. A dynamic analysis of the Loop 2 of CNA II’s primary system was performed employing the finite element method (FEM) for a beyond design basis earthquake scene, i.e. an earthquake with a mean probability of exceedance of 10-6 per year, to evaluate the possibility of occurrence of a DEGB with critical preexisting areas with circumferential through-wall cracks in the primary system. The model utilized displacement time histories as input data, applied at the supporting points of major components (reactor pressure vessel, stream generator, main coolant pump, pressurizer), obtained by numerical integration of the acceleration time histories at such points, provided by the designer.Publicado en: Mecánica Computacional vol. XXXV no.31Facultad de Ingenierí

Adherence issues related to sublingual immunotherapy as perceived by allergists

Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd

The dark side of the tradition: The polluting effect of Epiphany folk fires in the eastern Po Valley (Italy)

In the Veneto Region (Po Valley, Northeastern Italy) on the eve of Epiphany, an important religious celebration, during the night between January 5th and 6th thousands of folk fires traditionally burn wooden material. The object of this study is to characterize the 2013 episode, bymonitoring the effects on the air quality in the region's lowlands. The daily concentrations ofPM2.5 and PM10 exceeded 250 and 300 μg m−3, respectively and the PM10 hourly values were above 600 μg m−3 in many sites. The levels of total carbon, major inorganic ions, polycyclic aromatic hydrocarbons and biomass burning tracers (levoglucosan and K+)weremeasured in 84 samples of PM10 and 38 of PM2.5 collected at 32 sites between January 4th and 7th. Total carbon ranged from 11 μg m−3 before the pollution episode to 131 μg m−3 a day afterwards, K+ from 0.6 to 5.1 μg m−3, benzo(a)pyrene from 2 to 23 ng m−3, and levoglucosan from 0.5 to 8.3 μg m−3. The dispersion of the particulate matter was traced by analyzing the levels of PM10 and PM2.5 in 133 and 51 sites, respectively, in the Veneto and neighboring regions. In addition to biomass burning the formation of secondary inorganic aerosol was revealed to be a key factor on a multivariate statistical data processing. By providing direct information on the effects of an intense and widespread biomass burning episode in the Po Valley, this study also enables some general considerations on biomass burning practices