Decommissioning of a I Gen Gas-Graphite Power reactor: methods and Technologies for the graphite's retrieval and core dismantling

Il presente lavoro di tesi ha riguardato lo studio dello smantellamento di un reattore gas grafite di potenza di I Gen. L’indagine è stata focalizzata in particolare al recupero della grafite irraggiata che ne costituisce il core. Viene presentata una descrizione referenziata del reattore e dei suoi componenti per mettere in evidenza la particolare architettura e le specifiche problematiche ad essa correlate. A valle di un’indagine sulle esperienze internazionali in merito al decommissioning e allo smantellamento di questi tipi di reattori, si forniscono una possibile sequenza di accesso alla cavità del reattore e una procedura per il suo smantellamento; si descrivono sommariamente le tecnologie di taglio e di handling, attualmente allo stato dell’arte, considerate come più idonee a questo tipo di applicazione. Vengono descritte le principali criticità della grafite nuclear grade ed illustrati i fenomeni caratteristici che ne determinano l’evoluzione nel reattore. Sulla base dei dati resi disponibili dalla Sogin S.p:A. e ricorrendo ai dati di letteratura per quelli non disponibili, è stato effettuato un assessment della grafite irraggiata costituente il nocciolo del reattore, rivolto in particolare a determinarne le caratteristiche meccaniche e la resistenza residua post-irraggiamento. Per valutare la possibilità di prelevare la grafite dal nocciolo è stato ipotizzato un dispositivo di presa che agganci per attrito i blocchi di grafite del moderatore attraverso il canale assiale. Infine è stata valutata la fattibilità di tale metodo attraverso una serie di simulazioni agli elementi finiti dirette a verificare la resistenza del blocco in varie condizioni di carico e vincolo. Come risultato si è dimostrata la fattibilità, almeno in via preliminare, del metodo proposto, determinando l’inviluppo di utilizzo del dispositivo di presa nonché la compatibilità del metodo proposto con le tecnologie di handling precedentemente individuate.The PhD thesis has been focused on the study of the decommissioning of a gas-graphite reactor of the I gen. The investigation was pointed in particular to the retrieval techniques of irradiated graphite of the core. It has been presented a description of the reactor and its components in order to show the architecture and the specific problems related to it. After a review of international experiences regarding the decommissioning and dismantling of these types of reactors, it has been proposed a sequence of access to the cavity of the reactor and a procedure for its dismantling; it has been described the state of art on the cutting and handling technologies, considered as the most suitable for this type of application. the characteristic phenomena which determine the evolution of the graphite in the reactor are described and the main criticality of the nuclear grade graphite are illustrated . Based on data made available by Sogin S.p A. and with the data from literature , it has been performed an assessment of the irradiated graphite of the pile, addressed in particular to determine the mechanical characteristics and the post-irradiation residual strength. To evaluate the possibility to retrireve the graphite from the core it has been proposed a concept design of gripping device that hooks the bored graphite moderator brick for friction through the axial channel. Finally it has been evaluated the feasibility of this method by a series of FEM simulations to verify the strenght of the bricks under various load conditions and constraints. The feasibility of the proposed method has been proved as well as the compatibility of the proposed method with the handling technologies previously identified and the working range of the gripper tool was given

Dismantling of the graphite pile of Latina NPP: Characterization and handling/removal equipment for single brick or multi-bricks

This work describes the issues related the dismantling of graphite piles of the 1st generation gas cooled reactor of Latina NPP (Italy). The retrieval of the graphite is a strategic matter for the decommissioning of this type of plant: in this study were described and analysed the current approaches used to access the core and to perform the remote and dry extraction of graphite bricks from the top. Based on these data, the removal of the graphite of Latina NPP will be planned; the extraction of the graphite will be carried out layer by layer by means of a dedicated remote controlled handling systems. This equipment will be duly designed according to the nuclear, physical and mechanical constraints of the graphite piles in core. In doing that the issues regarding the irradiated graphite have been also analysed by FEM code, especially those related to the core geometry and to the proposed technique of hooking the graphite bricks by a ‘gripper’ tool inside the axial channel. Data on fresh nuclear grade and irradiated graphite, used for the numerical simulations, were obtained by means of experimental tests, which were carried out on samples extracted from the reactor, and from theoretical models. The results obtained could support the final design of proper lifting and gripper tools and handling equipment, for single brick or multi-bricks, and to implement waste management strategy for the graphite

Breastfeeding in Italy: the role of obstetrician-gynecologists

We report the exceptional case of an intrauterine fetal death Data for 2013 from the italian national institute of statistics (istat) show that the percentage of breastfeeding mothers in italy is increasing, however these percentages are still far from the standard recommended by the world health organization (who). Not breastfeeding is rarely recognized as a possible effect of the medicalization of birth but rather is perceived as a mother’s choice, even though, according to a survey done by the italian national institute of health in 2002, over 95% of women in italy said they wanted to breastfeed. The authors evaluate the role of the obstetrician-gynecologist who, together with the other health professionals involved in pregnancy and childbirth, all of whom have been trained and respect the mother-baby dyad, can help promote breastfeeding in a significant way

Maternal Diet and Nutrient Requirements in Pregnancy and Breastfeeding. An Italian Consensus Document

The importance of lifestyle and dietary habits during pregnancy and breastfeeding, for health of mothers and their offspring, is widely supported by the most recent scientific literature. The consumption of a varied and balanced diet from the preconceptional period is essential to ensure both maternal well-being and pregnancy outcomes. However, the risk of inadequate intakes of specific micronutrients in pregnancy and lactation is high even in the most industrialized countries. This particularly applies to docosahexaenoic acid (DHA), iron, iodine, calcium, folic acid, and vitamin D, also in the Italian population. Moreover, the risk of not reaching the adequate nutrient supply is increased for selected groups of women of childbearing age: those following exclusion diets, underweight or overweight/obese, smokers, adolescents, mothers who have had multiple or close pregnancies, and those with previous unfavorable pregnancy outcomes

Documento di consenso ANMCO/SICP/SIGO: Gravidanza e cardiopatie congenite

The success of cardiac surgery over the past 50 years has increased numbers and median age of survivors with congenital heart disease (CHD). Adults now represent two-thirds of patients with CHD; in the United States alone the number is estimated to exceed 1 million. In this population many affected women reach reproductive age and wish to have children. While in many CHD patients pregnancy can be accomplished successfully, some special situations with complex anatomy, iatrogenic or residual pathology are associated with an increased risk of severe maternal and fetal complications. Pre-conception counseling allows women to come to truly informed choices. Risk stratification tools can also help high-risk women to eventually renounce to pregnancy and to adopt safe contraception options. Once pregnant, women identified as intermediate or high-risk should receive multidisciplinary care involving a cardiologist, an obstetrician and an anesthesiologist with specific expertise in managing this peculiar medical challenge. This document is intended to provide cardiologists working in hospitals where an Obstetrics and Gynecology Department is available with a streamlined and practical tool, useful for them to select the best management strategies to deal with a woman affected by CHD who desires to plan pregnancy or is already pregnant

The effect of fetal sex on customized fetal growth charts

39noreservedmixedRizzo, Giuseppe*; Prefumo, Federico; Ferrazzi, Enrico; Zanardini, Cristina; Di Martino, Daniela; Boito, Simona; Aiello, Elisa; Ghi, Tullio; Altobelli, G.; Arduini, M.; Canzone, G.; Capece, A.; Carboni, E.; Cariello, L.; Cariati, E.; Cetin, I.; Chianchiano, N.; Clerici, G.; D’Addario, V.; Di Martino, D.; Cosmi, E.; Giacchello, R.; Giancotti, A.; Giorgina, M.; Maiandi, A.; Mandia, L.; Maruotti, G.; Mazzocco, A.; Nicoletti, L.; Periti, E.; Persico, N.; Rossi, A.; Stampalija, T.; Tenore, A.; Todros, T.; Visentin, S.; Verrotti, C.; Viora, E.; Volpe, P.Rizzo, Giuseppe; Prefumo, Federico; Ferrazzi, Enrico; Zanardini, Cristina; Di Martino, Daniela; Boito, Simona; Aiello, Elisa; Ghi, Tullio; Altobelli, G.; Arduini, M.; Canzone, G.; Capece, A.; Carboni, E.; Cariello, L.; Cariati, E.; Cetin, I.; Chianchiano, N.; Clerici, G.; D’Addario, V.; Di Martino, D.; Cosmi, E.; Giacchello, R.; Giancotti, A.; Giorgina, M.; Maiandi, A.; Mandia, L.; Maruotti, G.; Mazzocco, A.; Nicoletti, L.; Periti, E.; Persico, N.; Rossi, A.; Stampalija, T.; Tenore, A.; Todros, T.; Visentin, S.; Verrotti, C.; Viora, E.; Volpe, P