NUGENIA/TA2 Achievements in Severe Accidents Research (2015-2020)

Severe accident research is the only way to achieve the best possible management in case such unlikely events eventually happen. Early this century, the Severe Accident Research NETwork (SARNET) was born as an EC project and about 10 years later it became the technical area 2 of NUGENIA, the SNETP (Sustainable Nuclear Energy Technological Platform) pillar devoted to research on Gen. II and Gen. III Light Water Reactors (LWRs). This paper describes the most relevant outcomes from NUGENIA/TA2 research in the last five years concerning coolability of in-vessel and ex-vessel corium/debris, in-containment phenomena and source term; besides, the progress made and underway on severe accident modelling is outlined. Finally, the NUGENIA/TA2 commitment to knowledge dissemination through courses and conferences is highlighted

Proposed relation between SARNET network on severe accidents and TWG Gen.II/III

SA Research Priorities defined in SARNET network should be the basis for proposing in the future relevant R&D programs to address them, when needed, and launch projects with the endorsement of TWG

Status and perspectives of SARNET network

43 organisations (research, universities, industry, utilities, safety authorities and TSO) from 22 countries network their capabilities for R&D on Severe Accidents (SA) in SARNET (Severe Accident Research NETwork of excellence) in the EC FP7 for 4 years from April 2009. The overall work represents about 40 persons per year (230 researchers and 20 PhD students). A 43rd partner is currently joining the network: BARC (India). See www.sar-net.e

Wartime pediatric surgery

Autori su u ovom radu dali prikaz povijesnog razvitka i prilagodbe hrvatske dječje kirurgije ratnim prilikama. Tijekom agresije na Republiku Hrvatsku, kao posljedica ratnih zbivanja, ozlijeđeno j e 957, a poginulo 256 djece. Po uzorku ozljeda, najčešće, oko polovice svih ozljeda, su bile eksplozivne ozljede, kao posljedica artiljerijskih i minobacačkih napada, a na drugom su mjestu strijelne ozljede (31,3% u poginule i 25,4% u ranjene djece). U zbrinjavanju te djece veliku su ulogu odigrali dječji kirurzi iz cijele Hrvatske. Osim u matičnim zdravstvenim ustanovama, dječji su kirurzi učestvovali i u mobilnim kirurškim ekipama kao ispomoć u ratnim i rubnim bolnicama na bojištima Republike Hrvatske i Republike Bosne i Hercegovine. U takvim prilikama oni su postajali ratni kirurzi i radili su rame uz rame s općim kirurzima. Usprkos ratnim prilikama, hrvatska je dječja kirurgija uspjela zadržati, pa čak i podići, razinu mirnodopske elektivne kirurgije, te uspostaviti značajne međunarodne kontakte. Unatoč ratu, Hrvatsko društvo dječjih kirurga postalo je članom Europskog udruženja dječjih kirurga, zahvaljujući međunarodnom ugledu dječje kirurgije u nas.The article presents the history and the development of pediatric surgery in Croatia and its adjustment to the war circumstances. Among other victims of the war, there were 256 killed and 957 injured children. Almost one half of them were injured and killed by artillery atacks and nearly one third of them suffered from gunshot wounds. Croatian pediatric surgeons took major part in taking care of those children. Beside working in their own hospitals, pediatric surgeons of Croatia took part in mobile surgical teams, providing help to hospitals on or near the battlefields in the Republic of Croatia and the Republic of Bosnia and Hercegovina. Under those circumstances they have acted as general war surgeons. In spite of the war, Croatian pediatric surgery has maintained the high level of elective surgery. In 1994 Croatian Society of Pediatric Surgeons managed to become a member of the EUPSA (European Union of Pediatric Surgeons Associations)

Building a unique test section for local critical heat flux studies in light water reactor like accident conditions

Critical heat flux (CHF) has been studied for almost a century and yet there is no indisputable consensus reached on governing physical phenomena behind, not to mention, on modelling agreement of different correlations. When we are compelled to run our system at the safe distance from the CHF, and we can use all the accumulated knowledge so far, we will quite possibly cling to look-up tables delivered with that particular system. If this is not the case, than we will certainly stick to the system-specific correlation, which cannot be applied with confidence elsewhere. In the last two decades there were significant advancements applied both in numerical simulation capabilities and in unintrusive measuring techniques, which shed light on anticipated advancements in modelling the phenomenon. However, there are few reliable experimental measurements of instantaneous velocity and temperature fields in the wall boundary layer, and they are nil where local heat transfer coefficients are acquired. Therefore, at Reactor Engineering Division of Jožef Stefan Institute, a unique test section for local critical heat flux studies is under construction. The selected geometry and the test conditions will resemble light water reactor – like accident conditions. Moreover, to understand the phenomenon better, the design of the test section enables local measurements of heat transfer coefficients, and allows for control over the diabatic wall temperature. Measurements of single-phase convective heat transfer, conjugate heat transfer, flow boiling, convective condensation, and condensation-induced liquid hammer were all part of the test section’s design basis. In this context, the design and construction of the device is herein presented in considerable detail.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers

Overview of key themalhydraulic phenomena in severe accident unfolding: Current knowledge and further needs

Severe Accidents are closely and deeply linked with thermalhydraulics. This paper synthesizes such a relation during accident unfolding and provides an overview of the remaining gaps associated to thermalhydraulics that need to be addressed to properly reduce the uncertainties associated to SA and to optimize these events management. Some of those thermalhydraulic processes are common to other areas, but most of them are genuine of the SA domain, like corium and debris cooling, H2 distribution and combustion in containment and fuel-coolant interaction, just to mention a few. In addition to those processes of a bare thermalhydraulic nature, there are others governing SA consequences, like fission product transport and eventual release to the environment, that are heavily affected by thermalhydraulic boundary conditions and need to be investigated under the anticipated conditions. Anyway, there is a consensus that any investigation to be launched in the coming years should have a direct impact on reducing the uncertainties associated to their modelling and/or on optimizing their management

Current Status of NUGENIA-TA2: Severe Accidents

The SARNET network (Severe Accident NETwork of excellence) was co-funded by EC from 2004 to 2013 in FP6-FP7 and then integrated in NUGENIA. The main network activities are continuing in the NUGENIA Technical Area N°2; one of the three pillars of SNETP Association. IRSN coordinated SARNET/NUGENIA-TA2 until CIEMAT took over in Dec. 2018. This presentation is aimed at giving an update of TA

NUGENIA TA2: Current Status & Major Ongoing Activities

OBJECTIVES: To update the TA2 Community on the activities and actions taken by the Coordination Team (TA2CT) since the last general meeting (Paris, 13-15.03.2019). To spark brainstorming on project ideas in the frame of SNETP (SOIP) and HORIZON/EUROPE