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- Bechta, Sevostian, et al.
(author)
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On the EU-Japan roadmap for experimental research on corium behavior
- 2019
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In: Annals of Nuclear Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0306-4549 .- 1873-2100. ; 124, s. 541-547
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Journal article (peer-reviewed)abstract
- A joint research roadmap between Europe and Japan has been developed in severe accident field of light water reactors, focusing particularly on reactor core melt (corium) behavior. The development of this roadmap is one of the main targets of the ongoing EU project SAFEST. This paper presents information about ongoing severe accident studies in the area of corium behavior, rationales and comparison of research priorities identified in different projects and documents, expert ranking of safety issues, and finally the research areas and topics and their priorities suggested for the EU Japan roadmap and future bilateral collaborations. These results provide useful guidelines for (i) assessment of long-term goals and proposals for experimental support needed for proper understanding, interpretation and learning lessons of the Fukushima accident; (ii) analysis of severe accident phenomena; (iii) development of accident prevention and mitigation strategies, and corresponding technical measures; (iv) study of corium samples in European and Japanese laboratories; and (v) preparation of Fukushima site decommissioning.
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| 2. |
- Journeau, Christophe, et al.
(author)
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SAFEST ROADMAP FOR CORIUM EXPERIMENTAL RESEARCH IN EUROPE
- 2016
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In: PROCEEDINGS OF THE 24TH INTERNATIONAL CONFERENCE ON NUCLEAR ENGINEERING, 2016, VOL 4. - : ASME Press. - 9780791850046
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Conference paper (peer-reviewed)abstract
- SAFEST (Severe Accident Facilities for European Safety Targets) is a European project networking the European corium experimental laboratories with the objective to establish coordination activities, enabling the development of a common vision and research roadmaps for the next years, and of the management structure to achieve these goals. In this frame, a European roadmap on corium experimental research has been written to define research challenges to contribute to further reinforcement of Gen II and III NPP safety. It is based on the research priorities deteimined by SARNET SARP group as well as those from the recently formulated in the NUGENIA Roadmap for severe accidents and the recently published NUGENIA Global Vision report. It also takes into account issues identified in the analysis of the European stress tests and from the interpretation of the Fukushima accident. 19 relevant issues related to corium have been selected during these prioritization efforts. These issues have been compared to a survey of the European corium experimental facilities and corium analysis laboratories. Finally, the coherence between European infrastructures and R&D needs has been assessed and a table linking issues and infrastructures has been derived. It shows a few lacks in EU corium infrastructures, especially in the domains of core late reflooding impact on source term, Reactor Pressure Vessel failure and corium release, Spent Fuel Pool accidents, as well as the need for a large mass (100500 kg) prototypic corium facility.
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| 3. |
- Leta, Tesfaye H., et al.
(author)
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Periprosthetic Joint Infection After Total Knee Arthroplasty With or Without Antibiotic Bone Cement
- 2024
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In: JAMA Network Open. - 2574-3805. ; 7:5
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Journal article (peer-reviewed)abstract
- Importanc eDespite increased use of antibiotic-loaded bone cement (ALBC) in joint arthroplasty over recent decades, current evidence for prophylactic use of ALBC to reduce risk of periprosthetic joint infection (PJI) is insufficient. Objective To compare the rate of revision attributed to PJI following primary total knee arthroplasty (TKA) using ALBC vs plain bone cement. Design, Setting, and Participants This international cohort study used data from 14 national or regional joint arthroplasty registries in Australia, Denmark, Finland, Germany, Italy, New Zealand, Norway, Romania, Sweden, Switzerland, the Netherlands, the UK, and the US. The study included primary TKAs for osteoarthritis registered from January 1, 2010, to December 31, 2020, and followed-up until December 31, 2021. Data analysis was performed from April to September 2023. Exposure Primary TKA with ALBC vs plain bone cement. Main Outcomes and Measures The primary outcome was risk of 1-year revision for PJI. Using a distributed data network analysis method, data were harmonized, and a cumulative revision rate was calculated (1 - Kaplan-Meier), and Cox regression analyses were performed within the 10 registries using both cement types. A meta-analysis was then performed to combine all aggregated data and evaluate the risk of 1-year revision for PJI and all causes. Results Among 2 168 924 TKAs included, 93% were performed with ALBC. Most TKAs were performed in female patients (59.5%) and patients aged 65 to 74 years (39.9%), fully cemented (92.2%), and in the 2015 to 2020 period (62.5%). All participating registries reported a cumulative 1-year revision rate for PJI of less than 1% following primary TKA with ALBC (range, 0.21%-0.80%) and with plain bone cement (range, 0.23%-0.70%). The meta-analyses based on adjusted Cox regression for 1 917 190 TKAs showed no statistically significant difference at 1 year in risk of revision for PJI (hazard rate ratio, 1.16; 95% CI, 0.89-1.52) or for all causes (hazard rate ratio, 1.12; 95% CI, 0.89-1.40) among TKAs performed with ALBC vs plain bone cement. Conclusions and Relevance In this study, the risk of revision for PJI was similar between ALBC and plain bone cement following primary TKA. Any additional costs of ALBC and its relative value in reducing revision risk should be considered in the context of the overall health care delivery system.
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| 4. |
- Stuckert, Juri, et al.
(author)
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Experimental and modelling results of the QUENCH-20 experiment with BWR test bundle
- 2023
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In: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 410
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Journal article (peer-reviewed)abstract
- The experiment QUENCH-20 with BWR simulation bundle was conducted at KIT on 9th October 2019. This test was performed in the framework of EU SAFEST project and its international access to European SA research infrastructure of the users from Swedish Radiation Safety Authority (SSM) in collaboration with Westinghouse Sweden, GRS and KTH. The test objective was the investigation of the BWR fuel assembly degradation including a control blade with B4C neutron absorbers. The test bundle represented one quarter of a BWR fuel assembly. 24 electrically heated fuel rod simulators were filled with krypton (pressure of about 0.6 MPa), whereas the holes of absorber pins were filled with helium (overpressure 0.02 MPa). According to the pre-test calculations performed with ATHLET-CD, the bundle was heated to a temperature of 1230 K at the cladding of the central rod at the hottest elevation of 950 mm. This pre-oxidation phase in steam lasted 4 h. During the following transient stage, the bundle was heated to a maximal temperature of 2000 K. The cladding failures were observed at temperatures about 1700 K and lasted about 200 s. Massive absorber melt relocation was observed 50 s before the end of the transient stage. The test was terminated by the injection of quench water with a flow rate of 50 g/s into the bundle bottom. Fast temperature escalation from 2000 to 2300 K during 20 s was observed. The mass spec-trometer measured release of COx and little CH4 during the reflood as products of absorber oxidation; corre-sponding mass of reacted B4C was 4.3% of the total mass of B4C pins. Hydrogen production during the reflood amounted to 32 g (57.4 g during the whole test) including 10 g from B4C oxidation. The results of the post-test simulations with the AC2/ATHLET-CD code show a good agreement with the experimental observations con-cerning the thermal behavior. However, melting and relocation of BWR components was not calculated and the B4C oxidation was underestimated.
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