atw - International Journal for Nuclear Power | 11/12.2019

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Kommunikation und Training für Kerntechnik Suchen Sie die passende Weiter bildungs maßnahme im Bereich Kerntechnik? Wählen Sie aus folgenden Themen: Dozent/in Termin/e Ort 3 Atom-, Vertrags- und Exportrecht Atomrecht – Ihr Weg durch Genehmigungs- und Aufsichtsverfahren RA Dr. Christian Raetzke 18.02.2020 Berlin Atomrecht – Was Sie wissen müssen RA Dr. Christian Raetzke Akos Frank LL. M. 11.11.2020 Berlin Atomrecht – Das Recht der radioaktiven Abfälle RA Dr. Christian Raetzke 10.03.2020 Berlin Export kerntechnischer Produkte und Dienstleistungen – Chanchen und Regularien 3 Kommunikation und Politik RA Kay Höft M.A. (BWL) 17.06.2020 Berlin Public Hearing Workshop – Öffentliche Anhörungen erfolgreich meistern Dr. Nikolai A. Behr 10.11. - 11.11.2020 Berlin 3 Rückbau und Strahlenschutz In Kooperation mit dem TÜV SÜD Energietechnik GmbH Baden-Württemberg: Das neue Strahlenschutzgesetz – Folgen für Recht und Praxis Stilllegung und Rückbau in Recht und Praxis Dr. Maria Poetsch RA Dr. Christian Raetzke Dr. Stefan Kirsch RA Dr. Christian Raetzke 28.01. - 29.01.2020 16.06. - 17.06.2020 23.09. - 24.09.2020 Berlin 17.03. - 18.03.2020 Berlin 3 Nuclear English English for Nuclear Business Angela Lloyd 01.04. - 02.04.2020 Berlin 3 Wissenstransfer und Veränderungsmanagement Veränderungsprozesse gestalten – Heraus forderungen meistern, Beteiligte gewinnen Erfolgreicher Wissenstransfer in der Kerntechnik – Methoden und praktische Anwendung Dr. Tanja-Vera Herking Dr. Christien Zedler Dr. Tanja-Vera Herking Dr. Christien Zedler 21.01. - 22.01.2020 Berlin 24.03. - 25.03.2020 Berlin Haben wir Ihr Interesse geweckt? 3 Rufen Sie uns an: +49 30 498555-30 Kontakt INFORUM Verlags- und Verwaltungs gesellschaft mbH ı Robert-Koch-Platz 4 ı 10115 Berlin Petra Dinter-Tumtzak ı Fon +49 30 498555-30 ı Fax +49 30 498555-18 ı Seminare@KernD.de Die INFORUM-Seminare können je nach Inhalt ggf. als Beitrag zur Aktualisierung der Fachkunde geeignet sein.
atw Vol. 64 (2019) | Issue 11/12 ı November/December TMI and Lessons Learned – Afterwards and for the Future No technical development is perfect from the outset, each involves specific risks. A responsible approach to technology therefore requires a responsible and forward-looking approach to its risks, the best possible protection and, if necessary, further development. This also means that there are no such things as absolutely perfect technology and absolute safety. With a view to criticism of technologies, technology sceptics are provided with a comfortable approach for transporting their respective concerns by anniversaries. One such event is the 1979 Three-Mile-Island (TMI 2) accident. On 28 March 1979, shortly after 4 a.m., the feed water supply for the steam generators in unit 2 of the Three Mile Island (TMI 2) nuclear power plant near Harrisburg, Pennsylvania, USA, failed. Such a malfunction was taken into account in the operating procedures with a view to the future and can be easily dealt with by the plant and operators. The event is one of the design cases. But what began as a normal incident later developed into the most serious accident to date in a Western nuclear power plant due to a combination of technical defects, human error and organisational inadequacies. The technical aspects of the TMI-2 accident have been extensively reviewed and can be traced in detail in the literature: After the failure of the feed-water supply, the safety systems of the nuclear power plant reacted as designed. However, due to valves in the emergency feedwater system that were closed manually on site, the steam generators were not supplied with water and a link in the chain for the residual heat dissipation of the reactor, which was switched off but still supplies heat due to the decay heat, was missing. This error was corrected 8 minutes after the start of the fault. Subsequently, the increase in pressure in the primary circuit caused the safety relief valve on the pressure holder to open, the escape of steam from the primary circuit and the intended pressure reduction. However, the opened blow-off valve did not close as designed. This caused large quantities of coolant to escape from the primary circuit – a loss of coolant accident “ LOCA” had occurred. Only 2 hours later it was detected by the operators and corrected by closing other existing shut-off valves. After further misinterpretations about the condition of the reactor core and the primary circuit, the core was no longer cooled by water and the exothermic reaction between water vapour and the cladding tube material of the fuel elements then set on, releasing additional heat. About half of the fuel rod mass in the core melted or was severely damaged. Core masses shifted and partially reached the bottom of the reactor pressure vessel where they solidified. After it had been recognised that a core melt was in full swing, measures for core cooling were taken and it was possible to ensure the heat removal of the TMI-2 core again in the long term. Of the radioactive substances released in the plant, a small part was released into the environment. Triggered by fears of the additional radiation exposure associated with the release of a calculated average of 0.02 mSv – i.e. about 1 % of the natural annual radiation exposure – the Pennsylvania Department of Health kept a register for 18 years containing the data of more than 30,000 persons who had lived within a five-mile radius of the nuclear power plant at the time of the accident. This state register was closed in June 1997 after no unusual health developments had been identified. More than a dozen comprehensive studies on the physical health effects of the accident did not provide evidence of an abnormally high number of cancer cases in the region around the nuclear power plant years after the event. Despite all the shortcomings and shortcomings that led to the TMI-2 accident, the basic safety concept of Western nuclear power plants that had been established at an early stage was confirmed: The amount of radioactive substances released from the plant was low and there were no fatalities or injuries. On the other hand, the accident sequence underlines the suitability of successively staggered safety barriers, which, taking even serious accidents into account, aims at the confinement of the radioactive substances in the plant itself: The reactor building of TMI-2 withstood, the containment remained intact. In addition, research and development for reactor safety further minimised the risks in an international context during the past 40 years: Expressed in figures, even for running plants in Germany and elsewhere, a safety level was achieved, which is 100 times higher than the original international reference level. The reactor disaster at Fukushima in 2011 will not change this point of view either, as other foreseeable risks and specific boundary conditions were the causes. Safety is and remains an international task for all concerned. Nuclear safety and the maintenance and promotion of competences, especially when they are available with excellent know-how in research and development and are internationally recognised – as in Germany – are part of the overall social and political responsibility at the same level as other goals of environmental protection. Today's and future safety and the promotion of safety culture and technology, also for nuclear technology, cannot and must not be the subject of restricted or restrictive action. Research and development should always be allowed to advance in the spirit of freedom of science and technology. Christopher Weßelmann – Editor in Chief – 507 EDITORIAL Editorial TMI and Lessons Learned – Afterwards and for the Future
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Kommunikation und Training für Ker
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atw - International Journal for Nuclear Power | 11/12.2019

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