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ENSI

150 employees of the Swiss Federal Nuclear Safety Inspectorate ENSI work every day in various fields for the nuclear safety of the Swiss population.

Background articles

  • Background articles, Posts

    Ten Years on from Fukushima (2/6): The radiological effects of the accident

    After the nuclear accident in Fukushima Daiichi, extrapolations revealed that about one-eighth of the amount of radioactivity that escaped at Chernobyl was released into the surrounding area. The maximum estimated radiation dose for the population was 7.5 millisievert. However, various studies revealed that mental problems in the aftermath of the accident had a greater impact…

    ENSI, Fukushima, Ten Years on from Fukushima
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  • Background articles, Posts

    Ten Years on from Fukushima (1/6): The lead-up to the 2011 Disaster

    After Chernobyl, the Fukushima accident of 11 March 2011 is history’s most serious reactor accident. An expert team from ENSI carried out an in-depth analysis of the circumstances leading up to the disaster. As a result, ENSI was able to derive important conclusions both for its own regulatory role and for the safety of Swiss…

    ENSI, Fukushima, Ten Years on from Fukushima
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  • Background articles, Posts

    Series of articles on barriers 6/6: The containment holds radioactive substances in the reactor building

    The reactor pressure vessel is enclosed by the containment as the third barrier. This consists of a steel primary containment and a concrete secondary containment.

    Barrier Principle, Defense in depth, ENSI, Nuclear Power Plants, Nuclear Safety and Security, Radiation Protection, Security
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  • Background articles, Posts

    Series of articles on barriers 5/6: The water circuit (primary circuit part 2 of 2)

    With its pipelines, shut-off valves and other components, the cooling circuit, together with the reactor pressure vessel, is the second barrier for trapping radioactive substances.

    Barrier Principle, Defense in depth, ENSI, Nuclear Power Plants, Nuclear Safety and Security, Radiation Protection, Security
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  • Background articles, Posts

    Series of articles on barriers 4/6: The reactor pressure vessel (primary circuit part 1 of 2)

    The reactor pressure vessel, together with the water’s cooling circuit, is the second barrier for trapping radioactive substances.

    Barrier Principle, Defense in depth, ENSI, Nuclear Power Plants, Nuclear Safety and Security, Radiation Protection, Security
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  • Background articles, Posts

    Series of articles on barriers 3/6: The fuel rod cladding tubes (fuel assemblies part 2 of 2)

    The fuel pellets are filled into metal tubes. Together with the nuclear fuel matrix, the cladding tubes are the first barrier for trapping radioactive substances in nuclear power plants.

    Barrier Principle, Defense in depth, ENSI, Nuclear Power Plants, Nuclear Safety and Security, Radiation Protection, Security
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  • Background articles, Posts

    Series of articles on barriers 2/6: The nuclear fuel matrix (fuel assemblies part 1 of 2)

    The nuclear fuel is pressed into pellets and compacted using the sintering process before use in nuclear power plants. This process transforms the nuclear fuel into a ceramic material, which is able to retain the fission products that arise during operation in the nuclear fuel matrix.

    Barrier Principle, Defense in depth, ENSI, Nuclear Power Plants, Nuclear Safety and Security, Radiation Protection, Security
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  • Background articles, Posts

    Series of articles on barriers 1/6: Barriers protect people and the environment from radioactive substances

    The barrier concept aims to trap sources of radiation in nuclear facilities across several levels. Similar to the layers of an onion, independent barriers ensure that the risk from sources of radiation are minimised for people and the environment.

    Barrier Principle, Defense in depth, ENSI, Nuclear Power Plants, Nuclear Safety and Security, Radiation Protection, Security
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  • Background articles, Posts

    Prevention of sabotage and theft: an overview

    «The protection of nuclear installations and nuclear materials against sabotage, violent actions or theft has to be based on an in-depth defence system which involves structural, technical, organisational, personnel and administrative measures. In my section we examine the measures in effect at nuclear installations on the basis of national and international requirements. To determine the…

    Domains/Sections, ENSI, Organisation, Security
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