CONSULTING

especially for inspections and vessel head replacements at the two Beznau reactors, and load
reductions due to high air and water temperatures during the summer 2015. 835
With an average age of 41.2 years, Switzerland operates the oldest nuclear fleet and—with
Beznau-1, age 46 and turning 47 in July 2016—the oldest reactor in the world. In a compelling
2014 report, Dieter Majer, former Director for Nuclear Facility Safety of the German Nuclear
Regulator, recommended that especially the reactors Mühleberg and Beznau “should be shut
down immediately”. 836
Figure 51: Age of the Swiss Nuclear Fleet
Sources: IAEA-PRIS, MSC, 2016
Following the reactor pressure vessel problems identified at the Belgian Doel-3/Tihange-2
reactors (see Focus Belgium), inspections have been carried out at the two Beznau units. At the
pressure vessel of Beznau-1, a total of 925 crack indications, up to 7.5 x 7.5 mm in size and 60 mm
in depth have been identified. According to operator AXPO, the defaults, with a high degree of
confidence, would not be hydrogen flakes, as in the Belgian cases. At the pressure vessel of
Beznau-2, 77 indications have been found with a maximum size of 20 x 50 mm. 837 In
November 2015, the Swiss Nuclear Safety Inspectorate (ENSI) established an International
Review Panel to re-assess the integrity of the unit 1 pressure vessel. The unit remains shut down,
while the Panel is working. After evaluation of the identified defects in unit 2, in December 2015,
ENSI grants restart permission for the reactor.
In October 2013, operator BKW announced that it would close its Mühleberg reactor in 2019, due
to “indefinable and unquantifiable… technical, economic and political uncertainties [that] could
increase the economic risks of long-term operation.” 838 In January 2015, the federal regulator
accepted the upgrades proposed by the operator in order to continue operating Mühleberg until
835 Swissnuclear, “En 2015, les centrales nucléaires suisses ont fourni environ un tiers de notre
électricité”, Press Release, 26 February 2016.
836 Dieter Majer, “Risiko Altreaktoren Schweiz”, commissioned by Schweizerische Energie-Stiftung (SES),
February 2014, see http://www.energiestiftung.ch/energiethemen/atomenergie/risiken/risiko-altreaktoren/,
accessed 18 June 2016.
837 Christoph Pistner, “Beznau: Finding on the RPV”, Presentation at INRAG, 27 February 2016.
838 NIW, “Switzerland—News Briefs”, 1 November 2013.
Mycle Schneider, Antony Froggatt et al. 197 World Nuclear Industry Status Report 2016