Switzerland: Restart of Beznau NPP Unit 1

Posted March 8, 2018, 7:30 a.m.

The Swiss Federal Nuclear Safety Inspectorate ENSI has announced its decision that the Beznau 1 nuclear power plant may be put back into operation. The operator of the Beznau plant (Axpo) has demonstrated that the inclusions found in the steel of the reactor pressure vessel (RPV) have no negative impact on safety. The cause of the ultrasonic test indications has been convincingly established to be alumina agglomerates. The materials testing has shown that these agglomerates do not affect the key materials properties and the structural integrity analysis shows that the RPV does not contain any flaws that could lead to RPV failure. ENSI has verified and accepted the proof. ENSI was supported in its decision making process by an International Review Panel (IRP). “We can therefore conclude that the reactor pressure vessel is safe” says ENSI Director General and WENRA Chairman Hans Wanner. “From a safety perspective, there is nothing that speaks against allowing continued operation for Beznau 1.”

Beznau 1 was not allowed to go back into operation after flaw indications were detected from ultrasonic measurements of the RPV in 2015. The measurements were carried out as a result of the 2013 WENRA Recommendation in connection with flaw indications found in Belgian reactors.

More information

Flaw Indications in Swiss Nuclear Power Plant Beznau (2015)

ENSI Review of the Axpo Power AG Safety Case for the Reactor Pressure Vessel of the Beznau NPP Unit 1

Assessment of the Safety Case for the Reactor Pressure Vessel of the Beznau Unit 1 Nuclear Power Plant

Chronology: from the findings in Belgium to the proof of safety from Beznau 1

WENRA Recommendation in connection with flaw indications found in Belgian reactors

Updated Report - Activities in WENRA countries following the Recommendation regarding flaw indications found in Belgian reactors

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