TVO: Welding problems will not cause further delays to completion of Olkiluoto III

STUK orders welding works to be suspended during ongoing investigation

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The Radiation and Nuclear Safety Authority (STUK) has ordered the welding of the main circulation pipeline of Finland's fifth nuclear reactor, Olkiluoto III, to be suspended. Faults have once again been discovered in the welding seams, which are produced in France.
      STUK is requesting a clarification from the Finnish power company Teollisuuden Voima (TVO) and the French conglomerate Areva, which is constructing the installation, regarding the significance of the faults from the safety point of view. Only then can the welding work continue.
      According to TVO project manager Jouni Silvennoinen the faults in question are only very minor surface blemishes that have no effect on the pipeline’s strength or safety properties. Silvennoinen insists that the repairs will not cause further delays to the completion of Olkiluoto III.
      Areva discovered the faults in segments of the pipeline that are to be fitted between the evaporators and the reactor. Faults have been found in two welding joints. In all there will be four joints. Microscopic fractures were discovered already in the first weld.
     
STUK immediately demanded that Areva provide detailed plans on how to assess the cause of the faults, and how to proceed with the necessary further inspections.
      “We figured such measures should suffice”, says STUK section head Martti Vilpas.
      The second weld was flawless, but in the third weld completed at the beginning of May faults were again discovered. According to Vilpas, the faults are almost identical to those in the first weld. “Things cannot continue like this”, Vilpas emphasises.
     
Vilpas does not believe the observed faults are a result of a job poorly done.
      Rather, this is a question of factors related to the behaviour of the material.
      Vilpas believes the investigation into the matter may take up to a couple of weeks.


Previously in HS International Edition:
  TVO seeks EUR 2.4 billion in damages for Olkiluoto nuclear reactor delays (28.1.2009)
  Olkiluoto III start-up delayed again - reactor could go on stream only in 2012 (17.10.2008)
  Costs of delay in construction of Olkiluoto III approaching price of new reactor (29.1.2009)

See also:
  Siemens to give up nuclear joint venture with Areva (27.1.2009)

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