Highlights of the Olkiluoto-3 review by STUK

The new nuclear power plant project in Finland has been plagued by safety problems and delays. There have been problems e.g. in manufacturing the steel liner that is essential in protecting the core from external threats and containing dangerous substances in case of an accident as well as the concrete base slab that should support and protect the structure. This is a brief compilation of the findings of a report by the Finnish public nuclear safety authority published July 2006.

Dumping prizes, too tight schedules

• "The pressure to keep to the schedule is probably hard for TVO's [the company that ordered the plant] technical experts, as the plant vendor's plans are submitted late and the schedules do not allow enough time for their evaluation. […] As a result, documentation of poor quality is forwarded to [Finnish Nuclear Safety Authority]. […] This also involves the risk that problems are not detected, or tackling them at a later stage will cause considerable problems if TVO has approved deficient documentation."
• "In the case of a fixed-price contract it is to be expected that money becomes the most important criterion in the selection of a subcontractor. TVO has limited possibilities at the selection stage of subcontractors to control that quality and safety criteria are given a sufficient priority."

Incompetent subcontractors

• "FANP [plant supplier] seems to select cheaper suppliers despite bigger quality risks. FANP does not always enter safety-related requirements in the supplier's agreements, but tries to deal with them without incurring any costs. Due to the tight cost limits and delays in schedules subcontractors are not willing to meet afterwards additional requirements that exceed those specified in their agreements."
• "The working practices and equipment used by the manufacturer are outdated for this type of manufacturing."
• "[the contractor had] no earlier experience in deliveries to nuclear power plants. […]"
• "In the selection of the concrete supplier, the special quality requirements applied in a nuclear power plant construction were not brought up in the tender invitations, whereas cost factors were strongly emphasised in the selection."

No training

• "No training was provided to the staff involved in the fabrication of concrete concerning practices in the nuclear field and the safety significance of their own work."
• "safety culture training to all those participating in the plant delivery, as stipulated in IAEA regulations and in discussions between STUK and TVO, has in practice not been provided in most cases. One expert of TVO's quality organisation stated in the interview that, as far as he knew, this training had not been provided in any organisation. It has not been defined what the content of the training should be and who should be responsible for its provision."

Information not available

• "information about events has not in every case been openly communicated to TVO and further to STUK."
• "TVO has a limited insight of what is happening in the subcontractor network and what kind of problems are encountered."
• "forwarding of the nuclear field specific and technical safety requirements from the consortium to the consortium's subcontractors has been deficient"
• "The inspection documentation of the steel liner has not been available in full in construction inspections."

Safety ignored

• "Repeated use of an excessive root gap [in welding] is a clear quality non-conformance to the officially approved procedure and absolutely unacceptable to this extent. A situation like this should not be possible in a well functioning quality system."
• "Permissions have been granted by FANP for the continuation of manufacturing in situations where the design of the phases and the approval of the design documents have not been completed."
• "The quality control implemented by the subcontractor and the plant supplier has been deficient"
• "The problems observed in previous concreting operations did not result in effective corrective actions implemented in time."
• "The approved composition of concrete and the concreting specifications were not adhered to in concrete fabrication."
• "the documentation submitted by TVO's OL3 project to STUK is sometimes of poor quality and inspectors are invited to perform construction inspections on systems or structures for which the approval of design documentation or the quality control documentation has not yet been completed."
• "in many cases the specified quality cannot be realised in practice and the specification is changed instead"
• "it is questionable whether corrective actions are taken at the stage that from the point of view of the final result would be the best for their implementation."

Problems piling up

• "Although an abundance of technical non-conformancies have been identified in the manufacturing of different equipment, components, and in construction as well, and these have been recorded in nonconformance reports, the observations made during the investigation show that the plant vendor and its subcontractors have not essentially improved their working practices or attitudes toward safety."
• "During the investigation there were some 700 open non-conformancies."

All quotes are from the official translation of the report by the Finnish Radiation and Nuclear Safety Authority.

SOURCE: Olkiluoto.Info, Lauri Myllyvirta

Topics: NPP, Europe, Finland, Olkiluoto, AREVA