Insufficient guidance of subcontractors’ work in Olkiluoto 3 nuclear power plant project


This past March, the Finnish Radiation and Nuclear Safety Authority (STUK) appointed an investigation team to assess compliance with safety requirements in the construction of Olkiluoto 3 nuclear power plant unit. In its report published today, the investigation team states that the major problems involve project management, in particular with regard to construction work, but not nuclear safety. The power plant vendor has selected subcontractors with no prior experience in nuclear power plant construction to implement the project. These subcontractors have not received sufficient guidance and supervision to ensure smooth progress of their work. The investigation team provides recommendations both to the buyer and the vendor company. Furthermore, there is also room for improvement in the practices of the regulatory body.

On 7 March, 2006, the Finnish Radiation and Nuclear Safety Authority STUK appointed an investigation team after having noticed that the management of organisations participating in the construction of Olkiluoto 3 nuclear power plant unit (OL3 unit) do not fully comply with STUK’s expectations concerning good safety culture. The problems detected have hampered the progress of the project and increased pressures on the schedule of the subsequent construction phases.

The objective of the team was to make an evaluation of the practices of Teollisuuden Voima Oy (TVO), the utility who purchased the OL3 unit, and the turn key supplier, consortium FANP-Siemens (CFS). The team was also asked to make recommendations for improving the operations of both companies. Furthermore, the investigation group examined how STUK’s performance as regulator should be developed.

In its report, the investigation team emphasises working practises that would comply with good safety culture. It is important what kind of attitude to the safety is taken and how it is implemented in working practices.

”The objective is a well planned, conducted and documented work, and negligent attitude towards problems or quality must not be accepted”, states Seija Suksi, Investigation Manager at STUK and leader of the investigation team.

Design has taken longer than anticipated

The time and resources needed for the detailed design of the OL3 unit was clearly underestimated, when the overall schedule was agreed upon. Slow completion of design in relation to the potential working pace of constructors and equipment manufacturers, should they have had plans available in time, has complicated the controlled implementation of the project and confused schedules.

An additional problem arose from the fact that the supplier was not sufficiently familiar with the Finnish practises at the beginning of the project. According to Finnish requirements, the design of safety classified systems, structures and equipment is inspected both by TVO and by STUK. Designs and plans must be accepted by all involved parties before the manufacturing of equipment and components or construction at site can be started.

Need for promoting safety culture

The investigation indicated that the organisations participating in the OL3 project have not yet achieved a commonly shared view of the necessary emphasis on safety awareness at the construction phase. The project should be provided with a strong safety culture, involving subcontractors as well.

Problems in manufacturing of the equipment and in construction are related to the management of the project. Communication of requirements on quality and quality control, from FANP to subcontractors, has occasionally been deficient. Essential quality requirements and any possible extra costs arising thereof have not been clearly specified at the stage of the invitation to tender. Since subcontractors operate within tight cost frameworks and delayed schedules, they refuse to comply afterwards with additional demands that exceed the scope of the agreement.

The investigation found, however, no indication that these problems would have compromised the quality. The required standards have been maintained and, on the basis of tests and inspections conducted, they have been met, although in some cases only after corrective measures. The observed difficulties at the construction stage have therefore not influenced the safety of the power plant when it will be ready to operate. 

Quality control implemented largely as planned

The quality control of equipment manufacturing and site supervision of construction seems to have been implemented largely as planned, and it is the responsibility of competent employees in the organisations of both TVO and the vendor. Any deviations are carefully recorded and their correction is monitored. In this respect the quality control achieves the intended independency.

On the other hand, the quality control organisation’s authority, executive power and courage to immediately intervene in quality deviations detected and demand repair do not seem sufficient.  

Problem: inexperienced subcontractors with insufficient guidance

The number of subcontractors is large, and some of them have no previous experience in constructing nuclear power plants. The decisive factor in selecting subcontractors in the final phase has generally been the total price tag of the offer, if the bidder has met the specified criteria.

Subcontractor audits conducted by TVO have revealed deviations anticipating problems in production. FANP has not been able to correct all deviations prior to commencing production. A particularly problematic area has been the supervision of subcontractors' performance level and the guidance provided for them.

A sample case assessed by the investigation team was the construction of the reactor island base slab. One factor, among others, impeding the construction was the fact that the specific quality requirements for constructing a nuclear power plant were not clearly brought up when inviting tenders on concrete supply.  The process of designing the concrete composition, concrete manufacturing and the respective quality control measures involved problems in accountability and communication because there were many subcontractors. There was no manager on site with an overall responsibility for the preparation of the base slab and an authority to issue binding orders to all parties. Problems had arisen during minor concreting performed on site, but they did not result in measures for ensuring the smooth implementation of the main concreting. The approved concrete composition was altered during concrete mixing. Deviations in the concrete composition and in concrete pouring were not addressed openly and without delay.

As another example, the group monitored manufacturing of the reactor containment steel liner. The function of the steel liner is to ensure the leak-tightness the containment and thus prevent any leaks of radioactive substances into the environment even in case of reactor damage. The selection and supervision of the liner manufacturer was left to the subcontractor who designed the liner and supplied it to FANP. The manufacturer had no earlier experience on manufacturing equipment for nuclear power plants. Requirements concerning quality and construction supervision were a surprise to the manufacturer.  

Recommendations to TVO, the vendor and the regulatory authority


FANP should see to it that all design documents it submits to TVO are, the first time around, of the extent and quality that no considerable amendments or changes are required afterwards.

Tender invitations and purchase agreements should clearly provide all information concerning quality control requirements typical for nuclear power plant construction and exceeding the conventional standards applied in the branch.

A responsible manager should be appointed to each work entity at the construction site. This manager should have indisputable authority to give work-related orders. The guidance of subcontractors should be improved to ensure that they fulfil their tasks in the manner expected by FANP and produce acceptable quality. FANP’s management should make it clear to the FANP staff that they have a responsibility to inform the management without delay of any detected quality problems.


TVO’s management should communicate clearly to the entire personnel of the OL3 project that, in spite of the turn-key delivery, TVO is ultimately responsible for the safety of the power plant and that this responsibility cannot be assigned to the supplier on the terms of a purchasing agreement.

Furthermore, TVO should regularly inform the site managers and supervisors of the consortium CFS and respectively the CFS subcontractors about the safety and quality objectives of the OL3 project and the related practical operating methods. It should also be ensured that both TVO's own and also the consortium’s staff at the construction site have understood these objectives and implement them in their work.

TVO should ensure that its own project personnel strictly follow the general principles for nuclear power plant safety in their practical operating methods. It is of particular importance that the safety first approach shows consistently in all decisions and actions of the project management.


The findings of the STUK inspectors should be systematically collected and analysed with the intent to identify recurring events. Particular attention should be paid on observations concerning the defects and problems in the management of organisations.

STUK’s management should clarify to their inspectors which requirements concerning quality systems and safety culture, provided by the IAEA safety standards, should be examined with particular care in evaluating the performance of organisations that participate in the construction of the power plant and manufacturing of equipment, and indicate STUK’s expectations with regard to meeting the requirements.

Additional information:

Seija Suksi, Investigation Manager, STUK, tel. (09) 759 88 347
Jukka Laaksonen, Director General, STUK, tel. (09) 759 88 200
Riikka Laitinen-Sorvari, Information Officer, STUK, tel. (09) 759 88 210

The full report of the investigation team (pdf)

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