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Fennovoiman suunnittelujohtaja Petri Jyrälä

Petri Jyrälä has worked at Fennovoima since 2016, and currently heads Fennovoima's Engineering department.

Design progress

The basic design of the Hanhikivi 1 nuclear power plant has progressed well. Now we focus on ensuring the faultlessness and integrity of the design and finalizing the basic design documentation.

For the Hanhikivi 1 project, 2020 was a year with a strong focus on the plant layout design. We knew already in advance that we would have plenty of difficult discussions with the plant supplier RAOS Project, and that the need to modify the proposed design solutions would arise. Designing a nuclear power plant and reviewing the design is a massive effort, but the work has proceeded fluently and reliably.

Us having received the expected design documentation from the plant supplier for review has been vital for the progress of the review work. The reorganization carried out by Fennovoima two years ago has also proven effective: responsibilities and ownerships are clear and the entire organization’s decision-making capacity has improved.

Over the course of last year, we used a multidisciplinary team to assess all of the approximately 150 buildings included in the plant based on 3D modelling and technical drawings that give a view of the buildings from a variety of perspectives. We reviewed the layout design documentations building by building, highlighted deficiencies, and agreed with the necessary corrections with RAOS Project. We identified, among others, issues that required changes to ensure the ALARA (As Low As Reasonably Achievable) principle and issues that required changes to ensure the normal operation of the plant. For example, the locations of some pipelines and valves were changed to avoid an unnecessary radiation dose to the nuclear power plant’s operating personnel. The plant’s fire safety and evacuation routes were also further developed.

A little over a year ago, we stated that the design of the control building did not meet our expectations or the level required by safety requirements. The building was completely redesigned in 2020, in compliance with clear-cut design principles. The building is quite massive: a couple of Finnish Parliament Houses could be fitted inside it. Its design is still somewhat lagging behind that of the other buildings. However, we are satisfied with the much clearer and straightforward final result.

Not everything went according to plan last year: the progress of Instrumentation and Control system (I&C) design has been regrettably slow. This influences the plant’s technical design, its progress, the review of the design documentation, and licensing of these solutions. Also I&C has already been taken into account in the building layout design based on the preliminary design, however, and the design includes the space reservations required for I&C and electrical equipment.

All in all, the functional and physical design of the plant has mostly been finalized, and no major changes are to be expected. We have good assurance of the technical appropriateness of the design. Now we will focus on ensuring integrity and faultlessness of the design and finalizing the basic design documentation. Careful finalization of the design documentation and performing the necessary assessments and analyses are essential tasks to ensure that there will be no problems with the plant’s detailed design and component procurement at a later point in time.

We are gradually progressing via detailed design to the construction of the plant. For this reason, verifying the construction readiness of our own organization and the entire supply chain will be one of our key tasks in 2021.

Petri Jyrälä
Engineering Director

Petri Jyrälä, M.Sc. (Tech.) has more than ten years of experience in the nuclear power industry. He has worked at Fennovoima since 2016, and currently heads Fennovoima's Engineering department. Besides work, Petri enjoys spending time at his summer house and boating.

Petri Jyrälä, Fennovoiman suunnittelujohtaja