Inspections at the Olkiluoto nuclear power plant

STUK carries out inspections to oversee the operation and use of the Olkiluoto nuclear power plant. The periodic inspection programme covers safety management, main operational processes, procedures and technical acceptability of systems.

STUK draws up a plan for the inspection, setting out the subject of the inspection and any preparatory actions required of the licence holder. The result of the inspection and the resulting requirements are set out in the inspection report.

Periodic inspections

Below are summaries of the inspections carried out by STUK in year 2025 in accordance with the periodic inspection programme for the Olkiluoto nuclear power plant.

Radiation protection, 13–14 January 2025

In 2025, the radiation protection inspection was targeted at measuring employees' radiation doses. The inspection covered all plant units (OL1&2 and OL3). The inspection was used to verify organisational matters included in the approval of the dosimetric service, such as responsibilities and access rights, operating in accordance with instructions and the equipment used in the dosimetric service. The inspection also included a test, that was announced in advance, in which a small number of dosimeters were irradiated at different radiation doses in STUK’s metrological standard laboratory. In the test, TVO met the criteria set for determining the radiation doses of dosimeters.

Based on the inspection, STUK found that TVO has procedures that enable high-quality operations in determining employees' radiation doses. One requirement was presented in the inspection, concerning the notification to STUK of changes in the organisation of the approved dosimetric service.

Personnel resources and competence (TVO–Posiva joint inspection), 27–28 February 2025

The audit focused on Posiva’s and TVO’s shared HR and competence procedures and the assessment of their adequacy as well as the identification and management of competence needs. In other words, how the procedures of both licence holders enable Posiva to have the necessary and competent resources at its disposal.

Posiva uses TVO’s resources and expertise for many functions. TVO’s personnel planning work is also carried out in a managed manner in connection with the annual planning process and budgeting. The resource needs are coordinated in the personnel planning process. STUK considers that TVO ensures that Posiva has access to the competence it needs in many different ways. However, Posiva still needs to deploy practices like the personnel planning process and ensure the competence and sufficient working hours of the various system and equipment managers. With regard to guidelines, it is important for TVO and Posiva to identify what instructions are needed for each task.

There is an established service agreement model between TVO and Posiva for reserving and procuring resources. Human resources shared by TVO and Posiva are discussed in many cooperation forums and groups. If necessary, issues related to resourcing are escalated for resolution. Based on the inspection, STUK finds that Posiva’s procedures for managing external resources seem appropriate.

STUK made several observations during the inspection, which are essential from the point of view of safety ensuring as Posiva approaches the production phase. Based on the inspection, STUK does not present any requirements. Based on the inspection, the subject areas of this inspection as they relate to personnel planning and resource requirements as well as competence development and assessment, can be considered to be at an acceptable level.