Inspections at the Loviisa nuclear power plant

STUK carries out inspections to oversee the operation and use of the Loviisa 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 2026 in accordance with the periodic inspection programme for the Loviisa nuclear power plant.

Information security, 16 March 2026

The inspection focused on the Loviisa power plant’s information security personnel, the contractors’ information security guidelines, information security incidents, continuous improvement, and the information security of the Loviisa Long-term operation program (LTOP).

On the basis of the inspection, the resources of information security personnel, the contractors’ information security guidelines, the management of information security incidents, learning from these and continuous improvement, and the information security of the LTOP program are at an appropriate level. During the inspection, several positive observations were made, including the management’s commitment to information security and comprehensive risk management procedures.

No requirements were issued on the basis of the inspection. STUK monitors the progress of the matters recorded as observations during the inspection as part of normal overview.

Physical security arrangements, 17–18 March 2026

The inspection focused on the Loviisa power plant’s security arrangements, which are considered to include structural, technical, operational and organisational arrangements for the detection, delaying and prevention of illegal or unauthorised activities.

As a result of the inspection STUK concluded that with regard to security arrangements the licence holder’s personnel resources, competence, training and exercise activities as well as the management of modifications at the Loviisa nuclear power plant are appropriate and sufficient. Numerous good practices were observed during the inspection. For example, Fortum has developed the maintenance of a situational picture of security arrangements and reporting on this.

No requirements were issued on the basis of the inspection. STUK monitors the progress of the matters recorded as observations during the inspection as part of normal overview.

Radiation protection, 24–26 March 2026

During the inspection, the situation of Loviisa nuclear power plant’s administrative arrangements for radiation protection, radiation measurements, contamination management, and the situation of radiation safety deviations and observations, the ALARA programme of measures and key development projects were assessed.

Based on the inspection findings, the activities of the radiation protection group are systematic and their guidelines are mainly up to date. In connection with recent personnel changes, the qualification of the new quality manager for dosimetry was still in progress. Progress was noted with regard to contamination management, but systems that may contain radioactivity are located in areas that have no radiation protection classification and no official action has been taken to determine their possible deviations from the requirements of the YVL guides. During the plant tour, observations were made on deficiencies in the markings and boundaries of the supervised area located in the plant’s yard area.

STUK issued four requirements on the basis of the inspection: The qualification of the quality manager for dosimetry, the preparation of a report on radioactive systems located in unsupervised areas, and the improvement of the markings, boundaries, and instructions for the supervised area around the outside of the plant.

Fire protection, 31 March – 1 April 2026

The inspection focused on the structural, active, and operational fire protection arrangements at the Loviisa power plant. Areas covered in the inspection included the organisation, management of equipment separation, inspections of fire protection arrangements, ageing management, modification and repair work, utilisation of external user experiences in fire protection, and inspections carried out by the permit holder and other organisations. The inspection also included a tour of the plant. On the basis of the inspection, Fortum’s fire prevention operations and procedures are at a good level, and no deviations from regulations were observed. It was noted during the inspection that the follow-up phases for lead through sometimes remained unacknowledged for a long periods of time. As a result, the work tasks were listed as incomplete in the workflow management system, even though the fire unit had already been closed. An observation on the matter was recorded in the inspection report. Positive observations recorded during the inspection include the introduction of a fire protection index and the independent commissioning of fire tests on products on whose fire properties there is no experience.

No requirements were issued on the basis of the inspection.

Handling of nuclear fuel, 4–5 March 2026

During the inspection, Fortum’s procedures for fuel handling, especially the use of fuel charging machines and fuel handling machines and the implementation of corrective measures related to events in 2025 (Fall of a fuel assembly extension in intermediate storage in January and fall of an absorber in August). In addition, the progress of the project to modernise fuel charging machines was examined.

During the inspection, STUK verified that Fortum has implemented most of the measures defined on the basis of the events of 2025. One of the technical modifications related to the fall of the fuel assembly extension and one action related to training and procedures related to the fall of the absorber were still in progress, but their deadlines have not been exceeded. However, more detail should be added to the instructions and training for deviations in fuel handling. Fortum has launched related studies and exercises, but these were still in progress at the time of the inspection.

During the inspection, STUK observed that the majority of corrective measures determined by Fortum are related to administrative procedures. STUK considers it important that efforts are also made to respond to technical problems by means of technical measures, not just administrative measures.

The condition of the fuel charging and fuel handling machines was found to have deteriorated, especially due to their old electrical and automation systems. The number of faults is high and it is challenging to repair them. It was also found that the logbook of the fuel charging machine is not used in accordance with the instructions, which hampers the flow of information and the monitoring of the condition of the devices. STUK will now require an assessment of procedures and an update of the instructions if necessary.

The project to modernise the fuel charging machine has progressed, but as a whole the project has been delayed and its prioritisation has been insufficient in the past. Planned technical improvements such as improved grip indication and new camera solutions are important to ensure safety. STUK welcomes the progress of the project but will require Fortum to take a more active approach at the supplier interface in the future.

STUK issued one requirement on the basis of the inspection findings. Fortum must assess the procedures related to the use of the logbook for the fuel charging and fuel handling machines and, if necessary, update instructions so that appropriate recording can be verified during future annual outages.